@article{https://doi.org/10.1029/2005PA001141,
author = {{\'{S}}lubowska, Marta A and Ko{\c{c}}, Nal{\^{a}}n and Rasmussen, Tine L and Klitgaard-Kristensen, Dorthe},
doi = {10.1029/2005PA001141},
issn = {08838305},
journal = {Paleoceanography},
keywords = {Holocene,North Atlantic Current,Svalbard,deglaciation,foraminifera,stable isotope},
month = {dec},
number = {4},
pages = {PA4014},
title = {{Changes in the flow of Atlantic water into the Arctic Ocean since the last deglaciation: Evidence from the northern Svalbard continental margin, 80°N}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2005PA001141 http://doi.wiley.com/10.1029/2005PA001141},
volume = {20},
year = {2005}
}
@article{PMID:29180406,
author = {{\'{U}}jv{\'{a}}ri, G{\'{a}}bor and Stevens, Thomas and Moln{\'{a}}r, Mih{\'{a}}ly and Dem{\'{e}}ny, Attila and Lambert, Fabrice and Varga, Gy{\"{o}}rgy and Jull, A J Timothy and P{\'{a}}ll-Gergely, Barna and Buylaert, Jan-Pieter and Kov{\'{a}}cs, J{\'{a}}nos},
doi = {10.1073/pnas.1712651114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {dec},
number = {50},
pages = {E10632--E10638},
title = {{Coupled European and Greenland last glacial dust activity driven by North Atlantic climate}},
url = {http://europepmc.org/articles/PMC5740632},
volume = {114},
year = {2017}
}
@article{Osterhus2019,
author = {{\O}sterhus, Svein and Woodgate, Rebecca and Valdimarsson, H{\'{e}}ðinn and Turrell, Bill and de Steur, Laura and Quadfasel, Detlef and Olsen, Steffen M and Moritz, Martin and Lee, Craig M and Larsen, Karin Margretha H and J{\'{o}}nsson, Steingr{\'{i}}mur and Johnson, Clare and Jochumsen, Kerstin and Hansen, Bogi and Curry, Beth and Cunningham, Stuart and Berx, Barbara},
doi = {10.5194/os-15-379-2019},
issn = {1812-0792},
journal = {Ocean Science},
month = {apr},
number = {2},
pages = {379--399},
publisher = {Copernicus Publications},
title = {{Arctic Mediterranean exchanges: a consistent volume budget and trends in transports from two decades of observations}},
url = {https://www.ocean-sci.net/15/379/2019/ https://www.ocean-sci.net/15/379/2019/os-15-379-2019.pdf https://os.copernicus.org/articles/15/379/2019/},
volume = {15},
year = {2019}
}
@article{Ablain2019,
author = {Ablain, Micha{\"{e}}l and Meyssignac, Beno{\^{i}}t and Zawadzki, Lionel and Jugier, R{\'{e}}mi and Ribes, Aur{\'{e}}lien and Spada, Giorgio and Benveniste, Jer{\^{o}}me and Cazenave, Anny and Picot, Nicolas},
doi = {10.5194/essd-11-1189-2019},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {aug},
number = {3},
pages = {1189--1202},
title = {{Uncertainty in satellite estimates of global mean sea-level changes, trend and acceleration}},
url = {https://essd.copernicus.org/articles/11/1189/2019/},
volume = {11},
year = {2019}
}
@article{Abram2014,
abstract = {The Southern Annular Mode (SAM) is the primary pattern of climate variability in the Southern Hemisphere1,2 , influencing latitudinal rainfall distribution and temperatures from the subtropics to Antarctica. The positive summer trend in the SAMover recent decades is widely attributed to stratospheric ozonedepletion2 ;however, the brevity of observational records from Antarctica1 —one of the core zones that defines SAM variability—limits our understanding of long-term SAM be- haviour. Herewe reconstruct annual mean changes in the SAM since AD 1000 using, for the first time, proxy records that encompass the full mid-latitude to polar domain across the Drake Passage sector.We find that the SAM has undergone a progressive shift towards its positive phase since the fifteenth century, causing cooling of the main Antarctic continent at the same time that the Antarctic Peninsula has warmed. The positive trend in the SAM since ∼AD 1940 is reproduced by multimodel climate simulations forced with rising greenhouse gas levels and later ozone depletion, and the long-termaverage SAMindex is nowat its highest level for at least the past 1,000 years.Reconstructed SAMtrends before the twentieth century are more prominent than those in radiative-forcing climate experiments and may be associated with a teleconnected response to tropical Pacific climate. Our findings imply that predictions of further greenhouse-driven increases in the SAM overthecomingcentury3 alsoneedtoaccountforthepossibility of opposing effects from tropical Pacific climate changes},
author = {Abram, Nerilie J. and Mulvaney, Robert and Vimeux, Fran{\c{c}}oise and Phipps, Steven J. and Turner, John and England, Matthew H.},
doi = {10.1038/nclimate2235},
isbn = {1758-678X},
issn = {17586798},
journal = {Nature Climate Change},
number = {7},
pages = {564--569},
pmid = {1651522616},
title = {{Evolution of the Southern Annular Mode during the past millennium}},
volume = {4},
year = {2014}
}
@article{Abram2010,
abstract = {This study uses ice core methanesulphonic acid (MSA) records from the Antarctic Peninsula, where temperatures have been warming faster than anywhere else in the Southern Hemisphere, to reconstruct the 20th century history of sea ice change in the adjacent Bellingshausen Sea. Using satellite-derived sea ice and meteorological data, we show that ice core MSA records from this region are a reliable proxy for regional sea ice change, with years of increased winter sea ice extent recorded by increased ice core MSA concentrations. Our reconstruction suggests that the satellite-observed sea ice decline in the Bellingshausen Sea during recent decades is part of a long-term regional trend that has occurred throughout the 20th century. The long-term perspective on sea ice in the Bellingshausen Sea is consistent with evidence of 20th century warming on the Antarctic Peninsula and may reflect a progressive deepening of the Amundsen Sea Low due to increasing greenhouse gas concentrations and, more recently, stratospheric ozone depletion. As a first-order estimate, our MSA-based reconstruction suggests that sea ice in the Bellingshausen Sea has retreated southward by {\~{}}0.7° during the 20th century. Comparison with other 20th century sea ice observations, reconstructions, and model simulations provides a coherent picture of Antarctic sea ice decline during the 20th century, although with regional-scale differences evident in the timing and magnitude of this sea ice decline. This longer-term perspective contrasts with the small overall increase in Antarctic sea ice that is observed in post-1979 satellite data.},
author = {Abram, Nerilie J. and Thomas, Elizabeth R. and McConnell, Joseph R. and Mulvaney, Robert and Bracegirdle, Thomas J. and Sime, Louise C. and Aristarain, Alberto J.},
doi = {10.1029/2010JD014644},
isbn = {0148-0227},
issn = {01480227},
journal = {Journal of Geophysical Research: Atmospheres},
pages = {D23101},
title = {{Ice core evidence for a 20th century decline of sea ice in the Bellingshausen Sea, Antarctica}},
volume = {115},
year = {2010}
}
@article{Abram2020,
author = {Abram, Nerilie J. and Wright, Nicky M. and Ellis, Bethany and Dixon, Bronwyn C. and Wurtzel, Jennifer B. and England, Matthew H. and Ummenhofer, Caroline C. and Philibosian, Belle and Cahyarini, Sri Yudawati and Yu, Tsai-Luen and Shen, Chuan-Chou and Cheng, Hai and Edwards, R. Lawrence and Heslop, David},
doi = {10.1038/s41586-020-2084-4},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {7799},
pages = {385--392},
title = {{Coupling of Indo-Pacific climate variability over the last millennium (2020a)}},
url = {http://www.nature.com/articles/s41586-020-2084-4},
volume = {579},
year = {2020}
}
@article{ABRAM2020106302,
author = {Abram, Nerilie J and Hargreaves, Jessica A and Wright, Nicky M and Thirumalai, Kaustubh and Ummenhofer, Caroline C and England, Matthew H},
doi = {10.1016/j.quascirev.2020.106302},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Climate variability and impacts,Holocene,Indian Ocean Dipole (IOD),Last Glacial Maximum,Last Millennium,Palaeoclimate},
pages = {106302},
title = {{Palaeoclimate perspectives on the Indian Ocean Dipole (2020b)}},
url = {http://www.sciencedirect.com/science/article/pii/S027737912030264X},
volume = {237},
year = {2020}
}
@article{Ackley2003,
author = {Ackley, Stephen and Wadhams, Peter and Comiso, Josefino C. and Worby, Anthony P.},
doi = {10.1111/j.1751-8369.2003.tb00091.x},
isbn = {0800-0395},
issn = {08000395},
journal = {Polar Research},
pages = {19--25},
title = {{Decadal decrease of Antarctic sea ice extent inferred from whaling records revisited on the basis of historical and modern sea ice records}},
volume = {22},
year = {2003}
}
@article{Adler2017,
abstract = {Global precipitation variations over the satellite era are reviewed using the Global Precipitation Climatology Project (GPCP) monthly, globally complete analyses, which integrate satellite and surface gauge information. Mean planetary values are examined and compared, over ocean, with information from recent satellite programs and related estimates, with generally positive agreements, but with some indication of small underestimates for GPCP over the global ocean. Variations during the satellite era in global precipitation are tied to ENSO events, with small increases during El Ninos, and very noticeable decreases after major volcanic eruptions. No overall significant trend is noted in the global precipitation mean value, unlike that for surface temperature and atmospheric water vapor. However, there is a pattern of positive and negative trends across the planet with increases over tropical oceans and decreases over some middle latitude regions. These observed patterns are a result of a combination of inter-decadal variations and the effect of the global warming during the period. The results reviewed here indicate the value of such analyses as GPCP and the possible improvement in the information as the record lengthens and as new, more sophisticated and more accurate observations are included.},
author = {Adler, Robert F. and Gu, Guojun and Sapiano, Matthew and Wang, Jian Jian and Huffman, George J.},
doi = {10.1007/s10712-017-9416-4},
isbn = {1071201794},
issn = {15730956},
journal = {Surveys in Geophysics},
keywords = {Change,Global precipitation variability,Precipitation climatology,Satellite-based precipitation},
number = {4},
pages = {679--699},
publisher = {Springer Netherlands},
title = {{Global Precipitation: Means, Variations and Trends During the Satellite Era (1979–2014)}},
volume = {38},
year = {2017}
}
@article{Adler2018,
abstract = {The new Version 2.3 of the Global Precipitation Climatology Project (GPCP) Monthly analysis is described in terms of changes made to improve the homogeneity of the product, especially after 2002. These changes include corrections to cross-calibration of satellite data inputs and updates to the gauge analysis. Over-ocean changes starting in 2003 resulted in an overall precipitation increase of 1.8{\%} after 2009. Updating the gauge analysis to its final, high-quality version increases the global land total by 1.8{\%} for the post-2002 period. These changes correct a small, incorrect dip in the estimated global precipitation over the last decade given by the earlier Version 2.2. The GPCP analysis is also used to describe global precipitation in 2017. The general La Ni{\~{n}}a pattern for 2017 is noted and the evolution from the early 2016 El Ni{\~{n}}o pattern is described. The 2017 global value is one of the highest for the 1979–2017 period, exceeded only by 2016 and 1998 (both El Ni{\~{n}}o years), and reinforces the small positive trend. Results for 2017 also reinforce significant trends in precipitation intensity (on a monthly scale) in the tropics. These results for 2017 indicate the value of the GPCP analysis, in addition to research, for climate monitoring.},
author = {Adler, Robert F. and Sapiano, Mathew R.P. and Huffman, George J. and Wang, Jian Jian and Gu, Guojun and Bolvin, David and Chiu, Long and Schneider, Udo and Becker, Andreas and Nelkin, Eric and Xie, Pingping and Ferraro, Ralph and Shin, Dong Bin},
doi = {10.3390/atmos9040138},
issn = {20734433},
journal = {Atmosphere},
keywords = {Climate Data Record,Climate monitoring,Global precipitation},
number = {4},
pages = {138},
pmid = {30013797},
title = {{The Global Precipitation Climatology Project (GPCP) monthly analysis (New Version 2.3) and a review of 2017 global precipitation}},
volume = {9},
year = {2018}
}
@article{Ahn2012,
abstract = {During the last glacial period atmospheric carbon dioxide and temperature in Antarctica varied in a similar fashion on millennial time scales, but previous work indicates that these changes were gradual. In a detailed analysis of one event we now find that approximately half of the CO2 increase that occurred during the 1500-year cold period between Dansgaard-Oeschger (DO) events 8 and 9 happened rapidly, over less than two centuries. This rise in CO2 was synchronous with, or slightly later than, a rapid increase of Antarctic temperature inferred from stable isotopes. Citation: Ahn, J., E. J. Brook, A. Schmittner, and K. Kreutz (2012), Abrupt change in atmospheric CO2 during the last ice age, Geophys. Res. Lett., 39, L18711, doi:10.1029/2012GL053018.},
author = {Ahn, Jinho and Brook, Edward J. and Schmittner, Andreas and Kreutz, Karl},
doi = {10.1029/2012GL053018},
issn = {00948276},
journal = {Geophysical Research Letters},
pages = {L18711},
title = {{Abrupt change in atmospheric CO2 during the last ice age}},
volume = {39},
year = {2012}
}
@article{Ahn2014a,
abstract = {Reconstruction of atmospheric CO2 during times of past abrupt climate change may help us better understand climate-carbon cycle feedbacks. Previous ice core studies reveal simultaneous increases in atmospheric CO2 and Antarctic temperature during times when Greenland and the northern hemisphere experienced very long, cold stadial conditions during the last ice age. Whether this relationship extends to all of the numerous stadial events in the Greenland ice core record has not been clear. Here we present a high-resolution record of atmospheric CO2 from the Siple Dome ice core, Antarctica for part of the last ice age. We find that CO2 does not significantly change during the short Greenlandic stadial events, implying that the climate system perturbation that produced the short stadials was not strong enough to substantially alter the carbon cycle.},
author = {Ahn, Jinho and Brook, Edward J.},
doi = {10.1038/ncomms4723},
issn = {2041-1723},
journal = {Nature Communications},
month = {sep},
number = {1},
pages = {3723},
title = {{Siple Dome ice reveals two modes of millennial CO2 change during the last ice age}},
url = {http://www.nature.com/articles/ncomms4723},
volume = {5},
year = {2014}
}
@article{AIKEN2017236,
abstract = {Anthropogenically-induced global warming is expected to decrease primary productivity in the subtropical oceans by strengthening stratification of the water column and reducing the flux of nutrients from deep-waters to the sunlit surface layers. Identification of such changes is hindered by a paucity of long-term, spatially-resolved, biological time-series data at the basin scale. This paper exploits Atlantic Meridional Transect (AMT) data on physical and biogeochemical properties (1995–2014) in synergy with a wide range of remote-sensing (RS) observations from ocean colour, Sea Surface Temperature (SST), Sea Surface Salinity (SSS) and altimetry (surface currents), combined with different modelling approaches (both empirical and a coupled 1-D Ecosystem model), to produce a synthesis of the seasonal functioning of the North and South Atlantic Sub-Tropical Gyres (STGs), and assess their response to longer-term changes in climate. We explore definitive characteristics of the STGs using data of physical (SST, SSS and peripheral current systems) and biogeochemical variables (chlorophyll and nitrate), with inherent criteria (permanent thermal stratification and oligotrophy), and define the gyre boundary from a sharp gradient in these physical and biogeochemical properties. From RS data, the seasonal cycles for the period 1998–2012 show significant relationships between physical properties (SST and PAR) and gyre area. In contrast to expectations, the surface layer chlorophyll concentration from RS data (CHL) shows an upward trend for the mean values in both subtropical gyres. Furthermore, trends in physical properties (SST, PAR, gyre area) differ between the North and South STGs, suggesting the processes responsible for an upward trend in CHL may vary between gyres. There are significant anomalies in CHL and SST that are associated with El Ni{\~{n}}o events. These conclusions are drawn cautiously considering the short length of the time-series (1998–2012), emphasising the need to sustain spatially-extensive surveys such as AMT and integrate such observations with models, autonomous observations and RS data, to help address fundamental questions about how our planet is responding to climate change. A small number of dedicated AMT cruises in the keystone months of January and July would complement our understanding of seasonal cycles in the STGs.},
annote = {The Atlantic Meridional Transect programme (1995-2016)},
author = {Aiken, Jim and Brewin, Robert J W and Dufois, Francois and Polimene, Luca and Hardman-Mountford, Nick J and Jackson, Thomas and Loveday, Ben and Hoya, Silvana Mallor and Dall'Olmo, Giorgio and Stephens, John and Hirata, Takafumi},
doi = {10.1016/j.pocean.2016.08.004},
issn = {0079-6611},
journal = {Progress in Oceanography},
pages = {236--254},
title = {{A synthesis of the environmental response of the North and South Atlantic Sub-Tropical Gyres during two decades of AMT}},
url = {http://www.sciencedirect.com/science/article/pii/S0079661116300179},
volume = {158},
year = {2017}
}
@article{AitBrahim2019a,
author = {{Ait Brahim}, Y and Wassenburg, Jasper A and Sha, L and Cruz, F W and Deininger, M and Sifeddine, A and Bouchaou, L and Sp{\"{o}}tl, Christoph and Edwards, R. L. and Cheng, H},
doi = {10.1029/2019GL082405},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {jul},
number = {13},
pages = {7614--7623},
title = {{North Atlantic Ice‐Rafting, Ocean and Atmospheric Circulation During the Holocene: Insights From Western Mediterranean Speleothems}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082405},
volume = {46},
year = {2019}
}
@article{Naqvi2018,
abstract = {Measurements of total organic carbon (TOC) for two years in Kuwaiti waters showed high TOC levels (101.0–318.4, mean 161.2 $\mu$M) with maximal concentrations occurring within the polluted Kuwait Bay and decreasing offshore, indicating substantial anthropogenic component. Analysis of winter-time data revealed a large increase in density over the past four decades due to decrease in Shatt Al-Arab runoff, implying that the dissolved/suspended organic matter in surface waters of the northern Gulf could be quickly injected into the Gulf Deep Water (GDW). Our measurements together with an analysis of previously collected/published data suggest that the recent summer-time declining trend in oxygen in the GDW might be related to eutrophication. Higher preformed TOC and lower preformed dissolved oxygen contents of the high-salinity water mass that flows out of the Gulf and ventilates the mesopelagic oxygen minimum zone (OMZ) of the Northwestern Indian Ocean may cause expansion/intensification of the regional OMZ.},
author = {Al-Said, Turki and Naqvi, S.W.A. and Al-Yamani, Faiza and Goncharov, Alexandr and Fernandes, Loreta},
doi = {10.1016/j.marpolbul.2018.02.013},
issn = {0025326X},
journal = {Marine Pollution Bulletin},
keywords = {Arabian Gulf,Eutrophication,Hypoxia,Kuwait Bay,Tigris-Euphrates Delta region,Total organic carbon},
month = {apr},
number = {1},
pages = {35--42},
title = {{High total organic carbon in surface waters of the northern Arabian Gulf: Implications for the oxygen minimum zone of the Arabian Sea}},
url = {http://www.sciencedirect.com/science/article/pii/S0025326X18300948 https://linkinghub.elsevier.com/retrieve/pii/S0025326X18300948},
volume = {129},
year = {2018}
}
@article{Albani2015a,
abstract = {Abstract. Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP (Dust Indicators and Records from Terrestrial and MArine Palaeoenvironments) paleodust data sets in the last 2 decades provided a benchmark for paleoclimate models that include the dust cycle, following a time slice approach. We propose an innovative framework to organize a paleodust data set that builds on the positive experience of DIRTMAP and takes into account new scientific challenges by providing a concise and accessible data set of temporally resolved records of dust mass accumulation rates and particle grain size distributions. We consider data from ice cores, marine sediments, loess–paleosol sequences, lake sediments, and peat bogs for this compilation, with a temporal focus on the Holocene period. This global compilation allows the investigation of the potential, uncertainties, and confidence level of dust mass accumulation rate reconstructions and highlights the importance of dust particle size information for accurate and quantitative reconstructions of the dust cycle. After applying criteria that help to establish that the data considered represent changes in dust deposition, 45 paleodust records have been identified, with the highest density of dust deposition data occurring in the North Atlantic region. Although the temporal evolution of dust in the North Atlantic appears consistent across several cores and suggests that minimum dust fluxes are likely observed during the early to mid-Holocene period (6000–8000 years ago), the magnitude of dust fluxes in these observations is not fully consistent, suggesting that more work needs to be done to synthesize data sets for the Holocene. Based on the data compilation, we used the Community Earth System Model to estimate the mass balance of and variability in the global dust cycle during the Holocene, with dust loads ranging from 17.2 to 20.8 Tg between 2000 and 10 000 years ago and with a minimum in the early to mid-Holocene (6000–8000 years ago).},
author = {Albani, S. and Mahowald, N. M. and Winckler, G. and Anderson, R. F. and Bradtmiller, L. I. and Delmonte, B. and Fran{\c{c}}ois, R. and Goman, M. and Heavens, N. G. and Hesse, P. P. and Hovan, S. A. and Kang, S. G. and Kohfeld, K. E. and Lu, H. and Maggi, V. and Mason, J. A. and Mayewski, P. A. and McGee, D. and Miao, X. and Otto-Bliesner, B. L. and Perry, A. T. and Pourmand, A. and Roberts, H. M. and Rosenbloom, N. and Stevens, T. and Sun, J.},
doi = {10.5194/cp-11-869-2015},
issn = {1814-9332},
journal = {Climate of the Past},
month = {jun},
number = {6},
pages = {869--903},
title = {{Twelve thousand years of dust: the Holocene global dust cycle constrained by natural archives}},
volume = {11},
year = {2015}
}
@article{Albani2016,
author = {Albani, S. and Mahowald, N. M. and Murphy, L. N. and Raiswell, R. and Moore, J. K. and Anderson, R. F. and McGee, D. and Bradtmiller, L. I. and Delmonte, B. and Hesse, P. P. and Mayewski, P. A.},
doi = {10.1002/2016GL067911},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {apr},
number = {8},
pages = {3944--3954},
title = {{Paleodust variability since the Last Glacial Maximum and implications for iron inputs to the ocean}},
url = {http://doi.wiley.com/10.1002/2016GL067911},
volume = {43},
year = {2016}
}
@article{Alfaro-Sanchez2018,
author = {Alfaro-S{\'{a}}nchez, R. and Nguyen, H. and Klesse, S. and Hudson, A. and Belmecheri, S. and K{\"{o}}se, N. and Diaz, H. F. and Monson, R. K. and Villalba, R. and Trouet, V.},
doi = {10.1038/s41561-018-0242-1},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {dec},
number = {12},
pages = {933--938},
title = {{Climatic and volcanic forcing of tropical belt northern boundary over the past 800 years}},
url = {http://www.nature.com/articles/s41561-018-0242-1},
volume = {11},
year = {2018}
}
@article{Alkama2013,
author = {Alkama, R and Marchand, L and Ribes, A and Decharme, B},
doi = {10.5194/hess-17-2967-2013},
journal = {Hydrology and Earth System Sciences},
pages = {2967--2979},
title = {{Detection of global runoff changes: results from observations and CMIP5 experiments}},
volume = {17},
year = {2013}
}
@article{Alkama2011,
abstract = {While human influence has been detected in global and regional surface air temperature, detection–attribution studies of direct (i.e., land use and water management) and indirect (i.e., climate related) effects of human activities on land surface hydrology remain a crucial and controversial issue. In the present study, a set of global offline hydrological simulations is performed during the 1960–94 period using the Interactions between Soil, Biosphere, and Atmosphere–Total Runoff Integrating Pathways (ISBA-TRIP) modeling system. In contrast to previous numerical sensitivity studies, the model captures the observed trend in river runoff over most continents without including land use changes and/or biophysical CO2 effects, at least when the comparison is made over 154 large rivers with a minimum amount of missing data. The main exception is northern Asia, where the simulated runoff trend is negative, in line with the prescribed precipitation forcing but in contrast with the observed runoff trend. The authors hypothesize that the observed surface warming and the associated decline of permafrost and glaciers, not yet included in most land surface models, could have contributed to the increased runoff at high latitudes. They also emphasize that the runoff trend is a regional-scale issue, if not basin dependent. In line with recent observational studies, their results suggest that CO2 stomatal conductance effects and land use changes are not the primary drivers of the multidecadal runoff variability at continental scales. However, the authors do not rule out a human influence on land runoff, at least through the high-latitude surface warming observed over recent decades.},
author = {Alkama, R. and Decharme, B. and Douville, H. and Ribes, A.},
doi = {10.1175/2010JCLI3921.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jun},
number = {12},
pages = {3000--3014},
title = {{Trends in Global and Basin-Scale Runoff over the Late Twentieth Century: Methodological Issues and Sources of Uncertainty}},
url = {https://journals.ametsoc.org/jcli/article/24/12/3000/32696/Trends-in-Global-and-BasinScale-Runoff-over-the},
volume = {24},
year = {2011}
}
@article{Allan2014a,
author = {Allan, Richard P. and Liu, C and Zahn, M and Lavers, D. A. and Koukouvagias, E and Bodas-Salcedo, A},
doi = {10.1007/s10712-012-9213-z},
journal = {Surveys in Geophysics},
keywords = {a,allan,climate models {\'{a}} satellite,data {\'{a}} global change,department of meteorology,koukouvagias,lavers {\'{a}} e,liu {\'{a}} m,national centre for atmospheric,p,precipitation {\'{a}} water {\'{a}},r,sciences,zahn {\'{a}} d,{\'{a}} c},
pages = {533--552},
title = {{Physically Consistent Responses of the Global Atmospheric Hydrological Cycle in Models and Observations}},
volume = {35},
year = {2014}
}
@article{Allen2012,
author = {Allen, R J and Sherwood, S C and Norris, J R and Zender, C S},
doi = {10.1038/nature11097},
journal = {Nature},
pages = {350--354},
title = {{Recent Northern Hemisphere tropical expansion primarily driven by black carbon and tropospheric ozone}},
volume = {485},
year = {2012}
}
@article{Allen2017,
author = {Allen, R J and Kovilakam, M},
doi = {10.1175/JCLI-D-16-0735.1},
journal = {Journal of Climate},
pages = {6329--6350},
title = {{The Role of Natural Climate Variability in Recent Tropical Expansion}},
volume = {30},
year = {2017}
}
@article{Allison_2019,
abstract = {Observational estimates of global ocean heat content (OHC) change are used to assess Earth's energy imbalance over the 20th Century. However, intercomparison studies show that the mapping methods used to interpolate sparse ocean temperature profile data are a key source of uncertainty. We present a new approach to assessing OHC mapping methods using ‘synthetic profiles' generated from a state-of-the-art global climate model simulation. Synthetic profiles have the same sampling characteristics as the historical ocean temperature profile data but are based on model simulation data. Mapping methods ingest these data in the same way as they would real observations, but the resultant mapped fields can be compared to a model simulation ‘truth'. We use this approach to assess two mapping methods that are used routinely for climate monitoring and initialisation of decadal forecasts. The introduction of the Argo network of autonomous profiling floats during the 2000s drives clear improvements in the ability of these methods to reconstruct the variability and spatial structure of OHC changes. At depths below 2000 m, both methods underestimate the magnitude of the simulated ocean warming signal. Temporal variability and trends in OHC are better captured in the better-observed northern hemisphere than in the southern hemisphere. At all depths, the sampling characteristics of the historical data introduces some spurious variability in the estimates of global OHC on sub-annual to multi-annual timescales. However, many of the large scale spatial anomalies, especially in the upper ocean, are successfully reconstructed even with sparse observations from the 1960s, demonstrating the potential to construct historical ocean analyses for assessing decadal predictions. The value of using accurate global covariances for data-poor periods is clearly seen. The results of this ‘proof-of-concept' study are encouraging for gaining further insights into the capabilities and limitations of different mapping methods and for quantifying uncertainty in global OHC estimates.},
author = {Allison, L C and Roberts, C D and Palmer, M D and Hermanson, L and Killick, R E and Rayner, N A and Smith, D M and Andrews, M B},
doi = {10.1088/1748-9326/ab2b0b},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {aug},
number = {8},
pages = {84037},
publisher = {IOP Publishing},
title = {{Towards quantifying uncertainty in ocean heat content changes using synthetic profiles}},
url = {http://dx.doi.org/10.1088/1748-9326/ab2b0b https://doi.org/10.1088{\%}2F1748-9326{\%}2Fab2b0b},
volume = {14},
year = {2019}
}
@article{Alonso-Garcia2017,
author = {Alonso-Garcia, M and Kleiven, H. F and McManus, J F and Moffa-Sanchez, P and Broecker, W S and Flower, B P},
doi = {10.5194/cp-13-317-2017},
issn = {1814-9332},
journal = {Climate of the Past},
month = {apr},
number = {4},
pages = {317--331},
publisher = {Copernicus Publications},
title = {{Freshening of the Labrador Sea as a trigger for Little Ice Age development}},
url = {https://cp.copernicus.org/articles/13/317/2017/ https://cp.copernicus.org/articles/13/317/2017/cp-13-317-2017.pdf},
volume = {13},
year = {2017}
}
@techreport{AMAP2017,
address = {Oslo, Norway},
author = {AMAP},
doi = {https://www.amap.no/documents/doc/snow-water-ice-and-permafrost-in-the-arctic-swipa-2017/1610},
isbn = {978-82-7971-101-8},
pages = {269},
publisher = {Arctic Monitoring and Assessment Programme (AMAP)},
title = {{Snow, Water, Ice and Permafrost in the Arctic (SWIPA)}},
url = {https://www.amap.no/documents/doc/snow-water-ice-and-permafrost-in-the-arctic-swipa-2017/1610},
year = {2017}
}
@article{Ammann2003,
abstract = {A new monthly volcanic forcing dataset is included in a coupled GCM for a more physically consistent treatment of the stratospheric sulfate aerosol history from explosive volcanism. The volcanic forcing is different from previous versions in that there is an individual evolution of the aerosol for each event. Thus the seasonal and latitudinal dependence of the volcanic aerosol can affect global climate in a more realistic way prior to the satellite period, compared to earlier volcanic forcing datasets. Negative radiative forcing from volcanic activity is greatest in the early 20th century prior to 1915 and in the late 20th century after 1960. The combination of volcanic and solar forcing contributes to an early-20th century warming, followed by relative cooling in late 20th century. Consequently, the addition of natural forcing factors to the anthropogenic GHG forcing in late 20th century is required to simulate the observed late 20th century warming.},
author = {Ammann, Caspar M. and Meehl, Gerald A. and Washington, Warren M. and Zender, Charles S.},
doi = {10.1029/2003GL016875},
issn = {0094-8276},
journal = {Geophysical Research Letters},
number = {12},
title = {{A monthly and latitudinally varying volcanic forcing dataset in simulations of 20th century climate}},
volume = {30},
year = {2003}
}
@article{Zhisheng2015,
abstract = {This article provides a comprehensive review of the global monsoon that encompasses findings from studies of both modern monsoons and paleomonsoons. We introduce a definition for the global monsoon that incorporates its three-dimensional distribution and ultimate causes, emphasizing the direct drive of seasonal pressure system changes on monsoon circulation and depicting the intensity in terms of both circulation and precipitation. We explore the global monsoon climate changes across a wide range of timescales from tectonic to intraseasonal. Common features of the global monsoon are global homogeneity, regional diversity, seasonality, quasi-periodicity, irregularity, instability, and asynchroneity. We emphasize the importance of solar insolation, Earth orbital parameters, underlying surface properties, and land-air-sea interactions for global monsoon dynamics. We discuss the primary driving force of monsoon variability on each timescale and the relationships among dynamics on multiple timescales. Natural ...},
author = {An, Z and Wu, Guoxiong and Li, J and Sun, Y and Liu, Y and Zhou, W and Cai, Y and Duan, Anmin and Li, Li and Mao, J and Cheng, H and Shi, Z and Tan, L and Yan, H and Ao, H and Chang, H and Feng, H},
doi = {10.1146/annurev-earth-060313-054623},
isbn = {0084-6597$\backslash$r1545-4495},
issn = {0084-6597},
journal = {Annual Review of Earth and Planetary Sciences},
keywords = {asian monsoon,climate change,global monsoon,monsoon dynamics,monsoon variability,multitimescale,paleomonsoon,tibetan plateau},
number = {1},
pages = {29--77},
title = {{Global Monsoon Dynamics and Climate Change}},
url = {http://www.annualreviews.org/doi/10.1146/annurev-earth-060313-054623},
volume = {43},
year = {2015}
}
@article{Anagnostou2016,
abstract = {The Early Eocene Climate Optimum (EECO, which occurred about 51 to 53 million years ago), was the warmest interval of the past 65 million years, with mean annual surface air temperature over ten degrees Celsius warmer than during the pre-industrial period. Subsequent global cooling in the middle and late Eocene epoch, especially at high latitudes, eventually led to continental ice sheet development in Antarctica in the early Oligocene epoch (about 33.6 million years ago). However, existing estimates place atmospheric carbon dioxide (CO2) levels during the Eocene at 500-3,000 parts per million, and in the absence of tighter constraints carbon-climate interactions over this interval remain uncertain. Here we use recent analytical and methodological developments to generate a new high-fidelity record of CO2 concentrations using the boron isotope (delta11B) composition of well preserved planktonic foraminifera from the Tanzania Drilling Project, revising previous estimates. Although species-level uncertainties make absolute values difficult to constrain, CO2 concentrations during the EECO were around 1,400 parts per million. The relative decline in CO2 concentration through the Eocene is more robustly constrained at about fifty per cent, with a further decline into the Oligocene. Provided the latitudinal dependency of sea surface temperature change for a given climate forcing in the Eocene was similar to that of the late Quaternary period, this CO2 decline was sufficient to drive the well documented high- and low-latitude cooling that occurred through the Eocene. Once the change in global temperature between the pre-industrial period and the Eocene caused by the action of all known slow feedbacks (apart from those associated with the carbon cycle) is removed, both the EECO and the late Eocene exhibit an equilibrium climate sensitivity relative to the pre-industrial period of 2.1 to 4.6 degrees Celsius per CO2 doubling (66 per cent confidence), which is similar to the canonical range (1.5 to 4.5 degrees Celsius), indicating that a large fraction of the warmth of the early Eocene greenhouse was driven by increased CO2 concentrations, and that climate sensitivity was relatively constant throughout this period.},
author = {Anagnostou, Eleni and John, Eleanor H and Edgar, Kirsty M and Foster, Gavin L and Ridgwell, Andy and Inglis, Gordon N and Pancost, Richard D and Lunt, Daniel J and Pearson, Paul N},
doi = {10.1038/nature17423},
isbn = {1476-4687 (Electronic)$\backslash$r0028-0836 (Linking)},
issn = {14764687},
journal = {Nature},
month = {apr},
pages = {380--384},
pmid = {27111509},
publisher = {Nature Publishing Group},
title = {{Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate}},
volume = {533},
year = {2016}
}
@article{Anagnostou2020c,
author = {Anagnostou, E and John, E H and Babila, T L and Sexton, P F and Ridgwell, A and Lunt, D J and Pearson, P N and Chalk, T B and Pancost, R D and Foster, G L},
doi = {10.1038/s41467-020-17887-x},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {4436},
title = {{Proxy evidence for state-dependence of climate sensitivity in the Eocene greenhouse}},
url = {https://doi.org/10.1038/s41467-020-17887-x},
volume = {11},
year = {2020}
}
@article{Anchukaitis2017,
abstract = {Climate field reconstructions from networks of tree-ring proxy data can be used to characterize regional-scale climate changes, reveal spatial anomaly patterns associated with atmospheric circulation changes, radiative forcing, and large-scale modes of ocean-atmosphere variability, and provide spatiotemporal targets for climate model comparison and evaluation. Here we use a multiproxy network of tree-ring chronologies to reconstruct spatially resolved warm season (May–August) mean temperatures across the extratropical Northern Hemisphere (40-90°N) using Point-by-Point Regression (PPR). The resulting annual maps of temperature anomalies (750–1988 CE) reveal a consistent imprint of volcanism, with 96{\%} of reconstructed grid points experiencing colder conditions following eruptions. Solar influences are detected at the bicentennial (de Vries) frequency, although at other time scales the influence of insolation variability is weak. Approximately 90{\%} of reconstructed grid points show warmer temperatures during the Medieval Climate Anomaly when compared to the Little Ice Age, although the magnitude varies spatially across the hemisphere. Estimates of field reconstruction skill through time and over space can guide future temporal extension and spatial expansion of the proxy network.},
author = {Anchukaitis, Kevin J. and Wilson, Rob and Briffa, Keith R. and B{\"{u}}ntgen, Ulf and Cook, Edward R. and D'Arrigo, Rosanne and Davi, Nicole and Esper, Jan and Frank, David and Gunnarson, Bj{\"{o}}rn E. and Hegerl, Gabi and Helama, Samuli and Klesse, Stefan and Krusic, Paul J. and Linderholm, Hans W. and Myglan, Vladimir and Osborn, Timothy J. and Zhang, Peng and Rydval, Milos and Schneider, Lea and Schurer, Andrew and Wiles, Greg and Zorita, Eduardo},
doi = {10.1016/J.QUASCIREV.2017.02.020},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
month = {may},
pages = {1--22},
publisher = {Pergamon},
title = {{Last millennium Northern Hemisphere summer temperatures from tree rings: Part II, spatially resolved reconstructions}},
url = {https://www.sciencedirect.com/science/article/pii/S0277379117301592?via{\%}3Dihub},
volume = {163},
year = {2017}
}
@article{Anderson2018a,
author = {Anderson, H J and Moy, C M and Vandergoes, M J and Nichols, J E and Riesselman, C R and {Van Hale}, R},
doi = {10.1002/jqs.3045},
journal = {Journal of Quaternary Science},
number = {6},
pages = {689--701},
title = {{Southern Hemisphere westerly wind influence on southern New Zealand hydrology during the Lateglacial and Holocene}},
volume = {33},
year = {2018}
}
@article{Anderson2017,
abstract = {We present observations defining (i) the frequency and depth of convective penetration of water into the stratosphere over the United States in summer using the Next-Generation Radar system; (ii) the altitude-dependent distribution of inorganic chlorine estab-lished in the same coordinate system as the radar observations; (iii) the high resolution temperature structure in the stratosphere over the United States in summer that resolves spatial and structural var-iability, including the impact of gravity waves; and (iv) the resulting amplification in the catalytic loss rates of ozone for the dominant hal-ogen, hydrogen, and nitrogen catalytic cycles. The weather radar observations of ∼2,000 storms, on average, each summer that reach the altitude of rapidly increasing available inorganic chlorine, coupled with observed temperatures, portend a risk of initiating rapid hetero-geneous catalytic conversion of inorganic chlorine to free radical form on ubiquitous sulfate−water aerosols; this, in turn, engages the ele-ment of risk associated with ozone loss in the stratosphere over the central United States in summer based upon the same reaction net-work that reduces stratospheric ozone over the Arctic. The summer-time development of the upper-level anticyclonic flow over the United States, driven by the North American Monsoon, provides a means of retaining convectively injected water, thereby extending the time for catalytic ozone loss over the Great Plains. Trusted decadal forecasts of UV dosage over the United States in summer require understanding the response of this dynamical and photochemical system to in-creased forcing of the climate by increasing levels of CO 2 and CH 4 . stratospheric ozone | climate change | UV radiation human health effects | convection | water vapor},
author = {Anderson, James G. and Weisenstein, Debra K. and Bowman, Kenneth P. and Homeyer, Cameron R. and Smith, Jessica B. and Wilmouth, David M. and Sayres, David S. and Klobas, J. Eric and Leroy, Stephen S. and Dykema, John A. and Wofsy, Steven C.},
doi = {10.1073/pnas.1619318114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {25},
pages = {E4905--E4913},
pmid = {28584119},
title = {{Stratospheric ozone over the United States in summer linked to observations of convection and temperature via chlorine and bromine catalysis}},
volume = {114},
year = {2017}
}
@article{Anderson2019a,
abstract = {Abstract Enhanced ocean carbon storage during the Pleistocene ice ages lowered atmospheric CO2 concentrations by 80 to 100 ppm relative to interglacial levels. Leading hypotheses to explain this phenomenon invoke a greater efficiency of the ocean's biological pump, in which case carbon storage in the deep sea would have been accompanied by a corresponding reduction in dissolved oxygen. We exploit the sensitivity of organic matter preservation in marine sediments to bottom water oxygen concentration to constrain the level of dissolved oxygen in the deep central equatorial Pacific Ocean during the last glacial period (18,000?28,000 years BP) to have been within the range of 20?50 ?mol/kg, much less than the modern value of {\~{}}168 ?mol/kg. We further demonstrate that reduced oxygen levels characterized the water column below a depth of {\~{}}1,000 m. Converting the ice age oxygen level to an equivalent concentration of respiratory CO2, and extrapolating globally, we estimate that deep-sea CO2 storage during the last ice age exceeded modern values by as much as 850 Pg C, sufficient to balance the loss of carbon from the atmosphere ({\~{}}200 Pg C) and from the terrestrial biosphere ({\~{}}300?600 Pg C). In addition, recognizing the enhanced preservation of organic matter in ice age sediments of the deep Pacific Ocean helps reconcile previously unexplained inconsistencies among different geochemical and micropaleontological proxy records used to assess past changes in biological productivity of the ocean.},
annote = {doi: 10.1029/2018GB006049},
author = {Anderson, Robert F and Sachs, Julian P and Fleisher, Martin Q and Allen, Katherine A and Yu, Jimin and Koutavas, Athanasios and Jaccard, Samuel L},
doi = {10.1029/2018GB006049},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {alkenones,bottom-water oxygen,last glacial period,lipid biomarkers,ocean carbon storage},
month = {mar},
number = {3},
pages = {301--317},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Deep-Sea Oxygen Depletion and Ocean Carbon Sequestration During the Last Ice Age}},
url = {https://doi.org/10.1029/2018GB006049},
volume = {33},
year = {2019}
}
@article{Andersson2011,
author = {Andersson, A and Klepp, Christian and Fennig, K and Bakan, Stephan and Grassl, H and Schulz, J.},
doi = {10.1175/2010JAMC2341.1},
journal = {Journal of Applied Meteorology and Climatology},
pages = {379--398},
title = {{Evaluation of HOAPS-3 Ocean Surface Freshwater Flux Components}},
volume = {50},
year = {2011}
}
@article{Andersson2015,
author = {Andersson, Sandra M. and Martinsson, Bengt G. and Vernier, Jean-Paul and Friberg, Johan and Brenninkmeijer, Carl A. M. and Hermann, Markus and van Velthoven, Peter F. J. and Zahn, Andreas},
doi = {10.1038/ncomms8692},
issn = {2041-1723},
journal = {Nature Communications},
month = {jul},
pages = {7692},
publisher = {Nature Publishing Group},
title = {{Significant radiative impact of volcanic aerosol in the lowermost stratosphere}},
volume = {6},
year = {2015}
}
@article{Andrae2018,
abstract = {Since the late Miocene, plants using the C4 photosynthetic pathway have increased to become major components of many tropical and subtropical ecosystems. However, the drivers for this expansion remain under debate, in part because of the varied histories of C4 vegetation on different continents. Australia hosts the highest dominance of C4 vegetation of all continents, but little is known about the history of C4 vegetation there. Carbon isotope ratios of plant waxes from scientific ocean drilling sediments off north-western Australia reveal the onset of Australian C4 expansion at {\~{}}3.5 Ma, later than in many other regions. Pollen analysis from the same sediments reveals increasingly open C3-dominated biomes preceding the shift to open C4-dominated biomes by several million years. We hypothesize that the development of a summer monsoon climate beginning in the late Pliocene promoted a highly seasonal precipitation regime favorable to the expansion of C4 vegetation.},
author = {Andrae, J. W. and McInerney, F. A. and Polissar, P. J. and Sniderman, J. M.K. and Howard, S. and Hall, P. A. and Phelps, S. R.},
doi = {10.1029/2018GL077833},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {10},
title = {{Initial Expansion of C4 Vegetation in Australia During the Late Pliocene}},
volume = {45},
year = {2018}
}
@article{Andres2020,
abstract = {Full-ocean-depth observations of horizontal velocity, temperature and salinity along 68.5° W chiefly over the period October 2010–May 2014 are analyzed in conjunction with repeated shipboard acoustic Doppler current profiler (SADCP) upper-ocean velocity sections occupied upstream at 70.3° W and regional satellite-altimeter-based sea surface height (SSH) data to construct estimates of the time-averaged Gulf Stream velocity, property structures and transport. A stream-coordinate mean section is created from two moorings near 68.5° W where data are binned relative to distance from the Gulf Stream axis, rotated into along- and across-stream coordinates, and then averaged. Transport in the upper 600 m inferred from the moorings excluding times of large Stream axis curvature and Gulf Stream ring influences is 59.9 Sv (with 95{\%} confidence bounds between 58.6 and 61.6 Sv). This is in good agreement with a mean constructed from the SADCP sections at 70.3° W. Relative to the mean field at 70.3° W, the velocity core of the time-averaged Stream at 68.5° W appears broader with weaker maximum speed, consistent with a companion analysis of the altimetric SSH data. The time-averaged full-ocean-depth transport inferred from the moorings is 102.1 Sv (with 95{\%} confidence bounds between 99.1 and 106.3 Sv), which is stronger than the mean inferred from an ensemble of 10 full-depth lowered acoustic Doppler current profiler (LADCP) sections collected along the moored array. The 2010–2014 time-averaged Gulf Stream inferred from the moored observations is weaker by about 10{\%} than the time-averaged full-ocean-depth transport reported for the late 1980s at the same location using similar procedures, with much of this difference arising from flows at depths greater than 1000 m. Satellite altimetry provides spatial and temporal context for these results and suggests that there are small-scale recirculation cells flanking the separated Gulf Stream west of the New England Seamount Chain. Gulf Stream transport, which includes throughput and recirculating components, appears to be more sensitive to changes in these recirculations at 68.5° W compared to 70.3° W.},
author = {Andres, Magdalena and Donohue, Kathleen A and Toole, John M},
doi = {10.1016/j.dsr.2019.103179},
issn = {0967-0637},
journal = {Deep-Sea Research Part I: Oceanographic Research Papers},
keywords = {ADCP,Altimetry,Gulf stream,Line W program,Oleander program,Transport},
pages = {103179},
title = {{The Gulf Stream's path and time-averaged velocity structure and transport at 68.5°W and 70.3°W}},
url = {http://www.sciencedirect.com/science/article/pii/S0967063719303255},
volume = {156},
year = {2020}
}
@article{Andrews2017a,
abstract = {The effective radiative forcing (ERF) from the biogeophysical effects of historical land use change is quantified using the atmospheric component of the Met Office Hadley Centre Earth System model HadGEM2-ES. The global ERF at 2005 relative to 1860 (1700) is −0.4 (−0.5) Wm−2, making it the fourth most important anthropogenic driver of climate change over the historical period (1860–2005) in this model and larger than most other published values. The land use ERF is found to be dominated by increases in the land surface albedo, particularly in North America and Eurasia, and occurs most strongly in the northern hemisphere winter and spring when the effect of unmasking underlying snow, as well as increasing the amount of snow, is at its largest. Increased bare soil fraction enhances the seasonal cycle of atmospheric dust and further enhances the ERF. Clouds are shown to substantially mask the radiative effect of changes in the underlying surface albedo. Coupled atmosphere–ocean simulations forced only with time-varying historical land use change shows substantial global cooling (dT = −0.35 K by 2005) and the climate resistance (ERF/dT = 1.2 Wm−2 K−1) is consistent with the response of the model to increases in CO2 alone. The regional variation in land surface temperature change, in both fixed-SST and coupled atmosphere–ocean simulations, is found to be well correlated with the spatial pattern of the forced change in surface albedo. The forcing-response concept is found to work well for historical land use forcing—at least in our model and when the forcing is quantified by ERF. Our results suggest that land-use changes over the past century may represent a more important driver of historical climate change then previously recognised and an underappreciated source of uncertainty in global forcings and temperature trends over the historical period.},
author = {Andrews, Timothy and Betts, Richard A. and Booth, Ben B.B. and Jones, Chris D. and Jones, Gareth S.},
doi = {10.1007/s00382-016-3280-7},
isbn = {1432-0894},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Climate model,Earth system,Global temperature change,Land-use,Radiative forcing},
title = {{Effective radiative forcing from historical land use change}},
year = {2017}
}
@article{jmse5040057,
abstract = {Recent studies have shown significant sea surface salinity (SSS) changes at scales ranging from regional to global. In this study, we estimate global salinity means and trends using historical (1950–2014) SSS data from the UK Met Office Hadley Centre objectively analyzed monthly fields and recent data from the SMOS satellite (2010–2014). We separate the different components (regimes) of the global surface salinity by fitting a Gaussian Mixture Model to the data and using expectation–maximization to distinguish the means and trends of the data. The procedure uses a non-subjective method (Bayesian information criterion) to extract the optimal number of means and trends. The results show the presence of three separate regimes: Regime A (1950–1990) is characterized by small trend magnitudes; Regime B (1990–2009) exhibited enhanced trends; and Regime C (2009–2014) with significantly larger trend magnitudes. The salinity differences between regime means were around 0.01. The trend acceleration could be related to an enhanced global hydrological cycle or to a change in the sampling methodology. Understanding past SSS changes can provide insight into future climate evolution by complementing the knowledge acquired in recent decades from long-term temperature record analyses.},
author = {Aretxabaleta, Alfredo L and Smith, Keston W and Kalra, Tarandeep S},
doi = {10.3390/jmse5040057},
issn = {2077-1312},
journal = {Journal of Marine Science and Engineering},
number = {4},
title = {{Regime Changes in Global Sea Surface Salinity Trend}},
url = {https://www.mdpi.com/2077-1312/5/4/57},
volume = {5},
year = {2017}
}
@incollection{doi:10.1002/9781118778371.ch26,
abstract = {Summary Palaeo sea-ice estimation, first addressed in the mid-1970s, has advanced greatly through the development of additional proxies, increasingly robust statistical methods, and the acquisition of more highly resolved records in both the Antarctic and Arctic. The use of multiple proxies provides the most reliable records. An essential part of multi-proxy studies is the distribution of dinocysts in the Arctic, and diatoms in the Antarctic. These proxies combined with geochemical and sedimentological tracers, as well as new work focused on the use of biomarkers specific to organisms that live in sea ice, such as IP25, are allowing far greater understanding of sea ice type, persistence and extent. Through the ensuing proxy assessments, the history of sea ice development and variability throughout the polar regions is addressed, highlighting palaeo sea-ice reconstructions for specific time-slices, including the initiation of Arctic sea ice, and sea-ice variability since the Last Glacial Maximum at both poles.},
address = {Chichester, UK and Hoboken, NJ, USA},
author = {Armand, Leanne and Ferry, Alexander and Leventer, Amy},
booktitle = {Sea Ice (Third Edition)},
chapter = {26},
doi = {10.1002/9781118778371.ch26},
editor = {Thomas, David N.},
isbn = {9781118778371},
keywords = {Antarctic,Arctic,biomarkers,diatoms,dinocysts,highly branched isoprenoids,palaeoceanography,proxies,sea-ice cover,sea-ice extent},
pages = {600--629},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Advances in palaeo sea ice estimation}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/9781118778371.ch26},
year = {2017}
}
@article{Ashcroft2016,
abstract = {The El Ni{\~{n}}o--Southern Oscillation (ENSO) phenomenon plays a large role in the modulation of Australian rainfall, particularly in the highly populated southeast. However, this influence is not stationary over time: weak ENSO teleconnections in Australia have been identified during 1920--1950, and palaeoclimate reconstructions indicate that a breakdown in global ENSO teleconnections may have also occurred in the early to mid-1800s. A lack of long-term instrumental data has prevented detailed examination of this intriguing earlier period. This study uses newly recovered instrumental rainfall observations to determine whether the weakening of ENSO teleconnections in the nineteenth century is apparent in eastern and southern southeastern Australia (SEA). Quantitative rainfall and rainday data from 1788 to 2012 are compared with three ENSO indices derived from palaeoclimate data. Statistical analysis suggests a weakening of the relationship between ENSO and SEA rainfall in the early nineteenth century data ({\{}$\backslash$textasciitilde{\}}1835--1850), supporting results reported in previous global and regional studies based on palaeoclimate and documentary rainfall reconstructions. Possible causes of this weakening in teleconnection strength are then explored by examining a range of Southern Hemisphere circulation indices. The 1835--1850 period of low ENSO--SEA rainfall correlations appears to be characterised by a combination of reduced La Ni{\~{n}}a events and ENSO variance associated with a positive phase of the Interdecadal Pacific Oscillation, with the possible influence of a predominately negative phase of the Southern Annular Mode. However, current temporal and geographical data limitations prevent definitive conclusions from being drawn. Despite these caveats, this study illustrates the considerable value of historical instrumental climate data in assessing long-term variations in climate mode teleconnections, particularly in the data-poor Southern Hemisphere.},
author = {Ashcroft, Linden and Gergis, Jo{\"{e}}lle and Karoly, David John},
doi = {10.1007/s00382-015-2746-3},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {may},
number = {9},
pages = {2991--3006},
title = {{Long-term stationarity of El Ni{\~{n}}o–Southern Oscillation teleconnections in southeastern Australia}},
url = {https://doi.org/10.1007/s00382-015-2746-3},
volume = {46},
year = {2016}
}
@article{doi:10.1029/2006JC003798,
abstract = {Using observed data sets mainly for the period 1979–2005, we find that anomalous warming events different from conventional El Ni{\~{n}}o events occur in the central equatorial Pacific. This unique warming in the central equatorial Pacific associated with a horseshoe pattern is flanked by a colder sea surface temperature anomaly (SSTA) on both sides along the equator. empirical orthogonal function (EOF) analysis of monthly tropical Pacific SSTA shows that these events are represented by the second mode that explains 12{\%} of the variance. Since a majority of such events are not part of El Ni{\~{n}}o evolution, the phenomenon is named as El Ni{\~{n}}o Modoki (pseudo-El Ni{\~{n}}o) (“Modoki” is a classical Japanese word, which means “a similar but different thing”). The El Ni{\~{n}}o Modoki involves ocean-atmosphere coupled processes which include a unique tripolar sea level pressure pattern during the evolution, analogous to the Southern Oscillation in the case of El Ni{\~{n}}o. Hence the total entity is named as El Ni{\~{n}}o–Southern Oscillation (ENSO) Modoki. The ENSO Modoki events significantly influence the temperature and precipitation over many parts of the globe. Depending on the season, the impacts over regions such as the Far East including Japan, New Zealand, western coast of United States, etc., are opposite to those of the conventional ENSO. The difference maps between the two periods of 1979–2004 and 1958–1978 for various oceanic/atmospheric variables suggest that the recent weakening of equatorial easterlies related to weakened zonal sea surface temperature gradient led to more flattening of the thermocline. This appears to be a cause of more frequent and persistent occurrence of the ENSO Modoki event during recent decades.},
author = {Ashok, Karumuri and Behera, Swadhin K and Rao, Suryachandra A and Weng, Hengyi and Yamagata, Toshio},
doi = {10.1029/2006JC003798},
journal = {Journal of Geophysical Research: Oceans},
keywords = {El Nino Modoki,coupled process,teleconnection},
number = {C11},
title = {{El Ni{\~{n}}o Modoki and its possible teleconnection}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2006JC003798},
volume = {112},
year = {2007}
}
@article{Ashouri2015a,
author = {Ashouri, Hamed and Hsu, Kuo Lin and Sorooshian, Soroosh and Braithwaite, Dan and Knapp, K R and Cecil, L C and Nelson, B R and Prat, O P},
doi = {10.1175/BAMS-D-13-00068.1},
journal = {Bulletin of the American Meteorological Society},
number = {January},
pages = {69--84},
title = {{PERSIANN-CDR: Daily Precipitation Climate Data Record from Multisatellite Observations for Hydrological and Climate Studies}},
year = {2015}
}
@article{Atkinson2019,
abstract = {High-latitude ecosystems are among the fastest warming on the planet1. Polar species may be sensitive to warming and ice loss, but data are scarce and evidence is conflicting2–4. Here, we show that, within their main population centre in the southwest Atlantic sector, the distribution of Euphausia superba (hereafter, ‘krill') has contracted southward over the past 90 years. Near their northern limit, numerical densities have declined sharply and the population has become more concentrated towards the Antarctic shelves. A concomitant increase in mean body length reflects reduced recruitment of juvenile krill. We found evidence for environmental controls on recruitment, including a reduced density of juveniles following positive anomalies of the Southern Annular Mode. Such anomalies are associated with warm, windy and cloudy weather and reduced sea ice, all of which may hinder egg production and the survival of larval krill5. However, the total post-larval density has declined less steeply than the density of recruits, suggesting that survival rates of older krill have increased. The changing distribution is already perturbing the krill-centred food web6 and may affect biogeochemical cycling7,8. Rapid climate change, with associated nonlinear adjustments in the roles of keystone species, poses challenges for the management of valuable polar ecosystems3.},
author = {Atkinson, Angus and Hill, Simeon L and Pakhomov, Evgeny A and Siegel, Volker and Reiss, Christian S and Loeb, Valerie J and Steinberg, Deborah K and Schmidt, Katrin and Tarling, Geraint A and Gerrish, Laura and Sailley, S{\'{e}}vrine F},
doi = {10.1038/s41558-018-0370-z},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {2},
pages = {142--147},
title = {{Krill (Euphausia superba) distribution contracts southward during rapid regional warming}},
url = {https://doi.org/10.1038/s41558-018-0370-z},
volume = {9},
year = {2019}
}
@article{doi:10.1029/2019GL085098,
abstract = {Abstract We evaluate the stability of the radiometric calibration of the Atmospheric Infrared Sounder (AIRS) by analyzing the trend in the time series of the difference between the brightness temperatures measured in the 1,231-cm−1 atmospheric window channel, corrected for atmospheric transmission, relative to the Real-Time Global Sea Surface Temperature (RTGSST) for oceans between 30S and 30N. The observed bias relative to the RTGSST between 2002 and 2019 was less than 250 mK, with a 2–3-mK/yr trend. Establishing the stability of the 1,231-cm−1 channel at tropical ocean temperatures at the 2–3-mK/yr level is a necessary but not sufficient condition of establishing the calibration stability of all AIRS channels over the full dynamic range at a comparable level. Our analysis indirectly establishes the stability of the RTGSST for the 2002–2017 time period and region at the 2–3-mK/yr level, with a degradation since 2017.},
author = {Aumann, Hartmut H and Broberg, Steve and Manning, Evan and Pagano, Tom},
doi = {10.1029/2019GL085098},
journal = {Geophysical Research Letters},
keywords = {climate,hyperspectral,infrared,temperature sounder},
number = {21},
pages = {12504--12510},
title = {{Radiometric Stability Validation of 17 Years of AIRS Data Using Sea Surface Temperatures}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL085098},
volume = {46},
year = {2019}
}
@article{Austermanne1700457,
abstract = {Estimating minimum ice volume during the last interglacial based on local sea-level indicators requires that these indicators are corrected for processes that alter local sea level relative to the global average. Although glacial isostatic adjustment is generally accounted for, global scale dynamic changes in topography driven by convective mantle flow are generally not considered. We use numerical models of mantle flow to quantify vertical deflections caused by dynamic topography and compare predictions at passive margins to a globally distributed set of last interglacial sea-level markers. The deflections predicted as a result of dynamic topography are significantly correlated with marker elevations ({\textgreater}95{\%} probability) and are consistent with construction and preservation attributes across marker types. We conclude that a dynamic topography signal is present in the elevation of last interglacial sea-level records and that the signal must be accounted for in any effort to determine peak global mean sea level during the last interglacial to within an accuracy of several meters.},
author = {Austermann, Jacqueline and Mitrovica, Jerry X and Huybers, Peter and Rovere, Alessio},
doi = {10.1126/sciadv.1700457},
journal = {Science Advances},
number = {7},
publisher = {American Association for the Advancement of Science},
title = {{Detection of a dynamic topography signal in last interglacial sea-level records}},
url = {https://advances.sciencemag.org/content/3/7/e1700457},
volume = {3},
year = {2017}
}
@article{Avery2017,
author = {Avery, Melody A and Davis, Sean M and Rosenlof, Karen H and Ye, Hao and Dessler, Andrew E},
doi = {10.1038/ngeo2961},
issn = {17520908},
journal = {Nature Geoscience},
month = {may},
number = {6},
pages = {405--409},
publisher = {Nature Publishing Group},
title = {{Large anomalies in lower stratospheric water vapour and ice during the 2015-2016 El Nin{\~{o}}}},
volume = {10},
year = {2017}
}
@article{Ayache2018,
abstract = {The Meridional Overturning Circulation (AMOC) is believed to have played a key role in climate variability over the Holocene, but the reconstruction of its variations remains limited by inconsistencies among different proxy records used. To circumvent this issue, we propose a new statistical method to reconstruct the AMOC variations based on multiple sources of information, i.e. 22 proxy records of annual Sea Surface Temperature (SST) compiled in the North Atlantic and covering the Holocene (HAMOC database). Our approach consists of isolating the main variability modes hidden in the Atlantic Ocean through principal component analysis (PCA) and then evaluating their link with the AMOC. To estimate the skill of our method, we use a pseudo-proxy approach applied to observational SST data covering the period 1870–2010, as well as simulations from a comprehensive climate model (IPSL-CM5A-LR) where the AMOC variations are known. In instrumental observations and most of the model simulations, the first mode of SST variations from the PCA analysis over the North Atlantic can be related with the external radiative forcing, while the second mode is reminiscent of the AMOC variability and of its signature on SST. When computed over the Holocene period using the HAMOC database, the first mode is indeed well correlated with the insolation changes, marked by a general cooling of the Northern Atlantic from 9 thousand years ago (ka). The second mode, that we consider here as a reconstruction of standardized AMOC variations following the pseudo-proxy analysis in the model simulations and in the observations, is in general agreement with a few independent reconstructions of the deep branch of the AMOC recorded in the North Atlantic. Based on this new AMOC index reconstruction, we highlight that the Early Holocene may have been associated with an AMOC enhancement, followed by a general weakening trend from around 6–7 ka up to 2 ka, in line with the major hydro-dynamical re-organization which occurred in the North Atlantic from the mid-Holocene period. We find that the late Holocene period is marked by two fluctuations, with maxima at about 4.2 and 5 ka, in line with short-term variations identified in proxy records of the velocity of the Greenland-Iceland-Scotland overflow waters.},
author = {Ayache, Mohamed and Swingedouw, Didier and Mary, Yannick and Eynaud, Fr{\'{e}}d{\'{e}}rique and Colin, Christophe},
doi = {10.1016/j.gloplacha.2018.08.016},
issn = {0921-8181},
journal = {Global and Planetary Change},
pages = {172--189},
title = {{Multi-centennial variability of the AMOC over the Holocene: A new reconstruction based on multiple proxy-derived SST records}},
url = {http://www.sciencedirect.com/science/article/pii/S0921818118301231},
volume = {170},
year = {2018}
}
@article{Azorin-Molina2017,
author = {Azorin-Molina, C and Dunn, J. H. and Mears, C A and Berrisford, P and McVicar, T R},
doi = {10.1175/2017BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
language = {There's no section called 'Surface winds: Land surface wind speed'. Only 'Surface winds'. Thinking of another issue?},
number = {8},
pages = {S37--S39},
title = {{Land surface wind speed [in “State of the Climate in 2016”]}},
volume = {98},
year = {2017}
}
@article{Azorin-Molina2019,
author = {Azorin-Molina, C and Dunn, R J H and Mears, C A and Berrisford, P and McVicar, T R and Nicolas, J P},
doi = {10.1175/2019BAMSStateoftheClimate.1.},
journal = {Bulletin of the American Meteorological Society},
number = {9},
pages = {S43--S45},
title = {{Surface winds [in “State of the Climate in 2018”]}},
volume = {100},
year = {2019}
}
@article{Azorin-Molina2020,
author = {Azorin-Molina, C and Dunn, R J H and Ricciardulli, L and Mears, C A and McVicar, T R and Nicolas, J P and Compo, G P and Smith, C A},
doi = {10.1175/2020BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S63--S65},
title = {{Land and ocean surface winds [in “State of the Climate in 2019”]}},
volume = {101},
year = {2020}
}
@article{Bohm2015,
abstract = {Reconstruction of the Atlantic meridional overturning circulation from a highly resolved marine sedimentary record shows that a deep, vigorous overturning circulation mode has persisted for most of the last glacial cycle, dominating ocean circulation in the Atlantic, but that a shallower glacial mode prevailed during glacial maxima.},
author = {B{\"{o}}hm, E and Lippold, J and Gutjahr, M and Frank, M and Blaser, P and Antz, B and Fohlmeister, J and Frank, N and Andersen, M B and Deininger, M},
doi = {10.1038/nature14059},
issn = {1476-4687},
journal = {Nature},
number = {7532},
pages = {73--76},
title = {{Strong and deep Atlantic meridional overturning circulation during the last glacial cycle}},
url = {https://doi.org/10.1038/nature14059},
volume = {517},
year = {2015}
}
@article{Babila2018,
abstract = {Geologically abrupt carbon perturbations such as the Palaeocene–Eocene Thermal Maximum (PETM, approx. 56 Ma) are the closest geological points of comparison to current anthropogenic carbon emissions. Associated with the rapid carbon release during this event are profound environmental changes in the oceans including warming, deoxygenation and acidification. To evaluate the global extent of surface ocean acidification during the PETM, we present a compilation of new and published surface ocean carbonate chemistry and pH reconstructions from various palaeoceanographic settings. We use boron to calcium ratios (B/Ca) and boron isotopes ($\delta$11B) in surface- and thermocline-dwelling planktonic foraminifera to reconstruct ocean carbonate chemistry and pH. Our records exhibit a B/Ca reduction of 30–40{\%} and a $\delta$11B decline of 1.0–1.2‰ coeval with the carbon isotope excursion. The tight coupling between boron proxies and carbon isotope records is consistent with the interpretation that oceanic absorption of the carbon released at the onset of the PETM resulted in widespread surface ocean acidification. The remarkable similarity among records from different ocean regions suggests that the degree of ocean carbonate change was globally near uniform. We attribute the global extent of surface ocean acidification to elevated atmospheric carbon dioxide levels during the main phase of the PETM.},
author = {Babila, Tali L. and Penman, Donald E. and H{\"{o}}nisch, B{\"{a}}rbel and {Clay Kelly}, D. and Bralower, Timothy J. and Rosenthal, Yair and Zachos, James C.},
doi = {10.1098/rsta.2017.0072},
issn = {1364503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Boron isotope,Boron/calcium,Ocean acidification,Palaeocene-Eocene Thermal Maximum,Planktonic foraminifera},
number = {2130},
pages = {20170072},
publisher = {Royal Society Publishing},
title = {{Capturing the global signature of surface ocean acidification during the Palaeocene-Eocene Thermal Maximum}},
volume = {376},
year = {2018}
}
@article{bachem_sea_2016,
author = {Bachem, Paul E and Risebrobakken, Bj{\o}rg and McClymont, Erin L},
doi = {10.1016/j.epsl.2016.04.024},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {jul},
pages = {113--122},
title = {{Sea surface temperature variability in the Norwegian Sea during the late Pliocene linked to subpolar gyre strength and radiative forcing}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X16301960},
volume = {446},
year = {2016}
}
@article{Bachem2017,
abstract = {Abstract. The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST) and ice-rafted debris (IRD) in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.},
author = {Bachem, Paul E. and Risebrobakken, Bj{\o}rg and {De Schepper}, Stijn and McClymont, Erin L.},
doi = {10.5194/cp-13-1153-2017},
issn = {1814-9332},
journal = {Climate of the Past},
month = {sep},
number = {9},
pages = {1153--1168},
title = {{Highly variable Pliocene sea surface conditions in the Norwegian Sea}},
url = {https://cp.copernicus.org/articles/13/1153/2017/},
volume = {13},
year = {2017}
}
@article{badger_insensitivity_2019,
abstract = {Abstract. Atmospheric pCO2 is a critical component of the global carbon system and is considered to be the major control of Earth's past, present, and future climate. Accurate and precise reconstructions of its concentration through geological time are therefore crucial to our understanding of the Earth system. Ice core records document pCO2 for the past 800 kyr, but at no point during this interval were CO2 levels higher than today. Interpretation of older pCO2 has been hampered by discrepancies during some time intervals between two of the main ocean-based proxy methods used to reconstruct pCO2: the carbon isotope fractionation that occurs during photosynthesis as recorded by haptophyte biomarkers (alkenones) and the boron isotope composition ($\delta$11B) of foraminifer shells. Here, we present alkenone and $\delta$11B-based pCO2 reconstructions generated from the same samples from the Pliocene and across a Pleistocene glacial–interglacial cycle at Ocean Drilling Program (ODP) Site 999. We find a muted response to pCO2 in the alkenone record compared to contemporaneous ice core and $\delta$11B records, suggesting caution in the interpretation of alkenone-based records at low pCO2 levels. This is possibly caused by the physiology of CO2 uptake in the haptophytes. Our new understanding resolves some of the inconsistencies between the proxies and highlights that caution may be required when interpreting alkenone-based reconstructions of pCO2.},
author = {Badger, Marcus P S and Chalk, Thomas B and Foster, Gavin L and Bown, Paul R and Gibbs, Samantha J and Sexton, Philip F and Schmidt, Daniela N and P{\"{a}}like, Heiko and Mackensen, Andreas and Pancost, Richard D},
doi = {10.5194/cp-15-539-2019},
issn = {1814-9332},
journal = {Climate of the Past},
month = {mar},
number = {2},
pages = {539--554},
title = {{Insensitivity of alkenone carbon isotopes to atmospheric CO2 at low to moderate CO2 levels}},
url = {https://www.clim-past.net/15/539/2019/},
volume = {15},
year = {2019}
}
@article{Baggenstos14881,
abstract = {Earth{\{}$\backslash$textquoteright{\}}s radiative imbalance determines whether energy is flowing into or out of the ocean{\{}$\backslash$textendash{\}}atmosphere system. The present, anthropogenic, positive imbalance drives global warming. This study reconstructs the radiative imbalance for the last deglaciation, {\~{}}20,000 to 10,000 y ago. During the deglaciation, a positive imbalance was maintained for several thousand years, which brought the climate system from the last ice age into the Holocene warm period. We show that the imbalance varied significantly during this time, possibly due to changes in ocean circulation that affect the radiative energy fluxes, highlighting the importance of internal variability in Earth{\{}$\backslash$textquoteright{\}}s energy budget.The energy imbalance at the top of the atmosphere determines the temporal evolution of the global climate, and vice versa changes in the climate system can alter the planetary energy fluxes. This interplay is fundamental to our understanding of Earth{\{}$\backslash$textquoteright{\}}s heat budget and the climate system. However, even today, the direct measurement of global radiative fluxes is difficult, such that most assessments are based on changes in the total energy content of the climate system. We apply the same approach to estimate the long-term evolution of Earth{\{}$\backslash$textquoteright{\}}s radiative imbalance in the past. New measurements of noble gas-derived mean ocean temperature from the European Project for Ice Coring in Antarctica Dome C ice core covering the last 40,000 y, combined with recent results from the West Antarctic Ice Sheet Divide ice core and the sea-level record, allow us to quantitatively reconstruct the history of the climate system energy budget. The temporal derivative of this quantity must be equal to the planetary radiative imbalance. During the deglaciation, a positive imbalance of typically +0.2 W.m-2 is maintained for {\~{}}10,000 y, however, with two distinct peaks that reach up to 0.4 W.m-2 during times of substantially reduced Atlantic Meridional Overturning Circulation. We conclude that these peaks are related to net changes in ocean heat uptake, likely due to rapid changes in North Atlantic deep-water formation and their impact on the global radiative balance, while changes in cloud coverage, albeit uncertain, may also factor into the picture.},
author = {Baggenstos, Daniel and H{\"{a}}berli, Marcel and Schmitt, Jochen and Shackleton, Sarah A and Birner, Benjamin and Severinghaus, Jeffrey P and Kellerhals, Thomas and Fischer, Hubertus},
doi = {10.1073/pnas.1905447116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {30},
pages = {14881--14886},
publisher = {National Academy of Sciences},
title = {{Earth's radiative imbalance from the Last Glacial Maximum to the present}},
volume = {116},
year = {2019}
}
@article{CorrectingBiasesinHistoricalBathythermographDataUsingArtificialNeuralNetworks,
address = {Boston MA, USA},
author = {Bagnell, Aaron and DeVries, Timothy},
doi = {10.1175/JTECH-D-19-0103.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {10},
pages = {1781--1800},
publisher = {American Meteorological Society},
title = {{Correcting Biases in Historical Bathythermograph Data Using Artificial Neural Networks}},
url = {https://journals.ametsoc.org/view/journals/atot/37/10/jtechD190103.xml},
volume = {37},
year = {2020}
}
@article{Bailey2018a,
author = {Bailey, H. L. and Kaufman, D. S. and Sloane, H. J. and Hubbard, A. L. and Henderson, A. C. G. and Leng, M. J. and Welker, J. M.},
doi = {10.1016/j.quascirev.2018.06.027},
journal = {Quaternary Science Reviews},
pages = {27--38},
title = {{Holocene atmospheric circulation in the central North Pacific: A new terrestrial diatom and $\delta$18O dataset from the Aleutian Islands}},
volume = {194},
year = {2018}
}
@article{Baker2015,
author = {Baker, Andy and {C. Hellstrom}, John and Kelly, Bryce F J and Mariethoz, Gregoire and Trouet, Valerie},
doi = {10.1038/srep10307},
issn = {2045-2322},
journal = {Scientific Reports},
month = {sep},
number = {1},
pages = {10307},
publisher = {Nature Publishing Group},
title = {{A composite annual-resolution stalagmite record of North Atlantic climate over the last three millennia}},
url = {http://dx.doi.org/10.1038/srep10307 http://www.nature.com/articles/srep10307},
volume = {5},
year = {2015}
}
@article{Bakker2016c,
author = {Bakker, D C E and Pfeil, B and Landa, C S and Metzl, N and O'Brien, K M and Olsen, A and Smith, K and Cosca, C and Harasawa, S and Jones, S D and Nakaoka, S and Nojiri, Y and Schuster, U and Steinhoff, T and Sweeney, C and Takahashi, T and Tilbrook, B and Wada, C and Wanninkhof, R and Alin, S R and Balestrini, C F and Barbero, L and Bates, N R and Bianchi, A A and Bonou, F and Boutin, J and Bozec, Y and Burger, E F and Cai, W.-J. and Castle, R D and Chen, L and Chierici, M and Currie, K and Evans, W and Featherstone, C and Feely, R A and Fransson, A and Goyet, C and Greenwood, N and Gregor, L and Hankin, S and Hardman-Mountford, N J and Harlay, J and Hauck, J and Hoppema, M and Humphreys, M P and Hunt, C W and Huss, B and Ib{\'{a}}nhez, J S P and Johannessen, T and Keeling, R and Kitidis, V and K{\"{o}}rtzinger, A and Kozyr, A and Krasakopoulou, E and Kuwata, A and Landsch{\"{u}}tzer, P and Lauvset, S K and Lef{\`{e}}vre, N and {Lo Monaco}, C and Manke, A and Mathis, J T and Merlivat, L and Millero, F J and Monteiro, P M S and Munro, D R and Murata, A and Newberger, T and Omar, A M and Ono, T and Paterson, K and Pearce, D and Pierrot, D and Robbins, L L and Saito, S and Salisbury, J and Schlitzer, R and Schneider, B and Schweitzer, R and Sieger, R and Skjelvan, I and Sullivan, K F and Sutherland, S C and Sutton, A J and Tadokoro, K and Telszewski, M and Tuma, M and van Heuven, S M A C and Vandemark, D and Ward, B and Watson, A J and Xu, S},
doi = {10.5194/essd-8-383-2016},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {sep},
number = {2},
pages = {383--413},
publisher = {Copernicus Publications},
title = {{A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)}},
url = {https://essd.copernicus.org/articles/8/383/2016/ https://essd.copernicus.org/articles/8/383/2016/essd-8-383-2016.pdf},
volume = {8},
year = {2016}
}
@article{Ball2018a,
author = {Ball, W T and Alsing, J and Mortlock, D J and Staehelin, J and Haigh, J D and Peter, T and Tummon, F and St{\"{u}}bi, R and Stenke, A and Anderson, J and Bourassa, A and Davis, S M and Degenstein, D and Frith, S and Froidevaux, L and Roth, C and Sofieva, V and Wang, R and Wild, J and Yu, P and Ziemke, J R and Rozanov, E V},
doi = {10.5194/acp-18-1379-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {feb},
number = {2},
pages = {1379--1394},
publisher = {Copernicus Publications},
title = {{Evidence for a continuous decline in lower stratospheric ozone offsetting ozone layer recovery}},
url = {https://www.atmos-chem-phys.net/18/1379/2018/ https://www.atmos-chem-phys.net/18/1379/2018/acp-18-1379-2018.pdf},
volume = {18},
year = {2018}
}
@article{acp-19-12731-2019,
author = {Ball, W T and Alsing, J and Staehelin, J and Davis, S M and Froidevaux, L and Peter, T},
doi = {10.5194/acp-19-12731-2019},
journal = {Atmospheric Chemistry and Physics},
pages = {12731--12748},
title = {{Stratospheric ozone trends for 1985–2018: sensitivity to recent large variability}},
url = {https://acp.copernicus.org/articles/19/12731/2019/},
volume = {19},
year = {2019}
}
@article{Ballalai2019,
abstract = {Abstract Intensification of the Agulhas Leakage (AL) during glacial terminations has long been proposed as a necessary mechanism for reverting the Atlantic Meridional Overturning Circulation (AMOC) to its interglacial mode. However, lack of records showing the downstream evolution of AL signal and substantial temporal differences between AL intensification and resumption of deep-water convection have cast doubt on the importance of this mechanism to the AMOC. Here, we analyze a combination of new and previously published data relating to Mg/Ca-derived temperatures and ice volume-corrected seawater $\delta$18O records ($\delta$18OIVC-SW, as a proxy for relative changes in ocean salinity), which demonstrate propagation of AL signal via surface and thermocline waters to the western South Atlantic (Santos Basin) during Termination II and the early Last Interglacial. The saline AL waters were temporally stored in the upper subtropical South Atlantic until they were abruptly released in two stages into the North Atlantic via surface and thermocline waters at ca. 129 and 123 ka BP, respectively. Accounting for age model uncertainties, these two stages are coeval with the resumption of convection in the Labrador and Nordic seas during the Last Interglacial. We propose a mechanism whereby both active AL and a favorable ocean-atmosphere configuration in the tropical Atlantic were required to allow flux of AL waters into the North Atlantic, where they then contributed to enhancing the AMOC during the Last Interglacial period. Our results provide a framework that connects AL strengthening to the AMOC intensifications that followed glaciations.},
annote = {doi: 10.1029/2019PA003653},
author = {Ballalai, Jo{\~{a}}o M and Santos, Thiago P and Lessa, Douglas O and Venancio, Igor M and Chiessi, Cristiano M and Johnstone, Heather J H and Kuhnert, Henning and Claudio, Marcela R and Toledo, Felipe and Costa, Karen B and Albuquerque, Ana Luiza S},
doi = {10.1029/2019PA003653},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Agulhas rings,Atlantic Meridional Overturning Circulation,Brazil Current,Subtropical gyre,Termination II},
month = {nov},
number = {11},
pages = {1744--1760},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Tracking Spread of the Agulhas Leakage Into the Western South Atlantic and Its Northward Transmission During the Last Interglacial}},
url = {https://doi.org/10.1029/2019PA003653},
volume = {34},
year = {2019}
}
@article{doi:10.1002/grl.50382,
abstract = {The elusive nature of the post-2004 upper ocean warming has exposed uncertainties in the ocean's role in the Earth's energy budget and transient climate sensitivity. Here we present the time evolution of the global ocean heat content for 1958 through 2009 from a new observation-based reanalysis of the ocean. Volcanic eruptions and El Ni{\~{n}}o events are identified as sharp cooling events punctuating a long-term ocean warming trend, while heating continues during the recent upper-ocean-warming hiatus, but the heat is absorbed in the deeper ocean. In the last decade, about 30{\%} of the warming has occurred below 700 m, contributing significantly to an acceleration of the warming trend. The warming below 700 m remains even when the Argo observing system is withdrawn although the trends are reduced. Sensitivity experiments illustrate that surface wind variability is largely responsible for the changing ocean heat vertical distribution.},
author = {Balmaseda, Magdalena A and Trenberth, Kevin E and K{\"{a}}ll{\'{e}}n, Erland},
doi = {10.1002/grl.50382},
journal = {Geophysical Research Letters},
keywords = {ENSO,climate trends,climate variability,global warming,ocean heat content,ocean reanalyses},
number = {9},
pages = {1754--1759},
title = {{Distinctive climate signals in reanalysis of global ocean heat content}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/grl.50382},
volume = {40},
year = {2013}
}
@article{Bamber_2018,
abstract = {Since 1992, there has been a revolution in our ability to quantify the land ice contribution to sea level rise using a variety of satellite missions and technologies. Each mission has provided unique, but sometimes conflicting, insights into the mass trends of land ice. Over the last decade, over fifty estimates of land ice trends have been published, providing a confusing and often inconsistent picture. The IPCC Fifth Assessment Report (AR5) attempted to synthesise estimates published up to early 2013. Since then, considerable advances have been made in understanding the origin of the inconsistencies, reducing uncertainties in estimates and extending time series. We assess and synthesise results published, primarily, since the AR5, to produce a consistent estimate of land ice mass trends during the satellite era (1992–2016). We combine observations from multiple missions and approaches including sea level budget analyses. Our resulting synthesis is both consistent and rigorous, drawing on (i) the published literature, (ii) expert assessment of that literature, and (iii) a new analysis of Arctic glacier and ice cap trends combined with statistical modelling.
We present annual and pentad (five-year mean) time series for the East, West Antarctic and Greenland Ice Sheets and glaciers separately and combined. When averaged over pentads, covering the entire period considered, we obtain a monotonic trend in mass contribution to the oceans, increasing from 0.31 ± 0.35 mm of sea level equivalent for 1992–1996 to 1.85 ± 0.13 for 2012–2016. Our integrated land ice trend is lower than many estimates of GRACE-derived ocean mass change for the same periods. This is due, in part, to a smaller estimate for glacier and ice cap mass trends compared to previous assessments. We discuss this, and other likely reasons, for the difference between GRACE ocean mass and land ice trends.},
author = {Bamber, Jonathan L and Westaway, Richard M and Marzeion, Ben and Wouters, Bert},
doi = {10.1088/1748-9326/aac2f0},
journal = {Environmental Research Letters},
month = {jun},
number = {6},
pages = {63008},
publisher = {{\{}IOP{\}} Publishing},
title = {{The land ice contribution to sea level during the satellite era}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2Faac2f0},
volume = {13},
year = {2018}
}
@article{Banerjee2020d,
author = {Banerjee, A and {J C}, Fyfe and Polvani, L M and Waugh, D and Chang, K-L},
doi = {10.1038/s41586-020-2120-4},
journal = {Nature},
pages = {544--548},
title = {{A pause in southern hemisphere circulation trends due to the Montreal Protocol}},
volume = {579},
year = {2020}
}
@article{Barbarossa2018,
abstract = {FLO1K, global maps of mean, maximum and minimum annual streamflow at 1 km resolution from 1960 through 2015},
author = {Barbarossa, Valerio and Huijbregts, Mark A.J. and Beusen, Arthur H.W. and Beck, Hylke E. and King, Henry and Schipper, Aafke M.},
doi = {10.1038/sdata.2018.52},
issn = {20524463},
journal = {Scientific Data},
number = {February},
pages = {1--11},
title = {{Data Descriptor: FLO1K, global maps of mean, maximum and minimum annual streamflow at 1 km resolution from 1960 through 2015}},
volume = {5},
year = {2018}
}
@article{Bard2009,
abstract = {Several lines of evidence, including the varying extent of Northern Hemisphere ice sheets, point to fluctuating severity of glacial periods, despite the fact that ice cores extracted from the Antarctic ice sheet suggest that glacial conditions and the relationship between temperatures and atmospheric carbon dioxide concentrations have been constant for the past 800,000 years. A new 800,000-year record of sea surface temperature and ocean productivity, from an ocean sediment core obtained from the south-west Indian Ocean, reveals that during the coldest glacial periods, the subtropical front off the coast of South Africa migrated northwards, altering the strength of the Agulhas Current that carries heat and salt to the Atlantic meridional overturning circulation. This work suggests that the degree of northwards migration of the subtropical front can act to partially decouple global climate from atmospheric carbon dioxide concentrations.},
author = {Bard, Edouard and Rickaby, Rosalind E M},
doi = {10.1038/nature08189},
issn = {1476-4687},
journal = {Nature},
number = {7253},
pages = {380--383},
title = {{Migration of the subtropical front as a modulator of glacial climate}},
url = {https://doi.org/10.1038/nature08189},
volume = {460},
year = {2009}
}
@article{Barichivich2013,
abstract = {We combine satellite and ground observations during 1950-2011 to study the long-term links between multiple climate (air temperature and cryospheric dynamics) and vegetation (greenness and atmospheric CO(2) concentrations) indicators of the growing season of northern ecosystems ({\textgreater}45°N) and their connection with the carbon cycle. During the last three decades, the thermal potential growing season has lengthened by about 10.5 days (P {\textless} 0.01, 1982-2011), which is unprecedented in the context of the past 60 years. The overall lengthening has been stronger and more significant in Eurasia (12.6 days, P {\textless} 0.01) than North America (6.2 days, P {\textgreater} 0.05). The photosynthetic growing season has closely tracked the pace of warming and extension of the potential growing season in spring, but not in autumn when factors such as light and moisture limitation may constrain photosynthesis. The autumnal extension of the photosynthetic growing season since 1982 appears to be about half that of the thermal potential growing season, yielding a smaller lengthening of the photosynthetic growing season (6.7 days at the circumpolar scale, P {\textless} 0.01). Nevertheless, when integrated over the growing season, photosynthetic activity has closely followed the interannual variations and warming trend in cumulative growing season temperatures. This lengthening and intensification of the photosynthetic growing season, manifested principally over Eurasia rather than North America, is associated with a long-term increase (22.2{\%} since 1972, P {\textless} 0.01) in the amplitude of the CO(2) annual cycle at northern latitudes. The springtime extension of the photosynthetic and potential growing seasons has apparently stimulated earlier and stronger net CO(2) uptake by northern ecosystems, while the autumnal extension is associated with an earlier net release of CO(2) to the atmosphere. These contrasting responses may be critical in determining the impact of continued warming on northern terrestrial ecosystems and the carbon cycle.},
author = {Barichivich, Jonathan and Briffa, Keith R. and Myneni, Ranga B. and Osborn, Timothy J. and Melvin, Thomas M. and Ciais, Philippe and Piao, Shilong and Tucker, Compton},
doi = {10.1111/gcb.12283},
isbn = {1354-1013},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Carbon cycle,Climate change,NDVI,Phenology,Vegetation greening},
number = {10},
pages = {3167--3183},
pmid = {23749553},
title = {{Large-scale variations in the vegetation growing season and annual cycle of atmospheric CO2 at high northern latitudes from 1950 to 2011}},
volume = {19},
year = {2013}
}
@article{Baringer2018,
abstract = {The Atlantic meridional overturning circulation (AMOC) and the Atlantic meridional heat transport (AMHT) carry warm near-surface water northward, provide heat to the atmosphere at northern latitudes, and carry colder deep water southward. Buckley and Marshall (2016) present a summary of the dynamical forcing mechanisms of the AMOC and AMHT and the role they play in regulating climate variability around the Atlantic sector. Owing to the large amounts of heat, carbon, and fresh water transported by the AMOC, climate models suggest accurate estimation of its rate of change is critical to understanding and predicting our changing climate (e.g., W. Liu et al. 2017; Rahmstorf et al. 2015). Even on short time scales the AMOC/AMHT can impact climate (e.g., Duchez et al. 2016). These recognitions have led to the implementation of enhanced observing systems of the strength of the AMOC in the subpolar North Atlantic (Lozier et al. 2017) and the subtropical South Atlantic (Ansorge et al. 2014). These new observing systems will eventually provide a more complete spatial picture of the state of the AMOC.},
author = {Baringer, M. O. and Willis, J. and Smeed, David A and Moat, B I and Dong, Shenfu and Hobbs, Will and Rayner, Darren and Johns, William E and Goni, G and Lankhorst, M and Send, Uwe},
doi = {10.1175/2018BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S91--S94},
title = {{Meridional overturning and oceanic heat transport circulation observations in the North Atlantic Ocean [in “State of the Climate in 2017”]}},
volume = {99},
year = {2018}
}
@article{Barlow2018,
abstract = {During the Last Interglacial, global mean sea level reached approximately 6 to 9 m above the present level. This period of high sea level may have been punctuated by a fall of more than 4 m, but a cause for such a widespread sea-level fall has been elusive. Reconstructions of global mean sea level account for solid Earth processes and so the rapid growth and decay of ice sheets is the most obvious explanation for the sea-level fluctuation. Here, we synthesize published geomorphological and stratigraphic indicators from the Last Interglacial, and find no evidence for ice-sheet regrowth within the warm interglacial climate. We also identify uncertainties in the interpretation of local relative sea-level data that underpin the reconstructions of global mean sea level. Given this uncertainty, and taking into account our inability to identify any plausible processes that would cause global sea level to fall by 4 m during warm climate conditions, we question the occurrence of a rapid sea-level fluctuation within the Last Interglacial. We therefore recommend caution in interpreting the high rates of global mean sea-level rise in excess of 3 to 7 m per 1,000 years that have been proposed for the period following the Last Interglacial sea-level lowstand.},
author = {Barlow, Natasha L M and McClymont, Erin L and Whitehouse, Pippa L and Stokes, Chris R and Jamieson, Stewart S R and Woodroffe, Sarah A and Bentley, Michael J and Callard, S Louise and Cofaigh, Colm {\'{O}} and Evans, David J A and Horrocks, Jennifer R and Lloyd, Jerry M and Long, Antony J and Margold, Martin and Roberts, David H and Sanchez-Montes, Maria L},
doi = {10.1038/s41561-018-0195-4},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {9},
pages = {627--634},
title = {{Lack of evidence for a substantial sea-level fluctuation within the Last Interglacial}},
url = {https://doi.org/10.1038/s41561-018-0195-4},
volume = {11},
year = {2018}
}
@article{Barnes2014,
abstract = {Observed blocking trends are diagnosed to test the hypothesis that recent Arctic warming and sea ice loss has increased the likelihood of blocking over the Northern Hemisphere. To ensure robust results, we diagnose blocking using three unique blocking identification methods from the literature, each applied to four different reanalyses. No clear hemispheric increase in blocking is found for any blocking index, and while seasonal increases and decreases are found for specific isolated regions and time periods, there is no instance where all three methods agree on a robust trend. Blocking is shown to exhibit large interannual and decadal variability, highlighting the difficulty in separating any potentially forced response from natural variability.},
author = {Barnes, Elizabeth A. and Dunn-Sigouin, Etienne and Masato, Giacomo and Woollings, Tim},
doi = {10.1002/2013GL058745},
isbn = {1944-8007},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {2},
pages = {638--644},
title = {{Exploring recent trends in Northern Hemisphere blocking}},
volume = {41},
year = {2014}
}
@article{Barr2014,
abstract = {Climates of the last two millennia have been the focus of numerous studies due to the availability of high-resolution palaeoclimate records and the occurrence of divergent periods of climate, commonly referred to as the 'Medieval Climatic Anomaly' and 'The Little Ice Age'. The majority of these studies are centred in the Northern Hemisphere and, in comparison, the Southern Hemisphere is relatively under-studied. In Australia, there are few high-resolution, palaeoclimate studies spanning a millennium or more and, consequently, knowledge of long-term natural climate variability is limited for much of the continent. South-eastern Australia, which recently experienced a severe, decade-long drought, is one such region.Results are presented of investigations from two crater lakes in the south-east of mainland Australia. Fluctuations in lake-water conductivity, a proxy for effective moisture, are reconstructed at sub-decadal resolution over the past 1500 years using a statistically robust, diatom-conductivity transfer function. These data are interpreted in conjunction with diatom autecology. The records display coherent patterns of change at centennial scale, signifying that both lakes responded to regional-scale climate forcing, though the nature of that response varied between sites due to differing lake morphometry. Both sites provide evidence for a multi-decadal drought, commencing ca 650 AD, and a period of variable climate between ca 850 and 1400 AD. From ca 1400-1880 AD, coincident with the timing of the 'Little Ice Age', climates of the region are characterised by high effective moisture and a marked reduction in inter-decadal variability. The records provide context for climates of the historical period and reveal the potential for more extreme droughts and more variable climate than that experienced since European settlement of the region ca 170 years ago. {\textcopyright} 2014.},
author = {Barr, Cameron and Tibby, John and Gell, Peter and Tyler, Jonathan and Zawadzki, Atun and Jacobsen, Geraldine E.},
doi = {10.1016/j.quascirev.2014.05.001},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Climate variability,Diatoms,High-resolution,Little Ice Age,South-east Australia},
pages = {115--131},
publisher = {Elsevier Ltd},
title = {{Climate variability in south-eastern Australia over the last 1500 years inferred from the high-resolution diatom records of two crater lakes}},
url = {http://dx.doi.org/10.1016/j.quascirev.2014.05.001},
volume = {95},
year = {2014}
}
@article{Barr2019,
abstract = {The La Ni{\~{n}}a and El Ni{\~{n}}o phases of the El Ni{\~{n}}o-Southern Oscillation (ENSO) have major impacts on regional rainfall patterns around the globe, with substantial environmental, societal and economic implications. Long-term perspectives on ENSO behaviour, under changing background conditions, are essential to anticipating how ENSO phases may respond under future climate scenarios. Here, we derive a 7700-year, quantitative precipitation record using carbon isotope ratios from a single species of leaf preserved in lake sediments from subtropical eastern Australia. We find a generally wet (more La Ni{\~{n}}a-like) mid-Holocene that shifted towards drier and more variable climates after 3200 cal. yr BP, primarily driven by increasing frequency and strength of the El Ni{\~{n}}o phase. Climate model simulations implicate a progressive orbitally-driven weakening of the Pacific Walker Circulation as contributing to this change. At centennial scales, high rainfall characterised the Little Ice Age ({\~{}}1450–1850 CE) in subtropical eastern Australia, contrasting with oceanic proxies that suggest El Ni{\~{n}}o-like conditions prevail during this period. Our data provide a new western Pacific perspective on Holocene ENSO variability and highlight the need to address ENSO reconstruction with a geographically diverse network of sites to characterise how both ENSO, and its impacts, vary in a changing climate.},
author = {Barr, C. and Tibby, J. and Leng, M. J. and Tyler, J. J. and Henderson, A. C. G. and Overpeck, J. T. and Simpson, G. L. and Cole, J. E. and Phipps, S. J. and Marshall, J. C. and McGregor, G. B. and Hua, Q. and McRobie, F. H.},
doi = {10.1038/s41598-019-38626-3},
isbn = {4159801938626},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {1627},
pmid = {30733569},
title = {{Holocene El Ni{\~{n}}o–Southern Oscillation variability reflected in subtropical Australian precipitation}},
url = {http://www.nature.com/articles/s41598-019-38626-3},
volume = {9},
year = {2019}
}
@article{Barrett2018,
abstract = {A systematic comparison of El Ni{\~{n}}o Southern Oscillation reconstructions during the early to mid-nineteenth century is presented using a range of proxy and documentary sources. Reconstructions of the boreal winter Southern Oscillation Index (SOI) using data from ships' logbooks presented in a companion paper are evaluated and compared to previous ENSO reconstructions. Comparisons between ENSO reconstructions and the instrumental SOI during a period of overlap (1876--1977) are made. These same proxy and documentary reconstructions are then compared to the logbook-based reconstructions, over 1815--1854. The logbook-based reconstructions compare best with a recent multi-proxy reconstruction that used signals taken from different teleconnection regions, and they have an improved agreement with multi-proxy records compared to a previous attempt to reconstruct the SOI from ships' logbook data. The logbook-based and the multi-proxy reconstructions are found to capture El Ni{\~{n}}o events better than La Ni{\~{n}}a events, and East Pacific El Ni{\~{n}}o events better than Central Pacific El Ni{\~{n}}o events, thus suggesting a degree of bias in the historical reconstructions. These findings have important implications for future ENSO reconstructions, with a need for an increased understanding of the effects of different ENSO flavours for future reconstructions.},
author = {Barrett, Hannah G and Jones, Julie M and Bigg, Grant R},
doi = {10.1007/s00382-017-3797-4},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {may},
number = {9},
pages = {3131--3152},
title = {{Reconstructing El Ni{\~{n}}o Southern Oscillation using data from ships' logbooks, 1815–1854. Part II: Comparisons with existing ENSO reconstructions and implications for reconstructing ENSO diversity}},
volume = {50},
year = {2018}
}
@article{Barrucand2018,
author = {Barrucand, Mariana G. and Zitto, Miguel E. and Piotrkowski, Rosa and Canziani, Pablo and O'Neill, Alan},
doi = {10.1002/joc.5435},
issn = {08998418},
journal = {International Journal of Climatology},
month = {apr},
pages = {e1091--e1106},
title = {{Historical SAM index time series: linear and nonlinear analysis}},
url = {http://doi.wiley.com/10.1002/joc.5435},
volume = {38},
year = {2018}
}
@article{Bartoli2011,
abstract = {Several hypotheses have been put forward to explain the onset of intensive glaciations on Greenland, Scandinavia, and North America during the Pliocene epoch between 3.6 and 2.7 million years ago (Ma). A decrease in atmospheric CO2 may have played a role during the onset of glaciations, but other tectonic and oceanic events occurring at the same time may have played a part as well. Here we present detailed atmospheric CO2 estimates from boron isotopes in planktic foraminifer shells spanning 4.6?2.0 Ma. Maximal Pliocene atmospheric CO2 estimates gradually declined from values around 410 ?atm to early Pleistocene values of 300 ?atm at 2.0 Ma. After the onset of large-scale ice sheets in the Northern Hemisphere, maximal pCO2 estimates were still at 2.5 Ma +90 ?atm higher than values characteristic of the early Pleistocene interglacials. By contrast, Pliocene minimal atmospheric CO2 gradually decreased from 310 to 245 ?atm at 3.2 Ma, coinciding with the start of transient glaciations on Greenland. Values characteristic of early Pleistocene glacial atmospheric CO2 of 200 ?atm were abruptly reached after 2.7 Ma during the late Pliocene transition. This trend is consistent with the suggestion that ocean stratification and iron fertilization increased after 2.7 Ma in the North Pacific and Southern Ocean and may have led to increased glacial CO2 storage in the oceanic abyss after 2.7 Ma onward.},
annote = {doi: 10.1029/2010PA002055},
author = {Bartoli, Gretta and H{\"{o}}nisch, B{\"{a}}rbel and Zeebe, Richard E},
doi = {10.1029/2010PA002055},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {CO2,Northern Hemisphere glaciation,Pliocene},
month = {dec},
number = {4},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Atmospheric CO2 decline during the Pliocene intensification of Northern Hemisphere glaciations}},
url = {https://doi.org/10.1029/2010PA002055},
volume = {26},
year = {2011}
}
@article{Bastos2013,
abstract = {Global ecosystems remove about 25{\%} of anthropogenic CO2 emissions; however, the response of the land sink to climate variability and change is not yet fully understood. In 2011, the highest global value of net primary production (NPP) since 2000 was registered on the Moderate Resolution Imaging Spectroradiometer record, together with the highest value on the Carbon Dioxide Information Analysis Center record of carbon land sink strength since 1959. Here we show that El Ni{\~{n}}o/Southern Oscillation (ENSO) is responsible for much of the variability observed in the land sink and that the high NPP anomaly observed in 2011 was largely influenced by the strongest La Ni{\~{n}}a since the 1970s that lasted from late 2010 to early 2012. ENSO explains more than 40{\%} of global NPP variability, mainly driven by the response of Southern Hemisphere ecosystems, particularly in tropical and subtropical regions. Water availability, controlled by temperature and precipitation anomalies, appears to be the main factor driving the regional response of NPP to ENSO.},
author = {Bastos, A. and Running, Steven W. and Gouveia, C{\'{e}}lia and Trigo, Ricardo M.},
doi = {10.1002/jgrg.20100},
issn = {21698961},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {ENSO,La-Ni{\~{n}}a,carbon cycle,net primary production},
pages = {1247-- 1255},
title = {{The global NPP dependence on ENSO: La Ni{\~{n}}a and the extraordinary year of 2011}},
volume = {118},
year = {2013}
}
@article{Batchelor2019,
author = {Batchelor, Christine L. and Margold, Martin and Krapp, Mario and Murton, Della K. and Dalton, April S. and Gibbard, Philip L. and Stokes, Chris R. and Murton, Julian B. and Manica, Andrea},
doi = {10.1038/s41467-019-11601-2},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3713},
title = {{The configuration of Northern Hemisphere ice sheets through the Quaternary}},
url = {http://www.nature.com/articles/s41467-019-11601-2},
volume = {10},
year = {2019}
}
@article{https://doi.org/10.1029/2019MS001978,
annote = {e2019MS001978 2019MS001978},
author = {Bauer, Susanne E and Tsigaridis, Kostas and Faluvegi, Greg and Kelley, Maxwell and Lo, Ken K and Miller, Ron L and Nazarenko, Larissa and Schmidt, Gavin A and Wu, Jingbo},
doi = {10.1029/2019MS001978},
journal = {Journal of Advances in Modeling Earth Systems},
keywords = {CMIP6 historical simulation,GISS model,aerosol forcing,aerosol microphysics},
number = {8},
pages = {e2019MS001978},
title = {{Historical (1850–2014) Aerosol Evolution and Role on Climate Forcing Using the GISS ModelE2.1 Contribution to CMIP6}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019MS001978},
volume = {12},
year = {2020}
}
@article{Bauska2015,
abstract = {The stability of terrestrial carbon reservoirs is thought to be closely linked to variations in climate, but the magnitude of carbon-climate feedbacks has proved difficult to constrain for both modern and millennial timescales. Reconstructions of atmospheric CO{\textless}inf{\textgreater}2{\textless}/inf{\textgreater} concentrations for the past thousand years have shown fluctuations on multidecadal to centennial timescales, but the causes of these fluctuations are unclear. Here we report high-resolution carbon isotope measurements of CO{\textless}inf{\textgreater}2{\textless}/inf{\textgreater} trapped within the ice of the West Antarctic Ice Sheet Divide ice core for the past 1,000 years. We use a deconvolution approach to show that changes in terrestrial organic carbon stores best explain the observed multidecadal variations in the $\delta${\textless}sup{\textgreater}13{\textless}/sup{\textgreater}C of CO{\textless}inf{\textgreater}2{\textless}/inf{\textgreater} and in CO{\textless}inf{\textgreater}2{\textless}/inf{\textgreater} concentrations from 755 to 1850 CE. If significant long-term carbon emissions came from pre-industrial anthropogenic land-use changes over this interval, the emissions must have been offset by a natural terrestrial sink for 13 C-depleted carbon, such as peatlands. We find that on multidecadal timescales, carbon cycle changes seem to vary with reconstructed regional climate changes. We conclude that climate variability could be an important control of fluctuations in land carbon storage on these timescales.},
author = {Bauska, Thomas K. and Joos, Fortunat and Mix, Alan C. and Roth, Raphael and Ahn, Jinho and Brook, Edward J.},
doi = {10.1038/ngeo2422},
issn = {17520908},
journal = {Nature Geoscience},
pages = {383--387},
title = {{Links between atmospheric carbon dioxide, the land carbon reservoir and climate over the past millennium}},
volume = {8},
year = {2015}
}
@article{Bayr2014,
abstract = {This study investigates the global warming response of the Walker Circulation and the other zonal circulation cells (represented by the zonal stream function), in CMIP3 and CMIP5 climate models. The changes in the mean state are presented as well as the changes in the modes of variability. The mean zonal circulation weakens in the multi model ensembles nearly everywhere along the equator under both the RCP4.5 and SRES A1B scenarios. Over the Pacific the Walker Circulation also shows a significant eastward shift. These changes in the mean circulation are very similar to the leading mode of interannual variability in the tropical zonal circulation cells, which is dominated by El Ni{\~{n}}o Southern Oscillation variability. During an El Ni{\~{n}}o event the circulation weakens and the rising branch over the Maritime Continent shifts to the east in comparison to neutral conditions (vice versa for a La Ni{\~{n}}a event). Two-thirds of the global warming forced trend of the Walker Circulation can be explained by a long-term trend in this interannual variability pattern, i.e. a shift towards more El Ni{\~{n}}o-like conditions in the multi-model mean under global warming. Further, interannual variability in the zonal circulation exhibits an asymmetry between El Ni{\~{n}}o and La Ni{\~{n}}a events. El Ni{\~{n}}o anomalies are located more to the east compared with La Ni{\~{n}}a anomalies. Consistent with this asymmetry we find a shift to the east of the dominant mode of variability of zonal stream function under global warming. All these results vary among the individual models, but the multi model ensembles of CMIP3 and CMIP5 show in nearly all aspects very similar results, which underline the robustness of these results. The observed data (ERA Interim reanalysis) from 1979 to 2012 shows a westward shift and strengthening of the Walker Circulation. This is opposite to what the results in the CMIP models reveal. However, 75 {\%} of the trend of the Walker Circulation can again be explained by a shift of the dominant mode of variability, but here towards more La Ni{\~{n}}a-like conditions. Thus in both climate change projections and observations the long-term trends of the Walker Circulation seem to follow to a large part the pre-existing dominant mode of internal variability.},
author = {Bayr, Tobias and Dommenget, Dietmar and Martin, Thomas and Power, Scott B.},
doi = {10.1007/s00382-014-2091-y},
isbn = {0930-7575},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Asymmetry of ENSO,Changes in the modes of variability,ENSO variability,Global warming,Walker Circulation,Zonal atmospheric circutlation},
number = {9-10},
pages = {2747--2763},
title = {{The eastward shift of the Walker Circulation in response to global warming and its relationship to ENSO variability}},
volume = {43},
year = {2014}
}
@article{Beal2016,
abstract = {Western boundary currents—such as the Agulhas Current in the Indian Ocean—carry heat poleward, moderating Earth's climate and fuelling the mid-latitude storm tracks 1,2 . They could exacerbate or mitigate warming and extreme weather events in the future, depending on their response to anthropogenic climate change. Climate models show an ongoing poleward expansion and intensification of the global wind systems, most robustly in the Southern Hemisphere 3–5 , and linear dynamical theory 6,7 suggests that western boundary currents will intensify and shift poleward as a result 3,8 . Observational evidence of such changes comes from accelerated warming and air–sea heat flux rates within all western boundary currents, which are two or three times faster than global mean rates 5,9,10 . Here we show that, despite these expectations, the Agulhas Current has not intensified since the early 1990s. Instead, we find that it has broadened as a result of more eddy activity. Recent analyses of other western boundary currents—the Kuroshio and East Australia currents—hint at similar trends 11–15 . These results indicate that intensifying winds may be increasing the eddy kinetic energy of boundary currents, rather than their mean flow. This could act to decrease poleward heat transport and increase cross-frontal exchange of nutrients and pollutants between the coastal ocean and the deep ocean. Sustained in situ measurements are needed to properly understand the role of these current systems in a changing climate. To estimate the trend in Agulhas Current transport we build a 22-year proxy using three years of in situ measurements from the Agulhas Current Time-series (ACT) array 16 combined with coincident along-track satellite altimeter data spanning the years 1993–2015 (Fig. 1). We define two measures of transport for the Agulhas Current: a streamwise, southwestward jet transport T jet , and a geographically fixed, net boundary-layer transport T box . Over the three years of in situ data the mean and standard deviation of T jet are − 84 Sv (1 Sv = 10 6},
author = {Beal, Lisa M. and Elipot, Shane},
doi = {10.1038/nature19853},
isbn = {1476-4687 (Electronic)$\backslash$r0028-0836 (Linking)},
issn = {14764687},
journal = {Nature},
pages = {570--573},
pmid = {27828944},
title = {{Broadening not strengthening of the Agulhas Current since the early 1990s}},
volume = {540},
year = {2016}
}
@article{Beaufort2017a,
author = {Beaufort, Luc and Grelaud, M.},
doi = {10.1186/s40645-017-0123-z},
journal = {Progress in Earth and Planetary Science},
number = {1},
pages = {5},
publisher = {Progress in Earth and Planetary Science},
title = {{A 2700-year record of ENSO and PDO variability from the Californian margin based on coccolithophore assemblages and calcification}},
volume = {4},
year = {2017}
}
@article{doi:10.1002/2017JC013090,
abstract = {Abstract Comparison of satellite altimetry against a high-quality network of tide gauges suggests that sea-surface heights from the TOPEX altimeter may be biased by ±5 mm, in an approximate piecewise linear, or U-shaped, drift. This has been previously reported in at least two other studies. The bias is probably caused by use of an internal calibration-mode range correction, included in the TOPEX “net instrument” correction, which is suspect owing to changes in the altimeter's point target response. Removal of this correction appears to mitigate most of the drift problem. In addition, a new time series based on retracking the TOPEX waveforms, again without the calibration-mode correction, also reduces the drift aside for a clear problem during the first 2 years. With revision, the TOPEX measurements, combined with successor Jason altimeter measurements, show global mean sea level rising fairly steadily throughout most of 24 year time period, with rates around 3 mm/yr, although higher over the last few years.},
author = {Beckley, B D and Callahan, P S and {Hancock III}, D W and Mitchum, G T and Ray, R D},
doi = {10.1002/2017JC013090},
journal = {Journal of Geophysical Research: Oceans},
keywords = {TOPEX,mean sea level,satellite altimetry},
number = {11},
pages = {8371--8384},
title = {{On the “Cal-Mode” Correction to TOPEX Satellite Altimetry and Its Effect on the Global Mean Sea Level Time Series}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017JC013090},
volume = {122},
year = {2017}
}
@article{Befort2016a,
author = {Befort, D J and Wild, S and Kruschke, T and Ulbrich, U and Leckebusch, G C},
doi = {10.1002/asl.694},
journal = {Atmospheric Science Letters},
pages = {586--595},
title = {{Different long-term trends of extra-tropical cyclones and windstorms in ERA-20C and NOAA-20CR reanalyses}},
volume = {17},
year = {2016}
}
@article{Bellomo2015,
abstract = {Climate models simulate a weakening of the Walker Circulation in response to increased greenhouse gases, but it has not been possible to detect this weakening with observations because there are not direct measurements of atmospheric circulation strength. Indirect measurements, such as equatorial gradients in Sea Level Pressure (SLP), exhibit trends of inconsistent sign. In this study we estimate the change in mid-tropospheric velocity ($\omega$500) from observed change in cloud cover, which we argue is more closely tied to the overturning circulation than indirect measurements of SLP at the surface. Our estimates suggest a weakening and eastward shift of the Walker Circulation over the last century. Because changes in cloud cover in AMIP simulations forced with increased Sea Surface Temperature are remarkably similar in pattern, sign, and magnitude, we assert that the observed changes in cloud cover and the associated weakening of Walker Circulation are at least in part externally forced.},
author = {Bellomo, Katinka and Clement, Amy C.},
doi = {10.1002/2015GL065463},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {Walker circulation,cloud cover},
number = {18},
pages = {7758--7766},
title = {{Evidence for weakening of the Walker circulation from cloud observations}},
volume = {42},
year = {2015}
}
@article{Bellomo2018a,
abstract = {Previous studies suggest that internal variability, in particular the Atlantic Meridional Overturning Circulation (AMOC), drives the Atlantic Multidecadal Oscillation (AMV), while external radiative forcing only creates a steady increase in sea surface temperature (SST). This view has been recently challenged and new evidence has emerged that aerosols and greenhouse gases could play a role in driving the AMV. Here we examine the drivers of the AMV using the Community Earth System Model (CESM) Large Ensemble and Last Millennium Ensemble. By computing the ensemble mean we isolate the radiatively forced component of the AMV, while we estimate the role of internal variability using the ensemble spread. We find that phase changes of the AMV over the years 1854–2005 can be explained only in the presence of varying historical forcing. Further, we find that internal variability is large in North Atlantic SST at timescales shorter than 10–25 years, but at longer timescales the forced response dominates. Single forcing experiments show that greenhouse gases and tropospheric aerosols are the main drivers of the AMV in the latter part of the twentieth century. Finally, we show that the forced spatial pattern of SST is not distinct from the internal variability pattern, which has implications for detection and attribution.},
author = {Bellomo, Katinka and Murphy, Lisa N and Cane, Mark A and Clement, Amy C and Polvani, Lorenzo M},
doi = {10.1007/s00382-017-3834-3},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {9},
pages = {3687--3698},
title = {{Historical forcings as main drivers of the Atlantic multidecadal variability in the CESM large ensemble}},
url = {https://doi.org/10.1007/s00382-017-3834-3},
volume = {50},
year = {2018}
}
@article{essd-12-1649-2020,
author = {Bellouin, N and Davies, W and Shine, K P and Quaas, J and M{\"{u}}lmenst{\"{a}}dt, J and Forster, P M and Smith, C and Lee, L and Regayre, L and Brasseur, G and Sudarchikova, N and Bouarar, I and Boucher, O and Myhre, G},
doi = {10.5194/essd-12-1649-2020},
journal = {Earth System Science Data},
number = {3},
pages = {1649--1677},
title = {{Radiative forcing of climate change from the Copernicus reanalysis of atmospheric composition}},
url = {https://essd.copernicus.org/articles/12/1649/2020/},
volume = {12},
year = {2020}
}
@article{Belt2015,
abstract = {Analysis of {\textgreater}100 surface sediments from across the Barents Sea has shown that the relative abundances of the mono-unsaturated sea ice diatom-derived biomarker IP25 and a tri-unsaturated highly branched isoprenoid (HBI) lipid (HBI III) are characteristic of the overlying surface oceanographic conditions, most notably, the location of the seasonal sea ice edge. Thus, while IP25 is generally limited to locations experiencing seasonal sea ice, with higher abundances found for locations with longer periods of ice cover, HBI III is found in sediments from all sampling locations, but is significantly enhanced in sediments within the vicinity of the retreating sea ice edge or marginal ice zone (MIZ). The response of HBI III to this well-defined sea ice scenario also appears to be more selective than that of the more generic phytoplankton biomarker, brassicasterol. The potential for the combined analysis of IP25 and HBI III to provide more detailed assessments of past sea ice conditions than IP25 alone has been investigated by quantifying both biomarkers in three marine downcore records from locations with contrasting modern sea ice settings. For sediment cores from the western Barents Sea (intermittent seasonal sea ice) and the northern Norwegian Sea (ice-free), high IP25 and low HBI III during the Younger Dryas (ca. 12.9-11.9 cal.kyr BP) is consistent with extensive sea cover, with relatively short periods of ice-free conditions resulting from late summer retreat. Towards the end of the YD (ca. 11.9-11.5 cal.kyr BP), a general amelioration of conditions resulted in a near winter maximum ice edge scenario for both locations, although this was somewhat variable, and the eventual transition to predominantly ice-free conditions was later for the western Barents Sea site (ca. 9.9 cal.kyr BP) compared to NW Norway (ca. 11.5 cal.kyr BP). For both locations, coeval elevated HBI III (but absent IP25) potentially provides further evidence for increased Atlantic Water inflow during the early Holocene, but this interpretation requires further investigation. In contrast, IP25 and HBI III data obtained from a core from the northern Barents Sea demonstrate that seasonal sea ice prevailed throughout the Holocene, but with a gradual shift from winter ice edge conditions during the early Holocene to more sustained ice cover in the Neoglacial; a directional shift that has undergone a reverse in the last ca. 150 yr according to observational records. Our combined surface and downcore datasets suggest that combined analysis of IP25 and HBI III can provide information on temporal variations in the position of the maximum (winter) Arctic sea ice extent, together with insights into sea ice seasonality by characterisation of the MIZ. Combining IP25 with HBI III in the form of the previously proposed PIP25 index yields similar outcomes to those obtained using brassicasterol as the phytoplankton marker. Importantly, however, some problems associated with use of a variable balance factor employed in the PIP25 calculation, are potentially alleviated using HBI III.},
archivePrefix = {arXiv},
arxivId = {20},
author = {Belt, Simon T. and Cabedo-Sanz, Patricia and Smik, Lukas and Navarro-Rodriguez, Alba and Berben, Sarah M.P. and Knies, Jochen and Husum, Katrine},
doi = {10.1016/j.epsl.2015.09.020},
eprint = {20},
isbn = {0012-821X},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {Arctic,Biomarker,IP25,Paleoclimate,Proxy,Sea ice},
pages = {127--139},
pmid = {279758400002},
title = {{Identification of paleo Arctic winter sea ice limits and the marginal ice zone: Optimised biomarker-based reconstructions of late Quaternary Arctic sea ice}},
volume = {431},
year = {2015}
}
@article{Belt2018,
abstract = {Over the last decade or so, certain source-specific C25 highly branched isoprenoid (HBI) lipid biomarkers have emerged as useful proxies for Arctic and Antarctic sea ice. Thus, IP25 (Ice proxy with 25 carbon atoms) and IPSO25 (Ice proxy for the Southern Ocean with 25 carbon atoms) represent binary measures of past seasonal sea ice in the Arctic and Antarctic, respectively. A further tri-unsaturated HBI (generally referred to as HBI III) appears to provide proxy evidence for the region of open water found adjacent to sea ice (i.e. the marginal ice zone (MIZ)) in both polar regions. This review provides an update on current knowledge pertaining to each proxy. The first section focuses on describing those studies that have aimed to establish the underlying features of each proxy, including source identification and spatial distribution characteristics. The second section presents some important analytical considerations pertinent to the accurate identification and quantification of HBI biomarkers. The third section describes how each HBI proxy is normally interpreted within the sedimentary record for palaeo sea ice reconstruction purposes. This includes the interpretation of individual and combined biomarker profiles such as the PIP25 index and multivariate decision tree models. A summary of all previous palaeo sea ice reconstructions based on HBIs is also given, which includes examples that clarify or reinforce our understanding of the individual or combined biomarker signatures. Some knowledge gaps and areas for future research are also briefly described.},
author = {Belt, Simon T.},
doi = {10.1016/j.orggeochem.2018.10.002},
issn = {01466380},
journal = {Organic Geochemistry},
keywords = {Biomarkers,HBIs,IP 25,IPSO 25,Proxies,Sea ice},
month = {nov},
pages = {277--298},
title = {{Source-specific biomarkers as proxies for Arctic and Antarctic sea ice}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0146638018302274},
volume = {125},
year = {2018}
}
@article{https://doi.org/10.1029/2019GL083474,
abstract = {Abstract Gaps with missing data in the observational temperature record are responsible for an underestimation of the global warming between 1881–1910 and 1986–2015 by 0.1 °C. We found that missing data in the historical observations introduce a warm bias in the early part of the record and a cold bias toward the end. The effect of the nonuniform sampling was explored by comparing the global mean temperature estimated from gridded observations, climate model simulations, and reanalysis. Output from global simulations was subsampled by masking the grid boxes corresponding to those with missing data in the observations to mimic the geographical availability of temperature measurements. A combination of variance depending on region and a varying geographical data sampling over time explains the bias in the global mean. We propose a methodology for estimating the global mean temperature that reduces the effect of the nonuniform variance.},
author = {Benestad, R E and Erlandsen, H B and Mezghani, A and Parding, K M},
doi = {10.1029/2019GL083474},
journal = {Geophysical Research Letters},
keywords = {climate change,data sampling,global climate models,global mean temperature,missing data,variance},
number = {13},
pages = {7654--7662},
title = {{Geographical Distribution of Thermometers Gives the Appearance of Lower Historical Global Warming}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL083474},
volume = {46},
year = {2019}
}
@article{BENTLEY20141,
abstract = {A robust understanding of Antarctic Ice Sheet deglacial history since the Last Glacial Maximum is important in order to constrain ice sheet and glacial-isostatic adjustment models, and to explore the forcing mechanisms responsible for ice sheet retreat. Such understanding can be derived from a broad range of geological and glaciological datasets and recent decades have seen an upsurge in such data gathering around the continent and Sub-Antarctic islands. Here, we report a new synthesis of those datasets, based on an accompanying series of reviews of the geological data, organised by sector. We present a series of timeslice maps for 20 ka, 15 ka, 10 ka and 5 ka, including grounding line position and ice sheet thickness changes, along with a clear assessment of levels of confidence. The reconstruction shows that the Antarctic Ice sheet did not everywhere reach the continental shelf edge at its maximum, that initial retreat was asynchronous, and that the spatial pattern of deglaciation was highly variable, particularly on the inner shelf. The deglacial reconstruction is consistent with a moderate overall excess ice volume and with a relatively small Antarctic contribution to meltwater pulse 1a. We discuss key areas of uncertainty both around the continent and by time interval, and we highlight potential priorities for future work. The synthesis is intended to be a resource for the modelling and glacial geological community.},
annote = {Reconstruction of Antarctic Ice Sheet Deglaciation (RAISED)},
author = {Bentley, Michael J and Cofaigh, Colm {\'{O}} and Anderson, John B and Conway, Howard and Davies, Bethan and Graham, Alastair G C and Hillenbrand, Claus-Dieter and Hodgson, Dominic A and Jamieson, Stewart S R and Larter, Robert D and Mackintosh, Andrew and Smith, James A and Verleyen, Elie and Ackert, Robert P and Bart, Philip J and Berg, Sonja and Brunstein, Daniel and Canals, Miquel and Colhoun, Eric A and Crosta, Xavier and Dickens, William A and Domack, Eugene and Dowdeswell, Julian A and Dunbar, Robert and Ehrmann, Werner and Evans, Jeffrey and Favier, Vincent and Fink, David and Fogwill, Christopher J and Glasser, Neil F and Gohl, Karsten and Golledge, Nicholas R and Goodwin, Ian and Gore, Damian B and Greenwood, Sarah L and Hall, Brenda L and Hall, Kevin and Hedding, David W and Hein, Andrew S and Hocking, Emma P and Jakobsson, Martin and Johnson, Joanne S and Jomelli, Vincent and Jones, R Selwyn and Klages, Johann P and Kristoffersen, Yngve and Kuhn, Gerhard and Leventer, Amy and Licht, Kathy and Lilly, Katherine and Lindow, Julia and Livingstone, Stephen J and Mass{\'{e}}, Guillaume and McGlone, Matt S and McKay, Robert M and Melles, Martin and Miura, Hideki and Mulvaney, Robert and Nel, Werner and Nitsche, Frank O and O'Brien, Philip E and Post, Alexandra L and Roberts, Stephen J and Saunders, Krystyna M and Selkirk, Patricia M and Simms, Alexander R and Spiegel, Cornelia and Stolldorf, Travis D and Sugden, David E and van der Putten, Nathalie and van Ommen, Tas and Verfaillie, Deborah and Vyverman, Wim and Wagner, Bernd and White, Duanne A and Witus, Alexandra E and Zwartz, Dan},
doi = {10.1016/j.quascirev.2014.06.025},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Antarctic Ice Sheet,Glacial geology,Modelling,Quaternary},
pages = {1--9},
title = {{A community-based geological reconstruction of Antarctic Ice Sheet deglaciation since the Last Glacial Maximum}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379114002546},
volume = {100},
year = {2014}
}
@article{Bereiter2018,
author = {Bereiter, Bernhard and Shackleton, Sarah and Baggenstos, Daniel and Kawamura, Kenji and Severinghaus, Jeff and {Bereiter, B., Shackleton, S., Baggenstos, D., Kawamura, K., Severinghaus}, J.},
doi = {10.1038/nature25152},
journal = {Nature},
month = {jan},
number = {39},
pages = {39},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Mean global ocean temperatures during the last glacial transition}},
url = {https://doi.org/10.1038/nature25152 http://10.0.4.14/nature25152 https://www.nature.com/articles/nature25152{\#}supplementary-information},
volume = {553},
year = {2018}
}
@article{cp-15-1603-2019,
author = {Berends, C J and de Boer, B and Dolan, A M and Hill, D J and van de Wal, R S W},
doi = {10.5194/cp-15-1603-2019},
journal = {Climate of the Past},
number = {4},
pages = {1603--1619},
title = {{Modelling ice sheet evolution and atmospheric CO2 during the Late Pliocene}},
url = {https://cp.copernicus.org/articles/15/1603/2019/},
volume = {15},
year = {2019}
}
@article{BERGER1991297,
author = {Berger, A. and Loutre, M F},
doi = {10.1016/0277-3791(91)90033-Q},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
number = {4},
pages = {297--317},
title = {{Insolation values for the climate of the last 10 million years}},
url = {http://www.sciencedirect.com/science/article/pii/027737919190033Q},
volume = {10},
year = {1991}
}
@article{Berry2011,
author = {Berry, David I and Kent, Elizabeth C},
doi = {10.1002/joc.2059},
issn = {08998418},
journal = {International Journal of Climatology},
month = {jun},
number = {7},
pages = {987--1001},
title = {{Air-Sea fluxes from ICOADS: the construction of a new gridded dataset with uncertainty estimates}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.2059},
volume = {31},
year = {2011}
}
@article{rs10010126,
abstract = {Sea surface temperature is a key component of the climate record, with multiple independent records giving confidence in observed changes. As part of the European Space Agencies (ESA) Climate Change Initiative (CCI) the satellite archives have been reprocessed with the aim of creating a new dataset that is independent of the in situ observations, and stable with no artificial drift ({\textless}0.1 K decade−1 globally) or step changes. We present a method to assess the satellite sea surface temperature (SST) record for step changes using the Penalized Maximal t Test (PMT) applied to aggregate time series. We demonstrated the application of the method using data from version EXP1.8 of the ESA SST CCI dataset averaged on a 7 km grid and in situ observations from moored buoys, drifting buoys and Argo floats. The CCI dataset was shown to be stable after {\~{}}1994, with minimal divergence ({\~{}}0.01 K decade−1) between the CCI data and in situ observations. Two steps were identified due to the failure of a gyroscope on the ERS-2 satellite, and subsequent correction mechanisms applied. These had minimal impact on the stability due to having equal magnitudes but opposite signs. The statistical power and false alarm rate of the method were assessed.},
author = {Berry, David I and Corlett, Gary K and Embury, Owen and Merchant, Christopher J},
doi = {10.3390/rs10010126},
issn = {2072-4292},
journal = {Remote Sensing},
number = {1},
title = {{Stability Assessment of the (A)ATSR Sea Surface Temperature Climate Dataset from the European Space Agency Climate Change Initiative}},
url = {http://www.mdpi.com/2072-4292/10/1/126},
volume = {10},
year = {2018}
}
@article{Berry2004,
abstract = {Marine air temperature reports from ships can contain significant biases due to the solar heating of the instruments and their surroundings. However, there have been very few attempts to derive corrections. The biases can reverse the sign of the measured air–sea temperature differences and cause significant errors in the sea surface latent and sensible heat flux estimates. In this paper a new correction for the radiative heating errors is presented. The correction is based on the analytical solution of the heat budget for an idealized ship, using empirical coefficients to represent the physical parameters. For the first time heat storage is included in the correction model. The heating errors are estimated for the Ocean Weather Ship Cumulus and the coefficients determined. When the correction is applied to the Cumulus data the average estimated error is reduced from 0.32° to 0.04°C and the diurnal cycle in the error is removed. The rms error is reduced by 30{\%}. The correction technique, although not the coefficients derived here that are specific to the Cumulus, can be applied to air temperature data from any type of ship, or to data from groups of ships such as the Voluntary Observing Ships.},
author = {Berry, David I and Kent, Elizabeth C and Taylor, Peter K},
doi = {10.1175/1520-0426(2004)021<1198:AAMOHE>2.0.CO;2},
issn = {0739-0572},
journal = {Journal of Atmospheric and Oceanic Technology},
month = {aug},
number = {8},
pages = {1198--1215},
title = {{An Analytical Model of Heating Errors in Marine Air Temperatures from Ships}},
url = {https://doi.org/10.1175/1520-0426(2004)021{\%}3C1198:AAMOHE{\%}3E2.0.CO http://0.0.0.2},
volume = {21},
year = {2004}
}
@article{bertram_pliocene_2018,
author = {Bertram, Rachel A and Wilson, David J and van de Flierdt, Tina and McKay, Robert M and Patterson, Molly O and Jimenez-Espejo, Francisco J and Escutia, Carlota and Duke, Grace C and Taylor-Silva, Briar I and Riesselman, Christina R},
doi = {10.1016/j.epsl.2018.04.054},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {jul},
pages = {109--116},
title = {{Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X18302632},
volume = {494},
year = {2018}
}
@article{Berx2013,
author = {Berx, B and Hansen, B and {\O}sterhus, S and Larsen, K M and Sherwin, T and Jochumsen, K},
doi = {10.5194/os-9-639-2013},
issn = {1812-0792},
journal = {Ocean Science},
month = {jul},
number = {4},
pages = {639--654},
publisher = {Copernicus Publications},
title = {{Combining in situ measurements and altimetry to estimate volume, heat and salt transport variability through the Faroe–Shetland Channel}},
url = {https://os.copernicus.org/articles/9/639/2013/ https://os.copernicus.org/articles/9/639/2013/os-9-639-2013.pdf},
volume = {9},
year = {2013}
}
@article{doi:10.1098/rsta.2016.0452,
abstract = {We projected changes in weather extremes, hydrological impacts and vulnerability to food insecurity at global warming of 1.5°C and 2°C relative to pre-industrial, using a new global atmospheric general circulation model HadGEM3A-GA3.0 driven by patterns of sea-surface temperatures and sea ice from selected members of the 5th Coupled Model Intercomparison Project (CMIP5) ensemble, forced with the RCP8.5 concentration scenario. To provide more detailed representations of climate processes and impacts, the spatial resolution was N216 (approx. 60 km grid length in mid-latitudes), a higher resolution than the CMIP5 models. We used a set of impacts-relevant indices and a global land surface model to examine the projected changes in weather extremes and their implications for freshwater availability and vulnerability to food insecurity. Uncertainties in regional climate responses are assessed, examining ranges of outcomes in impacts to inform risk assessments. Despite some degree of inconsistency between components of the study due to the need to correct for systematic biases in some aspects, the outcomes from different ensemble members could be compared for several different indicators. The projections for weather extremes indices and biophysical impacts quantities support expectations that the magnitude of change is generally larger for 2°C global warming than 1.5°C. Hot extremes become even hotter, with increases being more intense than seen in CMIP5 projections. Precipitation-related extremes show more geographical variation with some increases and some decreases in both heavy precipitation and drought. There are substantial regional uncertainties in hydrological impacts at local scales due to different climate models producing different outcomes. Nevertheless, hydrological impacts generally point towards wetter conditions on average, with increased mean river flows, longer heavy rainfall events, particularly in South and East Asia with the most extreme projections suggesting more than a doubling of flows in the Ganges at 2°C global warming. Some areas are projected to experience shorter meteorological drought events and less severe low flows, although longer droughts and/or decreases in low flows are projected in many other areas, particularly southern Africa and South America. Flows in the Amazon are projected to decline by up to 25{\%}. Increases in either heavy rainfall or drought events imply increased vulnerability to food insecurity, but if global warming is limited to 1.5°C, this vulnerability is projected to remain smaller than at 2°C global warming in approximately 76{\%} of developing countries. At 2°C, four countries are projected to reach unprecedented levels of vulnerability to food insecurity.},
author = {Betts, Richard A and Alfieri, Lorenzo and Bradshaw, Catherine and Caesar, John and Feyen, Luc and Friedlingstein, Pierre and Gohar, Laila and Koutroulis, Aristeidis and Lewis, Kirsty and Morfopoulos, Catherine and Papadimitriou, Lamprini and Richardson, Katy J and Tsanis, Ioannis and Wyser, Klaus},
doi = {10.1098/rsta.2016.0452},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {may},
number = {2119},
pages = {20160452},
title = {{Changes in climate extremes, fresh water availability and vulnerability to food insecurity projected at 1.5°C and 2°C global warming with a higher-resolution global climate model}},
url = {https://royalsocietypublishing.org/doi/abs/10.1098/rsta.2016.0452 https://royalsocietypublishing.org/doi/10.1098/rsta.2016.0452},
volume = {376},
year = {2018}
}
@article{Betts2016a,
abstract = {The recent El Ni{\~{n}}o event has elevated the rise in CO2 concentration this year. Here, using emissions, sea surface temperature data and a climate model, we forecast that the CO2 concentration at Mauna Loa will for the first time remain above 400 ppm all year, and hence for our lifetimes.},
author = {Betts, Richard A. and Jones, Chris D. and Knight, Jeff R. and Keeling, Ralph F. and Kennedy, John J.},
doi = {10.1038/nclimate3063},
isbn = {1758-6798},
issn = {17586798},
journal = {Nature Climate Change},
pages = {806--810},
title = {{El Ni{\~{n}}o and a record CO2 rise}},
volume = {6},
year = {2016}
}
@article{https://doi.org/10.1029/2019GL086812,
abstract = {Abstract The newest generation of the Coupled Model Intercomparison Project (CMIP6) exhibits a larger spread in temperature projections at the end of the 21st century than the previous generation. Here, a modular Earth System Model emulator is used to evaluate the realism of the warming signal in CMIP6 models on both global and regional scales, by comparing their global trends and regional response parameters to observations. Subsequently, the emulator is employed to derive large “crossbred” multimodel initial-condition ensembles of regionally optimized land temperature projections by combining observationally constrained global mean temperature trend trajectories with observationally constrained local parameters. In the optimized ensembles, the warmest temperature projections are generally reduced and for the coolest projections both higher and lower values are found, depending on the region. The median shows less changes in large parts of the globe. These regional differences highlight the importance of a geographically explicit evaluation of Earth System Model projections.},
annote = {e2019GL086812 10.1029/2019GL086812},
author = {Beusch, Lea and Gudmundsson, Lukas and Seneviratne, Sonia I},
doi = {10.1029/2019GL086812},
journal = {Geophysical Research Letters},
number = {15},
pages = {e2019GL086812},
title = {{Crossbreeding CMIP6 Earth System Models With an Emulator for Regionally Optimized Land Temperature Projections}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086812},
volume = {47},
year = {2020}
}
@article{Bianchi1999,
abstract = {Climate fluctuations during the past millennium are relatively well documented1. On a longer timescale, there is growing evidence of millennial-scale variability of Holocene climate, at periodicities of ∼2,500 and 950 years (possibly caused by changes in solar flux)2,3 and ∼1,500 years (maybe related to an internal oscillation of the climate system)4,5,6. But the involvement of deep water masses in these Holocene climate changes has yet to be established. Here we use sediment grain-size data from the Iceland basin to reconstruct past changes in the speed of deep-water flow. The study site is under the influence of Iceland–Scotland Overflow Water (ISOW), the flow of which is an important component of the ‘thermohaline' circulation that modulates European climate. Flow changes coincide with some known climate events (the Little Ice Age and the Mediaeval Warm Period), and extend over the entire Holocene epoch with aquasi-periodicity of ∼1,500 years. The grain-size data indicate afaster ISOW flow when the climate of northern Europe is warmer. However, a second mode of operation is observed in the early Holocene, when warm climate intervals are associated with slower ISOW flow. At that time the melting remnant of land-based, glacial-age ice may have provided a sufficient source of fresh water to the ocean to reduce ISOW flow south of Iceland.},
author = {Bianchi, Giancarlo G and McCave, I Nicholas},
doi = {10.1038/17362},
issn = {1476-4687},
journal = {Nature},
number = {6719},
pages = {515--517},
title = {{Holocene periodicity in North Atlantic climate and deep-ocean flow south of Iceland}},
url = {https://doi.org/10.1038/17362},
volume = {397},
year = {1999}
}
@article{Biasutti2018a,
abstract = {Global constraints on momentum and energy govern the variability of the rainfall belt in the intertropical convergence zone and the structure of the zonal mean tropical circulation. The continental-scale monsoon systems are also facets of a momentum- and energy-constrained global circulation, but their modern and palaeo variability deviates substantially from that of the intertropical convergence zone. The mechanisms underlying deviations from expectations based on the longitudinal mean budgets are neither fully understood nor simulated accurately. We argue that a framework grounded in global constraints on energy and momentum yet encompassing the complexities of monsoon dynamics is needed to identify the causes of the mismatch between theory, models and observations, and ultimately to improve regional climate projections. In a first step towards this goal, disparate regional processes must be distilled into gross measures of energy flow in and out of continents and between the surface and the tropopause, so that monsoon dynamics may be coherently diagnosed across modern and palaeo observations and across idealized and comprehensive simulations. Accounting for zonal asymmetries in the circulation, land/ocean differences in surface fluxes, and the character of convective systems, such a monsoon framework would integrate our understanding at all relevant scales: from the fine details of how moisture and energy are lifted in the updrafts of thunderclouds, up to the global circulations.},
author = {Biasutti, Michela and Voigt, Aiko and Boos, William R. and Braconnot, Pascale and Hargreaves, Julia C. and Harrison, Sandy P. and Kang, Sarah M. and Mapes, Brian E. and Scheff, Jacob and Schumacher, Courtney and Sobel, Adam H. and Xie, Shang Ping},
doi = {10.1038/s41561-018-0137-1},
issn = {17520908},
journal = {Nature Geoscience},
number = {6},
pages = {392--400},
publisher = {Springer US},
title = {{Global energetics and local physics as drivers of past, present and future monsoons}},
volume = {11},
year = {2018}
}
@article{Bierman2016,
abstract = {10Be and 26Al isotopic evidence in quartz sand from the seafloor shows that a dynamic East Greenland Ice Sheet has existed for the past 7.5 million years.},
author = {Bierman, Paul R and Shakun, Jeremy D and Corbett, Lee B and Zimmerman, Susan R and Rood, Dylan H},
doi = {10.1038/nature20147},
issn = {1476-4687},
journal = {Nature},
number = {7632},
pages = {256--260},
title = {{A persistent and dynamic East Greenland Ice Sheet over the past 7.5 million years}},
url = {https://doi.org/10.1038/nature20147},
volume = {540},
year = {2016}
}
@incollection{BindoffN.etal.[H.-O.PortnerD.C.RobertsV.Masson-DelmotteP.ZhaiM.TignorE.PoloczanskaK.MintenbeckM.NicolaiA.OkemJ.PetzoldB.Rama2019,
author = {Bindoff, N.L. and Cheung, W.W.L. and Kairo, J.G. and Ar{\'{i}}stegui, J. and Guinder, V.A. and Hallberg, R. and Hilmi, N. and Jiao, N. and Karim, M.S. and Levin, L. and O'Donoghue, S. and Cuicapusa, S.R. Purca and Rinkevich, B. and Suga, T. and Tagliabue, A. and Williamson, P.},
booktitle = {IPCC Special Report on the Ocean and Cryosphere in a Changing Climate},
doi = {https://www.ipcc.ch/srocc/chapter/chapter-5},
editor = {P{\"{o}}rtner, Hans-Otto and Roberts, DC and Masson-Delmotte, V and Zhai, P and Tignor, M and Poloczanska, E and Mintenbeck, K and Alegr{\'{i}}a, A and Nicolai, M and Okem, A},
pages = {447--587},
publisher = {In Press},
title = {{Changing Ocean, Marine Ecosystems, and Dependent Communities}},
url = {https://www.ipcc.ch/srocc/chapter/chapter-5},
year = {2019}
}
@article{Binney2017a,
abstract = {Continental-scale estimates of vegetation cover, including land-surface properties and biogeographic trends, reflect the response of plant species to climate change over the past millennia. These estimates can help assess the effectiveness of simulations of climate change using forward and inverse modelling approaches. With the advent of transient and contiguous time-slice palaeoclimate simulations, vegetation datasets with similar temporal qualities are desirable. We collated fossil pollen records for the period 21,000–0 cal yr BP (kyr cal BP; calibrated ages) for Europe and Asia north of 40°N, using extant databases and new data; we filtered records for adequate dating and sorted the nomenclature to conform to a consistent yet extensive taxon list. From this database we extracted pollen spectra representing 1000-year time-slices from 21 kyr cal BP to present and used the biomization approach to define the most likely vegetation biome represented. Biomes were mapped for the 22 time slices, and key plant functional types (PFTs, the constituents of the biomes) were tracked though time. An error matrix and index of topographic complexity clearly showed that the accuracy of pollen-based biome assignments (when compared with modern vegetation) was negatively correlated with topographic complexity, but modern vegetation was nevertheless effectively mapped by the pollen, despite moderate levels of misclassification for most biomes. The pattern at 21 ka is of herb-dominated biomes across the whole region. From the onset of deglaciation (17–18 kyr cal BP), some sites in Europe record forest biomes, particularly the south, and the proportion of forest biomes gradually increases with time through 14 kyr cal BP. During the same period, forest biomes and steppe or tundra biomes are intermixed across the central Asian mountains, and forest biomes occur in coastal Pacific areas. These forest biome occurrences, plus a record of dated plant macrofossils, indicate that some tree populations existed in southern and Eastern Europe and central and far-eastern Eurasia. PFT composition of the herbaceous biomes emphasises the significant contribution of diverse forbs to treeless vegetation, a feature often obscured in pollen records. An increase in moisture ca. 14 kyr cal BP is suggested by a shift to woody biomes and an increase in sites recording initialization and development of lakes and peat deposits, particularly in the European portion of the region. Deforestation of W{\ldots}},
author = {Binney, Heather A. and Edwards, Mary and Macias-Fauria, Marc and Lozhkin, Anatoly and Anderson, Patricia and Kaplan, Jed O. and Andreev, Andrei and Bezrukova, Elena and Blyakharchuk, Tatiana and Jankovska, Vlasta and Khazina, Irina and Krivonogov, Sergey and Kremenetski, Konstantin and Nield, Jo and Novenko, Elena and Ryabogina, Natalya and Solovieva, Nadia and Willis, Kathy and Zernitskaya, Valentina},
doi = {10.1016/j.quascirev.2016.11.022},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
pages = {80--97},
title = {{Vegetation of Eurasia from the last glacial maximum to present: Key biogeographic patterns}},
volume = {157},
year = {2017}
}
@article{Binney2009a,
abstract = {We present a database of late-Quaternary plant macrofossil records for northern Eurasia (from 23° to 180°E and 46° to 76°N) comprising 281 localities, over 2300 samples and over 13,000 individual records. Samples are individually radiocarbon dated or are assigned ages via age models fitted to sequences of calibrated radiocarbon dates within a section. Tree species characteristic of modern northern forests (e.g. Picea, Larix, tree-Betula) are recorded at least intermittently from prior to the last glacial maximum (LGM), through the LGM and Lateglacial, to the Holocene, and some records locate trees close to the limits of the Scandinavian ice sheet, supporting the hypothesis that some taxa persisted in northern refugia during the last glacial cycle. Northern trees show differing spatio-temporal patterns across Siberia: deciduous trees were widespread in the Lateglacial, with individuals occurring across much of their contemporary ranges, while evergreen conifers expanded northwards to their range limits in the Holocene. {\textcopyright} 2009 Elsevier Ltd. All rights reserved.},
author = {Binney, Heather A. and Willis, Katherine J. and Edwards, Mary E. and Bhagwat, Shonil A. and Anderson, Patricia M. and Andreev, Andrei A. and Blaauw, Maarten and Damblon, Freddy and Haesaerts, Paul and Kienast, Frank and Kremenetski, Konstantin V. and Krivonogov, Sergey K. and Lozhkin, Anatoly V. and MacDonald, Glen M. and Novenko, Elena Y. and Oksanen, Pirita and Sapelko, Tatiana V. and V{\"{a}}liranta, Minna and Vazhenina, Ludmila},
doi = {10.1016/j.quascirev.2009.04.016},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
title = {{The distribution of late-Quaternary woody taxa in northern Eurasia: evidence from a new macrofossil database}},
year = {2009}
}
@article{doi:10.1175/1520-0442,
author = {Biondi, Franco and Gershunov, Alexander and Cayan, Daniel R.},
doi = {10.1175/1520-0442(2001)014<0005:NPDCVS>2.0.CO;2},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jan},
number = {1},
pages = {5--10},
title = {{North Pacific Decadal Climate Variability since 1661}},
url = {http://journals.ametsoc.org/doi/abs/10.1175/1520-0442{\%}282001{\%}29014{\%}3C0005{\%}3ANPDCVS{\%}3E2.0.CO{\%}3B2},
volume = {14},
year = {2001}
}
@article{Bisagni2017,
abstract = {The Gulf Stream (GS) is the northeastward-flowing surface limb of the Atlantic Ocean's meridional overturning circulation (AMOC) “conveyer belt” that flows towards Europe and the Nordic Seas. Changes in the GS position after its separation from the coast at Cape Hatteras, i.e., from 75°W to 50°W, may be key to understanding the AMOC, sea level variability and ecosystem behavior along the east coast of North America. In this study we compare secular change and inter-annual variability (IAV) of the Gulf Stream North Wall (GSNW) position with equator-ward Labrador Current (LC) transport along the southwestern Grand Banks near 52°W using 21 years (1993–2013) of satellite altimeter data. Results at 55°, 60°, and 65°W show a significant southward (negative) secular trend for the GSNW, decreasing to a small but insignificant southward trend at 70°W. IAV of de-trended GSNW position residuals also decreases to the west. The long-term secular trend of annual mean upper layer (200 m) LC transport near 52°W is positive. Furthermore, IAV of LC transport residuals near 52°W along the southwestern Grand Banks are significantly correlated with GSNW position residuals at 55°W at a lag of +1-year, with positive (negative) LC transport residuals corresponding to southward (northward) GSNW positions one year later. The Taylor-Stephens index (TSI) computed from the first principal component of the GSNW position from 79° to 65°W shows a similar relationship with a more distal LC index computed along altimeter ground track 250 located north of the Grand Banks across Hamilton Bank in the western Labrador Sea. Increased (decreased) sea height differences along ground track 250 are significantly correlated with a more southward (northward) TSI two years later (lag of +2-years). Spectral analysis of IAV reveals corresponding spectral peaks at 5–7 years and 2–3 years for the North Atlantic Oscillation (NAO), GSNW (70°−55°W) and LC transport near 52°W for the 1993–2013 period suggesting a connection between these phenomena. An upper-layer (200 m) slope water volume calculation using the LC IAV rms residual of +1.04 Sv near 52°W results in an estimated GSNW IAV residual of 79 km, or 63{\%} of the observed 125.6 km (1.13°) rms value at 55°W. A similar upper-layer slope water volume calculation using the positive long-term, upper-layer LC transport trend accounts for 68{\%} of the mean observed secular southward shift of the GSNW between 55° and 70°W over the 1993–2013 period. Our work prov{\ldots}},
author = {Bisagni, James J. and Gangopadhyay, Avijit and Sanchez-Franks, Alejandra},
doi = {10.1016/j.dsr.2017.04.001},
issn = {09670637},
journal = {Deep-Sea Research Part I: Oceanographic Research Papers},
pages = {1--10},
title = {{Secular change and inter-annual variability of the Gulf Stream position, 1993–2013, 70°−55°W}},
volume = {25},
year = {2017}
}
@article{Biskaborn2019,
abstract = {Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.},
author = {Biskaborn, Boris K and Smith, Sharon L and Noetzli, Jeannette and Matthes, Heidrun and Vieira, Gon{\c{c}}alo and Streletskiy, Dmitry A and Schoeneich, Philippe and Romanovsky, Vladimir E and Lewkowicz, Antoni G and Abramov, Andrey and Allard, Michel and Boike, Julia and Cable, William L and Christiansen, Hanne H and Delaloye, Reynald and Diekmann, Bernhard and Drozdov, Dmitry and Etzelm{\"{u}}ller, Bernd and Grosse, Guido and Guglielmin, Mauro and Ingeman-Nielsen, Thomas and Isaksen, Ketil and Ishikawa, Mamoru and Johansson, Margareta and Johannsson, Halldor and Joo, Anseok and Kaverin, Dmitry and Kholodov, Alexander and Konstantinov, Pavel and Kr{\"{o}}ger, Tim and Lambiel, Christophe and Lanckman, Jean-Pierre and Luo, Dongliang and Malkova, Galina and Meiklejohn, Ian and Moskalenko, Natalia and Oliva, Marc and Phillips, Marcia and Ramos, Miguel and Sannel, A Britta K and Sergeev, Dmitrii and Seybold, Cathy and Skryabin, Pavel and Vasiliev, Alexander and Wu, Qingbai and Yoshikawa, Kenji and Zheleznyak, Mikhail and Lantuit, Hugues},
doi = {10.1038/s41467-018-08240-4},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {264},
title = {{Permafrost is warming at a global scale}},
url = {https://doi.org/10.1038/s41467-018-08240-4},
volume = {10},
year = {2019}
}
@article{blake-mizen_southern_2019,
author = {Blake-Mizen, Keziah and Hatfield, Robert G and Stoner, Joseph S and Carlson, Anders E and Xuan, Chuang and Walczak, Maureen and Lawrence, Kira T and Channell, James E T and Bailey, Ian},
doi = {10.1016/j.quascirev.2019.01.015},
issn = {02773791},
journal = {Quaternary Science Reviews},
month = {apr},
pages = {40--51},
title = {{Southern Greenland glaciation and Western Boundary Undercurrent evolution recorded on Eirik Drift during the late Pliocene intensification of Northern Hemisphere glaciation}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379118308011},
volume = {209},
year = {2019}
}
@article{Blanchon2009,
abstract = {The potential for future rapid sea-level rise is perhaps the greatest threat from global warming. But the question of whether recent ice loss from Greenland and Antarctica is the first indication of such a rise is difficult to answer given the limited duration of the instrumental record. New evidence from an exceptionally exposed fossil reef in the Xcaret theme park in Mexico provides a detailed picture of the development of reef terraces, erosion surfaces and sea-level excursions in the region during the last interglacial. A combination of precise uranium-series dating and stratigraphic analysis, together with comparison with coral ages elsewhere, suggests that a sea-level jump of 2 to 3 metres occurred about 121,000 years ago, consistent with an episode of ice-sheet instability towards the end of the last interglacial. On that evidence, sustained rapid ice loss and sea-level rise in the near future are possible.},
author = {Blanchon, Paul and Eisenhauer, Anton and Fietzke, Jan and Liebetrau, Volker},
doi = {10.1038/nature07933},
issn = {1476-4687},
journal = {Nature},
number = {7240},
pages = {881--884},
title = {{Rapid sea-level rise and reef back-stepping at the close of the last interglacial highstand}},
url = {https://doi.org/10.1038/nature07933},
volume = {458},
year = {2009}
}
@article{Bliss2017,
abstract = {Two long records of melt onset (MO) on Arctic sea ice from passive microwave brightness temperatures (Tbs) obtained by a series of satellite-borne instruments are compared. The Passive Microwave (PMW) method and Advanced Horizontal Range Algorithm (AHRA) detect the increase in emissivity that occurs when liquid water develops around snow grains at the onset of early melting on sea ice. The timing of MO on Arctic sea ice influences the amount of solar radiation absorbed by the ice–ocean system throughout the melt season by reducing surface albedos in the early spring. This work presents a thorough comparison of these two methods for the time series of MO dates from 1979 through 2012. The methods are first compared using the published data as a baseline comparison of the publically available data products. A second comparison is performed on adjusted MO dates we produced to remove known differences in inter-sensor calibration of Tbs and masking techniques used to develop the original MO date products. These adjustments result in a more consistent set of input Tbs for the algorithms. Tests of significance indicate that the trends in the time series of annual mean MO dates for the PMW and AHRA are statistically different for the majority of the Arctic Ocean including the Laptev, E. Siberian, Chukchi, Beaufort, and central Arctic regions with mean differences as large as 38.3 days in the Barents Sea. Trend agreement improves for our more consistent MO dates for nearly all regions. Mean differences remain large, primarily due to differing sensitivity of in-algorithm thresholds and larger uncertainties in thin-ice regions.},
author = {Bliss, Angela and Miller, Jeffrey and Meier, Walter},
doi = {10.3390/rs9030199},
issn = {2072-4292},
journal = {Remote Sensing},
keywords = {Arctic,Melt,Melt onset,Passive microwave,Sea ice},
month = {feb},
number = {3},
pages = {199},
title = {{Comparison of Passive Microwave-Derived Early Melt Onset Records on Arctic Sea Ice}},
url = {http://www.mdpi.com/2072-4292/9/3/199},
volume = {9},
year = {2017}
}
@article{BlowesS.A.2019,
abstract = {Human activities are fundamentally altering biodiversity. Projections of declines at the global scale are contrasted by highly variable trends at local scales, suggesting that biodiversity change may be spatially structured. Here, we examined spatial variation in species richness and composition change using more than 50,000 biodiversity time series from 239 studies and found clear geographic variation in biodiversity change. Rapid compositional change is prevalent, with marine biomes exceeding and terrestrial biomes trailing the overall trend. Assemblage richness is not changing on average, although locations exhibiting increasing and decreasing trends of up to about 20{\%} per year were found in some marine studies. At local scales, widespread compositional reorganization is most often decoupled from richness change, and biodiversity change is strongest and most variable in the oceans.},
author = {Blowes, Shane A. and Supp, Sarah R. and Ant{\~{a}}o, Laura H. and Bates, Amanda and Bruelheide, Helge and Chase, Jonathan M. and Moyes, Faye and Magurran, Anne and McGill, Brian and Myers-Smith, Isla H. and Winter, Marten and Bjorkman, Anne D. and Bowler, Diana E. and Byrnes, Jarrett E. K. and Gonzalez, Andrew and Hines, Jes and Isbell, Forest and Jones, Holly P. and Navarro, Laetitia M. and Thompson, Patrick L. and Vellend, Mark and Waldock, Conor and Dornelas, Maria},
doi = {10.1126/science.aaw1620},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {6463},
pages = {339--345},
title = {{The geography of biodiversity change in marine and terrestrial assemblages}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.aaw1620},
volume = {366},
year = {2019}
}
@article{Bohlinger2014,
abstract = {Arctic stratospheric ozone depletion is closely linked to the occurrence of low stratospheric temperatures. There are indications that cold winters in the Arctic stratosphere have been getting colder, raising the question if and to what extent a cooling of the Arctic stratosphere may continue into the future. We use meteorological reanalyses from the European Centre for Medium Range Weather Forecasts (ECMWF) ERA-Interim and NASA's Modern-Era Retrospective-Analysis for Research and Applications (MERRA) for the past 32 yr together with calculations of the chemistry-climate model (CCM) ECHAM/MESSy Atmospheric Chemistry (EMAC) and models from the Chemistry-Climate Model Validation (CCMVal) project to infer radiative and dynamical contributions to long-term Arctic stratospheric temperature changes. For the past three decades the reanalyses show a warming trend in winter and cooling trend in spring and summer, which agree well with trends from the Radiosonde Innovation Composite Homogenization (RICH) adjusted radiosonde data set. Changes in winter and spring are caused by a corresponding change of planetary wave activity with increases in winter and decreases in spring. During winter the increase of planetary wave activity is counteracted by a residual radiatively induced cooling. Stratospheric radiatively induced cooling is detected throughout all seasons, being highly significant in spring and summer. This means that for a given dynamical situation, according to ERA-Interim the annual mean temperature of the Arctic lower stratosphere has been cooling by −0.41 ± 0.11 K decade−1 at 50 hPa over the past 32 yr. Calculations with state-of-the-art models from CCMVal and the EMAC model qualitatively reproduce the radiatively induced cooling for the past decades, but underestimate the amount of radiatively induced cooling deduced from reanalyses. There are indications that this discrepancy could be partly related to a possible underestimation of past Arctic ozone trends in the models. The models project a continued cooling of the Arctic stratosphere over the coming decades (2001–2049) that is for the annual mean about 40{\%} less than the modeled cooling for the past, due to the reduction of ozone depleting substances and the resulting ozone recovery. This projected cooling in turn could offset between 15 and 40{\%} of the Arctic ozone recovery.},
author = {Bohlinger, P. and Sinnhuber, B. M. and Ruhnke, R. and Kirner, O.},
doi = {10.5194/acp-14-1679-2014},
isbn = {1680-7316},
issn = {16807316},
journal = {Atmospheric Chemistry and Physics},
number = {3},
pages = {1679--1688},
title = {{Radiative and dynamical contributions to past and future Arctic stratospheric temperature trends}},
volume = {14},
year = {2014}
}
@article{doi:10.1175/BAMS-D-13-00047.1,
abstract = { Climate research, monitoring, prediction, and related services rely on accurate observations of the atmosphere, land, and ocean, adequately sampled globally and over sufficiently long time periods. The Global Climate Observing System, set up under the auspices of United Nations organizations and the International Council for Science to help ensure the availability of systematic observations of climate, developed the concept of essential climate variables (ECVs). ECV data records are intended to provide reliable, traceable, observation-based evidence for a range of applications, including monitoring, mitigating, adapting to, and attributing climate changes, as well as the empirical basis required to understand past, current, and possible future climate variability. The ECV concept has been broadly adopted worldwide as the guiding basis for observing climate, including by the United Nations Framework Convention on Climate Change (UNFCCC), WMO, and space agencies operating Earth observation satellites. This paper describes the rationale for these ECVs and their current selection, based on the principles of feasibility, relevance, and cost effectiveness. It also provides a view of how the ECV concept could evolve as a guide for rational and evidence-based monitoring of climate and environment. Selected examples are discussed to highlight the benefits, limitations, and future evolution of this approach. The article is intended to assist program managers to set priorities for climate observation, dataset generation and related research: for instance, within the emerging Global Framework for Climate Services (GFCS). It also helps the observation community and individual researchers to contribute to systematic climate observation, by promoting understanding of ECV choices and the opportunities to influence their evolution. },
author = {Bojinski, Stephan and Verstraete, Michel and Peterson, Thomas C and Richter, Carolin and Simmons, Adrian and Zemp, Michael},
doi = {10.1175/BAMS-D-13-00047.1},
journal = {Bulletin of the American Meteorological Society},
number = {9},
pages = {1431--1443},
title = {{The Concept of Essential Climate Variables in Support of Climate Research, Applications, and Policy}},
url = {https://doi.org/10.1175/BAMS-D-13-00047.1},
volume = {95},
year = {2014}
}
@article{Bokhorst2016,
abstract = {Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for impact assessments and adaptation strategies. Although much progress has been made in understanding and predicting snow-cover changes and their multiple consequences, many uncertainties remain. In this paper, we review advances in snow monitoring and modelling, and the impact of snow changes on ecosystems and society in Arctic regions. Interdisciplinary activities are required to resolve the current limitations on measuring and modelling snow characteristics through the cold season and at different spatial scales to assure human well-being, economic stability, and improve the ability to predict manage and adapt to natural hazards in the Arctic region.},
author = {Bokhorst, Stef and Pedersen, Stine H{\o}jlund and Brucker, Ludovic and Anisimov, Oleg and Bjerke, Jarle W. and Brown, Ross D. and Ehrich, Dorothee and Essery, Richard L.H. and Heilig, Achim and Ingvander, Susanne and Johansson, Cecilia and Johansson, Margareta and J{\'{o}}nsd{\'{o}}ttir, Ingibj{\"{o}}rg Svala and Inga, Niila and Luojus, Kari and Macelloni, Giovanni and Mariash, Heather and McLennan, Donald and Rosqvist, Gunhild Ninis and Sato, Atsushi and Savela, Hannele and Schneebeli, Martin and Sokolov, Aleksandr and Sokratov, Sergey A. and Terzago, Silvia and Vikhamar-Schuler, Dagrun and Williamson, Scott and Qiu, Yubao and Callaghan, Terry V.},
doi = {10.1007/s13280-016-0770-0},
isbn = {0044-7447, 1654-7209},
issn = {16547209},
journal = {Ambio},
keywords = {Climate change,Ecosystem services,Human health,Indigenous,Snow,Societal costs},
pages = {516--537},
pmid = {26984258},
title = {{Changing Arctic snow cover: A review of recent developments and assessment of future needs for observations, modelling, and impacts}},
volume = {45},
year = {2016}
}
@article{Booth2012,
abstract = {A state-of-the-art climate model shows that radiative forcing due to anthropogenic and volcanic aerosols explains the variability in sea surface temperature of the North Atlantic between 1950 and 2005.},
author = {Booth, Ben B B and Dunstone, Nick J and Halloran, Paul R and Andrews, Timothy and Bellouin, Nicolas},
doi = {10.1038/nature10946},
issn = {1476-4687},
journal = {Nature},
number = {7393},
pages = {228--232},
title = {{Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability}},
url = {https://doi.org/10.1038/nature10946},
volume = {484},
year = {2012}
}
@article{Bordbar2017a,
abstract = {While the Earth's surface has considerably warmed over the past two decades, the tropical Pacific has featured a cooling of sea surface temperatures in its eastern and central parts, which went along with an unprecedented strengthening of the equatorial trade winds, the surface component of the Pacific Walker Circulation (PWC). Previous studies show that this decadal trend in the trade winds is generally beyond the range of decadal trends simulated by climate models when forced by historical radiative forcing. There is still a debate on the origin of and the potential role that internal variability may have played in the recent decadal surface wind trend. Using a number of long control (unforced) integrations of global climate models and several observational data sets, we address the question as to whether the recent decadal to multidecadal trends are robustly classified as an unusual event or the persistent response to external forcing. The observed trends in the tropical Pacific surface climate are still within the range of the long-term internal variability spanned by the models but represent an extreme realization of this variability. Thus, the recent observed decadal trends in the tropical Pacific, though highly unusual, could be of natural origin. We note that the long-term trends in the selected PWC indices exhibit a large observational uncertainty, even hindering definitive statements about the sign of the trends.},
author = {Bordbar, Mohammad Hadi and Martin, Thomas and Latif, Mojib and Park, Wonsun},
doi = {10.1002/2016GL072355},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Pacific Walker Circulation,tropical Pacific climate change},
month = {may},
number = {9},
pages = {4246--4255},
title = {{Role of internal variability in recent decadal to multidecadal tropical Pacific climate changes}},
url = {http://doi.wiley.com/10.1002/2016GL072355},
volume = {44},
year = {2017}
}
@article{Bordi2015,
author = {Bordi, Isabella and Bonis, Roberto De and Fraedrich, Klaus and Sutera, Alfonso},
doi = {10.1007/s00704-014-1304-y},
journal = {Theoretical and Applied Climatology},
pages = {441--455},
title = {{Interannual variability patterns of the world' s total column water content: Amazon River basin}},
volume = {122},
year = {2015}
}
@article{Borge2017a,
abstract = {Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. We have systematically mapped the occurrence of palsas and peat plateaus in the northernmost county of Norway (Finnmark, {\~{}} 50 000 km2) by manual interpretation of aerial images from 2005{\&}ndash;2014 at a spatial resolution of 250 m2. At this resolution, mires and wetlands with palsas or peat plateaus occur in about 850 km2 of Finnmark, with the actual palsas and peat plateaus underlain by permafrost covering a surface area of approximately 110 km2. Secondly, we have quantified the lateral changes of the extent of palsas and peat plateaus for four study areas located along a NW{\&}ndash;SE transect through Finnmark by utilizing repeat aerial imagery from the 1950s to the 2010s. The results of the lateral changes reveal a total decrease of 33{\&}ndash;71 {\%} in the areal extent of palsas and peat plateaus during the study period, with the largest lateral change rates observed in the last decade. However, the results indicate that degradation of palsas and peat plateaus in northern Norway has been a consistent process during the second half of the 20th century and possibly even earlier. Significant rates of degradation are observed in all investigated time periods since the 1950s, and thermokarst landforms observed on aerial images from the 1950s suggest that lateral degradation was already an ongoing process at this time. The results of this study show that lateral erosion of palsas and peat plateaus is an important pathway for permafrost degradation in the sporadic permafrost zone in northern Scandinavia. While the environmental factors governing the rate of erosion are not yet fully understood, we note a moderate increase in both air temperature and precipitation during the last few decades in the region.},
author = {Borge, Amund F. and Westermann, Sebastian and Solheim, Ingvild and Etzelm{\"{u}}ller, Bernd},
doi = {10.5194/tc-11-1-2017},
isbn = {1994-0416},
issn = {19940424},
journal = {Cryosphere},
number = {1},
pages = {1--16},
title = {{Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years}},
volume = {11},
year = {2017}
}
@article{Born2010,
abstract = {Climate model simulations of the 8.2 ka event show an abrupt strengthening of the Atlantic subpolar gyre that allows us to connect two major but apparently contradictory climate events of the early Holocene: the freshwater outburst from proglacial lakes and the onset of Labrador Sea water formation. The 8.2 ka event is the largest climatic signal of our present interglacial with a widespread cooling in the North Atlantic region about 8200 years before present. It coincides with a meltwater outburst from North American proglacial lakes that is believed to have weakened the Atlantic meridional overturning circulation and northward heat transport, followed by a recovery of the deep ocean circulation and rising temperatures after a few centuries. Marine proxy data, however, date the onset of deep water formation in Labrador Sea to the same time. The subsequent strengthening of the slope current system created a regional signal recorded as an abrupt and persistent surface temperature decrease. Although similarities in timing are compelling, a mechanism to reconcile these apparently contradictory events was missing. Our simulations show that an abrupt and persistent strengthening of the Atlantic subpolar gyre provides a plausible explanation. The intense freshwater pulse triggered a transition of the gyre circulation into a different mode of operation, stabilized by internal feedbacks and persistent after the cessation of the perturbation. As a direct consequence, deep water formation around its center intensifies. This corresponds to the modern flow regime and stabilizes the meridional overturning circulation, possibly contributing to the Holocene's climatic stability.},
annote = {doi: 10.1029/2009GC003024},
author = {Born, A and Levermann, A},
doi = {10.1029/2009GC003024},
issn = {1525-2027},
journal = {Geochemistry, Geophysics, Geosystems},
keywords = {8.2 ka event,Holocene,North Atlantic,climate model,subpolar gyre},
month = {jun},
number = {6},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{The 8.2 ka event: Abrupt transition of the subpolar gyre toward a modern North Atlantic circulation}},
url = {https://doi.org/10.1029/2009GC003024},
volume = {11},
year = {2010}
}
@article{Borstad2011,
abstract = {ABSTRACT: There are few studies of the mechanistic links between physical environmental processes and biotic responses in marine ecosystems that have strong predictive power. At Triangle Island, the largest seabird colony along Canada's Pacific coast, annual breeding success of rhinoceros auklets Cerorhinca monocerata varies dramatically. Previous studies have correlated this variability with ocean temperature, but this relationship occasionally fails, suggesting that it is not causal. We used historical satellite data time series of sea surface temperature, chlorophyll, and winds to study the oceanography of this remote colony. We found that rhinoceros auklets bred more successfully when the spring transition in regional winds and the resulting spring phytoplankton bloom occurred early in April. These factors appear to control the annual recruitment of Pacific sandlance Ammodytes hexapterus, as measured by the percent by biomass of young-of-the-year sandlance in the nestling diet. These linkages imply bottom-up control in this system. Suggesting broader implications of our work, we also found that marine survival of economically and culturally important sockeye salmon Oncorhynchus nerka from nearby Smith Inlet was strongly correlated with the fledgling mass of the rhinoceros auklets, sandlance in the chicks' diets, and regional chlorophyll in April. The timing of the spring wind transition and phytoplankton bloom appear to be important for other predators in this system. We think that these relationships with wind and chlorophyll derived from satellite data are potentially valuable explanatory tools that will be widely applicable to studies of early marine survival of many marine species.},
annote = {10.3354/meps08950},
author = {Borstad, G and Crawford, W and Hipfner, J M and Thomson, R and Hyatt, K},
doi = {10.3354/meps08950},
journal = {Marine Ecology Progress Series},
pages = {285--302},
title = {{Environmental control of the breeding success of rhinoceros auklets at Triangle Island, British Columbia}},
url = {http://www.int-res.com/abstracts/meps/v424/p285-302/},
volume = {424},
year = {2011}
}
@article{Bosilovich2017,
author = {Bosilovich, Michael G. and Robertson, Franklin R and Takacs, Lawrence and Molod, Andrea and Mocko, D},
doi = {10.1175/JCLI-D-16-0338.1},
journal = {Journal of Climate},
pages = {1177--1196},
title = {{Atmospheric Water Balance and Variability in the MERRA-2 Reanalysis}},
volume = {30},
year = {2017}
}
@article{Bourassa2012,
author = {Bourassa, A. E. and McLinden, C. A. and Bathgate, A. F. and Elash, B. J. and Degenstein, D. A.},
doi = {10.1029/2011JD016976},
issn = {01480227},
journal = {Journal of Geophysical Research: Atmospheres},
language = {en},
month = {feb},
number = {D4},
pages = {D04303},
publisher = {American Geophysical Union},
title = {{Precision estimate for Odin-OSIRIS limb scatter retrievals}},
url = {http://doi.wiley.com/10.1029/2011JD016976},
volume = {117},
year = {2012}
}
@article{Bova2021a,
author = {Bova, Samantha and Rosenthal, Yair and Liu, Zhengyu and Godad, Shital P and Yan, Mi},
doi = {10.1038/s41586-020-03155-x},
issn = {1476-4687},
journal = {Nature},
number = {7843},
pages = {548--553},
title = {{Seasonal origin of the thermal maxima at the Holocene and the last interglacial}},
url = {https://doi.org/10.1038/s41586-020-03155-x},
volume = {589},
year = {2021}
}
@article{Bowen2015,
abstract = {The release of massive amounts of carbon led to abrupt warming 55.5 million years ago. An analysis of soil carbonates shows two distinct carbon injections at the event onset, each releasing over 0.9 petagrams of carbon per year over hundreds to thousands of years.},
author = {Bowen, Gabriel J and Maibauer, Bianca J and Kraus, Mary J and R{\"{o}}hl, Ursula and Westerhold, Thomas and Steimke, Amy and Gingerich, Philip D and Wing, Scott L and Clyde, William C},
doi = {10.1038/ngeo2316},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {1},
pages = {44--47},
title = {{Two massive, rapid releases of carbon during the onset of the Palaeocene–Eocene thermal maximum}},
url = {https://doi.org/10.1038/ngeo2316},
volume = {8},
year = {2015}
}
@misc{Bruhl2018,
author = {Br{\"{u}}hl, Christoph},
doi = {10.1594/WDCC/SSIRC_1},
publisher = {World Data Center for Climate (WDCC) at DKRZ},
title = {{Volcanic SO2 data derived from limb viewing satellites for the lower stratosphere from 1998 to 2012, and from nadir viewing satellites for the troposphere}},
url = {https://doi.org/10.1594/WDCC/SSIRC{\_}1},
year = {2018}
}
@article{BRADLEY201579,
abstract = {Many ice-sheet reconstructions assume monotonic Holocene retreat for the West Antarctic Ice Sheet, but an increasing number of glaciological observations infer that some portions of the ice sheet may be readvancing, following retreat behind the present-day margin. A readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice streams grounded on beds that deepen inland; and (ii) the inability of models of glacial isostatic adjustment to match present-day uplift rates. By combining a suite of ice loading histories that include a readvance with a model of glacial isostatic adjustment we report substantial improvements to predictions of present-day uplift rates, including reconciling one problematic observation of land sinking. We suggest retreat behind present grounding lines occurred when the bed was lower, and isostatic recovery has since led to shallowing, ice sheet re-grounding and readvance. The paradoxical existence of grounding lines in apparently unstable configurations on reverse bed slopes may be resolved by invoking the process of unstable advance, in accordance with our load modelling.},
author = {Bradley, Sarah L and Hindmarsh, Richard C A and Whitehouse, Pippa L and Bentley, Michael J and King, Matt A},
doi = {10.1016/j.epsl.2014.12.039},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Antarctic Ice sheet,Weddell Sea,deglaciation,glacial isostatic adjustment,grounding line stability,uplift rate},
pages = {79--89},
title = {{Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X14008000},
volume = {413},
year = {2015}
}
@article{BRADLEY201654,
author = {Bradley, Sarah L and Milne, Glenn A and Horton, Benjamin P and Zong, Yongqiang},
doi = {https://doi.org/10.1016/j.quascirev.2016.02.002},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Adjustment modelling,Antarctic ice sheet glacial isostatic,Eustatic sea level,Holocene sea level},
pages = {54--68},
title = {{Modelling sea level data from China and Malay-Thailand to estimate Holocene ice-volume equivalent sea level change}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379116300348},
volume = {137},
year = {2016}
}
@incollection{Braesicke2018,
address = {Geneva, Switzerland},
author = {Braesicke, A P. and Neu, J. and Fioletov, V. and Godin-Beekman, S. and Hubert, D. and Petropavlovskikh, I. and Shiotani, M. and {B.-M. Sinnhuber}},
booktitle = {Scientific Assessment of Ozone Depletion: 2018},
doi = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
pages = {3.1--3.74},
publisher = {World Meteorological Organization (WMO)},
series = {Global Ozone Research and Monitoring Project – Report No. 58},
title = {{Update on Global Ozone: Past, Present and Future}},
url = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
year = {2018}
}
@article{doi:10.1029/2008JD010896,
abstract = {An understanding of past variability in the El Ni{\~{n}}o–Southern Oscillation (ENSO), on interannual, interdecadal, and longer time scales, would be useful in assessing recent observed changes to ENSO and in determining the realism of climate model simulations. Using tree ring, coral, and ice core data, we reconstruct a proxy-based ENSO index between A.D. 1525 and 1982. Unlike most previous studies, which have drawn climate proxies from limited geographic regions, our network is Pacific basin–wide, using ENSO sensitive proxies from the western equatorial Pacific, New Zealand, the central Pacific, and subtropical North America. By considering multiple teleconnection regions, this network provides a more robust proxy ENSO signal. The common signal recorded in the multiproxy network has a high correlation with the Southern Oscillation Index (SOI), Ni{\~{n}}o 3.4 sea surface temperature (Ni{\~{n}}o3.4 SST), and a combined ocean-atmosphere ENSO index (CEI). The proportion of instrumental variance explained is 47{\%} for the SOI, 48{\%} for Ni{\~{n}}o3.4 SST, and 52{\%} for the CEI. The proxy ENSO index also displays skill in reproducing warm and cold extremes of the SOI. The proxy ENSO index over the last 450 years shows considerable amplitude and frequency modulation in the 3–10 year band on multidecadal time scales. There is a relative reduction in the amplitude of high-frequency variability during the sixteenth, early seventeenth, and mid–eighteenth centuries. In contrast, high-frequency ENSO variability has increased over the last 200 years. Variability during the first half of the twentieth century is similar to that evident in the nineteenth century.},
author = {Braganza, Karl and Gergis, Jo{\"{e}}lle L and Power, Scott B and Risbey, James S and Fowler, Anthony M},
doi = {10.1029/2008JD010896},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {ENSO,climate,reconstruction},
number = {D5},
title = {{A multiproxy index of the El Ni{\~{n}}o–Southern Oscillation, A.D. 1525–1982}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2008JD010896},
volume = {114},
year = {2009}
}
@article{Braithwaite2000,
abstract = {Until recently, concepts of coral reef growth and accumulation have been predominantly based on a Darwinian model. In this, the upwards and outwards growth of a reef core (a coral framework) takes place over a foreslope consisting of reef talus, with the simultaneous filling of the back-reef lagoon by reef-derived debris. The principal adaptations of this pattern relate to the influence of relative changes in sea level and commonly ignore oceanographic factors such as storm frequency and severity. Boreholes through the outer edge of a fringing reef in the Seychelles, western Indian Ocean, reveal a record of Holocene sediment accumulation first established approximately 8 ka ago. Faunal and floral associations show that growth of this body began in relatively deep water but that this shallowed to {\textless}5 m within 1 ka. Subsequent accumulation was of “keep-up” style but, as the rate of sea-level rise slowed, shoaling became more frequent and aggradation was limited by reducing accommodation space. Constructional facies are characterised either by massive corals, including Leptastrea, Porites and faviids, or by branching corals, typically Acropora of the danai-robusta group. Coral surfaces may be encrusted by red algae, foraminifera and vermetids, and are commonly bored by filamentous algae, clionids and molluscs. However, detrital facies are volumetrically dominant, and the paucity of a constructional framework requires a re-evaluation of models of reef accretion. New models relate the geometry of accretion to the interplay between extreme storm events and fairweather hydrodynamic conditions. These suggest that a contiguous framework forms in areas of moderate fairweather energy without extreme storm events. Severe storms destroy the continuity of reef structures and generate increasing volumes of coarse detritus. Low storm severity, coupled with low fairweather hydrodynamic energy, may promote the accumulation of fine-grained reef-derived sediments that inhibit framework growth. While ecology reflects year-by-year sea conditions, lithology and structure are controlled by exceptional storms, with the effects of changing sea level superimposed.},
author = {Braithwaite, C J R and Montaggioni, L F and Camoin, G F and Dalmasso, H and Dullo, W C and Mangini, A},
doi = {10.1007/s005310000078},
issn = {1437-3262},
journal = {International Journal of Earth Sciences},
number = {2},
pages = {431--445},
title = {{Origins and development of Holocene coral reefs: a revisited model based on reef boreholes in the Seychelles, Indian Ocean}},
url = {https://doi.org/10.1007/s005310000078},
volume = {89},
year = {2000}
}
@article{doi:10.1029/2019GL086843,
abstract = {Abstract Arctic sea-ice extent (SIE) has declined drastically in recent decades, yet its evolution prior to the satellite era is highly uncertain. Studies using SIE observations find little variability prior to the 1970s; however, these reconstructions are based on limited data, especially prior to the 1950s. We use ensemble Kalman filter data assimilation of surface air temperature observations with Last Millennium climate model simulations to create a fully gridded Arctic sea-ice concentration reconstruction from 1850 to 2018 and investigate the evolution of Arctic SIE during this period. We find a decline of ∼1.25×106 km2 during the early 20th-century warming (1910–1940). The 25-year trends during this period are ∼33–38{\%} smaller than the satellite era (1979–2018) but almost twice as large as previous estimates. Additionally, we find that variability of SIE on decadal timescales prior to the satellite era is ∼40{\%} greater than previously estimated.},
annote = {e2019GL086843 10.1029/2019GL086843},
author = {Brennan, M Kathleen and Hakim, Gregory J and Blanchard-Wrigglesworth, Edward},
doi = {10.1029/2019GL086843},
journal = {Geophysical Research Letters},
keywords = {Arctic sea ice,Early 20th-century warming,data assimilation},
number = {7},
pages = {e2019GL086843},
title = {{Arctic Sea-Ice Variability During the Instrumental Era}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086843},
volume = {47},
year = {2020}
}
@article{BREWIN2012117,
abstract = {Using a decade of satellite ocean-colour observations and a model that links chlorophyll-a to the size of the phytoplankton cells, parameterised using pigment data from the Indian Ocean, we examine the implications of the Indian Ocean Dipole (IOD) for phytoplankton size structure. The inferred interannual anomalies in phytoplankton size structure are related to those in sea-surface temperature (SST) and sea-surface height (SSH), derived using satellite radiometry and altimetry, and stratification, derived using the Simple Ocean Data Assimilation (SODA) database. In regions influenced by the Indian Ocean Dipole, we observe a tight correlation between phytoplankton size structure and the physical variables, such that interannual variations in the physical variables accounts for up to 70{\%} of the total variance in phytoplankton size structure. For much of the Indian Ocean, low temperature, low SSH and low stratification (indicative of a turbulent environment) are correlated with larger size classes, consistent with theories on coupling between physical–chemical processes and ecosystem structure. To the extent that phytoplankton function is related to its size structure, changes in physical forcing are likely to influence biogeochemical cycles in the region and the pelagic food web. The limitations of our approach are discussed and we highlight future challenges in satellite ocean-colour monitoring, should climate change lead to any modification in our marine ecosystem.},
annote = {Satellite Oceanography and Climate Change},
author = {Brewin, Robert J W and Hirata, Takafumi and Hardman-Mountford, Nick J and Lavender, Samantha J and Sathyendranath, Shubha and Barlow, Ray},
doi = {10.1016/j.dsr2.2012.04.009},
issn = {0967-0645},
journal = {Deep-Sea Research Part II: Topical Studies in Oceanography},
keywords = {Chlorophyll-a,Indian Ocean,Interannual,Ocean colour,Phytoplankton,Remote sensing,SeaWiFS,Size},
pages = {117--127},
title = {{The influence of the Indian Ocean Dipole on interannual variations in phytoplankton size structure as revealed by Earth Observation}},
url = {http://www.sciencedirect.com/science/article/pii/S0967064512000574},
volume = {77-80},
year = {2012}
}
@article{brierley_interannual_2015,
abstract = {Abstract. Following reconstructions suggesting weakened temperature gradients along the Equator in the early Pliocene, there has been much speculation about Pliocene climate variability. A major advance for our knowledge about the later Pliocene has been the coordination of modelling efforts through the Pliocene Model Intercomparison Project (PlioMIP). Here the changes in interannual modes of sea surface temperature variability will be presented across PlioMIP. Previously, model ensembles have shown little consensus in the response of the El Ni{\~{n}}o–Southern Oscillation (ENSO) to imposed forcings – either for the past or future. The PlioMIP ensemble, however, shows surprising agreement, with eight models simulating reduced variability and only one model indicating no change. The Pliocene's robustly weaker ENSO also saw a shift to lower frequencies. Model ensembles focussed on a wide variety of forcing scenarios have not yet shown this level of coherency. Nonetheless, the PlioMIP ensemble does not show a robust response of either ENSO flavour or sea surface temperature variability in the tropical Indian and North Pacific oceans. Existing suggestions linking ENSO properties to to changes in zonal temperature gradient, seasonal cycle and the elevation of the Andes Mountains are investigated, yet prove insufficient to explain the consistent response. The reason for this surprisingly coherent signal warrants further investigation.},
author = {Brierley, C M},
doi = {10.5194/cp-11-605-2015},
issn = {1814-9332},
journal = {Climate of the Past},
month = {mar},
number = {3},
pages = {605--618},
title = {{Interannual climate variability seen in the Pliocene Model Intercomparison Project}},
url = {https://www.clim-past.net/11/605/2015/},
volume = {11},
year = {2015}
}
@article{cp-16-1847-2020,
author = {Brierley, C M and Zhao, A and Harrison, S P and Braconnot, P and Williams, C J R and Thornalley, D J R and Shi, X and Peterschmitt, J.-Y. and Ohgaito, R and Kaufman, D S and Kageyama, M and Hargreaves, J C and Erb, M P and Emile-Geay, J and D'Agostino, R and Chandan, D and Carr{\'{e}}, M and Bartlein, P J and Zheng, W and Zhang, Z and Zhang, Q and Yang, H and Volodin, E M and Tomas, R A and Routson, C and Peltier, W R and Otto-Bliesner, B and Morozova, P A and McKay, N P and Lohmann, G and Legrande, A N and Guo, C and Cao, J and Brady, E and Annan, J D and Abe-Ouchi, A},
doi = {10.5194/cp-16-1847-2020},
journal = {Climate of the Past},
number = {5},
pages = {1847--1872},
title = {{Large-scale features and evaluation of the PMIP4-CMIP6 midHolocene simulations}},
url = {https://cp.copernicus.org/articles/16/1847/2020/},
volume = {16},
year = {2020}
}
@article{Brigham-Grette2013,
author = {Brigham-Grette, Julie and Melles, Martin and Minyuk, Pavel and Andreev, Andrei and Tarasov, Pavel and DeConto, Robert and Koenig, Sebastian and Nowaczyk, Norbert and Wennrich, Volker and Ros{\'{e}}n, Peter and Haltia, Eeva and Cook, Tim and Gebhardt, Catalina and Meyer-Jacob, Carsten and Snyder, Jeff and Herzschuh, Ulrike},
doi = {10.1126/science.1233137},
issn = {0036-8075},
journal = {Science},
month = {jun},
number = {6139},
pages = {1421--1427},
title = {{Pliocene Warmth, Polar Amplification, and Stepped Pleistocene Cooling Recorded in NE Arctic Russia}},
url = {https://www.science.org/doi/10.1126/science.1233137},
volume = {340},
year = {2013}
}
@article{Briner2016a,
abstract = {This synthesis paper summarizes published proxy climate evidence showing the spatial and temporal pattern of climate change through the Holocene in Arctic Canada and Greenland. Our synthesis includes 47 records from a recently published database of highly resolved Holocene paleoclimate time series from the Arctic (Sundqvist et al., 2014). We analyze the temperature histories represented by the database and compare them with paleoclimate and environmental information from 54 additional published records, mostly from datasets that did not fit the selection criteria for the Arctic Holocene database. Combined, we review evidence from a variety of proxy archives including glaciers (ice cores and glacial geomorphology), lake sediments, peat sequences, and coastal and deep-marine sediments. The temperature-sensitive records indicate more consistent and earlier Holocene warmth in the north and east, and a more diffuse and later Holocene thermal maximum in the south and west. Principal components analysis reveals two dominant Holocene trends, one with early Holocene warmth followed by cooling in the middle Holocene, the other with a broader period of warmth in the middle Holocene followed by cooling in the late Holocene. The temperature decrease from the warmest to the coolest portions of the Holocene is 3.0 ± 1.0 °C on average (n = 11 sites). The Greenland Ice Sheet retracted to its minimum extent between 5 and 3 ka, consistent with many sites from around Greenland depicting a switch from warm to cool conditions around that time. The spatial pattern of temperature change through the Holocene was likely driven by the decrease in northern latitude summer insolation through the Holocene, the varied influence of waning ice sheets in the early Holocene, and the variable influx of Atlantic Water into the study region.},
author = {Briner, Jason P. and McKay, Nicholas P. and Axford, Yarrow and Bennike, Ole and Bradley, Raymond S. and de Vernal, Anne and Fisher, David and Francus, Pierre and Fr{\'{e}}chette, Bianca and Gajewski, Konrad and Jennings, Anne and Kaufman, Darrell S. and Miller, Gifford and Rouston, Cody and Wagner, Bernd},
doi = {10.1016/j.quascirev.2016.02.010},
issn = {02773791},
journal = {Quaternary Science Reviews},
pages = {340--364},
title = {{Holocene climate change in Arctic Canada and Greenland}},
volume = {147},
year = {2016}
}
@article{Briner2020,
author = {Briner, Jason P. and Cuzzone, Joshua K. and Badgeley, Jessica A. and Young, Nicol{\'{a}}s E. and Steig, Eric J. and Morlighem, Mathieu and Schlegel, Nicole-Jeanne and Hakim, Gregory J. and Schaefer, Joerg M. and Johnson, Jesse V. and Lesnek, Alia J. and Thomas, Elizabeth K. and Allan, Estelle and Bennike, Ole and Cluett, Allison A. and Csatho, Beata and de Vernal, Anne and Downs, Jacob and Larour, Eric and Nowicki, Sophie},
doi = {10.1038/s41586-020-2742-6},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7827},
pages = {70--74},
title = {{Rate of mass loss from the Greenland Ice Sheet will exceed Holocene values this century}},
url = {http://www.nature.com/articles/s41586-020-2742-6},
volume = {586},
year = {2020}
}
@article{Bristow2017a,
abstract = {A third or more of the fixed nitrogen lost from the oceans as N2 is removed by anaerobic microbial processes in open ocean oxygen minimum zones. These zones have expanded over the past decades, and further anthropogenically induced expansion could accelerate nitrogen loss. However, in the Bay of Bengal there has been no indication of nitrogen loss, although oxygen levels are below the detection level of conventional methods (1 to 2 $\mu$M). Here we quantify the abundance of microbial genes associated with N2 production, measure nitrogen transformations in incubations of sampled seawater with isotopically labelled nitrogen compounds and analyse geochemical signatures of these processes in the water column. We find that the Bay of Bengal supports denitrifier and anammox microbial populations, mediating low, but significant N loss. Yet, unlike other oxygen minimum zones, our measurements using a highly sensitive oxygen sensor demonstrate that the Bay of Bengal has persistent concentrations of oxygen in the 10 to 200 nM range. We propose that this oxygen supports nitrite oxidation, thereby restricting the nitrite available for anammox or denitrification. If these traces of oxygen were removed, nitrogen loss in the Bay of Bengal oxygen minimum zone waters could accelerate to global significance.},
author = {Bristow, L A and Callbeck, C M and Larsen, M and Altabet, M A and Dekaezemacker, J and Forth, M and Gauns, M and Glud, R N and Kuypers, M M M and Lavik, G and Milucka, J and Naqvi, S W A and Pratihary, A and Revsbech, N. P. and Thamdrup, B and Treusch, A H and Canfield, D E},
doi = {10.1038/ngeo2847},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {1},
pages = {24--29},
title = {{N2 production rates limited by nitrite availability in the Bay of Bengal oxygen minimum zone}},
url = {https://doi.org/10.1038/ngeo2847},
volume = {10},
year = {2017}
}
@article{Broecker1989,
author = {Broecker, W S},
doi = {10.1029/PA004i002p00207},
issn = {08838305},
journal = {Paleoceanography},
month = {apr},
number = {2},
pages = {207--212},
title = {{The salinity contrast between the Atlantic and Pacific oceans during glacial time}},
volume = {4},
year = {1989}
}
@article{Bronnimann2015,
abstract = {Changes in the position and width of the tropical belt are societally and ecologically relevant, because they are associated with shifts of the subtropical dry zones. The tropical belt has widened since about 1980, but little is known about its earlier variability. Here we analyse historical surface and upper-level observations, three global reanalysis data sets, and a reconstruction of total column ozone, to show that the northern tropical edge retracted from 1945 to 1980, while the northern Hadley cell shifted southwards in both summer and winter. We present chemistry-climate model simulations that reproduce the retraction and southward shift. We find that retraction of the tropical belt was largely due to cooling sea-surface temperatures north of the Equator and warming south of the Equator, most prominently over the Atlantic. Substantial hydroclimatic anomalies such as European droughts of the 1940s and 1950s and the Sahel drought of the 1970s were associated with this shift of the Hadley cell. Our results suggest that multidecadal changes in the position of the northern Hadley cell are an important component of climate variability.},
author = {Bronnimann, Stefan and Fischer, Andreas M. and Rozanov, Eugene and Poli, Paul and Compo, Gilbert P. and Sardeshmukh, Prashant D.},
doi = {10.1038/ngeo2568},
issn = {17520908},
journal = {Nature Geoscience},
number = {12},
pages = {969--974},
title = {{Southward shift of the northern tropical belt from 1945 to 1980}},
volume = {8},
year = {2015}
}
@article{Bronselaer2020a,
abstract = {The Southern Ocean south of 30° S represents only one-third of the total ocean area, yet absorbs half of the total ocean anthropogenic carbon and over two-thirds of ocean anthropogenic heat. In the past, the Southern Ocean has also been one of the most sparsely measured regions of the global ocean. Here we use pre-2005 ocean shipboard measurements alongside novel observations from autonomous floats with biogeochemical sensors to calculate changes in Southern Ocean temperature, salinity, pH and concentrations of nitrate, dissolved inorganic carbon and oxygen over two decades. We find local warming of over 3 °C, salinification of over 0.2 psu near the Antarctic coast, and isopycnals are found to deepen between 65° and 40° S. We find deoxygenation along the Antarctic coast, but reduced deoxygenation and nitrate concentrations where isopycnals deepen farther north. The forced response of the Earth system model ESM2M does not reproduce the observed patterns. Accounting for meltwater and poleward-intensifying winds in ESM2M improves reproduction of the observed large-scale changes, demonstrating the importance of recent changes in wind and meltwater. Future Southern Ocean biogeochemical changes are likely to be influenced by the relative strength of meltwater input and poleward-intensifying winds. The combined effect could lead to increased Southern Ocean deoxygenation and nutrient accumulation, starving the global ocean of nutrients sooner than otherwise expected.},
author = {Bronselaer, Ben and Russell, Joellen L and Winton, Michael and Williams, Nancy L and Key, Robert M and Dunne, John P and Feely, Richard A and Johnson, Kenneth S and Sarmiento, Jorge L},
doi = {10.1038/s41561-019-0502-8},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {1},
pages = {35--42},
title = {{Importance of wind and meltwater for observed chemical and physical changes in the Southern Ocean}},
url = {https://doi.org/10.1038/s41561-019-0502-8},
volume = {13},
year = {2020}
}
@article{Brook2018,
abstract = {A growing network of ice cores reveals the past 800,000 years of Antarctic climate and atmospheric composition. The data show tight links among greenhouse gases, aerosols and global climate on many timescales, demonstrate connections between Antarctica and distant locations, and reveal the extraordinary differences between the composition of our present atmosphere and its natural range of variability as revealed in the ice core record. Further coring in extremely challenging locations is now being planned, with the goal of finding older ice and resolving the mechanisms underlying the shift of glacial cycles from 40,000-year to 100,000-year cycles about a million years ago, one of the great mysteries of climate science.},
author = {Brook, Edward J. and Buizert, Christo},
doi = {10.1038/s41586-018-0172-5},
isbn = {1476-4687 (Electronic) 0028-0836 (Linking)},
issn = {14764687},
journal = {Nature},
pages = {200--208},
pmid = {29899479},
title = {{Antarctic and global climate history viewed from ice cores}},
volume = {558},
year = {2018}
}
@incollection{BrownR.ShulerD.V.BulyginaO.DerksenC.LuojusK.Mudryk2017,
address = {Oslo, Norway},
author = {Brown, Ross and Schuler, Dagrun Vikhamar and Bulygina, Olga and Derksen, Chris and Luojus, Kari and Mudryk, Lawrence and Wang, Libo and Yang, Daqing},
booktitle = {Snow, Water, Ice and Permafrost in the Arctic (SWIPA) 2017},
doi = {https://www.amap.no/documents/doc/snow-water-ice-and-permafrost-in-the-arctic-swipa-2017/1610},
isbn = {978-82-7971-101-8},
pages = {25--64},
publisher = {Arctic Monitoring and Assessment Programme (AMAP)},
title = {{Arctic terrestrial snow cover}},
url = {https://www.amap.no/documents/doc/snow-water-ice-and-permafrost-in-the-arctic-swipa-2017/1610},
year = {2017}
}
@misc{Brown2002a,
address = {Boulder, CO, USA},
author = {Brown, R. D.},
doi = {10.7265/N5V985Z6},
publisher = {National Snow and Ice Center},
title = {{Reconstructed North American, Eurasian, and Northern Hemisphere Snow Cover Extent, 1915-1997, Version 1}},
url = {https://nsidc.org/data/G02131/versions/1},
year = {2002}
}
@article{Brucker2013,
abstract = {[1] Snow depth on sea ice (SD) is a key geophysical variable, knowledge of which is critical for calculating the energy and mass balance budgets. Moreover, accurate knowledge of the SD distribution is important to retrieve sea-ice thicknesses from altimetry data. So far, only space-based microwave radiometers (e.g., Advanced Microwave Scanning Radiometer for Earth Observing System ; AMSR-E) provide operational SD on seasonal sea-ice retrievals. A thorough assessment of these retrievals is needed on a large scale and on a variety of sea-ice types. Our study presents such an assessment on Arctic sea ice using NASA's airborne Operation IceBridge (OIB) SDs, retrieved from radar measurements. Between 2009 and 2011, {\$}610 12.5 km satellite grid cells were covered by seasonal sea ice where both satellite SD retrievals and OIB data were available. Using all the available data, the difference between the AMSR-E product and the averaged OIB snow-radar-derived SD is 0.0060.07 m. Satellite-derived SD was accurate in the Beaufort Sea and the Canadian Archipelago but underestimated ({\$}0.07 m) in the Nares Strait. The RMSE between the two products ranges between 0.03 and 0.15 m. The RMSE is less than 0.06 m over a shallow snow cover ({\textless}0.20 m), in areas where satellite-retrieved ice concentrations are higher than 90{\%}, surface smooth, and ice thicker than {\$}0.5 m. Locally the AMSR-E algorithm can significantly underestimate SD. Several regions where the retrievals were less accurate (error {\textgreater}0.10 m) have been identified and related to the presence of either low ice concentration or significant fraction of multiyear ice within the grid cell that has not been flagged. Citation: Brucker, L., and T. Markus (2013), Arctic-scale assessment of satellite passive microwave-derived snow depth on sea ice using Operation IceBridge airborne data,},
author = {Brucker, Ludovic and Markus, Thorsten},
doi = {10.1002/jgrc.20228},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Operation IceBridge Airborne data,SD on sea ice,evaluation of satellite product},
title = {{Arctic-scale assessment of satellite passive microwave-derived snow depth on sea ice using Operation IceBridge airborne data}},
year = {2013}
}
@article{Buckley2019a,
author = {Buckley, Brendan M and Ummenhofer, Caroline C. and D'Arrigo, R. D. and Hansen, K. G. and Truong, L. H. and Le, C. L. and Stahle, D. K.},
doi = {10.1007/s00382-019-04694-4},
isbn = {0123456789},
journal = {Climate Dynamics},
keywords = {climate,dendroclimatology,hydroclimate,interdecadal pacific oscillation,reconstruction,tropical tree rings,vietnamese cypress},
pages = {3181--3196},
title = {{Interdecadal Pacific Oscillation reconstructed from trans-Pacific tree rings: 1350–2004 CE}},
volume = {53},
year = {2019}
}
@article{doi:10.1002/2017GL075601,
abstract = {Abstract The sensitivity of the Greenland ice sheet to climate forcing is of key importance in assessing its contribution to past and future sea level rise. Surface mass loss occurs during summer, and accounting for temperature seasonality is critical in simulating ice sheet evolution and in interpreting glacial landforms and chronologies. Ice core records constrain the timing and magnitude of climate change but are largely limited to annual mean estimates from the ice sheet interior. Here we merge ice core reconstructions with transient climate model simulations to generate Greenland-wide and seasonally resolved surface air temperature fields during the last deglaciation. Greenland summer temperatures peak in the early Holocene, consistent with records of ice core melt layers. We perform deglacial Greenland ice sheet model simulations to demonstrate that accounting for realistic temperature seasonality decreases simulated glacial ice volume, expedites the deglacial margin retreat, mutes the impact of abrupt climate warming, and gives rise to a clear Holocene ice volume minimum.},
author = {Buizert, C and Keisling, B A and Box, J E and He, F and Carlson, A E and Sinclair, G and DeConto, R M},
doi = {10.1002/2017GL075601},
journal = {Geophysical Research Letters},
keywords = {Greenland ice sheet,Holocene thermal maximum,ice core,last deglaciation,mass balance},
number = {4},
pages = {1905--1914},
title = {{Greenland-Wide Seasonal Temperatures During the Last Deglaciation}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL075601},
volume = {45},
year = {2018}
}
@article{WAISDivideProjectMembers.2015,
abstract = {A new ice core from West Antarctica shows that, during the last ice age, abrupt Northern Hemisphere climate variations were followed two centuries later by a response in Antarctica, suggesting an oceanic propagation of the climate signal to the Southern Hemisphere high latitudes.},
author = {Buizert, Christo and Adrian, Betty and Ahn, Jinho and Albert, Mary and Alley, Richard B and Baggenstos, Daniel and Bauska, Thomas K and Bay, Ryan C and Bencivengo, Brian B and Bentley, Charles R and Brook, Edward J and Chellman, Nathan J and Clow, Gary D and Cole-Dai, Jihong and Conway, Howard and Cravens, Eric and Cuffey, Kurt M and Dunbar, Nelia W and Edwards, Jon S and Fegyveresi, John M and Ferris, Dave G and Fitzpatrick, Joan J and Fudge, T J and Gibson, Chris J and Gkinis, Vasileios and Goetz, Joshua J and Gregory, Stephanie and Hargreaves, Geoffrey M and Iverson, Nels and Johnson, Jay A and Jones, Tyler R and Kalk, Michael L and Kippenhan, Matthew J and Koffman, Bess G and Kreutz, Karl and Kuhl, Tanner W and Lebar, Donald A and Lee, James E and Marcott, Shaun A and Markle, Bradley R and Maselli, Olivia J and McConnell, Joseph R and McGwire, Kenneth C and Mitchell, Logan E and Mortensen, Nicolai B and Neff, Peter D and Nishiizumi, Kunihiko and Nunn, Richard M and Orsi, Anais J and Pasteris, Daniel R and Pedro, Joel B and Pettit, Erin C and {Buford Price}, P and Priscu, John C and Rhodes, Rachael H and Rosen, Julia L and Schauer, Andrew J and Schoenemann, Spruce W and Sendelbach, Paul J and Severinghaus, Jeffrey P and Shturmakov, Alexander J and Sigl, Michael and Slawny, Kristina R and Souney, Joseph M and Sowers, Todd A and Spencer, Matthew K and Steig, Eric J and Taylor, Kendrick C and Twickler, Mark S and Vaughn, Bruce H and Voigt, Donald E and Waddington, Edwin D and Welten, Kees C and Wendricks, Anthony W and White, James W C and Winstrup, Mai and Wong, Gifford J and Woodruff, Thomas E and {WAIS Divide Project Members}},
doi = {10.1038/nature14401},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7549},
pages = {661--665},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Precise interpolar phasing of abrupt climate change during the last ice age}},
url = {https://doi.org/10.1038/nature14401 http://www.nature.com/articles/nature14401},
volume = {520},
year = {2015}
}
@article{Burke2019,
abstract = {Understanding the mechanisms of climate that produce novel ecosystems is of joint interest to conservation biologists and palaeoecologists. Here, we define and differentiate transient from accumulated novelty and evaluate four climatic mechanisms proposed to cause species to reshuffle into novel assemblages: high climatic novelty, high spatial rates of change (displacement), high variance among displacement rates for individual climate variables, and divergence among displacement vector bearings. We use climate simulations to quantify climate novelty, displacement and divergence across Europe and eastern North America from the last glacial maximum to the present, and fossil pollen records to quantify vegetation novelty. Transient climate novelty is consistently the strongest predictor of transient vegetation novelty, while displacement rates (mean and variance) are equally important in Europe. However, transient vegetation novelty is lower in Europe and its relationship to climatic predictors is the opposite of expectation. For both continents, accumulated novelty is greater than transient novelty, and climate novelty is the strongest predictor of accumulated ecological novelty. These results suggest that controls on novel ecosystems vary with timescale and among continents, and that the twenty-first century emergence of novelty will be driven by both rapid rates of climate change and the emergence of novel climate states. This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'},
author = {Burke, Kevin D. and Williams, John W. and Brewer, Simon and Finsinger, Walter and Giesecke, Thomas and Lorenz, David J. and Ordonez, Alejandro},
doi = {10.1098/rstb.2019.0218},
issn = {14712970},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
keywords = {Climate analogue,Climate change,Novel climate,Novel ecosystem,Pollen},
pages = {20190218},
title = {{Differing climatic mechanisms control transient and accumulated vegetation novelty in Europe and eastern North America}},
volume = {374},
year = {2019}
}
@article{BURKE2019113,
abstract = {The record of volcanic forcing of climate over the past 2500 years is based primarily on sulfate concentrations in ice cores. Of particular interest are large volcanic eruptions with plumes that reached high altitudes in the stratosphere, as these afford sulfate aerosols the longest residence time in the atmosphere, and thus have the greatest impact on radiative forcing. Sulfur isotopes measured in ice cores can be used to identify these large eruptions because stratospheric sulfur is exposed to UV radiation, which imparts a time-evolving mass independent fractionation (MIF) that is preserved in the ice. However, sample size requirements of traditional measurement techniques mean that the MIF signal may be obscured, leading to an inconclusive result. Here we present a new method of measuring sulfur isotopes in ice cores by multi-collector inductively coupled plasma mass spectrometry, which reduces sample size requirements by three orders of magnitude. Our method allows us to measure samples containing as little as 10 nmol of sulfur, with a precision of 0.11‰ for $\delta$34S and 0.10‰ for $\Delta$33S, enabling a high-temporal resolution over ice core sulfate peaks. We tested this method on known tropical (Tambora 1815 and Samalas 1257) and extra-tropical (Katmai/Novarupta 1912) stratospheric eruptions from the Tunu2013 ice core in Greenland and the B40 ice core from Antarctica. These high-resolution sulfur isotope records suggest a distinct difference between the signatures of tropical versus extra-tropical eruptions. Furthermore, isotope mass balance on sulfate from extra-tropical eruptions provides a means to estimate the fraction of sulfate deposited that was derived from the stratosphere. This technique applied to unidentified eruptions in ice cores may thus improve the record of explosive volcanism and its forcing of climate.},
author = {Burke, Andrea and Moore, Kathryn A and Sigl, Michael and Nita, Dan C and McConnell, Joseph R and Adkins, Jess F},
doi = {https://doi.org/10.1016/j.epsl.2019.06.006},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Katmai,ice cores,mass-independent fractionation,stratosphere,sulfur,volcanoes},
pages = {113--119},
title = {{Stratospheric eruptions from tropical and extra-tropical volcanoes constrained using high-resolution sulfur isotopes in ice cores}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X19303395},
volume = {521},
year = {2019}
}
@article{Burls2017c,
author = {Burls, Natalie J and Fedorov, Alexey V},
doi = {10.1073/pnas.1703421114},
journal = {Proceedings of the National Academy of Sciences},
number = {49},
pages = {12888--12893},
title = {{Wetter subtropics in a warmer world: Contrasting past and future hydrological cycles}},
volume = {114},
year = {2017}
}
@article{Burmeister2016a,
abstract = {Abstract An extreme cold sea surface temperature event occurred in the Atlantic cold tongue region in boreal summer 2009. It was preceded by a strong negative Atlantic meridional mode event associated with north-westerly wind anomalies along the equator from March to May. Although classical equatorial wave dynamics suggest that westerly wind anomalies should be followed by a warming in the eastern equatorial Atlantic, an abrupt cooling took place. In the literature two mechanisms?meridional advection of subsurface temperature anomalies and planetary wave reflection?are discussed as potential causes of such an event. Here, for the first time we use in situ measurements in addition to satellite and reanalysis products to investigate the contribution of both mechanisms to the 2009 cold event. Our results suggest that meridional advection is less important in cold events than in corresponding warm events, and, in particular, did not cause the 2009 cold event. Argo float data confirm previous findings that planetary wave reflection contributed to the onset of the 2009 cold event. Additionally, our analysis suggests that higher baroclinic modes were involved.},
annote = {doi: 10.1002/2016JC011719},
author = {Burmeister, Kristin and Brandt, Peter and L{\"{u}}bbecke, Joke F},
doi = {10.1002/2016JC011719},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Atlantic cold tongue,Atlantic meridional mode,Atlantic zonal mode,meridional advection,planetary wave reflection},
month = {jul},
number = {7},
pages = {4777--4789},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Revisiting the cause of the eastern equatorial Atlantic cold event in 2009}},
url = {https://doi.org/10.1002/2016JC011719},
volume = {121},
year = {2016}
}
@article{Burn2014a,
author = {Burn, Michael J and Palmer, Suzanne E},
doi = {10.1002/jqs.2660},
journal = {Journal of Quaternary Science},
number = {8},
pages = {827--836},
title = {{Solar forcing of Caribbean drought events during the last millennium}},
volume = {29},
year = {2014}
}
@article{Burrows2019,
abstract = {As ocean temperatures rise, species distributions are tracking towards historically cooler regions in line with their thermal affinity1,2. However, different responses of species to warming and changed species interactions make predicting biodiversity redistribution and relative abundance a challenge3,4. Here, we use three decades of fish and plankton survey data to assess how warming changes the relative dominance of warm-affinity and cold-affinity species5,6. Regions with stable temperatures (for example, the Northeast Pacific and Gulf of Mexico) show little change in dominance structure, while areas with warming (for example, the North Atlantic) see strong shifts towards warm-water species dominance. Importantly, communities whose species pools had diverse thermal affinities and a narrower range of thermal tolerance showed greater sensitivity, as anticipated from simulations. The composition of fish communities changed less than expected in regions with strong temperature depth gradients. There, species track temperatures by moving deeper2,7, rather than horizontally, analogous to elevation shifts in land plants8. Temperature thus emerges as a fundamental driver for change in marine systems, with predictable restructuring of communities in the most rapidly warming areas using metrics based on species thermal affinities. The ready and predictable dominance shifts suggest a strong prognosis of resilience to climate change for these communities.},
author = {Burrows, Michael T and Bates, Amanda E and Costello, Mark J and Edwards, Martin and Edgar, Graham J and Fox, Clive J and Halpern, Benjamin S and Hiddink, Jan G and Pinsky, Malin L and Batt, Ryan D and {Garc{\'{i}}a Molinos}, Jorge and Payne, Benjamin L and Schoeman, David S and Stuart-Smith, Rick D and Poloczanska, Elvira S},
doi = {10.1038/s41558-019-0631-5},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {12},
pages = {959--963},
title = {{Ocean community warming responses explained by thermal affinities and temperature gradients}},
url = {https://doi.org/10.1038/s41558-019-0631-5},
volume = {9},
year = {2019}
}
@article{Businger1971,
abstract = {Wind and temperature profiles for a wide range of stability conditions have been analyzed in the context of Monin-Obukhov similarity theory. Direct measurements of heat and momentum fluxes enabled determination of the Obukhov length L, a key independent variable in the steady-state, horizontally homogeneous, atmospheric surface layer. The free constants in several interpolation formulas can be adjusted to give excellent fits to the wind and temperature gradient data. The behavior of the gradients under neutral conditions is unusual, however, and indicates that von K{\'{a}}rm{\'{a}}n's constant is ∼0.35, rather than 0.40 as usually assumed, and that the ratio of eddy diffusivities for heat and momentum at neutrality is ∼1.35, compared to the often-suggested value of 1.0. The gradient Richardson number, computed from the profiles, and the Obukhov stability parameter z/L, computed from the measured fluxes, are found to be related approximately linearly under unstable conditions. For stable conditions the Richard on number approaches a limit of ∼0.21 as stability increases. A comparison between profile-derived and measured fluxes shows good agreement over the entire stability range of the observations.},
author = {Businger, J A and Wyngaard, J C and Izumi, Y and Bradley, E F},
doi = {10.1175/1520-0469(1971)028<0181:FPRITA>2.0.CO;2},
issn = {0022-4928},
journal = {Journal of the Atmospheric Sciences},
month = {mar},
number = {2},
pages = {181--189},
title = {{Flux-Profile Relationships in the Atmospheric Surface Layer}},
url = {10.1175/1520-0469(1971)028{\%}3C0181:FPRITA{\%}3E2.0.CO http://0.0.0.2},
volume = {28},
year = {1971}
}
@article{Butler2018a,
abstract = {AbstractVarious criteria exist for determining the occurrence of a major sudden stratospheric warming (SSW), but the most common is based on the reversal of the climatological westerly zonal-mean zonal winds at 60° latitude and 10 hPa in the winter stratosphere. This definition was established at a time when observations of the stratosphere were sparse. Given greater access to data in the satellite era, a systematic analysis of the optimal parameters of latitude, altitude, and threshold for the wind reversal is now possible. Here, the frequency of SSWs, the strength of the wave forcing associated with the events, changes in stratospheric temperature and zonal winds, and surface impacts are examined as a function of the stratospheric wind reversal parameters. The results provide a methodical assessment of how to best define a standard metric for major SSWs. While the continuum nature of stratospheric variability makes it difficult to identify a decisively optimal threshold, there is a relatively narrow env...},
author = {Butler, Amy H. and Gerber, Edwin P.},
doi = {10.1175/JCLI-D-17-0648.1},
issn = {08948755},
journal = {Journal of Climate},
number = {6},
pages = {2337--2344},
title = {{Optimizing the definition of a sudden stratospheric warming}},
volume = {31},
year = {2018}
}
@article{Butler2015,
abstract = {AbstractSudden stratospheric warmings (SSWs) are large, rapid temperature rises in the winter polar stratosphere, occurring predominantly in the Northern Hemisphere. Major SSWs are also associated with a reversal of the climatological westerly zonal-mean zonal winds. Circulation anomalies associated with SSWs can descend into the troposphere with substantial surface weather impacts, such as wintertime extreme cold air outbreaks. After their discovery in 1952, SSWs were classified by the World Meteorological Organization. An examination of literature suggests that a single, original reference for an exact definition of SSWs is elusive, but in many references a definition involves the reversal of the meridional temperature gradient and, for major warmings, the reversal of the zonal circulation poleward of 60° latitude at 10 hPa.Though versions of this definition are still commonly used to detect SSWs, the details of the definition and its implementation remain ambiguous. In addition, other SSW definitions have been used in the last few decades, resulting in inconsistent classification of SSW events. We seek to answer the questions: How has the SSW definition changed, and how sensitive is the detection of SSWs to the definition used? For what kind of analysis is a ?standard? definition useful? We argue that a standard SSW definition is necessary for maintaining a consistent and robust metric to assess polar stratospheric wintertime variability in climate models and other statistical applications. To provide a basis for, and to encourage participation in, a communitywide discussion currently underway, we explore what criteria are important for a standard definition and propose possible ways to update the definition.},
author = {Butler, Amy H. and Seidel, Dian J. and Hardiman, Steven C. and Butchart, Neal and Birner, Thomas and Match, Aaron},
doi = {10.1175/BAMS-D-13-00173.1},
isbn = {6038621628},
issn = {00030007},
journal = {Bulletin of the American Meteorological Society},
number = {11},
pages = {1913--1928},
pmid = {17798761},
title = {{Defining sudden stratospheric warmings}},
volume = {96},
year = {2015}
}
@misc{Butler2017,
author = {Butler, Amy and Sjoberg, Jeremiah and Seidel, Dian and {NOAA ESRL Chemical Science Division}},
doi = {10.7289/V5NS0RWP},
pages = {63--76},
publisher = {NOAA National Centers for Environmental Information (NCEI)},
title = {{Sudden Stratospheric Warming Compendium, Version 1.0}},
url = {https://doi.org/10.7289/V5NS0RWP},
year = {2017}
}
@article{Byrne2018,
abstract = {In recent decades, the land surface has warmed substantially more than the ocean surface, and relative humidity has fallen over land. Amplified warming and declining relative humidity over land are also dominant features of future climate projections, with implications for climate-change impacts. An emerging body of research has shown how constraints from atmospheric dynamics and moisture budgets are important for projected future land–ocean contrasts, but these ideas have not been used to investigate temperature and humidity records over recent decades. Here we show how both the temperature and humidity changes observed over land between 1979 and 2016 are linked to warming over neighboring oceans. A simple analytical theory, based on atmospheric dynamics and moisture transport, predicts equal changes in moist static energy over land and ocean and equal fractional changes in specific humidity over land and ocean. The theory is shown to be consistent with the observed trends in land temperature and humidity given the warming over ocean. Amplified land warming is needed for the increase in moist static energy over drier land to match that over ocean, and land relative humidity decreases because land specific humidity is linked via moisture transport to the weaker warming over ocean. However, there is considerable variability about the best-fit trend in land relative humidity that requires further investigation and which may be related to factors such as changes in atmospheric circulations and land-surface properties.},
author = {Byrne, Michael P and O'Gorman, Paul A.},
doi = {10.1073/pnas.1722312115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {may},
number = {19},
pages = {4863--4868},
title = {{Trends in continental temperature and humidity directly linked to ocean warming}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1722312115},
volume = {115},
year = {2018}
}
@article{Byrne2018b,
author = {Byrne, Michael P and Pendergrass, Angeline G and Rapp, Anita D and Wodzicki, Kyle R},
doi = {10.1007/s40641-018-0110-5},
journal = {Current Climate Change Reports},
keywords = {Atmospheric dynamics,Climate change,Intertropical convergence zone,Models,Observations,Theory,Tropical precipitation,atmospheric dynamics,climate change,intertropical convergence zone,models,observations,theory,tropical precipitation},
number = {4},
pages = {355--370},
publisher = {Current Climate Change Reports},
title = {{Response of the Intertropical Convergence Zone to Climate Change: Location, Width, and Strength}},
volume = {4},
year = {2018}
}
@article{Caballero2013,
abstract = {Projections of future climate depend critically on refined estimates of climate sensitivity. Recent progress in temperature proxies dramatically increases the magnitude of warming reconstructed from early Paleogene greenhouse climates and demands a close examination of the forcing and feedback mechanisms that maintained this warmth and the broad dynamic range that these paleoclimate records attest to. Here, we show that several complementary resolutions to these questions are possible in the context of model simulations using modern and early Paleogene configurations. We find that (i) changes in boundary conditions representative of slow "Earth system" feedbacks play an important role in maintaining elevated early Paleogene temperatures, (ii) radiative forcing by carbon dioxide deviates significantly from pure logarithmic behavior at concentrations relevant for simulation of the early Paleogene, and (iii) fast or "Charney" climate sensitivity in this model increases sharply as the climate warms. Thus, increased forcing and increased slow and fast sensitivity can all play a substantial role in maintaining early Paleogene warmth. This poses an equifinality problem: The same climate can be maintained by a different mix of these ingredients; however, at present, the mix cannot be constrained directly from climate proxy data. The implications of strongly state-dependent fast sensitivity reach far beyond the early Paleogene. The study of past warm climates may not narrow uncertainty in future climate projections in coming centuries because fast climate sensitivity may itself be state-dependent, but proxies and models are both consistent with significant increases in fast sensitivity with increasing temperature.},
author = {Caballero, Rodrigo and Huber, Matthew},
doi = {10.1073/pnas.1303365110},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {hyperthermal,superrotation},
month = {aug},
number = {35},
pages = {14162--7},
pmid = {23918397},
publisher = {National Academy of Sciences},
title = {{State-dependent climate sensitivity in past warm climates and its implications for future climate projections}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/23918397 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC3761583},
volume = {110},
year = {2013}
}
@article{CABEDOSANZ201699,
abstract = {North Iceland represents a climatically sensitive region, in part, due to its location at the confluence of southward flowing and drift ice-laden polar waters from the Arctic Ocean delivered by the East Greenland Current, and the relatively warm and saline Irminger Current, a northerly flowing branch of the North Atlantic Current. Despite its pivotal location, there is a paucity of high resolution and long-term sea ice records for the region, with some disparities in certain previous investigations. Here, the identification of the biomarker IP25 as a reliable proxy for drift ice for North Iceland has been confirmed by measuring its abundance in surface sediments from the region and comparison of outcomes with documentary records of sea ice and other proxy data. By analysing IP25 in a well-dated marine sediment core from the North Icelandic Shelf (NIS) (MD99-2269), we also provide a high resolution (ca. 25 yr) record of drift sea ice for the region and complement this with a lower resolution record (ca. 100 yr) obtained from a second core site, located further east (JR51-GC35). Statistical treatment of equi-spaced time series reveals strong linear correlations between IP25 and a further drift ice proxy (quartz) in each core. Thus, linear regression analysis between both proxies gave correlation coefficients (R2) of 0.74 and 0.66 for MD99-2269 (25 yr) and JR51-GC35 (100 yr), respectively. Further, the individual proxies were well correlated between the two cores, with R = 0.91 and 0.77 for IP25 and quartz, respectively. The IP25-based sea ice record for MD99-2269, combined with other new biomarker and foraminifera data, and previously published proxy data for primary productivity and sea surface temperature, suggest that the paleoceanographic evolution for the NIS over the last 8 ka can be classified into three main intervals. The early mid Holocene (ca 8–6.2 cal ka BP) was characterized by relatively low or absent drift ice, low primary productivity and relatively high SSTs. During the mid-Holocene (ca 6.2–3.3 cal ka BP), drift ice increased concomitant with decreasing SSTs, although primary productivity was somewhat enhanced during this interval. IP25 first reached its mean value for the entire record at ca 5 cal ka BP, before increasing, continuously, ca 4.3 cal ka BP, broadly in line with the onset of Neoglaciation as seen in some other proxy records. Further increases in drift ice were evident during the late Holocene (ca 3.3 cal ka BP to present), culminating in maximum sea ice during the Little Ice Age. In addition, the IP25 record from MD99-2269 shows some positive regime shifts from the general trend, especially at ca 3.8, 2.7, 1.5, 0.7 and 0.4 cal ka BP, that have analogs in some other paleoceanographic reconstructions influenced by the East Greenland Current. The abrupt increases in IP25 at ca 1.5 and 0.7 cal ka BP are coincident with rapid cooling identified previously in an Icelandic lacustrine temperature record, suggesting significant coupling between the marine and terrestrial systems. The contribution of sea ice to the broader climate system is further evidenced through the identification of statistically significant periodicities (ca 1000 yr and ca 200–230 yr) in the drift ice proxy data that have counterparts in previous studies concerning atmospheric and oceanic variability and solar forcing mechanisms.},
author = {Cabedo-Sanz, Patricia and Belt, Simon T and Jennings, Anne E and Andrews, John T and Geirsd{\'{o}}ttir, {\'{A}}slaug},
doi = {https://doi.org/10.1016/j.quascirev.2016.06.012},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Drift ice,Holocene,IP,North Icelandic Shelf,Proxy,Sea ice},
pages = {99--115},
title = {{Variability in drift ice export from the Arctic Ocean to the North Icelandic Shelf over the last 8000 years: A multi-proxy evaluation}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379116302128},
volume = {146},
year = {2016}
}
@article{Caesar2018,
author = {Caesar, Levke and Rahmstorf, Stefan and Robinson, Alexander and Feulner, G and Saba, V},
doi = {10.1038/s41586-018-0006-5},
journal = {Nature},
number = {7700},
pages = {191},
publisher = {Nature Publishing Group},
title = {{Observed fingerprint of a weakening Atlantic Ocean overturning circulation}},
volume = {556},
year = {2018}
}
@article{Caesar2020,
author = {Caesar, L and McCarthy, G D and Thornalley, D J R and Cahill, N and Rahmstorf, S},
doi = {10.1038/s41561-021-00699-z},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {mar},
number = {3},
pages = {118--120},
title = {{Current Atlantic Meridional Overturning Circulation weakest in last millennium}},
url = {http://www.nature.com/articles/s41561-021-00699-z},
volume = {14},
year = {2021}
}
@article{Caley2014,
abstract = {Abstract The Indian-Atlantic water exchange south of Africa (Agulhas leakage) is a key component of the global ocean circulation. No quantitative estimation of the paleo-Agulhas leakage exists. We quantify the variability in interocean exchange over the past 640,000?years, using planktic foraminiferal assemblage data from two marine sediment records to define an Agulhas leakage efficiency index. We confirm the validity of our new approach with a numerical ocean model that realistically simulates the modern Agulhas leakage changes. Our results suggest that, during the past several glacial-interglacial cycles, the Agulhas leakage varied by {\~{}}10?sverdrup and more during major climatic transitions. This lends strong credence to the hypothesis that modifications in the leakage played a key role in changing the overturning circulation to full strength mode. Our results are instrumental for validating and quantifying the contribution of the Indian-Atlantic water leakage to the global climate changes.},
annote = {doi: 10.1002/2014GL059278},
author = {Caley, Thibaut and Peeters, Frank J C and Biastoch, Arne and Rossignol, Linda and van Sebille, Erik and Durgadoo, Jonathan and Malaiz{\'{e}}, Bruno and Giraudeau, Jacques and Arthur, Kristina and Zahn, Rainer},
doi = {10.1002/2014GL059278},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {numerical ocean model,overturning circulation,planktic foraminiferal,quantitative palaeo Agulhas leakage},
month = {feb},
number = {4},
pages = {1238--1246},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Quantitative estimate of the paleo-Agulhas leakage}},
url = {https://doi.org/10.1002/2014GL059278},
volume = {41},
year = {2014}
}
@article{Camoin1997,
abstract = {The sedimentological and chronological study of Holocene reef sequences recovered in drill cores through modern reefs of Mauritius, R{\'{e}}union Island and Mayotte allows the reconstruction of sea level changes and reef growth patterns during the Holocene. The branching-coral facies systematically predominates over coral head facies throughout the Holocene reef sequences, and Acropora is the main frame builder among the branching forms. The reconstructed sea level curves, based both on identification of coral assemblages and on radiometric U/Th ages, are characterized by a rapid rise between 10 and 7.5 ky BP, followed by a clear inflection between 7.5 and 7 ky BP. The stabilization of sea level at its present level occurred between 2000 and 3000 years ago, probably without a higher sea level stand. Rates of vertical reef accretion range between 0.9 and 7 mm. y-1. In Mauritius, and also probably in R{\'{e}}union Island, the reef first tracked, then caught-up to sea level to reach an equilibrium position (“catch-up” growth), while the barrier reef margin off Mayotte has been able to keep pace with rising sea level (“keep-up” growth).},
author = {Camoin, G F and Colonna, M and Montaggioni, L F and Casanova, J and Faure, G and Thomassin, B A},
doi = {10.1007/s003380050080},
issn = {1432-0975},
journal = {Coral Reefs},
number = {4},
pages = {247--259},
title = {{Holocene sea level changes and reef development in the southwestern Indian Ocean}},
url = {https://doi.org/10.1007/s003380050080},
volume = {16},
year = {1997}
}
@article{Campos2019,
abstract = {The number of paleoprecipitation records from the South American Monsoon domain that cover the last millennium has increased substantially in past years. However, hitherto most studies focused only on regional aspects, thereby neglecting the role of large-scale monsoon variability and the mechanisms that link proxy locations in space and time. Here we decompose the South American Monsoon into its main modes of variability by applying a Monte Carlo principal component analysis to a compilation of 11 well-dated summer paleoprecipitation records from tropical South America. The first mode represents changes in precipitation over the core monsoon domain, while the second mode is characterized by high loadings along the fringes of the South American Monsoon over Southeastern South America and the northern monsoon limit. Composite analysis reveals an enhanced monsoon with a wider, rather than a southward displaced, South Atlantic Convergence Zone during the early Little Ice Age, in contrast to previous interpretations.},
author = {Campos, J. L.P.S. and Cruz, F. W. and Ambrizzi, T. and Deininger, M. and Vuille, M. and Novello, V. F. and Strikis, N. M.},
doi = {10.1029/2019GL082513},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {South America Monsoon,climate variability,last millennium,precipitation,speleothems},
number = {14},
pages = {8261--8270},
title = {{Coherent South American Monsoon Variability During the Last Millennium Revealed Through High-Resolution Proxy Records}},
volume = {46},
year = {2019}
}
@article{Cao2019a,
author = {Cao, Jian and Wang, Bin and Liu, Jian},
doi = {10.1007/s00382-019-04711-6},
isbn = {0038201904711},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {3},
pages = {1661--1679},
publisher = {Springer Berlin Heidelberg},
title = {{Attribution of the Last Glacial Maximum climate formation}},
volume = {53},
year = {2019}
}
@article{Cao2018,
abstract = {Abstract To investigate the thermal characteristics and dynamics of permafrost as well as seasonally frozen ground over the upper reaches of the Heihe River Basin (URHR), an observation network with fourteen boreholes was established during 2011–2014. The in‐situ measurements indicated mean annual air temperature ranged from ‐5.2 to ‐2.3 ° at the monitored elevation range of ∼3600–4150 m, and mean annual ground surface temperature ranged from ‐1.3 to 1.7 ° during 2013–2017. The mean annual ground temperature at 16–18 m depth ranged from ‐1.71 ° on the high ({\textgreater} 4000 m asl.) north‐facing slope to about zero around areas near the lower limit of permafrost. Active layer thickness at the monitored sites varied significantly with the range of 0.77–4.90 m during 2011–2017, and maximum frozen depth in seasonally frozen ground was about 5 m. Permafrost thickness was between ∼136 m and less than 10 m. Both permafrost and seasonally frozen ground were found to be subject to serious warming during the measured period in the URHR. This study provides new quantitative insights for permafrost and seasonally frozen ground in the URHR.},
author = {Cao, Bin and Zhang, Tingjun and Peng, Xiaoqing and Mu, Cuicui and Wang, Qingfeng and Zheng, Lei and Wang, Kang and Zhong, Xinyue},
doi = {10.1029/2018JD028442},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {Heihe River Basin,Qilian Mountains,permafrost,seasonally frozen ground},
pages = {7935-- 7949},
title = {{Thermal Characteristics and Recent Changes of Permafrost in the Upper Reaches of the Heihe River Basin, Western China}},
volume = {123},
year = {2018}
}
@article{doi:10.1175/BAMS-D-13-00117.1,
abstract = {AbstractEl Ni{\~{n}}o–Southern Oscillation (ENSO) is a naturally occurring mode of tropical Pacific variability, with global impacts on society and natural ecosystems. While it has long been known that El Ni{\~{n}}o events display a diverse range of amplitudes, triggers, spatial patterns, and life cycles, the realization that ENSO's impacts can be highly sensitive to this event-to-event diversity is driving a renewed interest in the subject. This paper surveys our current state of knowledge of ENSO diversity, identifies key gaps in understanding, and outlines some promising future research directions.},
author = {Capotondi, Antonietta and Wittenberg, Andrew T and Newman, Matthew and {Di Lorenzo}, Emanuele and Yu, Jin-Yi and Braconnot, Pascale and Cole, Julia and Dewitte, Boris and Giese, Benjamin and Guilyardi, Eric and Jin, Fei-Fei and Karnauskas, Kristopher and Kirtman, Benjamin and Lee, Tong and Schneider, Niklas and Xue, Yan and Yeh, Sang-Wook},
doi = {10.1175/BAMS-D-13-00117.1},
journal = {Bulletin of the American Meteorological Society},
number = {6},
pages = {921--938},
title = {{Understanding ENSO Diversity}},
url = {https://doi.org/10.1175/BAMS-D-13-00117.1},
volume = {96},
year = {2015}
}
@article{CAPRON2019308,
author = {Capron, Emilie and Rovere, Alessio and Austermann, Jacqueline and Axford, Yarrow and Barlow, Natasha L M and Carlson, Anders E and de Vernal, Anne and Dutton, Andrea and Kopp, Robert E and McManus, Jerry F and Menviel, Laurie and Otto-Bliesner, Bette L and Robinson, Alexander and Shakun, Jeremy D and Tzedakis, Polychronis C and Wolff, Eric W},
doi = {10.1016/j.quascirev.2019.06.030},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Earth system modeling,Interglacials,Natural archives,Paleoclimatology,Polar ice sheets,Sea-level changes},
pages = {308--311},
title = {{Challenges and research priorities to understand interactions between climate, ice sheets and global mean sea level during past interglacials}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379119305207},
volume = {219},
year = {2019}
}
@article{Capron2017,
abstract = {The Last Interglacial (LIG, ∼129-116 thousand years ago, ka) represents an excellent case study to investigate the response of sensitive components of the Earth System and mechanisms of high-latitude amplification to a climate warmer than present-day. The Paleoclimate Model Intercomparison Project (Phase 4, hereafter referred as PMIP4) and the Coupled Model Intercomparison Project (Phase 6, hereafter referred as CMIP6) are coordinating the design of (1) a LIG Tier 1 equilibrium simulation to simulate the climate response at 127 ka, a time interval associated with a strong orbital forcing and greenhouse gas concentrations close to preindustrial levels and (2) associated Tier 2 sensitivity experiments to examine the role of the ocean, vegetation and dust feedbacks in modulating the response to this orbital forcing. Evaluating the capability of the CMIP6/PMIP4 models to reproduce the 127 ka polar and sub-polar climate will require appropriate data-based benchmarks which are currently missing. Based on a recent data synthesis that offers the first spatio-temporal representation of high-latitude (i.e. poleward of 40°N and 40°S) surface temperature evolution during the LIG, we produce a new 126–128 ka time slab, hereafter named 127 ka time slice. This 127 ka time slice represents surface temperature anomalies relative to preindustrial and is associated with quantitative estimates of the uncertainties related to relative dating and surface temperature reconstruction methods. It illustrates warmer-than-preindustrial conditions in the high-latitude regions of both hemispheres. In particular, summer sea surface temperatures (SST) in the North Atlantic region were on average 1.1 °C (with a standard error of the mean of 0.7 °C) warmer relative to preindustrial and 1.8 °C (with a standard error of the mean of 0.8 °C) in the Southern Ocean. In Antarctica, average 127 ka annual surface air temperature was 2.2 °C (with a standard error of the mean of 1.4 °C) warmer compared to preindustrial. We provide a critical evaluation of the latest LIG surface climate compilations that are available for evaluating LIG climate model experiments. We discuss in particular our new 127 ka time-slice in the context of existing LIG surface temperature time-slices. We also compare the 127 ka time slice with the ones published for the 125 and 130 ka time intervals and we discuss the potential and limits of a data-based time slice at 127 ka in the context of the upcoming coordinated modeling exercise. Finally we provide guidance on the use of the available LIG climate compilations for future model-data comparison exercises in the framework of the upcoming CMIP6/PMIP4 127 ka experiments. We do not recommend the use of LIG peak warmth-centered syntheses. Instead we promote the use of the most recent syntheses that are based on coherent chronologies between paleoclimatic records and provide spatio-temporal reconstruction of the LIG climate. In particular, we recommend using our new 127 ka data-based time slice in model-data comparison studies with a focus on the high-latitude climate.},
author = {Capron, E. and Govin, A. and Feng, R. and Otto-Bliesner, B.L. and Wolff, E.W.},
doi = {10.1016/J.QUASCIREV.2017.04.019},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
month = {jul},
pages = {137--150},
publisher = {Pergamon},
title = {{Critical evaluation of climate syntheses to benchmark CMIP6/PMIP4 127 ka Last Interglacial simulations in the high-latitude regions}},
url = {https://www.sciencedirect.com/science/article/pii/S0277379117303487?via{\%}3Dihub},
volume = {168},
year = {2017}
}
@article{Carilli2015,
author = {Carilli, Jessica E and McGregor, H.V. and Gaudry, Jessica J. and Donner, Simon and Gagan, Michael K and Stevenson, Samantha and Wong, Henri and Fink, David},
doi = {10.1002/2014PA002683.Received},
journal = {Paleoceanography},
keywords = {10.1002/2015PA002783 and coral,SST,SrCa,Walker circulation,d18O},
pages = {575--582},
title = {{Reply to comment by Karnauskas et al. on “Equatorial Pacific coral geochemical records show recent weakening of the Walker circulation”}},
volume = {30},
year = {2015}
}
@article{doi:10.1002/2014GL060800,
abstract = {Abstract Early Holocene summer warmth drove dramatic Greenland ice sheet (GIS) retreat. Subsequent insolation-driven cooling caused GIS margin readvance to late Holocene maxima, from which ice margins are now retreating. We use 10Be surface exposure ages from four locations between 69.4°N and 61.2°N to date when in the early Holocene south to west GIS margins retreated to within these late Holocene maximum extents. We find that this occurred at 11.1 ± 0.2 ka to 10.6 ± 0.5 ka in south Greenland, significantly earlier than previous estimates, and 6.8 ± 0.1 ka to 7.9 ± 0.1 ka in southwest to west Greenland, consistent with existing 10Be ages. At least in south Greenland, these 10Be ages likely provide a minimum constraint for when on a multicentury timescale summer temperatures after the last deglaciation warmed above late Holocene temperatures in the early Holocene. Current south Greenland ice margin retreat suggests that south Greenland may have now warmed to or above earliest Holocene summer temperatures.},
author = {Carlson, Anders E and Winsor, Kelsey and Ullman, David J and Brook, Edward J and Rood, Dylan H and Axford, Yarrow and LeGrande, Allegra N and Anslow, Faron S and Sinclair, Gaylen},
doi = {10.1002/2014GL060800},
journal = {Geophysical Research Letters},
keywords = {Greenland ice sheet,cosmogenic dating,early Holocene climate},
number = {15},
pages = {5514--5521},
title = {{Earliest Holocene south Greenland ice sheet retreat within its late Holocene extent}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014GL060800},
volume = {41},
year = {2014}
}
@article{Carmichael2016,
abstract = {Abstract. A range of proxy observations have recently provided constraints on how Earth's hydrological cycle responded to early Eocene climatic changes. However, comparisons of proxy data to general circulation model (GCM) simulated hydrology are limited and inter-model variability remains poorly characterised. In this work, we undertake an intercomparison of GCM-derived precipitation and P − E distributions within the extended EoMIP ensemble (Eocene Modelling Intercomparison Project; Lunt et al., 2012), which includes previously published early Eocene simulations performed using five GCMs differing in boundary conditions, model structure, and precipitation-relevant parameterisation schemes. We show that an intensified hydrological cycle, manifested in enhanced global precipitation and evaporation rates, is simulated for all Eocene simulations relative to the preindustrial conditions. This is primarily due to elevated atmospheric paleo-CO2, resulting in elevated temperatures, although the effects of differences in paleogeography and ice sheets are also important in some models. For a given CO2 level, globally averaged precipitation rates vary widely between models, largely arising from different simulated surface air temperatures. Models with a similar global sensitivity of precipitation rate to temperature (dP∕dT) display different regional precipitation responses for a given temperature change. Regions that are particularly sensitive to model choice include the South Pacific, tropical Africa, and the Peri-Tethys, which may represent targets for future proxy acquisition. A comparison of early and middle Eocene leaf-fossil-derived precipitation estimates with the GCM output illustrates that GCMs generally underestimate precipitation rates at high latitudes, although a possible seasonal bias of the proxies cannot be excluded. Models which warm these regions, either via elevated CO2 or by varying poorly constrained model parameter values, are most successful in simulating a match with geologic data. Further data from low-latitude regions and better constraints on early Eocene CO2 are now required to discriminate between these model simulations given the large error bars on paleoprecipitation estimates. Given the clear differences between simulated precipitation distributions within the ensemble, our results suggest that paleohydrological data offer an independent means by which to evaluate model skill for warm climates.},
author = {Carmichael, Matthew J and Lunt, Daniel J and Huber, Matthew and Heinemann, Malte and Kiehl, Jeffrey and LeGrande, Allegra and Loptson, Claire A and Roberts, Chris D and Sagoo, Navjit and Shields, Christine and Valdes, Paul J and Winguth, Arne and Winguth, Cornelia and Pancost, Richard D},
doi = {10.5194/cp-12-455-2016},
issn = {1814-9332},
journal = {Climate of the Past},
month = {feb},
number = {2},
pages = {455--481},
title = {{A model–model and data–model comparison for the early Eocene hydrological cycle}},
url = {https://cp.copernicus.org/articles/12/455/2016/},
volume = {12},
year = {2016}
}
@article{Carmichael2017,
abstract = {The Paleocene-Eocene Thermal Maximum (PETM) hyperthermal, {\~{}} 56 million years ago (Ma), is the most dramatic example of abrupt Cenozoic global warming. During the PETM surface temperatures increased between 5 and 9 °C and the onset likely took {\textless} 20 kyr. The PETM provides a case study of the impacts of rapid global warming on the Earth system, including both hydrological and associated biogeochemical feedbacks, and proxy data from the PETM can provide constraints on changes in warm climate hydrology simulated by general circulation models (GCMs). In this paper, we provide a critical review of biological and geochemical signatures interpreted as direct or indirect indicators of hydrological change at the PETM, explore the importance of adopting multi-proxy approaches, and present a preliminary model-data comparison. Hydrological records complement those of temperature and indicate that the climatic response at the PETM was complex, with significant regional and temporal variability. This is further illustrated by the biogeochemical consequences of inferred changes in hydrology and, in fact, changes in precipitation and the biogeochemical consequences are often conflated in geochemical signatures. There is also strong evidence in many regions for changes in the episodic and/or intra-annual distribution of precipitation that has not widely been considered when comparing proxy data to GCM output. Crucially, GCM simulations indicate that the response of the hydrological cycle to the PETM was heterogeneous – some regions are associated with increased precipitation – evaporation (P – E), whilst others are characterised by a decrease. Interestingly, the majority of proxy data come from the regions where GCMs predict an increase in PETM precipitation. We propose that comparison of hydrological proxies to GCM output can be an important test of model skill, but this will be enhanced by further data from regions of model-simulated aridity and simulation of extreme precipitation events.},
author = {Carmichael, Matthew J. and Inglis, Gordon N. and Badger, Marcus P.S. and Naafs, B. David A. and Behrooz, Leila and Remmelzwaal, Serginio and Monteiro, Fanny M. and Rohrssen, Megan and Farnsworth, Alexander and Buss, Heather L. and Dickson, Alexander J. and Valdes, Paul J. and Lunt, Daniel J. and Pancost, Richard D.},
doi = {10.1016/j.gloplacha.2017.07.014},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Climate models,Data-model comparisons,Hyperthermals,Paleogene,Paleohydrology,Proxies},
month = {oct},
number = {July},
pages = {114--138},
publisher = {Elsevier},
title = {{Hydrological and associated biogeochemical consequences of rapid global warming during the Paleocene–Eocene Thermal Maximum}},
url = {http://dx.doi.org/10.1016/j.gloplacha.2017.07.014 https://linkinghub.elsevier.com/retrieve/pii/S0921818117300723},
volume = {157},
year = {2017}
}
@article{Carn2016,
abstract = {Satellite instruments have been providing measurements of global volcanic emissions of sulfur dioxide (SO2) since 1978, based on observations in the ultraviolet (UV), infrared (IR) and microwave spectral bands. We review recent advances in satellite remote sensing of volcanic gases, focusing on increased instrument sensitivity to tropospheric SO2 emissions and techniques to determine volcanic plume altitude. A synthesis of {\~{}}36years of global UV, IR and microwave satellite measurements yields an updated assessment of the volcanic SO2 flux to the upper troposphere and lower stratosphere (UTLS) between 1978 and 2014 ({\~{}}1–2Tg/yr). The present availability of multiple UV and IR satellite SO2 products provides increased confidence in calculated SO2 loadings for many eruptions. We examine the temporal and latitudinal distribution of volcanic SO2 emissions and reassess the relationship between eruptive SO2 discharge and eruption magnitude, finding a first-order correlation between SO2 emission and volcanic explosivity index (VEI), but with significant scatter. Based on the observed SO2-VEI relation, we estimate the fraction of eruptive SO2 emissions released by the smallest eruptions ({\~{}}0.48Tg/yr), which is not recorded by satellite observations. A detailed breakdown of the sources of measured SO2 emissions reveals intuitively expected correlations between eruption frequency, SO2 loading and volcanic degassing style. We discuss new constraints on e-folding times for SO2 removal in volcanic plumes, and highlight recent measurements of volcanic hydrogen chloride (HCl) injections into the UTLS. An analysis of passive volcanic emissions of SO2 detected in Ozone Monitoring Instrument (OMI) SO2 data since 2004 provides new insight into the location and stability of the dominant sources of volcanic SO2 over the past decade. Since volcanic SO2 emissions constitute a random, highly variable perturbation to the atmosphere-climate system, continued monitoring of volcanic SO2 emissions from space by multiple UV and IR instruments to extend the current multi-decadal record is essential, and near-global, geostationary measurements of SO2 may be available by the end of the current decade.},
author = {Carn, S.A. and Clarisse, L. and Prata, A.J.},
doi = {10.1016/j.jvolgeores.2016.01.002},
issn = {03770273},
journal = {Journal of Volcanology and Geothermal Research},
pages = {99--134},
title = {{Multi-decadal satellite measurements of global volcanic degassing}},
volume = {311},
year = {2016}
}
@article{Carre2014,
abstract = {El Ni{\~{n}}o has changed quite a bit over the past 10,000 years. During some periods it was less variable than now, and during others it shifted from its current locale toward the central Pacific. Carr{\'{e}} et al. analyzed the shells of mollusks from Peru to construct a record of the El Ni{\~{n}}o–Southern Oscillation (ENSO) in the eastern Pacific over the Holocene period. They compared this record with other records from the rest of the Pacific to reveal how much the strength and frequency of El Ni{\~{n}}os changed and how their positions varied.Science, this issue p. 1045 Understanding the response of the El Ni{\~{n}}o–Southern Oscillation (ENSO) to global warming requires quantitative data on ENSO under different climate regimes. Here, we present a reconstruction of ENSO in the eastern tropical Pacific spanning the past 10,000 years derived from oxygen isotopes in fossil mollusk shells from Peru. We found that ENSO variance was close to the modern level in the early Holocene and severely damped {\~{}}4000 to 5000 years ago. In addition, ENSO variability was skewed toward cold events along coastal Peru 6700 to 7500 years ago owing to a shift of warm anomalies toward the Central Pacific. The modern ENSO regime was established {\~{}}3000 to 4500 years ago. We conclude that ENSO was sensitive to changes in climate boundary conditions during the Holocene, including but not limited to insolation.},
author = {Carr{\'{e}}, Matthieu and Sachs, Julian P. and Purca, Sara and Schauer, Andrew J. and Braconnot, Pascale and Falc{\'{o}}n, Rommel Angeles and Julien, Mich{\`{e}}le and Lavall{\'{e}}e, Dani{\`{e}}le},
doi = {10.1126/science.1252220},
issn = {0036-8075},
journal = {Science},
month = {aug},
number = {6200},
pages = {1045--1048},
title = {{Holocene history of ENSO variance and asymmetry in the eastern tropical Pacific}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1252220},
volume = {345},
year = {2014}
}
@article{Carter2019,
abstract = {Abstract We estimate anthropogenic carbon (Canth) accumulation rates in the Pacific Ocean between 1991 and 2017 from 14 hydrographic sections that have been occupied two to four times over the past few decades, with most sections having been recently measured as part of the Global Ocean Ship-based Hydrographic Investigations Program. The rate of change of Canth is estimated using a new method that combines the extended multiple linear regression method with improvements to address the challenges of analyzing multiple occupations of sections spaced irregularly in time. The Canth accumulation rate over the top 1,500 m of the Pacific increased from 8.8 (±1.1, 1$\sigma$) Pg of carbon per decade between 1995 and 2005 to 11.7 (±1.1) PgC per decade between 2005 and 2015. For the entire Pacific, about half of this decadal increase in the accumulation rate is attributable to the increase in atmospheric CO2, while in the South Pacific subtropical gyre this fraction is closer to one fifth. This suggests a substantial enhancement of the accumulation of Canth in the South Pacific by circulation variability and implies that a meaningful portion of the reinvigoration of the global CO2 sink that occurred between {\~{}}2000 and {\~{}}2010 could be driven by enhanced ocean Canth uptake and advection into this gyre. Our assessment suggests that the accuracy of Canth accumulation rate reconstructions along survey lines is limited by the accuracy of the full suite of hydrographic data and that a continuation of repeated surveys is a critical component of future carbon cycle monitoring.},
annote = {doi: 10.1029/2018GB006154},
author = {Carter, B R and Feely, R A and Wanninkhof, R and Kouketsu, S and Sonnerup, R E and Pardo, P C and Sabine, C L and Johnson, G C and Sloyan, B M and Murata, A and Mecking, S and Tilbrook, B and Speer, K and Talley, L D and Millero, F J and Wijffels, S E and Macdonald, A M and Gruber, N and Bullister, J L},
doi = {10.1029/2018GB006154},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {Pacific,anthropogenic carbon,decadal variability,eMLR,ocean acidification,repeat hydrography},
month = {may},
number = {5},
pages = {597--617},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Pacific Anthropogenic Carbon Between 1991 and 2017}},
url = {https://doi.org/10.1029/2018GB006154},
volume = {33},
year = {2019}
}
@article{Casanova-Masjoan2020,
abstract = {Abstract Data from repeat hydrographic surveys over the 25-year period 1993 to 2017, together with satellite altimetry data, are used to quantify the temporal and spatial variability of the North Icelandic Irminger Current (NIIC), East Icelandic Current (EIC), and the water masses they advect around northern Iceland. We focus on the warm, salty Atlantic Water (AW) flowing northward through Denmark Strait and the cooler, fresher, denser Atlantic-origin Overflow Water (AtOW) which has circulated cyclonically around the rim of the Nordic Seas before being advected to the Iceland slope via the EIC. The absolute geostrophic velocities reveal that approximately half of the NIIC recirculates just north of Denmark Strait, while the remaining half merges with the EIC to form a single current that extends to the northeast of Iceland, with no further loss in transport of either component. The AW percentage decreases by 75{\%} over this distance, while the AtOW percentage is higher than that of the AW in the merged current. The NIIC and merged NIIC-EIC are found to be baroclinically unstable, which causes the flow to become increasingly barotropic as it progresses around Iceland. A seasonal accounting of the water masses within the currents indicates that only in springtime is the NIIC dominated by AW inflow north of Denmark Strait. Overall, there is considerably more seasonal and along-stream variability in the properties of the flow prior to the merging of the NIIC and EIC. Over the 25-year time period, the NIIC became warmer, saltier, and increased in volume transport.},
annote = {doi: 10.1029/2020JC016283},
author = {Casanova-Masjoan, M and P{\'{e}}rez-Hern{\'{a}}ndez, M D and Pickart, R S and Valdimarsson, H and {\'{O}}lafsd{\'{o}}ttir, S R and Macrander, A and Grisol{\'{i}}a-Santos, D and Torres, D J and J{\'{o}}nsson, S and V{\aa}ge, K and Lin, P and Hern{\'{a}}ndez-Guerra, A},
doi = {10.1029/2020JC016283},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Atlantic Water inflow,East Icelandic Current,North Icelandic Irminger Current},
month = {sep},
number = {9},
pages = {e2020JC016283},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Along-Stream, Seasonal, and Interannual Variability of the North Icelandic Irminger Current and East Icelandic Current Around Iceland}},
url = {https://doi.org/10.1029/2020JC016283},
volume = {125},
year = {2020}
}
@article{Cattiaux2016,
author = {Cattiaux, Julien and Peings, Yannick and Saint-Martin, David and Trou-Kechout, Nadege and Vavrus, Stephen J},
doi = {10.1002/2016GL070309},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {aug},
number = {15},
pages = {8259--8268},
title = {{Sinuosity of midlatitude atmospheric flow in a warming world}},
url = {http://doi.wiley.com/10.1002/2016GL070309},
volume = {43},
year = {2016}
}
@article{Cavalieri2012,
abstract = {A comparison of snow depths on sea ice was made using airborne altimeters and an Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) simulator. The data were collected during the March 2006 National Aeronautics and Space Administration (NASA) Arctic field campaign utilizing the NASA P-3B aircraft. The campaign consisted of an initial series of coordinated surface and aircraft measurements over Elson Lagoon, Alaska and adjacent seas followed by a series of large-scale (100 km {\&}{\#}x00D7; 50 km) coordinated aircraft and AMSR-E snow depth measurements over portions of the Chukchi and Beaufort seas. This paper focuses on the latter part of the campaign. The P-3B aircraft carried the University of Colorado Polarimetric Scanning Radiometer (PSR-A), the NASA Wallops Airborne Topographic Mapper (ATM) lidar altimeter, and the University of Kansas Delay-Doppler (D2P) radar altimeter. The PSR-A was used as an AMSR-E simulator, whereas the ATM and D2P altimeters were used in combination to provide an independent estimate of snow depth. Results of a comparison between the altimeter-derived snow depths and the equivalent AMSR-E snow depths using PSR-A brightness temperatures calibrated relative to AMSR-E are presented. Data collected over a frozen coastal polynya were used to intercalibrate the ATM and D2P altimeters before estimating an altimeter snow depth. Results show that the mean difference between the PSR and altimeter snow depths is -2.4 cm (PSR minus altimeter) with a standard deviation of 7.7 cm. The RMS difference is 8.0 cm. The overall correlation between the two snow depth data sets is 0.59.},
author = {Cavalieri, Donald J. and Markus, Thorsten and Ivanoff, Alvaro and Miller, Jeff A. and Brucker, Ludovic and Sturm, Matthew and Maslanik, James A. and Heinrichs, John F. and Gasiewski, Albin J. and Leuschen, Carl and Krabill, William and Sonntag, John},
doi = {10.1109/TGRS.2011.2180535},
isbn = {0196-2892},
issn = {01962892},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
keywords = {Airborne altimetry,passive microwave remote sensing,sea ice,snow on sea ice},
title = {{A comparison of snow depth on sea ice retrievals using airborne altimeters and an AMSR-E simulator}},
year = {2012}
}
@article{Ceglar2019,
abstract = {This study focuses on the northward shift of homogeneous agro-climate zones in Europe analyzed for the observed past and projected climate conditions for the next decades. Statistical cluster analysis is used to derive eight main agro-climatic zones driven by two agro-meteorological indicators, namely, active temperature sum and thermal growing season length. The northward shift of homogeneous agro-climate zones and the corresponding change of crop growth suitability are analyzed together with the change of exposure of crops to temperature-related climate extremes during the growing season. Gradual warming over Europe has contributed to a lengthening of the growing season and an increased active temperature accumulation, accompanied by more frequent occurrence of warm extreme climate events. Using a set of five high-resolution regional climate scenarios, we calculate that a major part of Europe will be affected by further northward climate zone migration. In the next decades, the migration of agro-climatic zones in Eastern Europe may reach twice the velocity observed during the period 1975–2016. Several regions of the Mediterranean may lose suitability to grow specific crops in favor of northern European regions. This indicator-based assessment suggests that the potential advantages of the lengthening of the thermal growing season in northern and eastern Europe are often outbalanced by the risk of late frost and increased risk of early spring and summer heat waves.},
author = {Ceglar, A. and Zampieri, M. and Toreti, A. and Dentener, F.},
doi = {10.1029/2019EF001178},
issn = {23284277},
journal = {Earth's Future},
keywords = {Europe,agriculture,agro-climate zone,climate change,heat stress,migration velocity},
title = {{Observed Northward Migration of Agro-Climate Zones in Europe Will Further Accelerate Under Climate Change}},
year = {2019}
}
@article{10.3389/fmars.2019.00419,
abstract = {The air–sea interface is a key gateway in the Earth system. It is where the atmosphere sets the ocean in motion, climate/weather-relevant air–sea processes occur, and pollutants (i.e., plastic, anthropogenic carbon dioxide, radioactive/chemical waste) enter the sea. Hence, accurate estimates and forecasts of physical and biogeochemical processes at this interface are critical for sustainable blue economy planning, growth, and disaster mitigation. Such estimates and forecasts rely on accurate and integrated in situ and satellite surface observations. High-impact uses of ocean surface observations of essential ocean/climate variables (EOVs/ECVs) include (1) assimilation into/validation of weather, ocean, and climate forecast models to improve their skill, impact, and value; (2) ocean physics studies (i.e., heat, momentum, freshwater, and biogeochemical air–sea fluxes) to further our understanding and parameterization of air–sea processes; and (3) calibration and validation of satellite ocean products (i.e., currents, temperature, salinity, sea level, ocean color, wind, and waves). We review strengths and limitations, impacts, and sustainability of in situ ocean surface observations of several ECVs and EOVs. We draw a 10-year vision of the global ocean surface observing network for improved synergy and integration with other observing systems (e.g., satellites), for modeling/forecast efforts, and for a better ocean observing governance. The context is both the applications listed above and the guidelines of frameworks such as the Global Ocean Observing System (GOOS) and Global Climate Observing System (GCOS) (both co-sponsored by the Intergovernmental Oceanographic Commission of UNESCO, IOC–UNESCO; the World Meteorological Organization, WMO; the United Nations Environment Programme, UNEP; and the International Science Council, ISC). Networks of multiparametric platforms, such as the global drifter array, offer opportunities for new and improved in situ observations. Advances in sensor technology (e.g., low-cost wave sensors), high-throughput communications, evolving cyberinfrastructures, and data information systems with potential to improve the scope, efficiency, integration, and sustainability of the ocean surface observing system are explored.},
author = {Centurioni, Luca R and Turton, Jon and Lumpkin, Rick and Braasch, Lancelot and Brassington, Gary and Chao, Yi and Charpentier, Etienne and Chen, Zhaohui and Corlett, Gary and Dohan, Kathleen and Donlon, Craig and Gallage, Champika and Hormann, Verena and Ignatov, Alexander and Ingleby, Bruce and Jensen, Robert and Kelly-Gerreyn, Boris A and Koszalka, Inga M and Lin, Xiaopei and Lindstrom, Eric and Maximenko, Nikolai and Merchant, Christopher J and Minnett, Peter and O'Carroll, Anne and Paluszkiewicz, Theresa and Poli, Paul and Poulain, Pierre-Marie and Reverdin, Gilles and Sun, Xiujun and Swail, Val and Thurston, Sidney and Wu, Lixin and Yu, Lisan and Wang, Bin and Zhang, Dongxiao},
doi = {10.3389/fmars.2019.00419},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
pages = {419},
title = {{Global in situ Observations of Essential Climate and Ocean Variables at the Air-Sea Interface}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00419},
volume = {6},
year = {2019}
}
@article{Chai2020a,
abstract = {We investigate global trends in seasonal water discharge using data from 5668 hydrological stations in catchments whose total drainage area accounts for 2/3 of the Earth's total land area. Homogenization of water discharge, which occurs when the gap in water discharge between dry and flood seasons shrinks significantly, affects catchments occupying 2/5 of the total land area, and is mainly concentrated in Eurasia and North America. By contrast, polarization of water discharge, associated with widening of the gap in water discharge between dry and flood seasons, occurs in catchments covering 1/6 of the land area, most notably in the Amazon Basin and river basins in West Africa. Considering the major climatic and anthropogenic controlling factors, i.e. precipitation (P), evaporation (E), glacial runoff (G), and dam operations (D), the world's river basins are classified as P, DEP, GEP, and EP types. Contributions from each controlling factor to either the homogenization or polarization of the seasonal water discharge for each type of river have been analyzed. We found that homogenization of discharge is dominated by dam operations in GDEP and DEP river basins (contributing 48{\%} and 64{\%}) and by homogenized precipitation in GEP and EP river basins. Evaporation and precipitation are primary factors behind the polarization of discharge, contributing 56{\%} and 41{\%}. This study provides a basis for a possible decision tool for controlling drought/flood disasters and for assessing and preventing ecological damage in endangered regions.},
author = {Chai, Yuanfang and Yue, Yao and Zhang, Lin and Miao, Chiyuan and Borthwick, Alistair G.L. and Zhu, Boyuan and Li, Yitian and Dolman, A. J.},
doi = {10.1016/j.scitotenv.2019.136062},
issn = {18791026},
journal = {Science of the Total Environment},
keywords = {Dam operations,Evaporation,Glacial runoff,Global trends,Precipitation,Seasonal runoff},
pages = {136062},
pmid = {31887524},
publisher = {Elsevier B.V.},
title = {{Homogenization and polarization of the seasonal water discharge of global rivers in response to climatic and anthropogenic effects}},
url = {https://doi.org/10.1016/j.scitotenv.2019.136062},
volume = {709},
year = {2020}
}
@incollection{Chakraborty2020,
address = {Singapore},
author = {Chakraborty, Supriyo and Tiwari, Yogesh K. and Burman, Pramit Kumar Deb and Roy, Somnath Baidya and Valsala, Vinu},
booktitle = {Assessment of Climate Change over the Indian Region: A Report of the Ministry of Earth Sciences (MoES), Government of India},
doi = {10.1007/978-981-15-4327-2_4},
editor = {Krishnan, R. and Sanjay, J. and Gnanaseelan, Chellappan and Mujumdar, Milind and Kulkarni, Ashwini and Chakraborty, Supriyo},
pages = {73--92},
publisher = {Springer},
title = {{Observations and Modeling of GHG Concentrations and Fluxes Over India}},
year = {2020}
}
@article{Chalk2017a,
abstract = {During the Mid-Pleistocene Transition (MPT; 1,200-800 kya), Earth's orbitally paced ice age cycles intensified, lengthened from ∼40,000 (∼40 ky) to ∼100 ky, and became distinctly asymmetrical. Testing hypotheses that implicate changing atmospheric CO2 levels as a driver of the MPT has proven difficult with available observations. Here, we use orbitally resolved, boron isotope CO2 data to show that the glacial to interglacial CO2 difference increased from ∼43 to ∼75 $\mu$atm across the MPT, mainly because of lower glacial CO2 levels. Through carbon cycle modeling, we attribute this decline primarily to the initiation of substantive dust-borne iron fertilization of the Southern Ocean during peak glacial stages. We also observe a twofold steepening of the relationship between sea level and CO2-related climate forcing that is suggestive of a change in the dynamics that govern ice sheet stability, such as that expected from the removal of subglacial regolith or interhemispheric ice sheet phase-locking. We argue that neither ice sheet dynamics nor CO2 change in isolation can explain the MPT. Instead, we infer that the MPT was initiated by a change in ice sheet dynamics and that longer and deeper post-MPT ice ages were sustained by carbon cycle feedbacks related to dust fertilization of the Southern Ocean as a consequence of larger ice sheets.},
author = {Chalk, Thomas B. and Hain, Mathis P. and Foster, Gavin L. and Rohling, Eelco J. and Sexton, Philip F. and Badger, Marcus P. S. and Cherry, Soraya G. and Hasenfratz, Adam P. and Haug, Gerald H. and Jaccard, Samuel L. and Mart{\'{i}}nez-Garc{\'{i}}a, Alfredo and P{\"{a}}like, Heiko and Pancost, Richard D. and Wilson, Paul A.},
doi = {10.1073/PNAS.1702143114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
pmid = {29180424},
title = {{Causes of ice age intensification across the Mid-Pleistocene Transition}},
year = {2017}
}
@article{Chan2019b,
abstract = {Existing estimates of sea surface temperatures (SSTs) indicate that, during the early twentieth century, the North Atlantic and northeast Pacific oceans warmed by twice the global average, whereas the northwest Pacific Ocean cooled by an amount equal to the global average1–4. Such a heterogeneous pattern suggests first-order contributions from regional variations in forcing or in ocean–atmosphere heat fluxes5,6. These older SST estimates are, however, derived from measurements of water temperatures in ship-board buckets, and must be corrected for substantial biases7–9. Here we show that correcting for offsets among groups of bucket measurements leads to SST variations that correlate better with nearby land temperatures and are more homogeneous in their pattern of warming. Offsets are identified by systematically comparing nearby SST observations among different groups10. Correcting for offsets in German measurements decreases warming rates in the North Atlantic, whereas correcting for Japanese measurement offsets leads to increased and more uniform warming in the North Pacific. Japanese measurement offsets in the 1930s primarily result from records having been truncated to whole degrees Celsius when the records were digitized in the 1960s. These findings underscore the fact that historical SST records reflect both physical and social dimensions in data collection, and suggest that further opportunities exist for improving the accuracy of historical SST records9,11.},
author = {Chan, Duo and Kent, Elizabeth C and Berry, David I and Huybers, Peter},
doi = {10.1038/s41586-019-1349-2},
issn = {1476-4687},
journal = {Nature},
number = {7765},
pages = {393--397},
title = {{Correcting datasets leads to more homogeneous early-twentieth-century sea surface warming}},
url = {https://doi.org/10.1038/s41586-019-1349-2},
volume = {571},
year = {2019}
}
@article{Chan2015,
abstract = {Anthropogenic forcings have contributed to global and regional warming in the last few decades and likely affected terrestrial precipitation. Here we examine changes in major Koppen climate classes from gridded observed data and their uncertainties due to internal climate variability using control simulations from Coupled Model Intercomparison Project 5 (CMIP5). About 5.7{\%} of the global total land area has shifted toward warmer and drier climate types from 1950-2010, and significant changes include expansion of arid and high-latitude continental climate zones, shrinkage in polar and midlatitude continental climates, poleward shifts in temperate, continental and polar climates, and increasing average elevation of tropical and polar climates. Using CMIP5 multi-model averaged historical simulations forced by observed anthropogenic and natural, or natural only, forcing components, we find that these changes of climate types since 1950 cannot be explained as natural variations but are driven by anthropogenic factors.},
author = {Chan, Duo and Wu, Qigang},
doi = {10.1038/srep13487},
isbn = {2045-2322 (Electronic) 2045-2322 (Linking)},
issn = {20452322},
journal = {Scientific Reports},
number = {13487},
pmid = {26316255},
title = {{Significant anthropogenic-induced changes of climate classes since 1950}},
volume = {5},
year = {2015}
}
@article{Chandanpurkar2017,
abstract = {AbstractTotal continental freshwater discharge into the oceans is a key feature of the global water cycle, but it is currently impossible to observe using ground-based methods alone. To characterize the uncertainty across existing modeling and satellite approaches, the authors present ensembles of historic monthly global continental discharge estimates that enforce water mass balance over land and ocean. The authors combine independent measurements of ocean–landmass change from altimetry and GRACE with multiple estimates of evaporation minus precipitation (E − P) from remote sensing and reanalysis data to compute 28 time series of global discharge. Results reveal agreement in mass budget across approaches but a large spread in global E − P estimates that propagates into the discharge estimates. It is found that discharges with reanalysis-based E − P provide a closer comparison with current observation-based estimates. After combining GRACE- and altimetry-based mass change estimates with moisture convergen...},
author = {Chandanpurkar, Hrishikesh A. and Reager, John T. and Famiglietti, James S. and Syed, Tajdarul H.},
doi = {10.1175/JCLI-D-16-0708.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Hydrologic cycle,Hydrology,Remote sensing},
number = {21},
pages = {8481--8495},
title = {{Satellite- and reanalysis-based mass balance estimates of global continental discharge (1993-2015)}},
volume = {30},
year = {2017}
}
@article{doi:10.1175/2010JCLI4065.1,
abstract = { AbstractThe tropical Atlantic interhemispheric gradient in sea surface temperature significantly influences the rainfall climate of the tropical Atlantic sector, including droughts over West Africa and Northeast Brazil. This gradient exhibits a secular trend from the beginning of the twentieth century until the 1980s, with stronger warming in the south relative to the north. This trend behavior is on top of a multidecadal variation associated with the Atlantic multidecadal oscillation. A similar long-term forced trend is found in a multimodel ensemble of forced twentieth-century climate simulations. Through examining the distribution of the trend slopes in the multimodel twentieth-century and preindustrial models, the authors conclude that the observed trend in the gradient is unlikely to arise purely from natural variations; this study suggests that at least half the observed trend is a forced response to twentieth-century climate forcings. Further analysis using twentieth-century single-forcing runs indicates that sulfate aerosol forcing is the predominant cause of the multimodel trend. The authors conclude that anthropogenic sulfate aerosol emissions, originating predominantly from the Northern Hemisphere, may have significantly altered the tropical Atlantic rainfall climate over the twentieth century. },
author = {Chang, C.-Y. and Chiang, J C H and Wehner, M F and Friedman, A R and Ruedy, R},
doi = {10.1175/2010JCLI4065.1},
journal = {Journal of Climate},
number = {10},
pages = {2540--2555},
title = {{Sulfate Aerosol Control of Tropical Atlantic Climate over the Twentieth Century}},
url = {https://doi.org/10.1175/2010JCLI4065.1},
volume = {24},
year = {2011}
}
@article{Chang2016,
abstract = {Extratropical cyclones cause much of the high-impact weather over the midlatitudes. With increasing greenhouse gases, enhanced high-latitude warming will lead to weaker cyclone activity. Here we show that between 1979 and 2014, the number of strong cyclones in Northern Hemisphere in summer has decreased at a rate of 4{\%} per decade, with even larger decrease found near northeastern North America. Climate models project a decrease in summer cyclone activity, but the observed decreasing rate is near the fastest projected. Decrease in summer cyclone activity will lead to decrease in cloud cover, giving rise to higher maximum temperature, potentially enhancing the increase in maximum temperature by 0.5K or more over some regions. We also show that climate models may have biases in simulating the positive relationship between cyclone activity and cloud cover, potentially underestimating the impacts of cyclone decrease on accentuating the future increase in maximum temperature.},
author = {Chang, Edmund K.M. and Ma, Chen Geng and Zheng, Cheng and Yau, Albert M.W.},
doi = {10.1002/2016GL068172},
isbn = {0094-8276},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {5},
pages = {2200--2208},
title = {{Observed and projected decrease in Northern Hemisphere extratropical cyclone activity in summer and its impacts on maximum temperature}},
volume = {43},
year = {2016}
}
@article{Chang2016a,
abstract = {In this study, a comprehensive comparison of Northern Hemisphere winter storm track trend since 1959 derived from multiple reanalysis datasets and rawinsonde observations has been conducted. In addition, trends in terms of variance and cyclone track statistics have been compared. Previous studies, based largely on the National Center for Environmental Prediction--National Center for Atmospheric Research Reanalysis (NNR), have suggested that both the Pacific and Atlantic storm tracks have significantly intensified between the 1950s and 1990s. Comparison with trends derived from rawinsonde observations suggest that the trends derived from NNR are significantly biased high, while those from the European Center for Medium Range Weather Forecasts 40-year Reanalysis and the Japanese 55-year Reanalysis are much less biased but still too high. Those from the two twentieth century reanalysis datasets are most consistent with observations but may exhibit slight biases of opposite signs. Between 1959 and 2010, Pacific storm track activity has likely increased by 10 {\{}{\%}{\}} or more, while Atlantic storm track activity has likely increased by {\textless}10 {\{}{\%}{\}}. Our analysis suggests that trends in Pacific and Atlantic basin wide storm track activity prior to the 1950s derived from the two twentieth century reanalysis datasets are unlikely to be reliable due to changes in density of surface observations. Nevertheless, these datasets may provide useful information on interannual variability, especially over the Atlantic.},
author = {Chang, Edmund K.M. and Yau, Albert M.W.},
doi = {10.1007/s00382-015-2911-8},
issn = {14320894},
journal = {Climate Dynamics},
number = {5-6},
pages = {1435--1454},
publisher = {Springer Berlin Heidelberg},
title = {{Northern Hemisphere winter storm track trends since 1959 derived from multiple reanalysis datasets}},
volume = {47},
year = {2016}
}
@article{Charlton2007,
author = {Charlton, A. J. and Polvani, L. M. and Perlwitz, J and Sassi, F and Manzini, E and Shibata, K and Pawson, S and Nielsen, J. E. and Rind, D},
doi = {10.1175/JCLI3994.1},
journal = {Journal of Climate},
number = {3},
pages = {470--488},
title = {{A New Look at Stratospheric Sudden Warmings. Part II: Evaluation of Numerical Model Simulations}},
volume = {20},
year = {2007}
}
@article{refId0,
author = {Chatzistergos, Theodosios and Usoskin, Ilya G. and Kovaltsov, Gennady A. and Krivova, Natalie A. and Solanki, Sami K.},
doi = {10.1051/0004-6361/201630045},
issn = {0004-6361},
journal = {Astronomy {\&} Astrophysics},
month = {jun},
pages = {A69},
title = {{New reconstruction of the sunspot group numbers since 1739 using direct calibration and “backbone” methods}},
url = {https://doi.org/10.1051/0004-6361/201630045 http://www.aanda.org/10.1051/0004-6361/201630045},
volume = {602},
year = {2017}
}
@article{Chemke2019a,
abstract = {The Hadley circulation has large climate impacts at low latitudes by transferring heat and moisture between the tropics and subtropics. Climate projections show a robust weakening of the Northern Hemisphere Hadley circulation by the end of the twenty-first century. Over the past several decades, however, atmospheric reanalyses indicate a strengthening of the Hadley circulation. Here we show that the strengthening of the circulation in the Northern Hemisphere is not seen in climate models; instead, these models simulate a weakening of the circulation in the past 40 years. Using observations and a large ensemble of model simulations we elucidate this discrepancy between climate models and reanalyses, and show that it does not stem from internal climate variability or biases in climate models, but appears related to artefacts in the representation of latent heating in the reanalyses. Our results highlight the role of anthropogenic emissions in the recent slowdown of the atmospheric circulation, which is projected to continue in coming decades, and question the reliability of reanalyses for estimating trends in the Hadley circulation.},
author = {Chemke, Rei and Polvani, Lorenzo M.},
doi = {10.1038/s41561-019-0383-x},
issn = {1752-0894},
journal = {Nature Geoscience},
number = {7},
pages = {528--532},
publisher = {Springer US},
title = {{Opposite tropical circulation trends in climate models and in reanalyses}},
volume = {12},
year = {2019}
}
@article{doi:10.1002/2013JD021037,
abstract = {Abstract While the calibration accuracy of Advanced Microwave Sounding Unit-A (AMSU-A) was well characterized during its prelaunch period, its on-orbit performance remains important after the launch of each satellite. In this study, Global Positioning System (GPS) radio occultation (RO) data are used to carry out a postlaunch calibration to obtain an estimate of the accuracy of brightness temperatures measured by an AMSU-A instrument. At each scan angle, the mean difference and a linear regression relationship between AMSU-A observations and GPS RO brightness temperature simulations can first be derived using data in clear-sky conditions over ocean. The AMSU-A upper air sounding channels are then calibrated to GPS RO brightness temperature simulations using either the mean difference or the linear regression relationship. The effect of the above two calibration methods on the biases of AMSU-A data with respect to National Centers for Environmental Prediction global forecast system (NCEP GFS) 6 h forecast fields is finally examined. It is found that the magnitude and sign of biases vary with channels. After GPS RO calibration, biases are negative and of the same magnitude for all AMSU-A upper air sounding channels. The negative biases of AMSU-A brightness temperature are associated with a small warm bias in the physical temperature of NCEP GFS 6 h forecasts compared with GPS RO temperature retrieval above the low troposphere.},
author = {Chen, X and Zou, X},
doi = {10.1002/2013JD021037},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {AMSU-A,GPS RO,postlaunch calibration},
number = {7},
pages = {3924--3941},
title = {{Postlaunch calibration and bias characterization of AMSU-A upper air sounding channels using GPS RO Data}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013JD021037},
volume = {119},
year = {2014}
}
@article{Chen2019b,
abstract = {The long-term trend in tropopause has profound implications for the expansion of tropical zone and the variation of large-scale circulation. However, the changes of tropopause in China have not been explicitly investigated as yet. In this study, the trend of lapse rate tropopause (LRT) height over China has been comprehensively revisited for the period of 1979–2016, using the newly released quality-controlled radiosonde data from China Meteorological Administration. Results show that the LRT height in most parts of China shows a significant upwards trend with a rate of 370 m/decade, most likely due to global warming. The fastest increase occurs in northwest region, followed by the low-latitude regions (15°–25°N), while the slowest increase occurs in the high-latitude regions (45°–55°N). Overall, the LRT height varies with latitudes, exhibiting a “south high and north low” pattern. In particular, high LRT height over low latitudes is found to be expanding rapidly polewards in recent years, in contrast to almost constant LRT height over mid and high latitudes. In terms of the seasonality, tropopause height reaches the peak in summer and bottom in winter. The frequency distribution in the vertical direction exhibits a bimodal pattern with the major peak mostly occurring at around 15 km and a secondary peak occurring between 8 and 12 km. This bimodal distribution is similar to the findings revealed in previous studies. Our findings offer important circumstantial observational evidence for the polewards expansion of the Tropics under global warming.},
author = {Chen, Xinyan and Guo, Jianping and Yin, Jinfang and Zhang, Yong and Miao, Yucong and Yun, Yuxing and Liu, Lin and Li, Jian and Xu, Hui and Hu, Kaixi and Zhai, Panmao},
doi = {10.1002/joc.5866},
journal = {International Journal of Climatology},
number = {2},
pages = {1117--1127},
title = {{Tropopause trend across China from 1979 to 2016: A revisit with updated radiosonde measurements}},
volume = {39},
year = {2019}
}
@article{Chen2019,
author = {Chen, Chi and Park, Taejin and Wang, Xuhui and Piao, Shilong and Xu, Baodong and Chaturvedi, Rajiv K. and Fuchs, Richard and Brovkin, Victor and Ciais, Philippe and Fensholt, Rasmus and T{\o}mmervik, Hans and Bala, Govindasamy and Zhu, Zaichun and Nemani, Ramakrishna R. and Myneni, Ranga B.},
doi = {10.1038/s41893-019-0220-7},
issn = {23989629},
journal = {Nature Sustainability},
pages = {122--129},
title = {{China and India lead in greening of the world through land-use management}},
volume = {2},
year = {2019}
}
@article{Chen2011,
author = {Chen, I. Ching and Hill, Jane K. and Ohlem{\"{u}}ller, Ralf and Roy, David B. and Thomas, Chris D.},
doi = {10.1126/science.1206432},
issn = {00368075},
journal = {Science},
number = {6045},
pages = {1024--1026},
title = {{Rapid range shifts of species associated with high levels of climate warming}},
volume = {333},
year = {2011}
}
@article{Chen2017a,
abstract = {The acceleration of sea-level rise continues, but this has not been clear in the short altimeter record. This study closes the sea-level rise budget for 1993–2014 and illustrates the increased contribution from the Greenland ice sheet.},
author = {Chen, Xianyao and Zhang, Xuebin and Church, John A. and Watson, Christopher S. and King, Matt A. and Monselesan, Didier and Legresy, Benoit and Harig, Christopher},
doi = {10.1038/nclimate3325},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jun},
number = {7},
pages = {492--495},
publisher = {Nature Publishing Group},
title = {{The increasing rate of global mean sea-level rise during 1993–2014}},
volume = {7},
year = {2017}
}
@article{Chen2017c,
abstract = {Oceans worldwide are undergoing acidification due to the penetration of anthropogenic CO2 from the atmosphere1–4. The rate of acidification generally diminishes with increasing depth. Yet, slowing down of the thermohaline circulation due to global warming could reduce the pH in the deep oceans, as more organic material would decompose with a longer residence time. To elucidate this process, a time-series study at a climatically sensitive region with sufficient duration and resolution is needed. Here we show that deep waters in the Sea of Japan are undergoing reduced ventilation, reducing the pH of seawater. As a result, the acidification rate near the bottom of the Sea of Japan is 27{\%} higher than the rate at the surface, which is the same as that predicted assuming an air–sea CO2 equilibrium. This reduced ventilation may be due to global warming and, as an oceanic microcosm with its own deep- and bottom-water formations, the Sea of Japan provides an insight into how future warming might alter the deep-ocean acidification.},
author = {Chen, Chen-Tung Arthur and Lui, Hon-Kit and Hsieh, Chia-Han and Yanagi, Tetsuo and Kosugi, Naohiro and Ishii, Masao and Gong, Gwo-Ching},
doi = {10.1038/s41558-017-0003-y},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {12},
pages = {890--894},
title = {{Deep oceans may acidify faster than anticipated due to global warming}},
url = {https://doi.org/10.1038/s41558-017-0003-y},
volume = {7},
year = {2017}
}
@article{doi:10.1175/JCLI-D-15-0322.1,
abstract = {AbstractENSO-like variability is examined using a set of univariate indices based on unfiltered monthly global sea surface temperature (SST), sea level pressure (SLP), outgoing longwave radiation (OLR), sea level, and the three-dimensional ocean temperature (OT) fields. These indices, many of which correspond to the leading principal components (PCs) of the respective global fields, are highly correlated with each other. In combination with their spatial regression patterns, they provide a comprehensive description of ENSO-like variability in the atmosphere and ocean across time scales ranging from months to decades, from 1950 onward. The SLP and SST indices are highly correlated with one another back to the late nineteenth century. The interdecadal-scale shifts in the prevailing polarity of ENSO that occurred in the 1940s, the 1970s, and around the year 2000 are clearly evident in low-pass-filtered time series of these indices.On the basis of empirical mode decomposition, ENSO-like variability is partitioned into an interannual “ENSO cycle,” to which equatorial ocean wave dynamics imparts a distinctive equatorial signature, and a red noise background continuum, most prominent on the interdecadal time scale, which resembles the ENSO-like variability in some models in which the atmosphere is coupled to a slab ocean. The background continuum bears the imprint of the Pacific–North American (PNA) pattern, the leading mode of the Northern Hemisphere wintertime variability of the atmospheric circulation over the Pacific sector. The superposition of the ENSO cycle and the background continuum imparts a distinctive frequency dependence to the patterns of ENSO-like climate variability.},
author = {Chen, Xianyao and Wallace, John M},
doi = {10.1175/JCLI-D-15-0322.1},
journal = {Journal of Climate},
number = {24},
pages = {9623--9641},
title = {{ENSO-Like Variability: 1900–2013}},
url = {https://doi.org/10.1175/JCLI-D-15-0322.1},
volume = {28},
year = {2015}
}
@article{Chen2014a,
author = {Chen, Shangfeng and Wei, Ke and Chen, Wen and Song, Linye},
doi = {10.1002/2014JD021540},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jul},
number = {13},
pages = {7815--7832},
title = {{Regional changes in the annual mean Hadley circulation in recent decades}},
url = {http://doi.wiley.com/10.1002/2014JD021540},
volume = {119},
year = {2014}
}
@article{Chen2016,
author = {Chen, Biyan and Liu, Zhizhao},
doi = {10.1002/2016JD024917},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {10.1002/2016JD024917 and global PWV variability,global PWV trend,multiple source PWV analysis},
pages = {11442--11462},
title = {{Global water vapor variability and trend from the latest 36 year (1979 to 2014) data of ECMWF and NCEP reanalyses, radiosonde, GPS, and microwave satellite}},
volume = {121},
year = {2016}
}
@article{ChenW.ZoruP.WhiteL.OlthofI.ZhangY.FraserR.Leblanc2016,
author = {Chen, Wenjun and Zorn, Paul and White, Lori and Olthof, Ian and Zhang, Yu and Fraser, Robert and Leblanc, Sylvain},
doi = {10.4236/ajcc.2016.53026},
issn = {2167-9495},
journal = {American Journal of Climate Change},
number = {03},
pages = {334--359},
title = {{Decoupling between Plant Productivity and Growing Season Length under a Warming Climate in Canada's Arctic}},
url = {http://www.scirp.org/journal/doi.aspx?DOI=10.4236/ajcc.2016.53026},
volume = {05},
year = {2016}
}
@article{CHEN201661,
abstract = {The El Ni{\~{n}}o-Southern Oscillation (ENSO) is the primary driver of interannual climate variability in the tropics and subtropics. Despite substantial progress in understanding ocean–atmosphere feedbacks that drive ENSO today, relatively little is known about its behavior on centennial and longer timescales. Paleoclimate records from lakes, corals, molluscs and deep-sea sediments generally suggest that ENSO variability was weaker during the mid-Holocene (4–6 kyr BP) than the late Holocene (0–4 kyr BP). However, discrepancies amongst the records preclude a clear timeline of Holocene ENSO evolution and therefore the attribution of ENSO variability to specific climate forcing mechanisms. Here we present $\delta$18O results from a U–Th dated speleothem in Malaysian Borneo sampled at sub-annual resolution. The $\delta$18O of Borneo rainfall is a robust proxy of regional convective intensity and precipitation amount, both of which are directly influenced by ENSO activity. Our estimates of stalagmite $\delta$18O variance at ENSO periods (2–7 yr) show a significant reduction in interannual variability during the mid-Holocene (3240–3380 and 5160–5230 yr BP) relative to both the late Holocene (2390–2590 yr BP) and early Holocene (6590–6730 yr BP). The Borneo results are therefore inconsistent with lacustrine records of ENSO from the eastern equatorial Pacific that show little or no ENSO variance during the early Holocene. Instead, our results support coral, mollusc and foraminiferal records from the central and eastern equatorial Pacific that show a mid-Holocene minimum in ENSO variance. Reduced mid-Holocene interannual $\delta$18O variability in Borneo coincides with an overall minimum in mean $\delta$18O from 3.5 to 5.5 kyr BP. Persistent warm pool convection would tend to enhance the Walker circulation during the mid-Holocene, which likely contributed to reduced ENSO variance during this period. This finding implies that both convective intensity and interannual variability in Borneo are driven by coupled air-sea dynamics that are sensitive to precessional insolation forcing. Isolating the exact mechanisms that drive long-term ENSO evolution will require additional high-resolution paleoclimatic reconstructions and further investigation of Holocene tropical climate evolution using coupled climate models.},
author = {Chen, Sang and Hoffmann, Sharon S and Lund, David C and Cobb, Kim M and Emile-Geay, Julien and Adkins, Jess F},
doi = {10.1016/j.epsl.2016.02.050},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Borneo,ENSO,Holocene,speleothem,western Pacific rainfall},
pages = {61--71},
title = {{A high-resolution speleothem record of western equatorial Pacific rainfall: Implications for Holocene ENSO evolution}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X16300759},
volume = {442},
year = {2016}
}
@article{Chen2015,
abstract = {Quantifying and attributing the phenological changes in snow cover are essential for meteorological, hydrological, ecological, and societal implications. However, snow cover phenology changes have not been well documented. Evidence from multiple satellite and reanalysis data from 2001 to 2014 points out that the snow end date (De) advanced by 5.11 (+/-2.20) days in northern high latitudes (52-75 degrees N) and was delayed by 3.28 (+/-2.59) days in northern mid-latitudes (32-52 degrees N) at the 90{\%} confidence level. Dominated by changes in De, snow duration days (Dd) was shorter in duration by 5.57 (+/-2.55) days in high latitudes and longer by 9.74 (+/-2.58) days in mid-latitudes. Changes in De during the spring season were consistent with the spatiotemporal pattern of land surface albedo change. Decreased land surface temperature combined with increased precipitation in mid-latitudes and significantly increased land surface temperature in high latitudes, impacted by recent Pacific surface cooling, Arctic amplification and strengthening westerlies, result in contrasting changes in the Northern Hemisphere snow cover phenology. Changes in the snow cover phenology led to contrasting anomalies of snow radiative forcing, which is dominated by De and accounts for 51{\%} of the total shortwave flux anomalies at the top of the atmosphere.},
author = {Chen, Xiaona and Liang, Shunlin and Cao, Yunfeng and He, Tao and Wang, Dongdong},
doi = {10.1038/srep16820},
issn = {20452322},
journal = {Scientific Reports},
number = {1},
pages = {16820},
title = {{Observed contrast changes in snow cover phenology in northern middle and high latitudes from 2001–2014}},
volume = {5},
year = {2015}
}
@article{Chenge1601545,
abstract = {Earth{\{}$\backslash$textquoteright{\}}s energy imbalance (EEI) drives the ongoing global warming and can best be assessed across the historical record (that is, since 1960) from ocean heat content (OHC) changes. An accurate assessment of OHC is a challenge, mainly because of insufficient and irregular data coverage. We provide updated OHC estimates with the goal of minimizing associated sampling error. We performed a subsample test, in which subsets of data during the data-rich Argo era are colocated with locations of earlier ocean observations, to quantify this error. Our results provide a new OHC estimate with an unbiased mean sampling error and with variability on decadal and multidecadal time scales (signal) that can be reliably distinguished from sampling error (noise) with signal-to-noise ratios higher than 3. The inferred integrated EEI is greater than that reported in previous assessments and is consistent with a reconstruction of the radiative imbalance at the top of atmosphere starting in 1985. We found that changes in OHC are relatively small before about 1980; since then, OHC has increased fairly steadily and, since 1990, has increasingly involved deeper layers of the ocean. In addition, OHC changes in six major oceans are reliable on decadal time scales. All ocean basins examined have experienced significant warming since 1998, with the greatest warming in the southern oceans, the tropical/subtropical Pacific Ocean, and the tropical/subtropical Atlantic Ocean. This new look at OHC and EEI changes over time provides greater confidence than previously possible, and the data sets produced are a valuable resource for further study.},
author = {Cheng, Lijing and Trenberth, Kevin E and Fasullo, John and Boyer, Tim and Abraham, John and Zhu, Jiang},
doi = {10.1126/sciadv.1601545},
journal = {Science Advances},
number = {3},
pages = {e1601545},
publisher = {American Association for the Advancement of Science},
title = {{Improved estimates of ocean heat content from 1960 to 2015}},
url = {http://advances.sciencemag.org/content/3/3/e1601545},
volume = {3},
year = {2017}
}
@article{Cheng2020,
abstract = {Ocean salinity records the hydrological cycle and its changes, but data scarcity and the large changes in sampling make the reconstructions of long-term salinity changes challenging. Here, we present a new observational estimate of changes in ocean salinity since 1960 from the surface to 2000 m. We overcome some of the inconsistencies present in existing salinity reconstructions by using an interpolation technique that uses information on the spatio-temporal co-variability of salinity taken from model simulations. The interpolation technique is comprehensively evaluated using recent Argo-dominated observations through subsample tests. The new product strengthens previous findings that ocean surface and subsurface salinity contrasts have increased, i.e., the existing salinity pattern has amplified. We quantify this contrast by assessing the difference between the salinity in regions of high and low salinity averaged over the top 2000 m, a metric we refer to as SC2000. The increase in SC2000 is highly distinguishable from the sampling error and less affected by inter-annual variability and sampling error than if this metric was computed just for the surface. SC2000 increased by 0.5±0.3{\%} from 1960 to 1990 and by 1.0±0.1{\%} from 1991 to 2017 (1.6±0.2{\%} for 1960-2017), indicating an acceleration of the pattern amplification in recent decades. Combining this estimate with model simulations, we show that the change in SC2000 since 1960 emerges clearly as an anthropogenic signal from the natural variability. Based on the salinity-contrast metric and model simulations, we find a water cycle amplification of 2.1±3.9{\%} K-1 since 1960, with the larger error than salinity metric mainly being due to model uncertainty.},
author = {Cheng, Lijing and Trenberth, Kevin E and Gruber, Nicolas and Abraham, John P and Fasullo, John T and Li, Guancheng and Mann, Michael E and Zhao, Xuanming and Zhu, Jiang},
doi = {10.1175/JCLI-D-20-0366.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {sep},
number = {23},
pages = {10357--10381},
title = {{Improved estimates of changes in upper ocean salinity and the hydrological cycle}},
url = {https://doi.org/10.1175/JCLI-D-20-0366.1},
volume = {33},
year = {2020}
}
@article{HowWellCanWeCorrectSystematicErrorsinHistoricalXBTData,
address = {Boston MA, USA},
author = {Cheng, Lijing and Luo, Hao and Boyer, Timothy and Cowley, Rebecca and Abraham, John and Gouretski, Viktor and Reseghetti, Franco and Zhu, Jiang},
doi = {10.1175/JTECH-D-17-0122.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {5},
pages = {1103--1125},
publisher = {American Meteorological Society},
title = {{How Well Can We Correct Systematic Errors in Historical XBT Data?}},
url = {https://journals.ametsoc.org/view/journals/atot/35/5/jtech-d-17-0122.1.xml},
volume = {35},
year = {2018}
}
@article{doi:10.1029/2020GL087132,
abstract = {Abstract Several regions worldwide have seen significant trends in anthropogenic aerosol emissions during the period of detailed satellite observations since 2001. Over Europe (EUR) and North America (NAM) there were strong declines, over China increases then declines and over India, strong increases. Regional trends in model-simulated aerosol optical depth (AOD) and cloud radiative effects in both the Fifth and Sixth Coupled Model Intercomparison Projects (CMIP5 and CMIP6) are broadly consistent with the ones from satellite retrievals in most parts of EUR, NAM and India. CMIP6 models better match satellite-derived AOD trend in western NAM (increasing) and eastern China (decreasing), where CMIP5 models failed, pointing to improved anthropogenic aerosol emissions. Drop concentration trends in both observations and models qualitatively match AOD trends. The result for solar cloud radiative effect in models, however, is due to compensating errors: Models fail to reproduce observed liquid water path trends and show, in turn, opposite trends in cloud fraction.},
annote = {e2020GL087132 10.1029/2020GL087132},
author = {Cherian, Ribu and Quaas, Johannes},
doi = {10.1029/2020GL087132},
journal = {Geophysical Research Letters},
keywords = {CDNC,aerosol emission trend,aerosol optical depth,aerosol source regions,climate models,cloud radiative effects},
number = {9},
pages = {e2020GL087132},
title = {{Trends in AOD, Clouds, and Cloud Radiative Effects in Satellite Data and CMIP5 and CMIP6 Model Simulations Over Aerosol Source Regions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087132},
volume = {47},
year = {2020}
}
@article{Cherian2014,
author = {Cherian, Ribu and Quaas, Johannes and Salzmann, Marc and Wild, Martin},
doi = {10.1002/2013GL058715},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {mar},
number = {6},
pages = {2176--2181},
title = {{Pollution trends over Europe constrain global aerosol forcing as simulated by climate models}},
url = {http://doi.wiley.com/10.1002/2013GL058715},
volume = {41},
year = {2014}
}
@article{Cheung2013,
author = {Cheung, H N and Zhou, W and Mok, H Y and Wu, M C and Shao, Y},
doi = {10.1007/s00376-012-2006-y},
journal = {Advances in Atmospheric Sciences},
pages = {397--410},
title = {{Revisiting the Climatology of Atmospheric Blocking in the Northern Hemisphere}},
volume = {30},
year = {2013}
}
@article{Chevalier2015,
abstract = {Late Quaternary climate variability in the southern African subtropics is still only poorly resolved, with significant complexity and apparent contradictions in the regional dataset. To more effectively interpret and synthesize key regional records, we reanalysed the data from 13 pollen sequences from the summer rainfall zone of South Africa spanning the last 45,000 years, obtaining directly comparable quantitative reconstructions of mean annual temperature and summer rainfall. Temperature reconstructions from across the region provide consistent results, with all sites reflecting trends observed in southwest Indian Ocean sea-surface temperatures in the adjacent Mozambique Channel. Precipitation reconstructions are more heterogeneous, with two distinct subregions being identified. In the northeast, long-term trends in precipitation are determined by sea-surface and continental temperature trends, revealing a positive relationship between temperature and rainfall. This long-term pattern appears to be primarily driven by high northern latitude mechanisms, with direct local insolation being subordinate. Their relative impact reversed during terminal glacial period/early Holocene, at which time direct insolation forcing became the main driver of rainfall variability. Further south, in central South Africa, precipitation variability appears also to be influenced by the latitudinal position of the Southern Hemisphere westerlies, which combine with tropical flow to create tropical-temperate trough, advecting moisture into the interior. In this region, periods of maximum precipitation coincide with periods of elevated SSTs and equatorward expansions of the westerly storm track. This study allows for a fully constrained understanding of climate dynamics along the eastern African margin for the last 45,000 years, linking dynamics to drivers and describing how the climate systems evolved across the last glacial-interglacial transition.},
author = {Chevalier, Manuel and Chase, Brian M.},
doi = {10.1016/j.quascirev.2015.07.009},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Climate reconstruction,East Africa,Holocene,ITCZ,Insolation forcing,Palaeoclimatology,Pollen,Quaternary,Southern Africa},
pages = {117--130},
publisher = {Elsevier Ltd},
title = {{Southeast African records reveal a coherent shift from high- to low-latitude forcing mechanisms along the east African margin across last glacial-interglacial transition}},
url = {http://dx.doi.org/10.1016/j.quascirev.2015.07.009},
volume = {125},
year = {2015}
}
@article{doi:10.1175/JCLI-D-14-00387.1,
abstract = {AbstractEl Ni{\~{n}}o–Southern Oscillation (ENSO) events are associated with particular seasonal weather anomalies in many regions around the planet. When the statistical links are sufficiently strong, ENSO state information can provide useful seasonal forecasts with varying lead times. However, using conventional sea surface temperature or sea level pressure indices to characterize ENSO state leads to many instances of limited forecast skill (e.g., years identified as El Ni{\~{n}}o or La Ni{\~{n}}a with weather anomalies unlike the average), even in regions where there is considerable ENSO-associated anomaly, on average. Using outgoing longwave radiation (OLR) conditions to characterize ENSO state identifies a subset of the conventional ENSO years, called OLR El Ni{\~{n}}o and OLR La Ni{\~{n}}a years herein. Treating the OLR-identified subset of years differently can both usefully strengthen the level of statistical significance in the average (composite) and also greatly reduce the year-to-year deviations in the composite precipitation anomalies. On average, over most of the planet, the non-OLR El Ni{\~{n}}o and non-OLR La Ni{\~{n}}a years have much more limited statistical utility for precipitation. The OLR El Ni{\~{n}}o and OLR La Ni{\~{n}}a indices typically identify years in time to be of use to boreal wintertime and later seasonal forecasting efforts, meaning that paying attention to tropical Pacific OLR conditions may offer more than just a diagnostic tool. Understanding better how large-scale environmental conditions during ENSO events determine OLR behavior (and deep atmospheric convection) will lead to improved seasonal precipitation forecasts for many areas.},
author = {Chiodi, Andrew M and Harrison, D E},
doi = {10.1175/JCLI-D-14-00387.1},
journal = {Journal of Climate},
number = {15},
pages = {6133--6159},
title = {{Global Seasonal Precipitation Anomalies Robustly Associated with El Ni{\~{n}}o and La Ni{\~{n}}a Events – An OLR Perspective}},
url = {https://doi.org/10.1175/JCLI-D-14-00387.1},
volume = {28},
year = {2015}
}
@article{Chipperfield2018a,
abstract = {Abstract We use height-resolved and total column satellite observations and 3-D chemical transport model simulations to study stratospheric ozone variations during 1998?2017 as ozone-depleting substances decline. In 2017 extrapolar lower stratospheric ozone displayed a strong positive anomaly following much lower values in 2016. This points to large interannual variability rather than an ongoing downward trend, as reported recently by Ball et al. (2018, https://doi.org/10.5194/acp-18-1379-2018). The observed ozone variations are well captured by the chemical transport model throughout the stratosphere and are largely driven by meteorology. Model sensitivity experiments show that the contribution of past trends in short-lived chlorine species to the ozone changes is small. Similarly, the potential impact of modest trends in natural brominated short-lived species is small. These results confirm the important role that atmospheric dynamics plays in controlling ozone in the extrapolar lower stratosphere on multiannual time scales and the continued importance of monitoring ozone profiles as the stratosphere changes.},
author = {Chipperfield, Martyn P and Dhomse, Sandip and Hossaini, Ryan and Feng, Wuhu and Santee, Michelle L and Weber, Mark and Burrows, John P and Wild, Jeanette D and Loyola, Diego and Coldewey-Egbers, Melanie},
doi = {10.1029/2018GL078071},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {ozone,recovery,tropics},
month = {jun},
number = {11},
pages = {5718--5726},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{On the Cause of Recent Variations in Lower Stratospheric Ozone}},
url = {https://doi.org/10.1029/2018GL078071},
volume = {45},
year = {2018}
}
@article{Choi2016,
author = {Choi, Jae-Won and Kim, In-Gyum and Kim, Jeoung-Yun and Park, Cheol-Hong},
doi = {10.2151/sola.2016-022},
issn = {1349-6476},
journal = {Sola},
number = {0},
pages = {96--99},
title = {{The Recent Strengthening of Walker Circulation}},
url = {https://www.jstage.jst.go.jp/article/sola/12/0/12{\_}2016-022/{\_}article},
volume = {12},
year = {2016}
}
@article{DiffusiveNondiffusiveFluxDecompositionsinAtmosphericBoundaryLayers,
address = {Boston MA, USA},
author = {Chor, Tomas and McWilliams, James C and Chamecki, Marcelo},
doi = {10.1175/JAS-D-20-0093.1},
journal = {Journal of the Atmospheric Sciences},
number = {10},
pages = {3479--3494},
publisher = {American Meteorological Society},
title = {{Diffusive-Nondiffusive Flux Decompositions in Atmospheric Boundary Layers}},
url = {https://journals.ametsoc.org/view/journals/atsc/77/10/jasD200093.xml},
volume = {77},
year = {2020}
}
@article{Chou2013,
abstract = {Global temperatures have risen over the past few decades. The water vapour content of the atmosphere has increased as a result, strengthening the global hydrological cycle. This, in turn, has led to wet regions getting wetter, and dry regions drier. Climate model simulations suggest that a similar intensification of existing patterns may also apply to the seasonal cycle of rainfall. Here, we analyse regional and global trends in seasonal precipitation extremes over the past three decades, using a number of global and land-alone observational data sets. We show that globally the annual range of precipitation has increased, largely because wet seasons have become wetter. Although the magnitude of the shift is uncertain, largely owing to limitations inherent in the data sets used, the sign of the tendency is robust. On a regional scale, the tendency for wet seasons to get wetter occurs over climatologically rainier regions. Similarly, the tendency for dry season to get drier is seen in drier regions. Even if the total amount of annual rainfall does not change significantly, the enhancement in the seasonal precipitation cycle could have marked consequences for the frequency of droughts and floods. {\textcopyright} 2013 Macmillan Publishers Limited. All rights reserved.},
author = {Chou, Chia and Chiang, John C.H. and Lan, Chia Wei and Chung, Chia Hui and Liao, Yi Chun and Lee, Chia Jung},
doi = {10.1038/ngeo1744},
issn = {17520894},
journal = {Nature Geoscience},
number = {4},
pages = {263--267},
publisher = {Nature Publishing Group},
title = {{Increase in the range between wet and dry season precipitation}},
volume = {6},
year = {2013}
}
@article{christian_koutnik_roe_2018,
author = {Christian, John Erich and Koutnik, Michelle and Roe, Gerard},
doi = {10.1017/jog.2018.57},
journal = {Journal of Glaciology},
number = {246},
pages = {675--688},
publisher = {Cambridge University Press},
title = {{Committed retreat: controls on glacier disequilibrium in a warming climate}},
volume = {64},
year = {2018}
}
@article{doi:10.1002/2016RG000521,
abstract = {Abstract Knowledge of the temperature variability during the last one to two millennia is important for providing a perspective to present-day climate excursions, for assessing the sensitivity of the climate to different forcings, and for providing a test bed for climate models. Since systematic instrumental temperature records only extend back to the nineteenth century, such knowledge mainly relies on climate-sensitive proxy data. Here we critically assess some of the many challenges related to large-scale multiproxy temperature reconstructions. We begin with a review of available large-scale temperature reconstructions, focusing on the differences in low-frequency variability and the response to natural forcings such as major volcanic eruptions and changes in total solar irradiance. Then, we discuss different proxy selection strategies, review previously used reconstruction methods, and discuss their ability to reconstruct the amplitude of the low-frequency variability. To shed additional light on the challenges of large-scale reconstructions, we investigate the spatial and temporal correlation structures in the observed temperature field and discuss the implications of these correlation structures regarding the required number and positions of proxies. We demonstrate how the unavoidable uncertainty related to noisy proxies will show up as bias and variance in the reconstruction and that the partition between these forms of errors depends on the reconstruction method. Pseudo-proxy experiments are conducted to further discuss the influence of noise and the requirements regarding the geographical location and number of proxies necessary for reliably reconstructing the low-frequency variability. We conclude with recommendations for future large-scale temperature reconstructions.},
author = {Christiansen, Bo and Ljungqvist, Fredrik Charpentier},
doi = {10.1002/2016RG000521},
journal = {Reviews of Geophysics},
keywords = {climate variability,paleoclimate,temperature proxy records,temperature reconstructions},
number = {1},
pages = {40--96},
title = {{Challenges and perspectives for large-scale temperature reconstructions of the past two millennia}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016RG000521},
volume = {55},
year = {2017}
}
@article{doi:10.1080/01431161.2018.1444293,
abstract = { ABSTRACTThe Intergovernmental Panel on Climate Change Assessment Report 5 (IPCC AR5, 2013) discussed bulk atmospheric temperatures as indicators of climate variability and change. We examine four satellite datasets producing bulk tropospheric temperatures, based on microwave sounding units (MSUs), all updated since IPCC AR5. All datasets produce high correlations of anomalies versus independent observations from radiosondes (balloons), but differ somewhat in the metric of most interest, the linear trend beginning in 1979. The trend is an indicator of the response of the climate system to rising greenhouse gas concentrations and other forcings, and so is critical to understanding the climate. The satellite results indicate a range of near-global (+0.07 to +0.13°C decade−1) and tropical (+0.08 to +0.17°C decade−1) trends (1979–2016), and suggestions are presented to account for these differences. We show evidence that MSUs on National Oceanic and Atmospheric Administration's satellites (NOAA-12 and −14, 1990–2001+) contain spurious warming, especially noticeable in three of the four satellite datasets.Comparisons with radiosonde datasets independently adjusted for inhomogeneities and Reanalyses suggest the actual tropical (20°S-20°N) trend is +0.10 ± 0.03°C decade−1. This tropical result is over a factor of two less than the trend projected from the average of the IPCC climate model simulations for this same period (+0.27°C decade−1). },
author = {Christy, John R and Spencer, Roy W and Braswell, William D and Junod, Robert},
doi = {10.1080/01431161.2018.1444293},
journal = {International Journal of Remote Sensing},
number = {11},
pages = {3580--3607},
publisher = {Taylor {\&} Francis},
title = {{Examination of space-based bulk atmospheric temperatures used in climate research}},
url = {https://doi.org/10.1080/01431161.2018.1444293},
volume = {39},
year = {2018}
}
@article{Chung2019b,
abstract = {A strengthening of the Pacific Walker circulation (PWC) over recent decades triggered an intense debate on the validity of model-projected weakening of the PWC in response to anthropogenic warming. However, limitations of in situ observations and reanalysis datasets have hindered an unambiguous attribution of PWC changes to either natural or anthropogenic causes. Here, by conducting a comprehensive analysis based on multiple independent observational records, including satellite observations along with a large ensemble of model simulations, we objectively determine the relative contributions of internal variability and anthropogenic warming to the emergence of long-term PWC trends. Our analysis shows that the satellite-observed changes differ considerably from the model ensemble-mean changes, but they also indicate substantially weaker strengthening than implied by the reanalyses. Furthermore, some ensemble members are found to reproduce the observed changes in the tropical Pacific. These findings clearly reveal a dominant role of internal variability on the recent strengthening of the PWC.},
author = {Chung, Eui Seok and Timmermann, Axel and Soden, Brian J. and Ha, Kyung Ja and Shi, Lei and John, Viju O.},
doi = {10.1038/s41558-019-0446-4},
issn = {17586798},
journal = {Nature Climate Change},
number = {5},
pages = {405--412},
publisher = {Springer US},
title = {{Reconciling opposing Walker circulation trends in observations and model projections}},
url = {http://dx.doi.org/10.1038/s41558-019-0446-4},
volume = {9},
year = {2019}
}
@article{Church2011,
author = {Church, John A. and White, Neil J.},
doi = {10.1007/s10712-011-9119-1.},
journal = {Surveys in Geophysics},
pages = {585},
title = {{Sea-level rise from the late 19th to the early 21st Century}},
volume = {32},
year = {2011}
}
@article{doi:10.1029/2012GL051241,
abstract = {The Greenland $\delta$18O ice core record is used as a proxy for Greenland surface air temperatures and to interpret Atlantic Multidecadal Oscillation (AMO) variability. An analysis of annual $\delta$18O data from six Arctic ice cores (five from Greenland and one from Canada's Ellesmere Island) suggests a significant AMO spatial and temporal variability within a recent period of 660 years. A dominant AMO periodicity near 20 years is clearly observed in the southern (Dye3 site) and the central (GISP2, Crete and Milcent) regions of Greenland. This 20-year variability is, however, significantly reduced in the northern (Camp Century and Agassiz Ice Cap) region, likely due to a larger distance from the Atlantic Ocean, and a much lower snow accumulation. A longer time scale AMO component of 45–65 years, which has been seen clearly in the 20th century SST data, is detected only in central Greenland ice cores. We find a significant difference between the AMO cycles during the Little Ice Age (LIA) and the Medieval Warm Period (MWP). The LIA was dominated by a ∼20 year AMO cycle with no other decadal or multidecadal scale variability above the noise level. However, during the preceding MWP the 20 year cycle was replaced by a longer scale cycle centered near a period of 43 years with a further 11.5 year periodicity. An analysis of two coupled atmosphere-ocean general circulation models control runs (UK Met Office HadCM3 and NOAA GFDL CM2.1) agree with the shorter and longer time-scales of Atlantic Meridional Overturning Circulation (AMOC) and temperature fluctuations with periodicities close to those observed. However, the geographic variability of these periodicities indicated by ice core data is not captured in model simulations.},
author = {Chylek, Petr and Folland, Chris and Frankcombe, Leela and Dijkstra, Henk and Lesins, Glen and Dubey, Manvendra},
doi = {10.1029/2012GL051241},
journal = {Geophysical Research Letters},
keywords = {Arctic,Atlantic Multidecadal Oscillation,Greenland,Ice cores},
number = {9},
pages = {L09705},
title = {{Greenland ice core evidence for spatial and temporal variability of the Atlantic Multidecadal Oscillation}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012GL051241},
volume = {39},
year = {2012}
}
@article{https://doi.org/10.1029/2019GL086926,
abstract = {Abstract We use time series of time-variable gravity from the Gravitational Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) missions to evaluate the mass balance of the world's glaciers and ice caps (GIC) for the time period April 2002 to September 2019, excluding Antarctica and Greenland peripheral glaciers. We demonstrate continuity of the mass balance record across the GRACE/GRACE-FO data gap using independent data from the GMAO Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) reanalysis. We report an average mass loss of 281.5 ± 30 Gt/yr, an acceleration of 50 ± 20 Gt/yr per decade, and a 13-mm cumulative sea level rise for the analyzed period. Seven regions dominate the mass loss, with the largest share from the Arctic: Alaska (72.5 ± 8 Gt/yr), Canadian Arctic Archipelago (73.0 ± 9 Gt/yr), Southern Andes (30.4 ± 13 Gt/yr), High Mountain Asia (HMA) (28.8 ± 11 Gt/yr), Russian Arctic (20.2 ± 6 Gt/yr), Iceland (15.9 ± 4 Gt/yr), and Svalbard (12.1 ± 4 Gt/yr). At the regional level, the analysis of acceleration is complicated by a strong interannual to decadal variability in mass balance that is well reproduced by the GRACE-calibrated MERRA-2 data.},
annote = {e2019GL086926 10.1029/2019GL086926},
author = {Cirac{\`{i}}, E and Velicogna, I and Swenson, S},
doi = {10.1029/2019GL086926},
journal = {Geophysical Research Letters},
keywords = {climate model,freshwater,glacier,gravity,hydrology,sea level},
number = {9},
pages = {e2019GL086926},
title = {{Continuity of the Mass Loss of the World's Glaciers and Ice Caps From the GRACE and GRACE Follow-On Missions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086926},
volume = {47},
year = {2020}
}
@article{Clark2020a,
author = {Clark, Peter U and He, Feng and Golledge, Nicholas R and Mitrovica, Jerry X and Dutton, Andrea and Hoffman, Jeremy S and Dendy, Sarah},
doi = {10.1038/s41586-020-1931-7},
issn = {1476-4687},
journal = {Nature},
number = {7792},
pages = {660--664},
title = {{Oceanic forcing of penultimate deglacial and last interglacial sea-level rise}},
url = {https://doi.org/10.1038/s41586-020-1931-7},
volume = {577},
year = {2020}
}
@article{Clarkson2015b,
abstract = {The largest mass extinction in Earth{\&}{\#}039;s history occurred at the Permian-Triassic boundary 252 million years ago. Several ideas have been proposed for what devastated marine life, but scant direct evidence exists. Clarkson et al. measured boron isotopes across this period as a highly sensitive proxy for seawater pH. It appears that, although the oceans buffered the acidifiying effects of carbon release from contemporary pulses of volcanism, buffering failed when volcanism increased during the formation of the Siberian Traps. The result was a widespread drop in ocean pH and the elimination of shell-forming organisms.Science, this issue p. 229 Ocean acidification triggered by Siberian Trap volcanism was a possible kill mechanism for the Permo-Triassic Boundary mass extinction, but direct evidence for an acidification event is lacking. We present a high-resolution seawater pH record across this interval, using boron isotope data combined with a quantitative modeling approach. In the latest Permian, increased ocean alkalinity primed the Earth system with a low level of atmospheric CO2 and a high ocean buffering capacity. The first phase of extinction was coincident with a slow injection of carbon into the atmosphere, and ocean pH remained stable. During the second extinction pulse, however, a rapid and large injection of carbon caused an abrupt acidification event that drove the preferential loss of heavily calcified marine biota.},
author = {Clarkson, M O and Kasemann, S A and Wood, R A and Lenton, T M and Daines, S J and Richoz, S and Ohnemueller, F and Meixner, A and Poulton, S W and Tipper, E T},
doi = {10.1126/science.aaa0193},
journal = {Science},
month = {apr},
number = {6231},
pages = {229},
title = {{Ocean acidification and the Permo-Triassic mass extinction}},
url = {http://science.sciencemag.org/content/348/6231/229.abstract},
volume = {348},
year = {2015}
}
@article{Claustre2020a,
abstract = {Biogeochemical-Argo (BGC-Argo) is a network of profiling floats carrying sensors that enable observation of as many as six essential biogeochemical and bio-optical variables: oxygen, nitrate, pH, chlorophyll a, suspended particles, and downwelling irradiance. This sensor network represents today's most promising strategy for collecting temporally and vertically resolved observations of biogeochemical properties throughout the ocean. All data are freely available within 24 hours of transmission. These data fill large gaps in ocean-observing systems and support three ambitions: gaining a better understanding of biogeochemical processes (e.g., the biological carbon pump and air?sea CO2 exchanges) and evaluating ongoing changes resulting from increasing anthropogenic pressure (e.g., acidification and deoxygenation); managing the ocean (e.g., improving the global carbon budget and developing sustainable fisheries); and carrying out exploration for potential discoveries. The BGC-Argo network has already delivered extensive high-quality global data sets that have resulted in unique scientific outcomes from regional to global scales. With the proposed expansion of BGC-Argo in the near future, this network has the potential to become a pivotal observation system that links satellite and ship-based observations in a transformative manner.},
annote = {doi: 10.1146/annurev-marine-010419-010956},
author = {Claustre, Herv{\'{e}} and Johnson, Kenneth S and Takeshita, Yuichiro},
doi = {10.1146/annurev-marine-010419-010956},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {23--48},
publisher = {Annual Reviews},
title = {{Observing the Global Ocean with Biogeochemical-Argo}},
url = {https://doi.org/10.1146/annurev-marine-010419-010956},
volume = {12},
year = {2020}
}
@article{Cleator2019,
author = {Cleator, Sean F and Harrison, Sandy P and Nichols, Nancy K and Prentice, I Colin and Roulstone, Ian},
doi = {10.5194/cp-16-699-2020},
issn = {1814-9332},
journal = {Climate of the Past},
month = {apr},
number = {2},
pages = {699--712},
publisher = {Copernicus Publications},
title = {{A new multivariable benchmark for Last Glacial Maximum climate simulations}},
url = {https://cp.copernicus.org/articles/16/699/2020/},
volume = {16},
year = {2020}
}
@article{Clem2017,
abstract = {During 1979--2014, eastern tropical Pacific sea surface temperatures significantly cooled, which has generally been attributed to the transition of the Pacific Decadal Oscillation to its negative phase after 1999. We find the eastern tropical Pacific cooling to be associated with: (1) an intensified Walker Circulation during austral summer (December--February, DJF) and autumn (March--May, MAM); (2) a weakened South Pacific Hadley cell and subtropical jet during MAM; and (3) a strengthening of the circumpolar westerlies between 50 and 60{\{}$\backslash$textdegree{\}}S during DJF and MAM. Observed cooling in the eastern tropical Pacific is linearly congruent with 60--80 {\{}{\%}{\}} of the observed Southern Hemisphere positive zonal-mean zonal wind trend between 50 and 60{\{}$\backslash$textdegree{\}}S during DJF ({\{}$\backslash$textasciitilde{\}}35 {\{}{\%}{\}} of the interannual variability), and around half of the observed positive zonal-mean zonal wind trend during MAM ({\{}$\backslash$textasciitilde{\}}15 {\{}{\%}{\}} of the interannual variability). Although previous studies have linked the strengthened DJF and MAM circumpolar westerlies to stratospheric ozone depletion and increasing greenhouse gases, we note that the continuation of the positive SAM trends into the twenty-first century is partially associated with eastern tropical Pacific cooling, especially during MAM when zonal wind anomalies associated with eastern tropical Pacific cooling project strongly onto the observed trends. Outside of DJF and MAM, eastern tropical Pacific cooling is associated with opposing zonal wind anomalies over the Pacific and Indian sectors, which we infer is the reason for the absence of significant positive SAM trends outside of DJF and MAM despite significant eastern tropical Pacific cooling seen during all seasons.},
author = {Clem, Kyle R. and Renwick, James A. and McGregor, James},
doi = {10.1007/s00382-016-3329-7},
issn = {14320894},
journal = {Climate Dynamics},
number = {1-2},
pages = {113--129},
publisher = {Springer Berlin Heidelberg},
title = {{Relationship between eastern tropical Pacific cooling and recent trends in the Southern Hemisphere zonal-mean circulation}},
volume = {49},
year = {2017}
}
@article{Clette2014,
author = {Clette, Fr{\'{e}}d{\'{e}}ric and Svalgaard, Leif and Vaquero, Jos{\'{e}} M. and Cliver, Edward W.},
doi = {10.1007/s11214-014-0074-2},
issn = {0038-6308},
journal = {Space Science Reviews},
month = {dec},
number = {1-4},
pages = {35--103},
title = {{Revisiting the Sunspot Number}},
url = {http://link.springer.com/10.1007/s11214-014-0074-2},
volume = {186},
year = {2014}
}
@article{clotten_seasonal_2018,
author = {Clotten, Caroline and Stein, Ruediger and Fahl, Kirsten and {De Schepper}, Stijn},
doi = {10.1016/j.epsl.2017.10.011},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {jan},
pages = {61--72},
shorttitle = {Seasonal sea ice cover during the warm {\{}Pliocene{\}}},
title = {{Seasonal sea ice cover during the warm Pliocene: Evidence from the Iceland Sea (ODP Site 907)}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X17305708},
volume = {481},
year = {2018}
}
@article{Cobb67,
abstract = {The El Ni{\~{n}}o{\{}$\backslash$textendash{\}}Southern Oscillation (ENSO) drives large changes in global climate patterns from year to year, yet its sensitivity to continued anthropogenic greenhouse forcing is uncertain. We analyzed fossil coral reconstructions of ENSO spanning the past 7000 years from the Northern Line Islands, located in the center of action for ENSO. The corals document highly variable ENSO activity, with no evidence for a systematic trend in ENSO variance, which is contrary to some models that exhibit a response to insolation forcing over this same period. Twentieth-century ENSO variance is significantly higher than average fossil coral ENSO variance but is not unprecedented. Our results suggest that forced changes in ENSO, whether natural or anthropogenic, may be difficult to detect against a background of large internal variability.},
author = {Cobb, Kim M and Westphal, Niko and Sayani, Hussein R and Watson, Jordan T and {Di Lorenzo}, Emanuele and Cheng, H and Edwards, R L and Charles, Christopher D},
doi = {10.1126/science.1228246},
issn = {0036-8075},
journal = {Science},
number = {6115},
pages = {67--70},
publisher = {American Association for the Advancement of Science},
title = {{Highly Variable El Ni{\~{n}}o-Southern Oscillation Throughout the Holocene}},
url = {http://science.sciencemag.org/content/339/6115/67},
volume = {339},
year = {2013}
}
@article{Coddington2016,
author = {Coddington, O. and Lean, J. L. and Pilewskie, P. and Snow, M. and Lindholm, D.},
doi = {10.1175/BAMS-D-14-00265.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
month = {jul},
number = {7},
pages = {1265--1282},
title = {{A Solar Irradiance Climate Data Record}},
url = {http://journals.ametsoc.org/doi/10.1175/BAMS-D-14-00265.1},
volume = {97},
year = {2016}
}
@article{Cohen2020,
author = {Cohen, J and Zhang, X and Francis, J and Jung, T and Kwok, R and Overland, J and Ballinger, T and Bhatt, U S and Chen, H W and Coumou, D and Feldstein, S and Handorf, D and Henderson, G and Ionita, M and Kretschmer, M and Laliberte, F and Lee, S and Linderholm, H W and Maslowski, W and Peings, Y and Pfeiffer, K and Yoon, J},
doi = {10.1038/s41558-019-0662-y},
journal = {Nature Climate Change},
pages = {20--29},
title = {{Divergent consensuses on Arctic amplification influence on midlatitude severe winter weather}},
volume = {10},
year = {2020}
}
@article{Coen2020MultidecadalTA,
author = {{Collaud Coen}, M and Andrews, E and Alastuey, A and Arsov, T and Backman, J and Brem, B and Bukowiecki, N and Couret, C{\'{e}}dric and Eleftheriadis, K and Flentje, H and Fiebig, M and Gysel-Beer, Martin and Hand, J and Hoffer, Andr{\'{a}}s and Hooda, R and Hueglin, C and Joubert, W and Keywood, M and Kim, J and Kim, Sang Woo and Labuschagne, C and Lin, Neng-Huei and Lin, Yong and Myhre, C and Luoma, Krista and Lyamani, H and Marinoni, A and Mayol-Bracero, O and Mihalopoulos, N and Pandolfi, M and Prats, N and Prenni, A J and Putaud, J.-P. and Ries, L and Reisen, F and Sellegri, K and Sharma, S and Sheridan, P and Sherman, J and Sun, Junying and Titos, G and Torres, E and Tuch, T and Weller, R and Wiedensohler, A and Zieger, P and Laj, P},
doi = {10.5194/acp-20-8867-2020},
journal = {Atmospheric Chemistry and Physics},
number = {14},
pages = {8867--8908},
title = {{Multidecadal trend analysis of aerosol radiative properties at a global scale}},
volume = {20},
year = {2020}
}
@article{Collins2011,
abstract = {We describe here the development and evaluation of an Earth system model suitable for centennial-scale climate prediction. The principal new components added to the physical climate model are the terrestrial and ocean ecosystems and gas-phase tropospheric chemistry, along with their coupled interactions. The individual Earth system components are described briefly and the relevant interactions between the components are explained. Because the multiple interactions could lead to unstable feedbacks, we go through a careful process of model spin up to ensure that all components are stable and the interactions balanced. This spun-up configuration is evaluated against observed data for the Earth system components and is generally found to perform very satisfactorily. The reason for the evaluation phase is that the model is to be used for the core climate simulations carried out by the Met Office Hadley Centre for the Coupled Model Intercomparison Project (CMIP5), so it is essential that addition of the extra complexity does not detract substantially from its climate performance. Localised changes in some specific meteorological variables can be identified, but the impacts on the overall simulation of present day climate are slight. This model is proving valuable both for climate predictions, and for investigating the strengths of biogeochemical feedbacks. {\textcopyright} 2011. Author(s).},
author = {Collins, W. J. and Bellouin, N. and Doutriaux-Boucher, M. and Gedney, N. and Halloran, P. and Hinton, T. and Hughes, J. and Jones, C. D. and Joshi, M. and Liddicoat, S. and Martin, G. and O'Connor, F. and Rae, J. and Senior, C. and Sitch, S. and Totterdell, I. and Wiltshire, A. and Woodward, S.},
doi = {10.5194/gmd-4-1051-2011},
issn = {19919603},
journal = {Geoscientific Model Development},
number = {4},
pages = {1051--1075},
title = {{Development and evaluation of an Earth-System model – HadGEM2}},
volume = {4},
year = {2011}
}
@incollection{Collinsetal.,
author = {Collins, M. and Sutherland, M. and Bower, L. and Cheong, S.-M.},
booktitle = {IPCC Special Report on the Ocean and Cryosphere in a Changing Climate},
doi = {https://www.ipcc.ch/srocc/chapter/chapter-6},
editor = {P{\"{o}}rtner, Hans-Otto and Roberts, DC and Masson-Delmotte, V and Zhai, P and Tignor, M and Poloczanska, E and Mintenbeck, K and Alegr{\'{i}}a, A and Nicolai, M and Okem, A},
pages = {589--656},
publisher = {In Press},
title = {{Extremes, Abrupt Changes and Managing Risks}},
url = {https://www.ipcc.ch/srocc/chapter/chapter-6},
year = {2019}
}
@article{Comiso2017,
abstract = {The Antarctic sea ice extent has been slowly increasing contrary to expected trends due to global warming and results from coupled climate models. After a record high extent in 2012 the extent was even higher in 2014 when the magnitude exceeded 20 × 106 km2 for the first time during the satellite era. The positive trend is confirmed with newly reprocessed sea ice data that addressed inconsistency issues in the time series. The variability in sea ice extent and ice area was studied alongside surface ice temperature for the 34-yr period starting in 1981, and the results of the analysis show a strong correlation of −0.94 during the growth season and −0.86 during the melt season. The correlation coefficients are even stronger with a one-month lag in surface temperature at −0.96 during the growth season and −0.98 during the melt season, suggesting that the trend in sea ice cover is strongly influenced by the trend in surface temperature. The correlation with atmospheric circulation as represented by the southern annular mode (SAM) index appears to be relatively weak. A case study comparing the record high in 2014 with a relatively low ice extent in 2015 also shows strong sensitivity to changes in surface temperature. The results suggest that the positive trend is a consequence of the spatial variability of global trends in surface temperature and that the ability of current climate models to forecast sea ice trend can be improved through better performance in reproducing observed surface temperatures in the Antarctic region.},
author = {Comiso, Josefino C and Gersten, Robert A and Stock, Larry V and Turner, John and Perez, Gay J. and Cho, Kohei},
doi = {10.1175/JCLI-D-16-0408.1},
issn = {0894-8755},
journal = {Journal of Climate},
keywords = {Earth temperature,Global warming,Ice sheets,Sea ice -- Antarctica,Time series analysis},
month = {mar},
number = {6},
pages = {2251--2267},
title = {{Positive Trend in the Antarctic Sea Ice Cover and Associated Changes in Surface Temperature}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0408.1},
volume = {30},
year = {2017}
}
@article{geosciences9030135,
abstract = {Observed changes in Northern Hemisphere snow cover from satellite records were compared to those predicted by all available Coupled Model Intercomparison Project Phase 5 (“CMIP5”) climate models over the duration of the satellite's records, i.e., 1967–2018. A total of 196 climate model runs were analyzed (taken from 24 climate models). Separate analyses were conducted for the annual averages and for each of the seasons (winter, spring, summer, and autumn/fall). A longer record (1922–2018) for the spring season which combines ground-based measurements with satellite measurements was also compared to the model outputs. The climate models were found to poorly explain the observed trends. While the models suggest snow cover should have steadily decreased for all four seasons, only spring and summer exhibited a long-term decrease, and the pattern of the observed decreases for these seasons was quite different from the modelled predictions. Moreover, the observed trends for autumn and winter suggest a long-term increase, although these trends were not statistically significant. Possible explanations for the poor performance of the climate models are discussed.},
author = {Connolly, Ronan and Connolly, Michael and Soon, Willie and Legates, David R and Cionco, Rodolfo Gustavo and {Velasco Herrera}, V{\'{i}}ctor. M},
doi = {10.3390/geosciences9030135},
issn = {2076-3263},
journal = {Geosciences},
number = {3},
pages = {135},
title = {{Northern Hemisphere Snow-Cover Trends (1967–2018): A Comparison between Climate Models and Observations}},
url = {https://www.mdpi.com/2076-3263/9/3/135},
volume = {9},
year = {2019}
}
@article{Conroy2017,
abstract = {The relationship between salinity and the stable oxygen isotope ratio of seawater ({\$}\delta{\$}18Osw) is of utmost importance to the quantitative reconstruction of past changes in salinity from {\$}\delta{\$}18O values of marine carbonates. This relationship is often considered to be uniform across water masses, but the constancy of the {\$}\delta{\$}18Osw-salinity relationship across space and time remains uncertain, as {\$}\delta{\$}18Osw responds to varying atmospheric vapor sources and pathways, while salinity does not. Here we present new {\$}\delta{\$}18Osw-salinity data from sites spanning the tropical Pacific Ocean. New data from Palau, Papua New Guinea, Kiritimati, and Gal{\'{a}}pagos show slopes ranging from 0.09 ‰/psu in the Gal{\'{a}}pagos to 0.32‰/psu in Palau. The slope of the {\$}\delta{\$}18Osw-salinity relationship is higher in the western tropical Pacific versus the eastern tropical Pacific in observations and in two isotope-enabled climate model simulations. A comparison of {\$}\delta{\$}18Osw-salinity relationships derived from short-term spatial surveys and multiyear time series at Papua New Guinea and Gal{\'{a}}pagos suggests spatial relationships can be substituted for temporal relationships at these sites, at least within the time period of the investigation. However, the {\$}\delta{\$}18Osw-salinity relationship varied temporally at Palau, likely in response to water mass changes associated with interannual El Ni{\~{n}}o–Southern Oscillation (ENSO) variability, suggesting nonstationarity in this local {\$}\delta{\$}18Osw-salinity relationship. Applying local {\$}\delta{\$}18Osw-salinity relationships in a coral {\$}\delta{\$}18O forward model shows that using a constant, basinwide {\$}\delta{\$}18Osw-salinity slope can both overestimate and underestimate the contribution of {\$}\delta{\$}18Osw to carbonate {\$}\delta{\$}18O variance at individual sites in the western tropical Pacific.},
author = {Conroy, Jessica L and Thompson, Diane M and Cobb, Kim M and Noone, David and Rea, Solanda and Legrande, Allegra N},
doi = {10.1002/2016PA003073},
issn = {08838305},
journal = {Paleoceanography},
keywords = {paleoclimate,salinity,seawater,stable oxygen isotope,tropical Pacific},
month = {may},
number = {5},
pages = {484--497},
title = {{Spatiotemporal variability in the $\delta$18O-salinity relationship of seawater across the tropical Pacific Ocean}},
volume = {32},
year = {2017}
}
@article{Cook2019,
author = {Cook, Edward R and Kushnir, Yochanan and Smerdon, Jason E and Williams, A Park and Anchukaitis, Kevin J and Wahl, Eugene R},
doi = {10.1007/s00382-019-04696-2},
isbn = {0123456789},
issn = {0930-7575},
journal = {Climate Dynamics},
keywords = {Euro-Mediterranean tree rings,Millennium reconstruction,North Atlantic Oscillation,Stochastic forcing,euro-mediterranean tree rings,millennium reconstruction,north atlantic oscillation,stochastic forcing},
month = {aug},
number = {3-4},
pages = {1567--1580},
publisher = {Springer Berlin Heidelberg},
title = {{A Euro-Mediterranean tree-ring reconstruction of the winter NAO index since 910 C.E.}},
url = {http://dx.doi.org/10.1007/s00382-019-04696-2 http://link.springer.com/10.1007/s00382-019-04696-2},
volume = {53},
year = {2019}
}
@article{Cook2015b,
abstract = {Climate model projections suggest widespread drying in the Mediterranean Basin and wetting in Fennoscandia in the coming decades largely as a consequence of greenhouse gas forcing of climate. To place these and other “Old World” climate projections into historical perspective based on more complete estimates of natural hydroclimatic variability, we have developed the “Old World Drought Atlas” (OWDA), a set of year-to-year maps of tree-ring reconstructed summer wetness and dryness over Europe and the Mediterranean Basin during the Common Era. The OWDA matches historical accounts of severe drought and wetness with a spatial completeness not previously available. In addition, megadroughts reconstructed over north-central Europe in the 11th and mid-15th centuries reinforce other evidence from North America and Asia that droughts were more severe, extensive, and prolonged over Northern Hemisphere land areas before the 20th century, with an inadequate understanding of their causes. The OWDA provides new data to determine the causes of Old World drought and wetness and attribute past climate variability to forced and/or internal variability.},
author = {Cook, Edward R and Seager, Richard and Kushnir, Yochanan and Briffa, Keith R and B{\"{u}}ntgen, Ulf and Frank, David and Krusic, Paul J and Tegel, Willy and van der Schrier, Gerard and Andreu-Hayles, Laia and Baillie, Mike and Baittinger, Claudia and Bleicher, Niels and Bonde, Niels and Brown, David and Carrer, Marco and Cooper, Richard and {\v{C}}ufar, Katarina and Dittmar, Christoph and Esper, Jan and Griggs, Carol and Gunnarson, Bj{\"{o}}rn and G{\"{u}}nther, Bj{\"{o}}rn and Gutierrez, Emilia and Haneca, Kristof and Helama, Samuli and Herzig, Franz and Heussner, Karl-uwe and Hofmann, Jutta and Janda, Pavel and Kontic, Raymond and K{\"{o}}se, Nesibe and Kyncl, Tom{\'{a}}{\v{s}} and Levani{\v{c}}, Tom and Linderholm, Hans and Manning, Sturt and Melvin, Thomas M. and Miles, Daniel and Neuwirth, Burkhard and Nicolussi, Kurt and Nola, Paola and Panayotov, Momchil and Popa, Ionel and Rothe, Andreas and Seftigen, Kristina and Seim, Andrea and Svarva, Helene and Svoboda, Miroslav and Thun, Terje and Timonen, Mauri and Touchan, Ramzi and Trotsiuk, Volodymyr and Trouet, Valerie and Walder, Felix and Wa{\.{z}}ny, Tomasz and Wilson, Rob and Zang, Christian},
doi = {10.1126/sciadv.1500561},
issn = {2375-2548},
journal = {Science Advances},
month = {nov},
number = {10},
pages = {e1500561},
title = {{Old World megadroughts and pluvials during the Common Era}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.1500561},
volume = {1},
year = {2015}
}
@article{Cooper2020,
author = {Cooper, O. R. and Schultz, M. G. and Schr{\"{o}}der, S. and Chang, K.-L. and Gaudel, A. and {Carbajal Ben{\'{i}}tez}, G. and Cuevas, E. and Fr{\"{o}}hlich, M. and Galbally, I. E. and Kubistin, D. and Lu, X. and McClure-Begley, A. and Molloy, S. and N{\'{e}}d{\'{e}}lec, P. and O'Brien, J. and Oltmans, S. J. and Petropavlovskikh, I. and Ries, L. and Senik, I. and Sj{\"{o}}berg, K. and Solberg, S. and Spain, T. G. and Spangl, W. and Steinbacher, M. and Tarasick, D. and Thouret, V. and {X. Xu}},
doi = {10.1525/elementa.420},
journal = {Elementa: Science of the Anthropocene},
number = {1},
pages = {23},
title = {{Multi-decadal surface ozone trends at globally distributed remote locations}},
volume = {8},
year = {2020}
}
@article{Corbett2015,
author = {Corbett, J. G. and Loeb, N. G.},
doi = {10.1002/2015JD023484},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {nov},
number = {22},
pages = {11,608--11,616},
title = {{On the relative stability of CERES reflected shortwave and MISR and MODIS visible radiance measurements during the Terra satellite mission}},
url = {http://doi.wiley.com/10.1002/2015JD023484},
volume = {120},
year = {2015}
}
@article{Cornes2013,
abstract = {A westerly index for Europe is developed back to 1692 using newly recovered and corrected Mean Sea-level Pressure (MSLP) data from London and Paris. The index is compared against various instrumental and proxy indices of the North Atlantic Oscillation (NAO). In the winter, the Paris-London index depicts a spatial pattern of atmospheric circulation that is bi-modal, with centres of action that are shifted eastwards compared to the NAO. Owing to asymmetry in the NAO the Paris-London index provides a good depiction of positive NAO conditions as well as extreme negative phases of the NAO that arise from reversals of the pressure centres, but less extreme negative NAO conditions are associated with westerly index values approaching zero. The merit in using the Paris-London index lies with its consistency over time as a measure of westerly wind flow, which may not be the case with other proxy-based indices. In the summer, the Paris-London index bears a close relationship to the reconstructed high-summer NAO series of Folland et al. (2009) as well as the summer Luterbacher et al. (1999) NAO reconstruction. An important finding is that the summer NAO was highly variable during the early nineteenth century but was predominately positive on the decadal time scale during that period. Since circa 1970 the summer index has mostly been negative, indicating reduced westerlies and increased blocking conditions that are exceptional in the context of the last 250 years. Copyright {\{}$\backslash$copyright{\}} 2012 Royal Meteorological Society},
author = {Cornes, Richard C. and Jones, Philip D. and Briffa, Keith R. and Osborn, Timothy J.},
doi = {10.1002/joc.3416},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {Little Ice Age,NAO reconstruction,Sea-level pressure,Zonal flow},
number = {1},
pages = {228--248},
title = {{Estimates of the North Atlantic Oscillation back to 1692 using a Paris–London westerly index}},
volume = {33},
year = {2013}
}
@article{doi:10.1002/gdj3.100,
abstract = {Abstract A new data set of Night Marine Air Temperature (NMAT) is presented that builds on the HadNMAT2 data set, which was released in 2013. In a similar manner to HadNMAT2, the new data set (CLASSnmat) provides uninterpolated, monthly global values at a 5° resolution back to 1880. In addition to being extended to the end of 2019, four main developments are made in CLASSnmat: (1) the NMAT values are extracted from the most recent version of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS Release 3) and a revised method of eliminating duplicated observations is used; (2) values of NMAT are adjusted to 2m and 20m heights in addition to the 10 m height used in HadNMAT2; (3) a refinement is made to the corrections necessary during World War 2, which uses more of the NMAT observations and hence results in a more extensive spatial coverage for this period than was possible in HadNMAT2; (4) an updated gridding method is used that allows for an improved propagation of uncertainty from the individual NMAT values through to the gridded estimates. In this paper, the method used to construct CLASSnmat (version 1.0.0.0) is described.},
author = {Cornes, Richard C and Kent, Elizabeth.C. and Berry, David.I. and Kennedy, John J},
doi = {10.1002/gdj3.100},
journal = {Geoscience Data Journal},
keywords = {NMAT,climate change,global surface temperature,marine,observations},
number = {2},
pages = {170--184},
title = {{CLASSnmat: A global night marine air temperature data set, 1880–2019}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/gdj3.100},
volume = {7},
year = {2020}
}
@article{Cortijo1997,
author = {Cortijo, Elsa and Labeyrie, Laurent and Vidal, Laurence and Vautravers, Maryline and Chapman, Mark and Duplessy, Jean-Claude and Elliot, Mary and Arnold, Maurice and Turon, Jean-Louis and Auffret, G{\'{e}}rard},
doi = {10.1016/S0012-821X(96)00217-8},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {jan},
number = {1-2},
pages = {29--45},
title = {{Changes in sea surface hydrology associated with Heinrich event 4 in the North Atlantic Ocean between 40° and 60°N}},
volume = {146},
year = {1997}
}
@article{Costa2018,
abstract = {In the Subarctic Pacific, variability in productivity on glacial-interglacial timescales is often attributed to changes in stratification and nutrient delivery to the surface, but the mechanisms driving this relationship are poorly constrained. Records extending beyond the last glacial maximum from both the open ocean and the marginal seas are required to investigate the timing and magnitude of different influential processes through the full glacial cycle. In this study we generated 231Pa/230Th over 210,000 years in order to capture two full glacial cycles of paleoproductivity on the Juan de Fuca Ridge in the East Subarctic Pacific. The sedimentary 231Pa/230Th ratios are always equal to or greater than the seawater production ratio (0.093), consistent with enhanced biological scavenging in this region. The temporal pattern of 231Pa/230Th burial is remarkably coherent with changes in climate, with high values (0.20) during peak interglacial periods descending to low values (0.10) during peak glacial conditions, consistent with other long productivity records from this region. We investigate the possible contributions of temperature, sea ice formation, Bering Strait closure, wind strength, upwelling, and subsurface nutrient concentrations as possible mechanisms by which physical and/or chemical stratification emerged during glacial periods. Due to the low sea surface salinity in the North Pacific, cooling actually weakens the density gradient in surface (0–200 m) waters. To create the steep density profiles that characterize physical stratification, additional processes to reduce the salinity of surface waters must occur during glacial periods. We suggest that regional sea ice formation and Bering Strait closure may have contributed to freshening surface waters and enhancing physical stratification during glacial periods. Additionally, simulated weak winds in this region due to the southward shift of the glacial westerlies may have further reduced surface mixing depths in the Subarctic Pacific. Finally, previous model simulations suggest strong glacial wind stress curl in the Subarctic Pacific, but enhanced Ekman divergence of nutrient-poor subsurface waters would have little impact on stimulating productivity in surface waters of the Subarctic Pacific. We therefore suggest that the combined effects of surface freshening, weak winds, and lower subsurface nutrient concentrations may all have contributed to lower productivity during glacial periods in the Subarctic Pacific.},
author = {Costa, Kassandra M and McManus, Jerry F and Anderson, Robert F},
doi = {10.1029/2018PA003363},
issn = {25724517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Subarctic Pacific,productivity,stratification},
month = {sep},
number = {9},
pages = {914--933},
title = {{Paleoproductivity and Stratification Across the Subarctic Pacific Over Glacial-Interglacial Cycles}},
volume = {33},
year = {2018}
}
@article{Cotte2007,
abstract = {Several studies have provided evidence of a reduction of the Antarctic sea ice extent. However, these studies were conducted either at a global scale or at a regional scale, and possible inter-regional differences were not analysed. Using the long-term whaling database we investigated circum-Antarctic changes in summer sea ice extent from 1931 to 1987. Accounting for bias inherent in the whaling method, this analysis provides new insight into the historical ice edge reconstruction and inter-regional differences. We highlight a reduction of the sea ice extent occurring in the 1960s, mainly in the Weddell sector where the change ranged from 3° to 7.9° latitude through summer. Although the whaling method may not be appropriate for detecting fine-scale change, these results provide evidence for a heterogeneous circumpolar change of the sea ice extent. The shift is temporally and spatially consistent with other environmental changes detected in the Weddell sector and also with a shift in the Southern Hemisphere annular mode. The large reduction of the sea ice extent has probably influenced the ecosystem of the Weddell Sea, particularly the krill biomass. {\textcopyright} 2006 Elsevier Ltd. All rights reserved.},
author = {Cott{\'{e}}, C{\'{e}}dric and Guinet, Christophe},
doi = {10.1016/j.dsr.2006.11.001},
isbn = {0967-0637},
issn = {09670637},
journal = {Deep-Sea Research Part I: Oceanographic Research Papers},
keywords = {Antarctic zone,Environmental assessment,Long-term changes,Sea ice,Whaling},
pages = {243--252},
title = {{Historical whaling records reveal major regional retreat of Antarctic sea ice}},
volume = {57},
year = {2007}
}
@article{Coumou2014,
abstract = {The recent decade has seen an exceptional number of high-impact summer extremes in the Northern Hemisphere midlatitudes. Many of these events were associated with anomalous jet stream circulation patterns characterized by persistent high-amplitude quasi-stationary Rossby waves. Two mechanisms have recently been proposed that could provoke such patterns: (i) a weakening of the zonal mean jets and (ii) an amplification of quasi-stationary waves by resonance between free and forced waves in midlati- tude waveguides. Based upon spectral analysis of the midtropo- sphere wind field, we show that the persistent jet stream patterns were, in the first place, due to an amplification of quasi-stationary waves with zonal wave numbers 6–8. However, we also detect a weakening of the zonal mean jet during these events; thus both mechanisms appear to be important. Furthermore, we demon- strate that the anomalous circulation regimes lead to persistent surface weather conditions and therefore to midlatitude synchro- nization of extreme heat and rainfall events on monthly time- scales. The recent cluster of resonance events has resulted in a statistically significant increase in the frequency of high-ampli- tude quasi-stationary waves of wave numbers 7 and 8 in July and August. We show that this is a robust finding that holds for dif- ferent pressure levels and reanalysis products. We argue that re- cent rapid warming in the Arctic and associated changes in the zonal mean zonal wind have created favorable conditions for dou- ble jet formation in the extratropics, which promotes the develop- ment of resonant flow regimes.},
author = {Coumou, D. and Petoukhov, V. and Rahmstorf, S. and Petri, S. and Schellnhuber, H. J.},
doi = {10.1073/pnas.1412797111},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {34},
pages = {12331--12336},
pmid = {25114245},
title = {{Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer}},
volume = {111},
year = {2014}
}
@article{Coumou2015,
abstract = {Rapid warming in the Arctic could influence mid-latitude circulation by reducing the poleward temperature gradient. The largest changes are generally expected in autumn or winter, but whether significant changes have occurred is debated. Here we report significant weakening of summer circulation detected in three key dynamical quantities: (i) the zonal-mean zonal wind, (ii) the eddy kinetic energy (EKE), and (iii) the amplitude of fast-moving Rossby waves.Weakening of the zonal wind is explained by a reduction in the poleward temperature gradient. Changes in Rossby waves and EKE are consistent with regression analyses of climate model projections and changes over the seasonal cycle. Monthly heat extremes are associated with low EKE, and thus the observed weakening might have contributed to more persistent heat waves in recent summers. nhancedwarminginthe},
author = {Coumou, Dim and Lehmann, Jascha and Beckmann, Johanna},
doi = {10.1126/science.1261768},
isbn = {0036-8075, 1095-9203},
issn = {10959203},
journal = {Science},
number = {6232},
pages = {324--327},
pmid = {25765067},
title = {{The weakening summer circulation in the Northern Hemisphere mid-latitudes}},
volume = {348},
year = {2015}
}
@article{doi:10.1002/2015GL064888,
abstract = {Abstract The level of agreement between climate model simulations and observed surface temperature change is a topic of scientific and policy concern. While the Earth system continues to accumulate energy due to anthropogenic and other radiative forcings, estimates of recent surface temperature evolution fall at the lower end of climate model projections. Global mean temperatures from climate model simulations are typically calculated using surface air temperatures, while the corresponding observations are based on a blend of air and sea surface temperatures. This work quantifies a systematic bias in model-observation comparisons arising from differential warming rates between sea surface temperatures and surface air temperatures over oceans. A further bias arises from the treatment of temperatures in regions where the sea ice boundary has changed. Applying the methodology of the HadCRUT4 record to climate model temperature fields accounts for 38{\%} of the discrepancy in trend between models and observations over the period 1975–2014.},
author = {Cowtan, Kevin and Hausfather, Zeke and Hawkins, Ed and Jacobs, Peter and Mann, Michael E and Miller, Sonya K and Steinman, Byron A and Stolpe, Martin B and Way, Robert G},
doi = {10.1002/2015GL064888},
journal = {Geophysical Research Letters},
keywords = {climate models,temperature record},
number = {15},
pages = {6526--6534},
title = {{Robust comparison of climate models with observations using blended land air and ocean sea surface temperatures}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015GL064888},
volume = {42},
year = {2015}
}
@article{doi:10.1002/qj.3235,
abstract = {Sea surface temperatures form a vital part of global mean surface temperature records. Historical observation methods have changed substantially over time from buckets to engine-room intake sensors, hull sensors and drifting buoys, rendering their use for climatological studies problematic. There are substantial uncertainties in the relative biases of different observations which may impact the global temperature record. Island and coastal weather stations can be compared to coastal sea surface temperature observations to obtain an assessment of changes in bias over time. The process is made more challenging by differences in the rate of warming between air temperatures and sea surface temperatures, and differences across coastal boundaries. A preliminary sea surface temperature reconstruction homogenized using coastal weather station data suggests significant changes to the sea surface temperature record, although there are substantial uncertainties, only some of which can be quantified. A large warm excursion in versions 4 and 5 of the NOAA Extended Reconstructed Sea Surface Temperature during World War 2 is rejected, as is a cool excursion around 1910 present in all existing records. The mid-century plateau is cooler than in existing reconstructions.},
author = {Cowtan, Kevin and Rohde, Robert and Hausfather, Zeke},
doi = {10.1002/qj.3235},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {bucket correction,climate change,global mean surface temperature,sea surface temperature},
number = {712},
pages = {670--681},
title = {{Evaluating biases in sea surface temperature records using coastal weather stations}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.3235},
volume = {144},
year = {2018}
}
@article{doi:10.1002/qj.2297,
abstract = {Abstract Incomplete global coverage is a potential source of bias in global temperature reconstructions if the unsampled regions are not uniformly distributed over the planet's surface. The widely used Hadley Centre–Climatic Reseach Unit Version 4 (HadCRUT4) dataset covers on average about 84{\%} of the globe over recent decades, with the unsampled regions being concentrated at the poles and over Africa. Three existing reconstructions with near-global coverage are examined, each suggesting that HadCRUT4 is subject to bias due to its treatment of unobserved regions. Two alternative approaches for reconstructing global temperatures are explored, one based on an optimal interpolation algorithm and the other a hybrid method incorporating additional information from the satellite temperature record. The methods are validated on the basis of their skill at reconstructing omitted sets of observations. Both methods provide results superior to excluding the unsampled regions, with the hybrid method showing particular skill around the regions where no observations are available. Temperature trends are compared for the hybrid global temperature reconstruction and the raw HadCRUT4 data. The widely quoted trend since 1997 in the hybrid global reconstruction is two and a half times greater than the corresponding trend in the coverage-biased HadCRUT4 data. Coverage bias causes a cool bias in recent temperatures relative to the late 1990s, which increases from around 1998 to the present. Trends starting in 1997 or 1998 are particularly biased with respect to the global trend. The issue is exacerbated by the strong El Ni{\~{n}}o event of 1997–1998, which also tends to suppress trends starting during those years.},
author = {Cowtan, Kevin and Way, Robert G},
doi = {10.1002/qj.2297},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {coverage bias,instrumental temperature record,temperature trends},
number = {683},
pages = {1935--1944},
title = {{Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.2297},
volume = {140},
year = {2014}
}
@article{Craig2017,
author = {Craig, Philip M and Ferreira, David and Methven, John},
doi = {10.1080/16000870.2017.1330454},
journal = {Tellus A: Dynamic Meteorology and Oceanography},
keywords = {evaporation,freshwater transport,meridional overturning,moisture flux,precipitation,run-off,salinity},
number = {1},
pages = {1--15},
publisher = {Taylor {\&} Francis},
title = {{The contrast between Atlantic and Pacific surface water fluxes}},
url = {https://doi.org/10.1080/16000870.2017.1330454},
volume = {69},
year = {2017}
}
@article{doi:10.1029/2011JC007255,
abstract = {We reconstruct trends in ice volume and deep ocean temperature for the past 108 Myr, resolving variations on timescales of ∼2 Myr and longer. We use a sea level record as a proxy for ice volume, a benthic foraminiferal Mg/Cabf record as a proxy for temperature, and a benthic foraminiferal $\delta$18Obf record as a proxy for both. This allows us to construct dual estimates of temperature and ice volume variations for the interval 10–60 Ma: extracting temperature from $\delta$18Obf by using sea level as a proxy for ice volume to constrain the $\delta$18Osw component, and extracting seawater $\delta$18Osw (which reflects ice volume) from $\delta$18Obf by using Mg/Cabf to constrain the temperature component. Each of these approaches requires numerous assumptions, but the range of plausible solutions are concordant on timescales {\textgreater}2 Myr and within an uncertainty of ±2°C temperature and ±0.4‰ $\delta$18Osw. The agreement between the two approaches for the last 50 Myr provides empirical justification for the use of $\delta$18Obf, Mg/Cabf, and sea level records as robust climate proxies. Our reconstructions indicate differences between deep ocean cooling and continental ice growth in the late Cenozoic: cooling occurred gradually in the middle–late Eocene and late Miocene–Pliocene while ice growth occurred rapidly in the earliest Oligocene, middle Miocene, and Plio-Pleistocene. These differences are consistent with climate models that imply that temperatures, set by the long-term CO2 equilibrium, should change only gradually on timescales {\textgreater}2 Myr, but growth of continental ice sheets may be rapid in response to climate thresholds due to feedbacks that are not yet fully understood.},
author = {Cramer, B S and Miller, K G and Barrett, P J and Wright, J D},
doi = {10.1029/2011JC007255},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Mg/Ca,benthic foraminifera,ice volume,sea level,temperature,$\delta$18O},
number = {C12},
title = {{Late Cretaceous-Neogene trends in deep ocean temperature and continental ice volume: Reconciling records of benthic foraminiferal geochemistry ($\delta$18O and Mg/Ca) with sea level history}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011JC007255},
volume = {116},
year = {2011}
}
@article{Cropper2015,
abstract = {We present the construction of a continuous, daily (09:00 UTC), station-based (Azores–Iceland) North Atlantic Oscillation (NAO) Index back to 1871 which is extended back to 1850 with additional daily mean data. The constructed index more than doubles the length of previously existing, widely available, daily NAO time series. The index is created using entirely observational sea-level pressure (SLP) data from Iceland and 73.5{\%} of observational SLP data from the Azores – the remainder being filled in via reanalysis (Twentieth Century Reanalysis Project and European Mean Sea Level Pressure) SLP data. Icelandic data are taken from the Southwest Iceland pressure series. We construct and document a new Ponta Delgada SLP time series based on recently digi-tized and newly available data that extend back to 1872. The Ponta Delgada time series is created by splicing together several fractured records (from Ponta Delgada, Lajes, and Santa Maria) and filling in the major gaps (pre-1872, 1888–1905, and 1940– 1941) and occasional days (145) with reanalysis data. Further homogeneity corrections are applied to the Azores record, and the daily (09:00 UTC) NAO index is then calculated. The resulting index, with its extended temporal length and daily resolution, is the first reconstruction of daily NAO back into the 19th Century and therefore is useful for researchers across multiple disciplines.},
author = {Cropper, Thomas and Hanna, Edward and Valente, Maria Ant{\'{o}}nia and J{\'{o}}nsson, Trausti},
doi = {10.1002/gdj3.23},
issn = {20496060},
journal = {Geoscience Data Journal},
keywords = {atmospheric science,climate,daily,north atlantic oscillation,weather},
number = {1},
pages = {12--24},
title = {{A daily Azores-Iceland North Atlantic Oscillation index back to 1850}},
url = {http://doi.wiley.com/10.1002/gdj3.23},
volume = {2},
year = {2015}
}
@article{Crosta2021,
abstract = {Antarctic sea ice has paradoxically become more extensive over the past four decades despite a warming climate. The regional expression of this trend has been linked to changes in vertical redistribution of ocean heat and large-scale wind-field shifts. However, the short length of modern observations has hindered attempts to attribute this trend to anthropogenic forcing or natural variability. Here, we present two new decadal-resolution records of sea ice and sea surface temperatures that document pervasive regional climate heterogeneity in Indian Antarctic sea-ice cover over the last 2,000 years. Data assimilation of our marine records in a climate model suggests that the reconstructed dichotomous regional conditions were driven by the multi-decadal variability of the El Ni{\~{n}}o Southern Oscillation and Southern Annular Mode (SAM). For example, during an El Ni{\~{n}}o/SAM– combination, the northward sea-ice transport was reduced while heat advection from the subtropics to the Southern Ocean increased, which resulted in reduced sea-ice extent in the Indian sector as sea ice was compacted along the Antarctic coast. Our results therefore indicate that natural variability is large in the Southern Ocean and suggest that it has played a crucial role in the recent sea-ice trends and their decadal variability in this region.},
author = {Crosta, Xavier and Etourneau, Johan and Orme, Lisa C and Dalaiden, Quentin and Campagne, Philippine and Swingedouw, Didier and Goosse, Hugues and Mass{\'{e}}, Guillaume and Miettinen, Arto and McKay, Robert M and Dunbar, Robert B and Escutia, Carlota and Ikehara, Minoru},
doi = {10.1038/s41561-021-00697-1},
issn = {1752-0908},
journal = {Nature Geoscience},
pages = {156--160},
title = {{Multi-decadal trends in Antarctic sea-ice extent driven by ENSO-SAM over the last 2,000 years}},
url = {https://doi.org/10.1038/s41561-021-00697-1},
volume = {14},
year = {2021}
}
@article{cp-2020-65,
author = {Cuesta-Valero, F J and Garcia-Garcia, A and Beltrami, H and Gonz{\'{a}}lez-Rouco, J F and Garcia-Bustamante, E},
doi = {10.5194/cp-17-451-2021},
journal = {Climate of the Past},
number = {1},
pages = {451--468},
title = {{Long-Term Global Ground Heat Flux and Continental Heat Storage from Geothermal Data}},
url = {https://doi.org/10.5194/cp-17-451-2021},
volume = {17},
year = {2021}
}
@article{Cui2011a,
abstract = {The transient global warming event known as the Palaeocene–Eocene Thermal Maximum occurred about 55.9 Myr ago. The warming was accompanied by a rapid shift in the isotopic signature of sedimentary carbonates, suggesting that the event was triggered by a massive release of carbon to the ocean–atmosphere system. However, the source, rate of emission and total amount of carbon involved remain poorly constrained. Here we use an expanded marine sedimentary section from Spitsbergen to reconstruct the carbon isotope excursion as recorded in marine organic matter. We find that the total magnitude of the carbon isotope excursion in the ocean–atmosphere system was about 4‰. We then force an Earth system model of intermediate complexity to conform to our isotope record, allowing us to generate a continuous estimate of the rate of carbon emissions to the atmosphere. Our simulations show that the peak rate of carbon addition was probably in the range of 0.3–1.7 Pg C yr−1, much slower than the present rate of carbon emissions.},
author = {Cui, Ying and Kump, Lee R. and Ridgwell, Andy J. and Charles, Adam J. and Junium, Christopher K. and Diefendorf, Aaron F. and Freeman, Katherine H. and Urban, Nathan M. and Harding, Ian C.},
doi = {10.1038/ngeo1179},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {481--485},
title = {{Slow release of fossil carbon during the Palaeocene–Eocene Thermal Maximum}},
url = {http://www.nature.com/articles/ngeo1179},
volume = {4},
year = {2011}
}
@article{Cummins2020,
abstract = {Oceanographic observations collected at Station P (145°W, 50°N) in the northeast Pacific extend for over six decades, representing one of the longest available records of subsurface ocean water properties. As such, this record is well suited to examine secular trends in properties of the subarctic waters of the North Pacific. In this paper, previously published trends are reviewed and updated, based on a newly compiled dataset for the station. Vertically integrated quantities such as ocean heat content and steric height are examined, as well as local water properties through the water column including temperature, salinity and, in particular, oxygen. Consideration is also given to upper-ocean stratification, along with depths of the mixed layer and isopycnal surfaces. The results provide a comprehensive view of long-term changes to ocean conditions in the deep waters of the subarctic Pacific. Increases in 0/2000 dbar ocean heat content and steric height are evident, due primarily to ocean warming through the upper 500 dbar of the water column. However, about a third of the overall 0/2000 dbar steric height trend is due to halosteric effects. A significant freshening trend is evident through the upper layer to the top of the permanent pycnocline. Significant changes are also found below the permanent pycnocline, in particular warming on isopycnal surfaces along with downward migration of isopycnals. On the other hand, no robust trend emerges in the strength of the stratification associated with the permanent pycnocline, a result that likely has implications for turbulent exchanges between the surface mixed layer and the deep ocean, including the supply of nutrients to the euphotic zone. Statistically significant declines in dissolved oxygen are observed on isopycnals below the pycnocline, down to great depth. Column-integrated dissolved oxygen has declined at a rate of 0.72 mol m−2 y−1, representing a net loss over six decades of 11.7 ± 3.5{\%} in total oxygen content per square metre. This is substantially greater than the global average of 2{\%}, underscoring the northeast Pacific as a region of comparatively rapid deoxygenation. Changes in solubility due to local warming have made only a minor contribution to the observed decline.},
author = {Cummins, Patrick F and Ross, Tetjana},
doi = {10.1016/j.pocean.2020.102329},
issn = {0079-6611},
journal = {Progress in Oceanography},
pages = {102329},
title = {{Secular trends in water properties at Station P in the northeast Pacific: An updated analysis}},
url = {http://www.sciencedirect.com/science/article/pii/S0079661120300689},
volume = {186},
year = {2020}
}
@article{Curran2003,
abstract = {The instrumental record of Antarctic sea ice in recent decades does not reveal a clear signature of warming despite observational evidence from coastal Antarctica. Here we report a significant correlation (P {\textless} 0.002) between methanesulphonic acid (MSA) concentrations from a Law Dome ice core and 22 years of satellite-derived sea ice extent (SIE) for the 80 degrees E to 140 degrees E sector. Applying this instrumental calibration to longer term MSA data (1841 to 1995 A.D.) suggests that there has been a 20{\%} decline in SIE since about 1950. The decline is not uniform, showing large cyclical variations, with periods of about 11 years, that confuse trend detection over the relatively short satellite era.},
author = {Curran, Mark A.J. and {Van Ommen}, Tas D. and Morgan, Vin I. and Phillips, Katrina L. and Palmer, Anne S.},
doi = {10.1126/science.1087888},
isbn = {1095-9203 (Electronic)$\backslash$r0036-8075 (Linking)},
issn = {00368075},
journal = {Science},
number = {5648},
pages = {1203--1206},
pmid = {14615537},
title = {{Ice Core Evidence for Antarctic Sea Ice Decline since the 1950s}},
volume = {302},
year = {2003}
}
@article{DAgostino2017,
abstract = {attributed to the different reproduction of the links between the HC width and factors affecting it (such as mean global temperature, tropopause height, meridional temperature contrast and planetary waves), which appear more robust in ERA-20CM than in ERA-20C, particularly for the two lat-ter factors. Further, in ERA-Interim these correlations are not statistically significant. These outcomes suggest that data assimilation degrades the links between the HC and features influencing its dynamics.},
author = {D'Agostino, Roberta and Lionello, Piero},
doi = {10.1007/s00382-016-3250-0},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {ERA-20CM/C,ERA-Interim,Global warming,Hadley Circulation,Trends,Twentieth century},
number = {9-10},
pages = {3047--3060},
publisher = {Springer Berlin Heidelberg},
title = {{Evidence of global warming impact on the evolution of the Hadley Circulation in ECMWF centennial reanalyses}},
volume = {48},
year = {2017}
}
@article{DArrigo2014,
abstract = {We show evidence for the influence of the Pacific Decadal Oscillation (PDO) on Myanmar's monsoonal hydroclimate using both instrumental and 20th century reanalysis data, and a tree-ring width chronology from Myanmar's central Dry Zone. The ‘regime shifts' identified in the instrumental PDO for the past century are clearly evident in the Myanmar teak. The teak record and PDO index correlate most significantly and positively during December–May, at r = 0.41 (0.002, n = 109). We generated composite climate anomalies for southern Asia and adjacent ocean areas during negative and positive PDO phases and above/below average teak growth for the May–September wet monsoon season. They show that negative (positive) PDO phases correspond to dry (wet) conditions, due to reduced (enhanced) moisture flux into central Myanmar. Multitaper Method (MTM) and Singular Spectrum Analysis (SSA) spectral analyses reveal considerable multidecadal variability over the past several centuries of the teak chronology, consistent with the PDO.},
author = {D'Arrigo, Rosanne and Ummenhofer, Caroline C},
doi = {10.1002/joc.3995},
isbn = {0031-8965},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {Acute gastroenteritis,Children,Immunochromatography,Pediatric emergency,Rotavirus},
month = {mar},
number = {4},
pages = {634--640},
title = {{The climate of Myanmar: evidence for effects of the Pacific Decadal Oscillation}},
url = {http://doi.wiley.com/10.1002/joc.3995},
volume = {35},
year = {2015}
}
@article{Datwyler2018b,
abstract = {The Southern Annular Mode (SAM) is the leading mode of atmospheric interannual variability in the Southern Hemisphere (SH) extra-tropics. Here, we assess the stationarity of SAM spatial correlations with instrumental and paleoclimate proxy data for the past millennium. The instrumental period shows that temporal non-stationarities in SAM teleconnections are not consistent across the SH land areas. This suggests that the influence of the SAM index is modulated by regional effects. However, within key-regions with good proxy data coverage (South America, Tasmania, New Zealand), teleconnections are mostly stationary over the instrumental period. Using different stationarity criteria for proxy record selection, we provide new austral summer and annual mean SAM index reconstructions over the last 36 millennium. Our summer SAM reconstructions are very robust to changes in proxy record selection 37 and the selection of the calibration period, particularly on the multi-decadal timescale. In contrast, the weaker performance and lower agreement in the annual mean SAM reconstructions point towards 39 changing teleconnection patterns that may be particularly important outside the summer months. The summer SAM reconstructions show no significant relationship to solar, greenhouse gas and volcanic forcing, with the exception of an extremely strong negative anomaly following the AD 1257 Samalas eruption. Our results clearly portend that the temporal stationarity of the proxy-climate relationships should be taken into account in the design of comprehensive regional and hemispherical climate reconstructions. Furthermore, reconstructed pre-industrial summer SAM trends are very similar to trends obtained by model control simulations. We find that recent trends in the summer SAM lie outside the 5-95{\%} range of pre-industrial natural variability. Keywords:},
author = {D{\"{a}}twyler, Christoph and Neukom, Raphael and Abram, Nerilie J. and Gallant, Ailie J.E. and Grosjean, Martin and Jacques-Coper, Mart{\'{i}}n and Karoly, David J. and Villalba, Ricardo},
doi = {10.1007/s00382-017-4015-0},
isbn = {0000000312462},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Climate change,Climate reconstruction,Holocene,Paleoclimate,Southern Hemisphere},
number = {5-6},
pages = {2321--2339},
publisher = {Springer Berlin Heidelberg},
title = {{Teleconnection stationarity, variability and trends of the Southern Annular Mode (SAM) during the last millennium}},
url = {http://dx.doi.org/10.1007/s00382-017-4015-0},
volume = {51},
year = {2018}
}
@article{doi:10.1002/joc.5983,
abstract = {The El Ni{\~{n}}o–Southern Oscillation (ENSO) is the earth's dominant mode of inter-annual climate variability. It alternates between warm (El Ni{\~{n}}o) and cold (La Ni{\~{n}}a) states, with global impacts on climate and society. This study provides new ENSO reconstructions based on a large, updated collection of proxy records. We use a novel reconstruction approach that employs running principal components, which allows us to take covariance changes between proxy records into account and thereby identify periods of likely teleconnection changes. Using different implementations of the principal component analysis enables us to identify periods within the last millennium when quantifications of ENSO are most robust. These periods range from 1580 to the end of the 17th century and from 1825 to present. We incorporate an assessment of consistency among our new and existing ENSO reconstructions leading to five short phases of low agreement among the reconstructions between 1700 and 1786. We find a consistent spatial pattern of proxy covariance during these four phases, differing from the structure seen over the instrumental period. This pattern points towards changes in teleconnections in the west Pacific/Australasian region, compared to the present state. Using our new reconstructions, we find a significant response of ENSO towards more La Ni{\~{n}}a-like conditions 3–5 years after major volcanic events. We further show that our new reconstructions and existing reconstructions largely agree on the state of ENSO during volcanic eruptions in the years 1695 and 1784, which helps put into perspective the climatic response to these events. During all other large volcanic eruptions of the last 1000 years, there is no reconstruction coherency with regard to the state of ENSO.},
author = {D{\"{a}}twyler, Christoph and Abram, Nerilie J and Grosjean, Martin and Wahl, Eugene R and Neukom, Raphael},
doi = {10.1002/joc.5983},
issn = {0899-8418},
journal = {International Journal of Climatology},
keywords = {Holocene,PCA,climate change,climate reconstruction,natural climate variability,paleoclimatology,proxy records,volcanic forcing},
month = {apr},
number = {5},
pages = {2711--2724},
title = {{El Ni{\~{n}}o-Southern Oscillation variability, teleconnection changes and responses to large volcanic eruptions since AD 1000}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.5983 https://onlinelibrary.wiley.com/doi/abs/10.1002/joc.5983},
volume = {39},
year = {2019}
}
@article{Da2019,
abstract = {Quantifying ancient atmospheric pCO2 provides valuable insights into the interplay between greenhouse gases and global climate. Beyond the 800-ky history uncovered by ice cores, discrepancies in both the trend and magnitude of pCO2 changes remain among different proxy-derived results. The traditional paleosol pCO2 paleobarometer suffers from largely unconstrained soil-respired CO2 concentration (S(z)). Using finely disseminated carbonates precipitated in paleosols from the Chinese Loess Plateau, here we identified that their S(z) can be quantitatively constrained by soil magnetic susceptibility. Based on this approach, we reconstructed pCO2 during 2.6–0.9 Ma, which documents overall low pCO2 levels ({\textless}300 ppm) comparable with ice core records, indicating that the Earth system has operated under late Pleistocene pCO2 levels for an extended period. The pCO2 levels do not show statistically significant differences across the mid-Pleistocene Transition (ca. 1.2–0.8 Ma), suggesting that CO2 is probably not the driver of this important climate change event.},
author = {Da, Jiawei and Zhang, Yi Ge and Li, Gen and Meng, Xianqiang and Ji, Junfeng},
doi = {10.1038/s41467-019-12357-5},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {4342},
title = {{Low CO2 levels of the entire Pleistocene epoch}},
url = {https://doi.org/10.1038/s41467-019-12357-5},
volume = {10},
year = {2019}
}
@article{Dahutia2018,
author = {Dahutia, Papori and Pathak, Binita and Bhuyan, Pradip Kumar},
doi = {10.1002/joc.5240},
issn = {08998418},
journal = {International Journal of Climatology},
month = {mar},
number = {3},
pages = {1234--1256},
title = {{Aerosols characteristics, trends and their climatic implications over Northeast India and adjoining South Asia}},
url = {http://doi.wiley.com/10.1002/joc.5240},
volume = {38},
year = {2018}
}
@incollection{Dai2016,
abstract = {Streamflow trends from 1948 to 2012 are statistically significant only in 55 (27.5{\%}, 29 negative vs. 26 positive) of the world's largest 200 rivers. Continental runoff decreased slightly from 1949 to 1993, it then recovered to slightly above the 1950–1980 mean. The streamflow and runoff changes are consistent with precipitation records, and they all show decreases from 1950 to 2012 over most Africa, East and South Asia, eastern Australia, the southeast and northwest United States; but increases over Argentina and Uruguay, central and northern Australia, the central and northeast United States, most of Europe, and Russia. These changes resulted partly from the Interdecadal Pacific Oscillation (IPO) and other climate variations, with low (high) land precipitation and runoff during El Ni{\~{n}}o (La Ni{\~{n}}a) events. Under the RCP8.5 scenario, models project mean streamflow to increase in the 21st century by 5{\%}–80{\%} over most of Asia, northern Europe, northern and eastern North America, central and eastern Africa, southeastern and northwestern South America, and central and northern Australia; but decrease by 5{\%}–50{\%} over the Mediterranean region, southwestern North America and Central America, northern and southern South America, southern Africa, and southwestern and southeastern Australia. The projected change patterns in precipitation, runoff, and streamflow are similar, with a fairly constant runoff ratio during the 21st century.},
author = {Dai, Aiguo},
booktitle = {Terrestrial Water Cycle and Climate Change: Natural and Human-Induced Impacts},
doi = {10.1002/9781118971772.ch2},
editor = {Tang, Q. and Oki, T.},
isbn = {9781118971772},
issn = {1118971779},
keywords = {CMIP5 models,Climate models,Continental runoff changes,Hydroclimatic changes,Land precipitation,Streamflow changes},
pages = {17--37},
title = {{Historical and Future Changes in Streamflow and Continental Runoff: A Review}},
year = {2016}
}
@article{Dai2009,
abstract = {A new data set of historical monthly streamflow at the farthest downstream stations for world's 925 largest ocean-reaching rivers has been created for community use. Available new gauge records are added to a network of gauges that covers {\~{}}80 ´ 106 km2 or {\~{}}80{\%} of global ocean-draining land areas and accounts for about 73{\%} of global total runoff. For most of the large rivers, the record for 1948-2004 is fairly complete. Data gaps in the records are filled through linear regression using streamflow simulated by a land surface model (CLM3) forced with observed precipitation and other atmospheric forcings that is significantly (and often strongly) correlated with the observed streamflow for most rivers. Compared with previous studies, the new data set has improved homogeneity and enables more reliable assessments of decadal and long-term changes in continental freshwater discharge into the oceans. The model-simulated runoff ratio over drainage areas with and without gauge records is used to estimate the contribution from the areas not monitored by the gauges in deriving the total discharge into the global oceans. Results reveal large variations in yearly streamflow for most of world's large rivers and for continental discharge, but only about one-third of the top 200 rivers (including the Congo, Mississippi, Yenisey, Paran{\'{a}}, Ganges, Columbia, Uruguay, and Niger) show statistically significant trends during 1948-2004, with the rivers having downward trends (45) out-numbering those with upward trends (19). The interannual variations are correlated with the El Ni{\~{n}}o-Southern Oscillation (ENSO) events for discharge into the Atlantic, Pacific, Indian, and global ocean as a whole. For ocean basins other than the Arctic, and for the global ocean as a whole, the discharge data show small or downward trends, which are statistically significant for the Pacific (-10.1 km3 yr-1) and Indian Ocean (-5.4 km3 yr-1). Precipitation is a major driver for the discharge trends and large interannual to decadal variations. Comparisons with the CLM3 simulation suggest that direct human influence on annual streamflow is likely small compared with climatic forcing during 1948-2004 for 3 most of world's major rivers. For the Arctic drainage areas, upward trends in streamflow are not accompanied by increasing precipitation, especially over Siberia, based on available data, although recent surface warming and associated downward trends in snow cover and soil-ice content over the northern high-latitudes contribute to increased runoff in these regions. Our results are qualitatively consistent with climate model projections, but contradict an earlier report of increasing continental runoff during the recent decades based on limited records.},
author = {Dai, Aiguo and Qian, Taotao and Trenberth, Kevin E. and Milliman, John D.},
doi = {10.1175/2008JCLI2592.1},
isbn = {0894-8755},
issn = {08948755},
journal = {Journal of Climate},
number = {10},
pages = {2773--2792},
pmid = {39984168},
title = {{Changes in continental freshwater discharge from 1948 to 2004}},
volume = {22},
year = {2009}
}
@article{Dai2017,
author = {Dai, Aiguo and Zhao, Tianbao},
doi = {10.1007/s10584-016-1705-2},
journal = {Climatic Change},
keywords = {Drought,Historical drought change,PDSI,Precipitation,Streamflow,Uncertainties},
pages = {519--533},
title = {{Uncertainties in historical changes and future projections of drought. Part I: estimates of historical drought changes}},
volume = {144},
year = {2017}
}
@article{Daly2012,
abstract = {In many regions of the world, the extremes of winter cold are a major determinant of the geographic distribution of perennial plant species and of their successful cultivation. In the United States, the U.S. Department of Agriculture (USDA) Plant Hardiness Zone Map (PHZM) is the primary reference for defining geospatial patterns of extreme winter cold for the horticulture and nursery industries, home gardeners, agrometeorologists, and plant scientists. This paper describes the approaches followed for updating the USDA PHZM, the last version of which was published in 1990. The new PHZM depicts 1976-2005 mean annual extreme minimum temperature, in 2.8 degrees C (5 degrees F) half zones, for the conterminous United States, Alaska, Hawaii, and Puerto Rico. Station data were interpolated to a grid with the Parameter-Elevation Regressions on Independent Slopes Model (PRISM) climate-mapping system. PRISM accounts for the effects of elevation, terrain-induced airmass blockage, coastal effects, temperature inversions, and cold-air pooling on extreme minimum temperature patterns. Climatologically aided interpolation was applied, based on the 1971-2000 mean minimum temperature of the coldest month as the predictor grid. Evaluation of a standard-deviation map and two 15-yr maps (1976-90 and 1991-2005 averaging periods) revealed substantial vertical and horizontal gradients in trend and variability, especially in complex terrain. The new PHZM is generally warmer by one 2.8 degrees C (5 degrees F) half zone than the previous PHZM throughout much of the United States, as a result of a more recent averaging period. Nonetheless, a more sophisticated interpolation technique, greater physiographic detail, and more comprehensive station data were the main causes of zonal changes in complex terrain, especially in the western United States. The updated PHZM can be accessed online (http://www.planthardiness.ars.usda.gov).},
author = {Daly, Christopher and Widrlechner, Mark P. and Halbleib, Michael D. and Smith, Joseph I. and Gibson, Wayne P.},
doi = {10.1175/2010JAMC2536.1},
isbn = {1558-8424},
issn = {15588424},
journal = {Journal of Applied Meteorology and Climatology},
keywords = {Agriculture,Climate classification/regimes,Land use,Societal impacts,Winter/cool season},
number = {2},
pages = {242--264},
title = {{Development of a new USDA plant hardiness zone map for the United States}},
volume = {51},
year = {2012}
}
@article{Dang2020,
abstract = {Dynamics driving the El Ni{\~{n}}o–Southern Oscillation (ENSO) over longer-than-interannual time scales are poorly understood. Here, we compile thermocline temperature records of the Indo-Pacific warm pool over the past 25,000 years, which reveal a major warming in the Early Holocene and a secondary warming in the Middle Holocene. We suggest that the first thermocline warming corresponds to heat transport of southern Pacific shallow overturning circulation driven by June (austral winter) insolation maximum. The second thermocline warming follows equatorial September insolation maximum, which may have caused a steeper west-east upper-ocean thermal gradient and an intensified Walker circulation in the equatorial Pacific. We propose that the warm pool thermocline warming ultimately reduced the interannual ENSO activity in the Early to Middle Holocene. Thus, a substantially increased oceanic heat content of the warm pool, acting as a negative feedback for ENSO in the past, may play its role in the ongoing global warming.},
author = {Dang, Haowen and Jian, Zhimin and Wang, Yue and Mohtadi, Mahyar and Rosenthal, Yair and Ye, Liming and Bassinot, Franck and Kuhnt, Wolfgang},
doi = {10.1126/sciadv.abc0402},
issn = {2375-2548},
journal = {Science Advances},
month = {oct},
number = {42},
pages = {eabc0402},
pmid = {33055161},
title = {{Pacific warm pool subsurface heat sequestration modulated Walker circulation and ENSO activity during the Holocene}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.abc0402},
volume = {6},
year = {2020}
}
@article{Dangendorf2019,
abstract = {Previous studies reconstructed twentieth-century global mean sea level (GMSL) from sparse tide-gauge records to understand whether the recent high rates obtained from satellite altimetry are part of a longer-term acceleration. However, these analyses used techniques that can only accurately capture either the trend or the variability in GMSL, but not both. Here we present an improved hybrid sea-level reconstruction during 1900–2015 that combines previous techniques at time scales where they perform best. We find a persistent acceleration in GMSL since the 1960s and demonstrate that this is largely ({\~{}}76{\%}) associated with sea-level changes in the Indo-Pacific and South Atlantic. We show that the initiation of the acceleration in the 1960s is tightly linked to an intensification and a basin-scale equatorward shift of Southern Hemispheric westerlies, leading to increased ocean heat uptake, and hence greater rates of GMSL rise, through changes in the circulation of the Southern Ocean.},
author = {Dangendorf, S{\"{o}}nke and Hay, Carling and Calafat, Francisco M and Marcos, Marta and Piecuch, Christopher G and Berk, Kevin and Jensen, J{\"{u}}rgen},
doi = {10.1038/s41558-019-0531-8},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {9},
pages = {705--710},
title = {{Persistent acceleration in global sea-level rise since the 1960s}},
url = {https://doi.org/10.1038/s41558-019-0531-8},
volume = {9},
year = {2019}
}
@article{https://doi.org/10.1029/2019EA000942,
abstract = {Abstract A new model was recently introduced to correct for higher-order ionospheric residual biases in radio occultation (RO) data. The model depends on the $\alpha$1 and $\alpha$2 dual-frequency bending angle difference squared, and a factor $\kappa$, which varies with time, season, solar activity, and height, needing only the F10.7 solar radio flux index as additional background information. To date, this kappa-correction was analyzed in simulation studies. In this study, we test it on real observed Metop-A RO data. The goal is to improve the accuracy of monthly mean RO climate records, potentially raising the accuracy of RO data toward higher stratospheric altitudes. We performed a thorough analysis of the kappa-correction, evaluating its ionospheric sensitivity during the solar cycle for monthly RO climatologies and comparing the kappa-corrected RO stratospheric climatologies to three other data sets from reanalysis and passive infrared sounding. We find a clear dependence of the kappa-correction on solar activity, geographic location, and altitude; hence, it reduces systematic errors that vary with the solar cycle. From low to high solar activity conditions, the correction can increase from values of about 0.2 K to more than 2.0 K at altitudes between 40 to 45 km. The correction shifts RO climatologies toward warmer temperatures. With respect to other data sets, however, we found it difficult to draw firm conclusions, because the biases in the other data sets appear to be at similar magnitude as the size of the kappa-correction. Further validation with more accurate data will be useful.},
annote = {e2019EA000942 10.1029/2019EA000942},
author = {Danzer, J and Schwaerz, M and Kirchengast, G and Healy, S B},
doi = {10.1029/2019EA000942},
journal = {Earth and Space Science},
number = {7},
pages = {e2019EA000942},
title = {{Sensitivity Analysis and Impact of the Kappa-Correction of Residual Ionospheric Biases on Radio Occultation Climatologies}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019EA000942},
volume = {7},
year = {2020}
}
@article{Darby2012a,
author = {Darby, Dennis A and Ortiz, Joseph D and Grosch, Chester E and Lund, Steven P},
doi = {10.1038/ngeo1629},
issn = {1752-0894},
journal = {Nature Geoscience},
number = {12},
pages = {897--900},
publisher = {Nature Publishing Group},
title = {{1,500-year cycle in the Arctic Oscillation identified in Holocene Arctic sea-ice drift}},
url = {http://dx.doi.org/10.1038/ngeo1629},
volume = {5},
year = {2012}
}
@article{Davini2012a,
author = {Davini, P and Cagnazzo, C and Gualdi, S and Navarra, A},
doi = {10.1175/JCLI-D-12-00032.1},
journal = {Journal of Climate},
number = {19},
pages = {6496--6509.},
title = {{Bidimensional diagnostics, variability, and trends of Northern Hemisphere blocking}},
volume = {25},
year = {2012}
}
@article{Davis2013,
author = {Davis, N A and Birner, T},
doi = {10.1002/jgrd.50610},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jul},
number = {14},
pages = {7773--7787},
title = {{Seasonal to multidecadal variability of the width of the tropical belt}},
url = {http://doi.wiley.com/10.1002/jgrd.50610},
volume = {118},
year = {2013}
}
@article{Davis2012,
author = {Davis, S M and Rosenlof, K H},
doi = {10.1175/JCLI-D-11-00127.1},
journal = {Journal of Climate},
number = {4},
pages = {1061--1078},
title = {{A multi‐diagnostic intercomparison of tropical width time series using reanalyses and satellite observations}},
volume = {25},
year = {2012}
}
@article{Davis2016,
author = {Davis, S M and Rosenlof, K H and Hassler, B and Hurst, D F and Read, W G and V{\"{o}}mel, H and Selkirk, H and Fujiwara, M and Damadeo, R},
doi = {10.5194/essd-8-461-2016},
journal = {Earth System Science Data},
number = {2},
pages = {461--490},
title = {{The Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database: a long-term database for climate studies}},
volume = {8},
year = {2016}
}
@article{Davis2017,
author = {Davis, Nicholas A. and Birner, Thomas},
doi = {10.1175/JCLI-D-16-0371.1},
journal = {Journal of Climate},
pages = {1211--1231},
title = {{On the Discrepancies in Tropical Belt Expansion between Reanalyses and Climate Models and among Tropical Belt Width Metrics}},
volume = {30},
year = {2017}
}
@article{Davis2019,
abstract = {A new analysis of sea surface temperature (SST) observations indicates notable uncertainty in observed decadal climate variability in the second half of the twentieth century, particularly during the decades following World War II. The uncertainties are revealed by exploring SST data binned separately for the two predominant measurement types: “engine-room intake” (ERI) and “bucket” measurements. ERI measurements indicate large decreases in global-mean SSTs from 1950 to 1975, whereas bucket measurements indicate increases in SST over this period before bias adjustments are applied but decreases after they are applied. The trends in the bias adjustments applied to the bucket data are larger than the global-mean trends during the period 1950–75, and thus the global-mean trends during this period derive largely from the adjustments themselves. This is critical, since the adjustments are based on incomplete information about the underlying measurement methods and are thus subject to considerable uncertainty. The uncertainty in decadal-scale variability is particularly pronounced over the North Pacific, where the sign of low-frequency variability through the 1950s to 1970s is different for each measurement type. The uncertainty highlighted here has important—but in our view widely overlooked—implications for the interpretation of observed decadal climate variability over both the Pacific and Atlantic basins during the mid-to-late twentieth century.},
author = {Davis, Luke L B and Thompson, David W J and Kennedy, John J and Kent, Elizabeth C},
doi = {10.1175/BAMS-D-18-0104.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
month = {may},
number = {4},
pages = {621--629},
title = {{The Importance of Unresolved Biases in Twentieth-Century Sea Surface Temperature Observations}},
url = {https://doi.org/10.1175/BAMS-D-18-0104.1},
volume = {100},
year = {2019}
}
@article{Davis2017c,
author = {Davis, S. M. and Rosenlof, K. H. and Hurst, D. F. and Selkirk, H. B. and V{\"{o}}mel, H.},
doi = {10.1175/2017BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S51--S5},
title = {{Stratospheric Water Vapor [in “State of the Climate in 2016”]}},
volume = {98},
year = {2017}
}
@article{DeBoer2015,
author = {de Boer, B and Dolan, A M and Bernales, J and Gasson, E and Goelzer, H and Golledge, N R and Sutter, J and Huybrechts, P and Lohmann, G and Rogozhina, I and Abe-Ouchi, A and Saito, F and van de Wal, R S W},
doi = {10.5194/tc-9-881-2015},
issn = {1994-0424},
journal = {The Cryosphere},
month = {may},
number = {3},
pages = {881--903},
publisher = {Copernicus Publications},
title = {{Simulating the Antarctic ice sheet in the late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project}},
url = {https://www.the-cryosphere.net/9/881/2015/ https://www.the-cryosphere.net/9/881/2015/tc-9-881-2015.pdf},
volume = {9},
year = {2015}
}
@article{DeJong2012,
abstract = {Field observations and time series of vegetation greenness data from satellites provide evidence of changes in terres- trial vegetation activity over the past decades for several regions in the world. Changes in vegetation greenness over time may consist of an alternating sequence of greening and/or browning periods. This study examined this effect using detection of trend changes in normalized difference vegetation index (NDVI) satellite data between 1982 and 2008. Time series of 648 fortnightly images were analyzed using a trend breaks analysis (BFAST) procedure. Both abrupt and gradual changes were detected in large parts of the world, especially in (semi-arid) shrubland and grass- land biomes where abrupt greening was often followed by gradual browning. Many abrupt changes were found around large-scale natural influences like the Mt Pinatubo eruption in 1991 and the strong 1997/98 El Nin o event. The net global figure considered over the full length of the time series showed greening since the 1980s. This is in line with previous studies, but the change rates for individual short-term segments were found to be up to five times higher. Temporal analysis indicated that the area with browning trends increased over time while the area with greening trends decreased. The Southern Hemisphere showed the strongest evidence of browning. Here, periods of gradual browning were generally longer than periods of gradual greening. Net greening was detected in all biomes, most conspicuously in croplands and least conspicuously in needleleaf forests. For 15{\%} of the global land area, trends were found to change between greening and browning within the analysis period. This demonstrates the importance of accounting for trend changes when analyzing long-term NDVI time series.},
author = {de Jong, Rogier and Verbesselt, Jan and Schaepman, Michael E. and de Bruin, Sytze},
doi = {10.1111/j.1365-2486.2011.02578.x},
isbn = {1354-1013},
issn = {13541013},
journal = {Global Change Biology},
keywords = {GIMMS NDVI,Global greening and browning,Gradual and abrupt change detection,Time series analysis,Trend breaks},
number = {2},
pages = {642--655},
title = {{Trend changes in global greening and browning: Contribution of short-term trends to longer-term change}},
volume = {18},
year = {2012}
}
@article{DeJong2016,
abstract = {Abstract Deep convection is presumed to be vital for the North Atlantic Meridional Overturning Circulation, even though observational evidence for the link remains inconclusive. Modeling studies have suggested that convection will weaken as a result of enhanced freshwater input. The emergence of anomalously low sea surface temperature in the subpolar North Atlantic has led to speculation that this process is already at work. Here we show that strong atmospheric forcing in the winter of 2014?2015, associated with a high North Atlantic Oscillation (NAO) index, produced record mixed layer depths in the Irminger Sea. Local mixing removed the stratification of the upper 1400?m and ventilated the basin to middepths resembling a state similar to the mid-1990s when a positive NAO also prevailed. We show that the strong local atmospheric forcing is predominantly responsible for the negative sea surface temperature anomalies observed in the subpolar North Atlantic in 2015 and that there is no evidence of permanently weakened deep convection.},
author = {de Jong, Marieke Femke and de Steur, Laura},
doi = {10.1002/2016GL069596},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Atlantic Meridional Overturning Circulation,Irminger Sea,deep convection,sea surface temperature anomaly,surface forcing,time series},
month = {jul},
number = {13},
pages = {7106--7113},
title = {{Strong winter cooling over the Irminger Sea in winter 2014–2015, exceptional deep convection, and the emergence of anomalously low SST}},
url = {https://doi.org/10.1002/2016GL069596},
volume = {43},
year = {2016}
}
@article{DeJongetal.2018,
author = {de Jong, M.F. and Oltmanns, M. and Karstensen, J. and de Steur, L.},
doi = {10.5670/oceanog.2018.109},
journal = {Oceanography},
number = {1},
pages = {50--59},
title = {{Deep convection in the Irminger Sea observed with a dense mooring array}},
volume = {31},
year = {2018}
}
@article{DeLaMare1997,
abstract = {A decline in Antarctic sea-ice extent is a commonly predicted effect of a warming climate. Direct global estimates of the Antarctic sea-ice cover from satellite observations, only possible since the 1970s, have shown no clear trends. Comparisons between satellite observations and ice-edge charts obtained from early ship records suggest that sea-ice extent in the 1970s was less than during the 1930s, an indication supported by limited regional observations. But these observations have been regarded as inconclusive, owing to the limited spatial and temporal scope of the early records. A significant data source has, however, been overlooked. The southern limit of whaling was constrained by sea ice, and since 1931 whaling records have been collected for every whale caught, giving a circumpolar coverage from spring to autumn until 1987. Here, an analysis of these catch records indicates that, averaged over October to April, the Antarctic summer sea-ice edge has moved southwards by 2.8 degree of latitude between the mid 1950s and early 1970s. This suggests a decline in the area covered by sea ice of some 25{\%}. This abrupt change poses a challenge to model simulations of recent climate change, and could imply changes in Antarctic deep-water formation and in biological productivity, both important processes affectiing atmospheric CO sub(2) concentrations.},
author = {{de La Mare}, William K.},
doi = {10.1038/37956},
isbn = {0028-0836},
issn = {00280836},
journal = {Nature},
pages = {57--60},
title = {{Abrupt mid-twentieth-century decline in Antarctic sea-ice extent from whaling records}},
volume = {389},
year = {1997}
}
@article{DeLaMare2009,
abstract = {Changes in the extent of Antarctic sea-ice are difficult to quantify for the pre-satellite era. The available direct data are sparse. A substantially larger set of proxy records based on whaling positions indicated a large shift in whaling positions between the 1930s to 1950s compared with whaling positions in the 1970s to mid 1980s. However, these findings have been questioned. Further analyses here using historic ice charts, direct sea-ice observations and whaling positions agree that a substantial southward shift in the ice-edge did occur. The analyses indicate the average change is around 1.89° to 2.80° of latitude with a reasonable mid-range estimate of 2.41°. Regional analyses show that the largest changes occurred in the South Atlantic, but change is also detected across the Indian Ocean to the Ross Sea; a 220° span of longitude. A recently published proposition that the shift in ice-edges is an artefact caused by bias in the satellite derived records is not supported.},
author = {{de La Mare}, William K.},
doi = {10.1007/s10584-008-9473-2},
isbn = {1058400894},
issn = {01650009},
journal = {Climatic Change},
pages = {461--493},
title = {{Changes in Antarctic sea-ice extent from direct historical observations and whaling records}},
volume = {92},
year = {2009}
}
@article{DelaVega2020a,
author = {de la Vega, Elwyn and Chalk, Thomas B and Wilson, Paul A and Bysani, Ratna Priya and Foster, Gavin L},
doi = {10.1038/s41598-020-67154-8},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {11002},
title = {{Atmospheric CO2 during the Mid-Piacenzian Warm Period and the M2 glaciation}},
url = {https://doi.org/10.1038/s41598-020-67154-8},
volume = {10},
year = {2020}
}
@article{DeSchepper2014,
author = {{De Schepper}, Stijn and Gibbard, Philip L. and Salzmann, Ulrich and Ehlers, J{\"{u}}rgen},
doi = {10.1016/j.earscirev.2014.04.003},
issn = {00128252},
journal = {Earth-Science Reviews},
month = {aug},
pages = {83--102},
title = {{A global synthesis of the marine and terrestrial evidence for glaciation during the Pliocene Epoch}},
volume = {135},
year = {2014}
}
@article{DeVernal2013b,
abstract = {Sea ice cover extent expressed in terms of mean annual concentration was reconstructed from the application of the modern analogue technique to dinocyst assemblages. The use of an updated database, which includes 1492 sites and 66 taxa, yields sea ice concentration estimates with an accuracy of ±1.1/10. Holocene reconstructions of sea ice cover were made from dinocyst counts in 35 cores of the northern North Atlantic and Arctic seas. In the Canadian Arctic, the results show high sea ice concentration ({\textgreater}7/10) with little variations throughout the interval. In contrast, in Arctic areas such as the Chukchi Sea and the Barents Sea, the reconstructions show large amplitude variations of sea ice cover suggesting millennial type oscillations with a pacing almost opposite in western vs. eastern Arctic. Other records show tenuous changes with some regionalism either in trends or sea ice cover variability. During the mid-Holocene, and notably at 6±0.5ka, minimum sea ice concentration is recorded in the eastern Fram Strait, northern Baffin Bay and Labrador Sea. However, this minimum cannot be extrapolated at the scale of the Arctic and circum-Arctic. The comparison of recent observations and reconstructions suggests larger variations in the Arctic sea ice cover during the last decades than throughout the Holocene. {\textcopyright} 2013 Elsevier Ltd.},
author = {{De Vernal}, Anne and Hillaire-Marcel, Claude and Rochon, Andr{\'{e}} and Fr{\'{e}}chette, Bianca and Henry, Maryse and Solignac, Sandrine and Bonnet, Sophie},
doi = {10.1016/j.quascirev.2013.07.006},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
pages = {111--121},
title = {{Dinocyst-based reconstructions of sea ice cover concentration during the Holocene in the Arctic Ocean, the northern North Atlantic Ocean and its adjacent seas}},
volume = {79},
year = {2013}
}
@article{DeConto2016,
abstract = {Polar temperatures over the last several million years have, at times, been slightly warmer than today, yet global mean sea level has been 6–9 metres higher as recently as the Last Interglacial (130,000 to 115,000 years ago) and possibly higher during the Pliocene epoch (about three million years ago). In both cases the Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability. Here we use a model coupling ice sheet and climate dynamics— including previously underappreciated processes linking atmospheric warming with hydrofracturing of buttressing ice shelves and structural collapse of marine-terminating ice cliffs—that is calibrated against Pliocene and Last Interglacial sea-level estimates and applied to future greenhouse gas emission scenarios. Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated. In this case atmospheric warming will soon become the dominant driver of ice loss, but prolonged ocean warming will delay its recovery for thousands of years.},
author = {DeConto, Robert M and Pollard, David},
doi = {10.1038/nature17145},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {7596},
pages = {591--597},
publisher = {Nature Publishing Group},
title = {{Contribution of Antarctica to past and future sea-level rise}},
volume = {531},
year = {2016}
}
@article{doi:10.1002/qj.828,
abstract = {Abstract ERA-Interim is the latest global atmospheric reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). The ERA-Interim project was conducted in part to prepare for a new atmospheric reanalysis to replace ERA-40, which will extend back to the early part of the twentieth century. This article describes the forecast model, data assimilation method, and input datasets used to produce ERA-Interim, and discusses the performance of the system. Special emphasis is placed on various difficulties encountered in the production of ERA-40, including the representation of the hydrological cycle, the quality of the stratospheric circulation, and the consistency in time of the reanalysed fields. We provide evidence for substantial improvements in each of these aspects. We also identify areas where further work is needed and describe opportunities and objectives for future reanalysis projects at ECMWF. Copyright {\textcopyright} 2011 Royal Meteorological Society},
author = {Dee, D P and Uppala, S M and Simmons, A J and Berrisford, P and Poli, P and Kobayashi, S and Andrae, U and Balmaseda, M A and Balsamo, G and Bauer, P and Bechtold, P and Beljaars, A C M and van de Berg, L and Bidlot, J and Bormann, N and Delsol, C and Dragani, R and Fuentes, M and Geer, A J and Haimberger, L and Healy, S B and Hersbach, H and H{\'{o}}lm, E V and Isaksen, L and K{\aa}llberg, P and K{\"{o}}hler, M and Matricardi, M and McNally, A P and Monge-Sanz, B M and Morcrette, J.-J. and Park, B.-K. and Peubey, C and de Rosnay, P and Tavolato, C and Th{\'{e}}paut, J.-N. and Vitart, F},
doi = {10.1002/qj.828},
issn = {00359009},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {4D-Var,ERA-40,forecast model,hydrological cycle,observations,stratospheric circulation},
month = {apr},
number = {656},
pages = {553--597},
title = {{The ERA-Interim reanalysis: configuration and performance of the data assimilation system}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.828},
volume = {137},
year = {2011}
}
@article{doi:10.1002/qj.493,
abstract = {Abstract This article describes the performance of the variational bias correction system for satellite radiance data in ERA-Interim, and considers implications for the representation of climate signals in reanalysis. We briefly review the formulation of the method and its ability to automatically develop bias estimates when radiance measurements from newly available satellite sensors are first introduced in the reanalysis. We then present several results obtained from the first 19 years (1989–2007) of ERA-Interim. These include the identification of Microwave Sounding Unit (MSU) instrument calibration errors, the response of the system to the Pinatubo eruption in 1991, and the detection of a long-term drift in biases of tropospheric AMSU-A data. We find that our results support the notion that global reanalysis provides an appropriate framework for climate monitoring. Copyright {\textcopyright} 2009 Royal Meteorological Society},
author = {Dee, D P and Uppala, S},
doi = {10.1002/qj.493},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {MSU calibration,climate monitoring,data assimilation},
number = {644},
pages = {1830--1841},
title = {{Variational bias correction of satellite radiance data in the ERA-Interim reanalysis}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.493},
volume = {135},
year = {2009}
}
@article{Delaygue2019,
author = {Delaygue, Gilles and Br{\"{o}}nnimann, Stefan and Jones, Philip D and Blanchet, Juliette and Schwander, Mikha{\"{e}}l},
doi = {10.1007/s00382-018-4506-7},
isbn = {0123456789},
issn = {1432-0894},
journal = {Climate Dynamics},
keywords = {British Isles weather,Climate r,Lamb weather types,british isles weather,climate reconstruction,lamb weather types,little ice age,north atlantic oscillation},
pages = {6131--6148},
publisher = {Springer Berlin Heidelberg},
title = {{Reconstruction of Lamb weather type series back to the eighteenth century}},
url = {http://dx.doi.org/10.1007/s00382-018-4506-7},
volume = {52},
year = {2019}
}
@article{DENDY2017234,
abstract = {Estimates of peak global mean sea level (GMSL) during the Last Interglacial (LIG, ∼129-116 ka) based on geological sea level high-stand markers require a correction for the contaminating influence of glacial isostatic adjustment (GIA). This correction is obtained by calculating the viscoelastic response of the Earth to changes in the ice and ocean load prior to and following the LIG. While ice retreat over the last deglaciation is relatively well constrained, changes in ice cover prior to the LIG are more uncertain. We investigate the sensitivity of numerical predictions of GIA during the LIG to variations in the geometry of pre-LIG ice cover and the timing of the deglaciation into the LIG, with a particular focus on Marine Isotope Stage (MIS) 6 (∼190-130 ka). We demonstrate that reconstructing the pre-LIG ice history by replicating the last glacial cycle back in time, rather than using ice volume approximations based on oxygen isotope records, can introduce errors in LIG high-stand predictions of ∼5 m at sites on the peripheral bulge of major ice complexes, and up to ∼2 m at far-field sites. We also demonstrate that predictions of LIG sea level are more sensitive to the geographic distribution of ice cover during MIS 6 than previously recognized. Adopting simulations which vary the relative size of Late Pleistocene ice cover over North America and Eurasia can yield a change in predicted high-stand elevations of ∼5 m in both the near and far field of northern hemisphere ice sheets. This far-field sensitivity arises, in part, from the reorientation of Earth's rotation axis during MIS 6, which in turn drives sea-level changes with a distinct geographic signature. In future work we will apply the insights gained here to re-evaluate the observed geographic variability in geological high-stand markers of LIG age and estimates of GMSL based upon them.},
author = {Dendy, S and Austermann, J and Creveling, J R and Mitrovica, J X},
doi = {10.1016/j.quascirev.2017.06.013},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {234--244},
title = {{Sensitivity of Last Interglacial sea-level high stands to ice sheet configuration during Marine Isotope Stage 6}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379116304164},
volume = {171},
year = {2017}
}
@article{Deng2013,
abstract = {The Pacific Decadal Oscillation (PDO) has been shown to have significant climatic and environmental impacts across the Pan-Pacific Basin; however, there are no records of PDO activity from the South China Sea (SCS), the largest marginal sea in the northwest Pacific Ocean. This study suggests that a series of geochemical profiles obtained from a modern coral in the northern SCS records annual PDO activity dating back to 1853. These geochemical data are significantly correlated with the PDO index, and their patterns of variation closely match those of the PDO index over the last century. The relationship between the PDO and coral geochemistry may be related to the influence of the PDO on rainfall on Hainan Island. Rainfall patterns influence the volume of terrestrial runoff, which, in turn, is a primary determinant of $\delta$ 18 O and $\Delta$$\delta$ 18 O values in coral; however, coral $\delta$ 13 C values are also influenced by the 13 C Suess effect. The results indicate that Sr/Ca ratios in coral are affected by a combination of sea surface temperature and terrestrial runoff. Key Points PDO activity since 1853 was recorded by a coral from the northern SCS Coral profiles were affected by PDO on decadal-interdecadal time scales Annual resolution coral proxy is capable to study long term climate variability {\textcopyright}2013. American Geophysical Union. All Rights Reserved.},
author = {Deng, Wenfeng and Wei, Gangjian and Xie, Luhua and Ke, Ting and Wang, Zhibing and Zeng, Ti and Liu, Ying},
doi = {10.1002/jgrc.20180},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Pacific Decadal Oscillation,South China Sea,coral},
month = {may},
number = {5},
pages = {2358--2366},
title = {{Variations in the Pacific Decadal Oscillation since 1853 in a coral record from the northern South China Sea}},
url = {http://doi.wiley.com/10.1002/jgrc.20180},
volume = {118},
year = {2013}
}
@article{Deng2018,
abstract = {AbstractGlobal monsoon precipitation (GMP) brings the majority of water for the local agriculture and ecosystem. The Northern Hemisphere (NH) GMP shows an upward trend over the past decades, while the trend in the Southern Hemisphere (SH) GMP is weak and insignificant. The first three singular value decomposition modes between NH GMP and global SST during boreal summer reflect, in order, the Atlantic multidecadal oscillation (AMO), eastern Pacific (EP) El Ni{\~{n}}o, and central Pacific (CP) El Ni{\~{n}}o, when the AMO dominates the NH climate and contributes to the increased trend. However, the first three modes between SH GMP and global SST during boreal winter are revealed as EP El Ni{\~{n}}o, the AMO, and CP El Ni{\~{n}}o, when the EP El Ni{\~{n}}o becomes the most significant driver of the SH GMP, and the AMO-induced rainfall anomalies may cancel out each other within the SH global monsoon domain and thus result in a weak trend. The intensification of NH GMP is proposed to favor the occurrences of droughts and heat waves (HWs) in...},
author = {Deng, Kaiqiang and Yang, Song and Ting, Mingfang and Tan, Yaheng and He, Shan},
doi = {10.1175/JCLI-D-17-0569.1},
issn = {0894-8755},
journal = {Journal of Climate},
number = {17},
pages = {6947--6966},
title = {{Global Monsoon Precipitation: Trends, Leading Modes, and Associated Drought and Heat Wave in the Northern Hemisphere}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0569.1},
volume = {31},
year = {2018}
}
@article{Deng2017,
author = {Deng, Wenfeng and Liu, Xi and Chen, Xuefei and Wei, Gangjian and Zeng, Ti and Xie, Luhua and Zhao, Jian-xin},
doi = {10.1002/2016JC012458},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
month = {jan},
number = {1},
pages = {264--275},
title = {{A comparison of the climates of the Medieval Climate Anomaly, Little Ice Age, and Current Warm Period reconstructed using coral records from the northern South China Sea}},
url = {http://doi.wiley.com/10.1002/2016JC012458},
volume = {122},
year = {2017}
}
@article{Dennison2016a,
author = {Dennison, F W and McDonald, A J and Morgenstern, O},
doi = {10.1002/2016JD025033},
journal = {Journal of Geophysical Research: Atmospheres},
number = {24},
pages = {14358--14371},
title = {{The Influence of Ozone Forcing on Blocking in the Southern Hemisphere}},
volume = {121},
year = {2016}
}
@article{Denniston2016,
abstract = {The seasonal north-south migration of the intertropical convergence zone (ITCZ) defines the tropical rain belt (TRB), a region of enormous terrestrial and marine biodiversity and home to 40{\%} of people on Earth. The TRB is dynamic and has been shown to shift south as a coherent system during periods of Northern Hemisphere cooling. However, recent studies of Indo-Pacific hydroclimate suggest that during the Little Ice Age (LIA; AD 1400-1850), the TRB in this region contracted rather than being displaced uniformly southward. This behaviour is not well understood, particularly during climatic fluctuations less pronounced than those of the LIA, the largest centennial-scale cool period of the last millennium. Here we show that the Indo-Pacific TRB expanded and contracted numerous times over multi-decadal to centennial scales during the last 3,000 yr. By integrating precisely-dated stalagmite records of tropical hydroclimate from southern China with a newly enhanced stalagmite time series from northern Australia, our study reveals a previously unidentified coherence between the austral and boreal summer monsoon. State-of-the-art climate model simulations of the last millennium suggest these are linked to changes in the structure of the regional manifestation of the atmosphere's meridional circulation.},
author = {Denniston, Rhawn F. and Ummenhofer, Caroline C. and Wanamaker, Alan D. and Lachniet, Matthew S. and Villarini, Gabriele and Asmerom, Yemane and Polyak, Victor J. and Passaro, Kristian J. and Cugley, John and Woods, David and Humphreys, William F.},
doi = {10.1038/srep34485},
issn = {20452322},
journal = {Scientific Reports},
pages = {1--9},
publisher = {Nature Publishing Group},
title = {{Expansion and Contraction of the Indo-Pacific Tropical Rain Belt over the Last Three Millennia}},
url = {http://dx.doi.org/10.1038/srep34485},
volume = {6},
year = {2016}
}
@article{Deplazes2013a,
author = {Deplazes, Gaudenz and L{\"{u}}ckge, Andreas and Peterson, Larry C and Timmermann, Axel and Hamann, Yvonne and Hughen, Konrad A and R{\"{o}}hl, Ursula and Laj, Carlo and Cane, Mark A and Sigman, Daniel M and Haug, Gerald H},
doi = {10.1038/ngeo1712},
issn = {1752-0894},
journal = {Nature Geoscience},
number = {3},
pages = {213--217},
publisher = {Nature Publishing Group},
title = {{Links between tropical rainfall and North Atlantic climate during the last glacial period}},
volume = {6},
year = {2013}
}
@incollection{DerksenC.R.BrownL.Mudryk2015,
author = {Derksen, C. and Brown, R. and Mudryk, L. and Luojus, K.},
booktitle = {Arctic Report Card 2015},
doi = {https://www.arctic.noaa.gov/Report-Card/Report-Card-2015},
pages = {17--21},
title = {{Terrestrial Snow Cover}},
url = {https://www.arctic.noaa.gov/Report-Card/Report-Card-2015},
year = {2015}
}
@incollection{DerksenCBurgessDDuguayCHowellSMudrykLSmithSThackerayC2019,
address = {Ottawa, ON, Canada},
author = {Derksen, C. and Burgess, D. and Duguay, C. and Howell, S. and Mudryk, L. and Smith, S. and Thackeray, C. and Kirchmeier-Young, M.},
booktitle = {Canada's Changing Climate Report},
editor = {Bush, E. and Lemmen, D.S.},
pages = {194--260},
publisher = {Government of Canada},
title = {{Changes in Snow, Ice and Permafrost Across Canada}},
url = {https://changingclimate.ca/CCCR2019/chapter/5-0},
year = {2019}
}
@article{Desbruyeres2019,
author = {Desbruy{\`{e}}res, D G and Mercier, H and Maze, G and Daniault, N},
doi = {10.5194/os-15-809-2019},
issn = {1812-0792},
journal = {Ocean Science},
month = {jun},
number = {3},
pages = {809--817},
publisher = {Copernicus Publications},
title = {{Surface predictor of overturning circulation and heat content change in the subpolar North Atlantic}},
url = {https://os.copernicus.org/articles/15/809/2019/ https://os.copernicus.org/articles/15/809/2019/os-15-809-2019.pdf},
volume = {15},
year = {2019}
}
@article{Deschamps2012,
abstract = {Past sea-level records provide invaluable information about the response of ice sheets to climate forcing. Some such records suggest that the last deglaciation was punctuated by a dramatic period of sea-level rise, of about 20 metres, in less than 500 years. Controversy about the amplitude and timing of this meltwater pulse (MWP-1A) has, however, led to uncertainty about the source of the melt water and its temporal and causal relationships with the abrupt climate changes of the deglaciation. Here we show that MWP-1A started no earlier than 14,650 years ago and ended before 14,310 years ago, making it coeval with the B{\o}lling warming. Our results, based on corals drilled offshore from Tahiti during Integrated Ocean Drilling Project Expedition 310, reveal that the increase in sea level at Tahiti was between 12 and 22 metres, with a most probable value between 14 and 18 metres, establishing a significant meltwater contribution from the Southern Hemisphere. This implies that the rate of eustatic sea-level rise exceeded 40 millimetres per year during MWP-1A.},
author = {Deschamps, Pierre and Durand, Nicolas and Bard, Edouard and Hamelin, Bruno and Camoin, Gilbert and Thomas, Alexander L and Henderson, Gideon M and Okuno, Jun'ichi and Yokoyama, Yusuke},
doi = {10.1038/nature10902},
issn = {1476-4687},
journal = {Nature},
number = {7391},
pages = {559--564},
title = {{Ice-sheet collapse and sea-level rise at the B{\o}lling warming 14,600 years ago}},
url = {https://doi.org/10.1038/nature10902},
volume = {483},
year = {2012}
}
@article{Dessler2016,
abstract = {Climate models predict that tropical lower-stratospheric humidity will increase as the climate warms. We examine this trend in two state-of-the-art chemistry-climate models. Under high greenhouse gas emissions scenarios, the stratospheric entry value of water vapor increases by {\~{}}1 part per million by volume (ppmv) over this century in both models. We show with trajectory runs driven by model meteorological fields that the warming tropical tropopause layer (TTL) explains 50–80{\%} of this increase. The remainder is a consequence of trends in evaporation of ice convectively lofted into the TTL and lower stratosphere. Our results further show that, within the models we examined, ice lofting is primarily important on long time scales — on interannual time scales, TTL temperature variations explain most of the variations in lower stratospheric humidity. Assessing the ability of models to realistically represent ice-lofting processes should be a high priority in the modeling community.},
author = {Dessler, A E and Ye, H and Wang, T and Schoeberl, M R and Oman, L D and Douglass, A R and Butler, A H and Rosenlof, K H and Davis, S M and Portmann, R W},
doi = {10.1002/2016GL067991},
issn = {0094-8276},
journal = {Geophysical research letters},
month = {mar},
number = {5},
pages = {2323--2329},
title = {{Transport of ice into the stratosphere and the humidification of the stratosphere over the 21st century}},
volume = {43},
year = {2016}
}
@article{DiCapua2016,
author = {{Di Capua}, Giorgia and Coumou, Dim},
doi = {10.1088/1748-9326/11/9/094028},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {sep},
number = {9},
pages = {094028},
title = {{Changes in meandering of the Northern Hemisphere circulation}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/11/9/094028},
volume = {11},
year = {2016}
}
@article{Diallo2018,
author = {Diallo, M and Riese, M and Birner, T and Konopka, P and M{\"{u}}ller, R and Hegglin, M I and Santee, M L and Baldwin, M and Legras, B and Ploeger, F},
doi = {10.5194/acp-18-13055-2018},
journal = {Atmospheric Chemistry and Physics},
number = {17},
pages = {13055--13073},
title = {{Response of stratospheric water vapor and ozone to the unusual timing of El Ni{\~{n}}o and the QBO disruption in 2015–2016}},
volume = {18},
year = {2018}
}
@article{Dickson2012b,
abstract = {Uncertainty over the trajectory of seawater oxygenation in the coming decades is of particular concern in the light of geological episodes of abrupt global warming that were frequently accompanied by lowered seawater oxygen concentrations. Here we present an assessment of global seawater oxygenation from an interval of one of these warming episodes, the Paleocene-Eocene Thermal Maximum (PETM, 55.9 m.y. ago). Our results, obtained from Integrated Ocean Drilling Program Expedition 302 Site M0004 in the Arctic Ocean, are based on molybdenum isotope determinations and molybdenum, rhenium, and uranium abundances. These data indicate a small global expansion of low-oxygen marine environments in the upper part of the PETM interval compared with the present day. More extensive seawater deoxygenation may have occurred for as long as ∼100 k.y., associated with a high rate of global warming and carbon oxidation at the start of the PETM. Our data also reveal molybdenum isotope compositions in Arctic Ocean deposits that are outside the range currently documented in marine environments. These exceptional compositions could reflect either the influence of hydrothermal inputs or equilibrium isotope fractionations associated with molybdenum sulfide speciation.},
author = {Dickson, Alexander J. and Cohen, Anthony S. and Coe, Angela L.},
doi = {10.1130/G32977.1},
issn = {00917613},
journal = {Geology},
month = {jul},
number = {7},
pages = {639--642},
title = {{Seawater oxygenation during the Paleocene-Eocene Thermal Maximum}},
volume = {40},
year = {2012}
}
@article{Dieng2017b,
abstract = {We revisit the global mean sea level (GMSL) budget during the whole altimetry era (January 1993- December 2015) using a large number of data sets. The budget approach allows quantifying the TOPEX A altimeter drift (amounting 1.5 +/- 0.5 mm/yr over 1993-1998). Accounting for this correction and using ensemble means for the GMSL and components leads to closure of the sea level budget (trend of the residual time series being 0.0 +/- 0.22 mm/yr). The new GMSL rate over January 1993-December 2015 is now close to 3.0 mm/yr. An important increase of the GMSL rate, of 0.8 mm/yr, is found during the 2nd half of the altimetry era (2004-2015) compared to the 1993-2004 time span, mostly due to Greenland mass loss increase but also to slight increase of all other components of the budget.},
author = {Dieng, H. B. and Cazenave, A. and Meyssignac, B. and Ablain, M.},
doi = {10.1002/2017GL073308},
isbn = {0094-8276},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {8},
pages = {3744--3751},
title = {{New estimate of the current rate of sea level rise from a sea level budget approach}},
volume = {44},
year = {2017}
}
@article{DiNezio2013,
abstract = {The Indo-Pacific warm pool - the main source of heat and moisture to the global atmosphere - plays a prominent role in tropical and global climate variability. During the Last Glacial Maximum, temperatures within the warm pool were cooler than today and precipitation patterns were altered, but the mechanism responsible for these shifts remains unclear. Here we use a synthesis of proxy reconstructions of warm pool hydrology and a multi-model ensemble of climate simulations to assess the drivers of these changes. The proxy data suggest drier conditions throughout the centre of the warm pool and wetter conditions in the western Indian and Pacific oceans. Only one model out of twelve simulates a pattern of hydroclimate change similar to our reconstructions, as measured by the Cohen's $\kappa$ statistic. Exposure of the Sunda Shelf by lower glacial sea level plays a key role in the hydrologic pattern simulated by this model, which results from changes in the Walker circulation driven by weakened convection over the warm pool. We therefore conclude that on glacial-interglacial timescales, the growth and decay of ice sheets exert a first-order influence on tropical climate through the associated changes in global sea level. {\textcopyright} 2013 Macmillan Publishers Limited. All rights reserved.},
author = {DiNezio, Pedro N. and Tierney, Jessica E.},
doi = {10.1038/ngeo1823},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jun},
number = {6},
pages = {485--491},
publisher = {Nature Publishing Group},
title = {{The effect of sea level on glacial Indo-Pacific climate}},
url = {http://www.nature.com/articles/ngeo1823},
volume = {6},
year = {2013}
}
@article{DiNezio2018a,
abstract = {The mechanisms driving glacial-interglacial changes in the climate of the Indo-Pacific warm pool are poorly understood. Here, we address this question by combining paleoclimate proxies with model simulations of the Last Glacial Maximum climate. We find evidence of two mechanisms explaining key patterns of ocean cooling and rainfall change interpreted from proxy data. Exposure of the Sahul shelf excites a positive ocean-atmosphere feedback involving a stronger surface temperature gradient along the equatorial Indian Ocean and a weaker Walker circulation—a response explaining the drier/wetter dipole across the basin. Northern Hemisphere cooling by ice sheet albedo drives a monsoonal retreat across Africa and the Arabian Peninsula—a response that triggers a weakening of the Indian monsoon via cooling of the Arabian Sea and associated reductions in moisture supply. These results demonstrate the importance of air-sea interactions in the Indian Ocean, amplifying externally forced climate changes over a large part of the tropics.},
author = {DiNezio, Pedro N. and Tierney, Jessica E. and Otto-Bliesner, Bette L. and Timmermann, Axel and Bhattacharya, Tripti and Rosenbloom, Nan and Brady, Esther},
doi = {10.1126/sciadv.aat9658},
issn = {23752548},
journal = {Science Advances},
number = {12},
pages = {1--12},
pmid = {30547084},
title = {{Glacial changes in tropical climate amplified by the Indian Ocean}},
volume = {4},
year = {2018}
}
@article{amt-7-4463-2014,
author = {Dirksen, R J and Sommer, M and Immler, F J and Hurst, D F and Kivi, R and V{\"{o}}mel, H},
doi = {10.5194/amt-7-4463-2014},
journal = {Atmospheric Measurement Techniques},
number = {12},
pages = {4463--4490},
title = {{Reference quality upper-air measurements: GRUAN data processing for the Vaisala RS92 radiosonde}},
url = {https://www.atmos-meas-tech.net/7/4463/2014/},
volume = {7},
year = {2014}
}
@article{Do2017,
abstract = {This study investigates the presence of trends in annual maximum daily streamflow data from the Global Runoff Data Centre database, which holds records of 9213 stations across the globe. The records were divided into three reference datasets representing different compromises between spatial coverage and minimum record length, followed by further filtering based on continent, K{\"{o}}ppen-Weiger climate classification, presence of dams, forest cover changes and catchment size. Trends were evaluated using the Mann-Kendall nonparametric trend test at the 10{\%} significance level, combined with a field significance test. The analysis found substantial differences between reference datasets in terms of the specific stations that exhibited significant increasing or decreasing trends, showing the need for careful construction of statistical methods. The results were more consistent at the continental scale, with decreasing trends for a large number of stations in western North America and the data-covered regions of Australia, and increasing trends in parts of Europe, eastern North America, parts of South America and southern Africa. Interestingly, neither the presence of dams nor changes in forest cover had a large effect on the trend results, but the catchment size was important, as catchments exhibiting increasing (decreasing) trends tended to be smaller (larger). Finally, there were more stations with significant decreasing trends than significant increasing trends across all the datasets analysed, indicating that limited evidence exists for the hypothesis that flood hazard is increasing when averaged across the data-covered regions of the globe.},
author = {Do, Hong X. and Westra, Seth and Leonard, Michael},
doi = {10.1016/j.jhydrol.2017.06.015},
isbn = {0022-1694},
issn = {00221694},
journal = {Journal of Hydrology},
keywords = {Annual maximum streamflow,Climate change,Global flood hazard,Trend analysis},
pages = {28--43},
publisher = {Elsevier B.V.},
title = {{A global-scale investigation of trends in annual maximum streamflow}},
url = {http://dx.doi.org/10.1016/j.jhydrol.2017.06.015},
volume = {552},
year = {2017}
}
@article{Do2018,
abstract = {This is the first part of a two paper series presenting the Global Streamflow Indices and Metadata archive (GSIM), a worldwide collection of metadata and indices derived from more than 35,002 daily streamflow timeseries. This paper focuses on the compilation of the daily streamflow timeseries based on 12 free-to-access streamflow databases (seven national databases and five international collections). It also describes the development of three metadata products (freely available at https://iacweb.ethz.ch/staff/lukasgu/GSIM/GSIM{\_}metadata.zip): (1) a GSIM catalogue collating basic metadata associated with each timeseries, (2) catchment boundaries for the contributing area of each gauge, and (3) catchment metadata extracted from 12 gridded global data products representing essential properties such as land cover type, soil type, climate and topographic characteristics. The second paper in the series then explores production and analysis of streamflow indices. Having collated an unprecedented number of stations and associated metadata, GSIM can be used to advance large-scale hydrological research and improve understanding of the global water cycle.},
author = {Do, Hong Xuan and Gudmundsson, Lukas and Leonard, Michael and Westra, Seth},
doi = {10.5194/essd-10-765-2018},
issn = {18663516},
journal = {Earth System Science Data},
number = {2},
pages = {765--785},
title = {{The Global Streamflow Indices and Metadata Archive (GSIM) – Part 1: The production of a daily streamflow archive and metadata}},
volume = {10},
year = {2018}
}
@article{cp-14-1851-2018,
author = {Dolman, A M and Laepple, T},
doi = {10.5194/cp-14-1851-2018},
journal = {Climate of the Past},
number = {12},
pages = {1851--1868},
title = {{Sedproxy: a forward model for sediment-archived climate proxies}},
url = {https://cp.copernicus.org/articles/14/1851/2018/},
volume = {14},
year = {2018}
}
@article{Domingues2008,
abstract = {Changes in the climate system's energy budget are predominantly revealed in ocean temperatures1, 2 and the associated thermal expansion contribution to sea-level rise2. Climate models, however, do not reproduce the large decadal variability in globally averaged ocean heat content inferred from the sparse observational database3, 4, even when volcanic and other variable climate forcings are included. The sum of the observed contributions has also not adequately explained the overall multi-decadal rise2. Here we report improved estimates of near-global ocean heat content and thermal expansion for the upper 300 m and 700 m of the ocean for 1950–2003, using statistical techniques that allow for sparse data coverage5, 6, 7 and applying recent corrections8 to reduce systematic biases in the most common ocean temperature observations9. Our ocean warming and thermal expansion trends for 1961–2003 are about 50 per cent larger than earlier estimates but about 40 per cent smaller for 1993–2003, which is consistent with the recognition that previously estimated rates for the 1990s had a positive bias as a result of instrumental errors8, 9, 10. On average, the decadal variability of the climate models with volcanic forcing now agrees approximately with the observations, but the modelled multi-decadal trends are smaller than observed. We add our observational estimate of upper-ocean thermal expansion to other contributions to sea-level rise and find that the sum of contributions from 1961 to 2003 is about 1.5 plusminus 0.4 mm yr-1, in good agreement with our updated estimate of near-global mean sea-level rise (using techniques established in earlier studies6, 7) of 1.6 plusminus 0.2 mm yr-1},
author = {Domingues, Catia M. and Church, John A. and White, Neil J. and Gleckler, Peter J. and Wijffels, Susan E. and Barker, Paul M. and Dunn, Jeff R.},
doi = {10.1038/nature07080},
isbn = {0028-0836$\backslash$r1476-4687},
issn = {14764687},
journal = {Nature},
month = {jun},
number = {7198},
pages = {1090--1093},
pmid = {18563162},
publisher = {Nature Publishing Group},
title = {{Improved estimates of upper-ocean warming and multi-decadal sea-level rise}},
url = {http://www.nature.com/articles/nature07080},
volume = {453},
year = {2008}
}
@article{Donat2013,
abstract = {F or more than a decade, the World Meteorological Organization (WMO) Commission for Climatology (CCl)/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI) has been facilitating the international coordination of a suite of indices that primarily represent the more extreme aspects of climate. The main aim of this team has been to fill in data gaps using a consistent and traceable approach in order to provide a clear global picture of the long-term variability of extremes, to provide the necessary data to perform appropriate “detection and attribution” studies, and to be able to evaluate climate models and assess their efficacy in simulating and projecting the future of climate extremes. To this end, the ETCCDI held a number of regional workshops over many years, the data from which were used to help create HadEX, the first global land-based, gridded dataset of temperature and precipitation extremes covering the second half of the twentieth century. While HadEX facilitated the analysis of trends in extremes, its relatively short record (1951–2003) and static nature (i.e., it is not updated) presents critical gaps in our ability to adequately assess and monitor changes in extremes. Furthermore, much of the data from the regional workshops is not publically available, making it difficult to independently reproduce the results of HadEX. For these reasons, the authors set out to develop a new dataset to address these issues using the world's largest repository of daily in situ observations of temperature and precipitation—the National Climatic Data Center (NCDC)'s Global Historical Climatology Network (GHCN)-Daily dataset. This article describes the resulting dataset, termed GHCNDEX—an operationally updated, global land gridded dataset of climate extremes. We also demonstrate the application of the dataset for climate change and climate monitoring purposes in addition to assessing some issues regarding uncertainty by comparing the results with existing datasets.},
author = {Donat, M.G. and Alexander, L.V. and Yang, H. and Durre, I. and Vose, R. and Caesar, J.},
doi = {10.1175/BAMS-D-12-00109.1},
issn = {1520-0477},
journal = {Bulletin of the American Meteorological Society},
month = {jul},
number = {7},
pages = {997--1006},
title = {{Global Land-Based Datasets for Monitoring Climatic Extremes}},
url = {https://journals.ametsoc.org/doi/10.1175/BAMS-D-12-00109.1},
volume = {94},
year = {2013}
}
@article{Donat2013a,
abstract = {In this study, we present the collation and analysis of the gridded land-based dataset of indices of temperature and precipitation extremes: HadEX2. Indices were calculated based on station data using a consistent approach recommended by the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices, resulting in the production of 17 temperature and 12 precipitation indices derived from daily maximum and minimum temperature and precipitation observations. High-quality in situ observations from over 7000 temperature and 11,000 precipitation meteorological stations across the globe were obtained to calculate the indices over the period of record available for each station. Monthly and annual indices were then interpolated onto a 3.75° × 2.5° longitude-latitude grid over the period 1901–2010. Linear trends in the gridded fields were computed and tested for statistical significance. Overall there was very good agreement with the previous HadEX dataset during the overlapping data period. Results showed widespread significant changes in temperature extremes consistent with warming, especially for those indices derived from daily minimum temperature over the whole 110 years of record but with stronger trends in more recent decades. Seasonal results showed significant warming in all seasons but more so in the colder months. Precipitation indices also showed widespread and significant trends, but the changes were much more spatially heterogeneous compared with temperature changes. However, results indicated more areas with significant increasing trends in extreme precipitation amounts, intensity, and frequency than areas with decreasing trends.},
author = {Donat, M. G. and Alexander, L. V. and Yang, H. and Durre, I. and Vose, R. and Dunn, R. J.H. and Willett, K. M. and Aguilar, E. and Brunet, M. and Caesar, J. and Hewitson, B. and Jack, C. and {Klein Tank}, A. M.G. and Kruger, A. C. and Marengo, J. and Peterson, T. C. and Renom, M. and {Oria Rojas}, C. and Rusticucci, M. and Salinger, J. and Elrayah, A. S. and Sekele, S. S. and Srivastava, A. K. and Trewin, B. and Villarroel, C. and Vincent, L. A. and Zhai, P. and Zhang, X. and Kitching, S.},
doi = {10.1002/jgrd.50150},
isbn = {2169-8996},
issn = {21698996},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {climate extremes,global gridded dataset,observations,precipitation,temperature},
number = {5},
pages = {2098--2118},
title = {{Updated analyses of temperature and precipitation extreme indices since the beginning of the twentieth century: The HadEX2 dataset}},
volume = {118},
year = {2013}
}
@article{Dong2016,
author = {Dong, Lu and Zhou, Tianjun and Dai, Aiguo and Song, Fengfei and Wu, Bo and Chen, Xiaolong},
doi = {10.1038/srep21251},
journal = {Scientific Reports},
month = {feb},
pages = {21251},
publisher = {The Author(s)},
title = {{The Footprint of the Inter-decadal Pacific Oscillation in Indian Ocean Sea Surface Temperatures}},
url = {https://doi.org/10.1038/srep21251 10.1038/srep21251 https://www.nature.com/articles/srep21251{\#}supplementary-information},
volume = {6},
year = {2016}
}
@article{Dong2013,
abstract = {The Walker circulation is one of the major components of the large-scale tropical atmospheric circulation and variations in its strength are critical to equatorial Pacific Ocean circulation. It has been argued in the literature that during the 20th century the Walker circulation weakened, and that this weakening was attributable to anthropogenic climate change. By using updated observations, we show that there has been a rapid interdecadal enhancement of the Walker circulation since the late 1990s. Associated with this enhancement is enhanced precipitation in the tropical western Pacific, anomalous westerlies in the upper troposphere, descent in the central and eastern tropical Pacific, and anomalous surface easterlies in the western and central tropical Pacific. The characteristics of associated oceanic changes are a strengthened thermocline slope and an enhanced zonal SST gradient across the tropical Pacific. Many characteristics of these changes are similar to those associated with the mid-1970s climate shift with an opposite sign. We also show that the interdecadal variability of the Walker circulation in the tropical Pacific is inversely correlated to the interdecadal variability of the zonal circulation in the tropical Atlantic. An enhancement of the Walker circulation in the tropical Pacific is associated with a weakening zonal circulation in the tropical Atlantic and vise versa, implying an inter-Atlantic-Pacific connection of the zonal overturning circulation variation. Whether these recent changes will be sustained is not yet clear, but our research highlights the importance of understanding the interdecadal variability, as well as the long-term trends, that influence tropical circulation.},
author = {Dong, Buwen and Lu, Riyu},
doi = {10.1007/s00376-012-2069-9},
isbn = {0256-1530},
issn = {02561530},
journal = {Advances in Atmospheric Sciences},
keywords = {Interdecadal Pacific Oscillation,Walker circulation,interdecadal change,late 1990s},
number = {2},
pages = {247--262},
title = {{Interdecadal enhancement of the walker circulation over the Tropical Pacific in the late 1990s}},
volume = {30},
year = {2013}
}
@article{doi:10.1175/JCLI-D-17-0663.1,
abstract = { AbstractRemote influences of ENSO are known to vary with different phases of the interdecadal Pacific oscillation (IPO). Here, observational and reanalysis data from 1920 to 2014 are analyzed to present a global synthesis of the IPO's modulation on ENSO teleconnections, followed by a modeling investigation. Regressions of surface air temperature T, precipitation P, and atmospheric circulations upon IPO and ENSO indices reveal substantial differences between ENSO and IPO teleconnections to regional T and P in terms of spatial pattern, magnitude, and seasonality. The IPO's modulation on ENSO teleconnections asymmetrically varies with both IPO and ENSO phases. For a given ENSO phase, IPO's modulations are not symmetric between its two phases; for a given IPO SST anomaly, its influence depends on whether it is superimposed on El Ni{\~{n}}o, La Ni{\~{n}}a, or neutral ENSO. The IPO modulations are linked to the atmospheric response to tropical SST anomalies, manifested in the local Hadley circulation and the local Walker circulation at low latitudes and the Rossby wave train in the extratropics, including the Pacific–North American (PNA) pattern in the Northern Hemisphere. A set of numerical experiments using CAM5 forced with different combinations of the IPO- and ENSO-related SSTs further shows that the asymmetric modulation arises from the nonlinear Clausius–Clapeyron relation, so that the atmospheric circulation response to the same IPO-induced SST departure is larger during a warm rather than a cold ENSO phase, and the response to a warm IPO state is larger than that to a cold IPO state. The asymmetry depends primarily on the tropical Pacific mean state and tropical SST anomalies and secondarily on extratropical SST anomalies. },
author = {Dong, Bo and Dai, Aiguo and Vuille, Mathias and Timm, Oliver Elison},
doi = {10.1175/JCLI-D-17-0663.1},
journal = {Journal of Climate},
number = {18},
pages = {7337--7361},
title = {{Asymmetric Modulation of ENSO Teleconnections by the Interdecadal Pacific Oscillation}},
url = {https://doi.org/10.1175/JCLI-D-17-0663.1},
volume = {31},
year = {2018}
}
@article{Dong2019a,
abstract = {The Gulf Stream, the main heat-carrier from low to high latitudes in the North Atlantic Ocean, influences the climate and weather in the northern hemisphere. In this study we determine and analyze the position, speed, and width of the Gulf Stream (GS) from 80°W–50°W using satellite altimeter sea surface height (SSH) measurements to examine the possible link between changes in the strength of the GS and coastal sea levels along the U.S. East Coast. During our 24-year study period (1993–2016), the GS experienced a southward shift east of 65°W after passing the New England Seamount chain. This southward shift was accompanied by a weakening of the GS, associated with an increase in SSH to the north of the GS. West of 70°W, however, we found no statistically significant trends in the GS properties, consistent with results based on in situ measurements. This lack of a trend to the west fails to support a direct link between a long-term slowdown of the GS west of 70°W and sea level rise acceleration along the U.S. East Coast, though a slowdown of the GS east of 65°W may contribute to sea level rise. It is also possible that heat carried to the region by the GS may be responsible for these observed sea level changes.},
author = {Dong, Shenfu and Baringer, Molly O and Goni, Gustavo J},
doi = {10.1038/s41598-019-42820-8},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {6672},
title = {{Slow Down of the Gulf Stream during 1993–2016}},
url = {https://doi.org/10.1038/s41598-019-42820-8},
volume = {9},
year = {2019}
}
@article{Dornelas296,
abstract = {Although the rate of species extinction has increased markedly as a result of human activity across the biosphere, conservation has focused on endangered species rather than on shifts in assemblages. Dornelas et al. (p. 296; see the Perspective by Pandolfi and Lovelock), using an extensive set of biodiversity time series of species occurrences in both marine and terrestrial habitats from the past 150 years, find species turnover above expected but do not find evidence of systematic biodiversity loss. This result could be caused by homogenization of species assemblages by invasive species, shifting distributions induced by climate change, and asynchronous change across the planet. All of which indicates that it is time to review conservation priorities. The extent to which biodiversity change in local assemblages contributes to global biodiversity loss is poorly understood. We analyzed 100 time series from biomes across Earth to ask how diversity within assemblages is changing through time. We quantified patterns of temporal $\alpha$ diversity, measured as change in local diversity, and temporal $\beta$ diversity, measured as change in community composition. Contrary to our expectations, we did not detect systematic loss of $\alpha$ diversity. However, community composition changed systematically through time, in excess of predictions from null models. Heterogeneous rates of environmental change, species range shifts associated with climate change, and biotic homogenization may explain the different patterns of temporal $\alpha$ and $\beta$ diversity. Monitoring and understanding change in species composition should be a conservation priority.},
author = {Dornelas, Maria and Gotelli, Nicholas J and McGill, Brian and Shimadzu, Hideyasu and Moyes, Faye and Sievers, Caya and Magurran, Anne E},
doi = {10.1126/science.1248484},
issn = {0036-8075},
journal = {Science},
number = {6181},
pages = {296--299},
publisher = {American Association for the Advancement of Science},
title = {{Assemblage Time Series Reveal Biodiversity Change but Not Systematic Loss}},
url = {http://science.sciencemag.org/content/344/6181/296},
volume = {344},
year = {2014}
}
@article{Dornelas2018a,
abstract = {Motivation: The BioTIME database contains raw data on species identities and abundances in eco- logical assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.},
author = {Dornelas, Maria and Ant{\~{a}}o, Laura H. and Moyes, Faye and Bates, Amanda E. and Magurran, Anne E. and Adam, Du{\v{s}}an and Akhmetzhanova, Asem A. and Appeltans, Ward and Arcos, Jos{\'{e}} Manuel and Arnold, Haley},
doi = {10.1111/geb.12729},
issn = {14668238},
journal = {Global Ecology and Biogeography},
number = {7},
pages = {760--786},
title = {{BioTIME: A database of biodiversity time series for the Anthropocene}},
volume = {27},
year = {2018}
}
@article{Dornelas2019,
abstract = {Scientists disagree about the nature of biodiversity change. While there is evidence for widespread declines from population surveys, assemblage surveys reveal a mix of declines and increases. These conflicting conclusions may be caused by the use of different metrics: assemblage metrics may average out drastic changes in individual populations. Alternatively, differences may arise from data sources: populations monitored individually, versus whole-assemblage monitoring. To test these hypotheses, we estimated population change metrics using assemblage data. For a set of 23 241 populations, 16 009 species, in 158 assemblages, we detected significantly accelerating extinction and colonisation rates, with both rates being approximately balanced. Most populations (85{\%}) did not show significant trends in abundance, and those that did were balanced between winners (8{\%}) and losers (7{\%}). Thus, population metrics estimated with assemblage data are commensurate with assemblage metrics and reveal sustained and increasing species turnover.},
author = {Dornelas, Maria and Gotelli, Nicholas J. and Shimadzu, Hideyasu and Moyes, Faye and Magurran, Anne E. and McGill, Brian J.},
doi = {10.1111/ele.13242},
issn = {14610248},
journal = {Ecology Letters},
number = {5},
pages = {847--854},
title = {{A balance of winners and losers in the Anthropocene}},
volume = {22},
year = {2019}
}
@article{Dowdeswell1020,
abstract = {Are the rates at which we observe ice shelves shrinking today representative of how fast they shrank in the past? Dowdeswell et al. report observations of the Antarctic seafloor that reveal the presence of submarine grounding-zone wedges on the Larsen continental shelf (see the Perspective by Jakobsson). The authors interpret these ridges as being caused by the tidal rise and fall of the ice shelf at the grounding line, which squeezes the underlying sediments when it rests on the seafloor. From this, they calculated that ice shelf retreat at this location about 14,000 years ago was at times as much as 100 times as fast as the average over the past 10,000 years.Science, this issue p. 1020; see also p. 939A suite of grounding-line landforms on the Antarctic seafloor, imaged at submeter horizontal resolution from an autonomous underwater vehicle, enables calculation of ice sheet retreat rates from a complex of grounding-zone wedges on the Larsen continental shelf, western Weddell Sea. The landforms are delicate sets of up to 90 ridges, {\textless}1.5 meters high and spaced 20 to 25 meters apart. We interpret these ridges as the product of squeezing up of soft sediment during the rise and fall of the retreating ice sheet grounding line during successive tidal cycles. Grounding-line retreat rates of 40 to 50 meters per day ({\textgreater}10 kilometers per year) are inferred during regional deglaciation of the Larsen shelf. If repeated today, such rapid mass loss to the ocean would have clear implications for increasing the rate of global sea level rise.},
author = {Dowdeswell, J A and Batchelor, C L and Montelli, A and Ottesen, D and Christie, F D W and Dowdeswell, E K and Evans, J},
doi = {10.1126/science.aaz3059},
issn = {0036-8075},
journal = {Science},
number = {6494},
pages = {1020--1024},
publisher = {American Association for the Advancement of Science},
title = {{Delicate seafloor landforms reveal past Antarctic grounding-line retreat of kilometers per year}},
url = {https://science.sciencemag.org/content/368/6494/1020},
volume = {368},
year = {2020}
}
@article{dowsett_mid-piacenzian_2019,
author = {Dowsett, Harry J and Robinson, Marci M and Foley, Kevin M and Herbert, Timothy D and Otto-Bliesner, Bette L and Spivey, Whittney},
doi = {10.29041/strat.16.3.119-144},
issn = {1547139X, 2331656X},
journal = {Stratigraphy},
month = {sep},
number = {3},
pages = {119--144},
title = {{The mid-Piacenzian of the North Atlantic Ocean}},
url = {http://www.micropress.org/microaccess/stratigraphy/issue-352/article-2140},
volume = {16},
year = {2019}
}
@article{acp-20-4787-2020,
author = {Droste, E S and Adcock, K E and Ashfold, M J and Chou, C and Fleming, Z and Fraser, P J and Gooch, L J and Hind, A J and Langenfelds, R L and {Leedham Elvidge}, E and {Mohd Hanif}, N and O'Doherty, S and Oram, D E and Ou-Yang, C.-F. and Panagi, M and Reeves, C E and Sturges, W T and Laube, J C},
doi = {10.5194/acp-20-4787-2020},
journal = {Atmospheric Chemistry and Physics},
number = {8},
pages = {4787--4807},
title = {{Trends and emissions of six perfluorocarbons in the Northern Hemisphere and Southern Hemisphere}},
url = {https://acp.copernicus.org/articles/20/4787/2020/},
volume = {20},
year = {2020}
}
@article{Druzhinin_2019,
abstract = {Prediction of the properties of the atmospheric flows over sea is important for local and regional weather forecast. This prediction typically relies on the performance of large-scale meteorological models based on bulk formulae for air velocity, temperature and humidity. The bulk formulas relate turbulent fluxes of momentum, heat and vapor to bulk air velocity, humidity and air-sea temperature difference. The most widely used parameterizations used to compute the coefficients of proportionality in the bulk formulae are formulated on the basis of the Monin-Obukhov similarity theory (MOST) for different types of air stratification (stable, neutral and unstable). In our previous studies we showed that MOST quite accurately predicts the properties of the air-flow over waved water surface under neutral and stable stratification conditions provided that stratification effects are relatively weak and flow is in a statistically stationary state. In the present work, we perform direct numerical simulation and study the air flow over a waved water surface under unstable stratification conditions where the sea surface temperature is larger than the bulk air temperature. Such situation occurs in the tropical cyclone conditions as well as in polar lows at high latitudes. Our results show that in this case, the air flow dynamics is dominated by the development of large-scale cylindrical coherent vortex structures elongated in the direction of the mean wind. These structures cause a notable deviations from the MOST predictions for the air velocity and temperature profiles.},
author = {Druzhinin, O and Troitskaya, Yu and Zilitinkevich, S},
doi = {10.1088/1742-6596/1163/1/012018},
journal = {Journal of Physics: Conference Series},
month = {feb},
pages = {12018},
publisher = {{\{}IOP{\}} Publishing},
title = {{The study of the unstably-stratified marine atmospheric boundary layer by direct numerical simulation}},
url = {https://doi.org/10.1088/1742-6596/1163/1/012018},
volume = {1163},
year = {2019}
}
@article{Du2014a,
abstract = {The tropical Indian Ocean (TIO) displays a uniform basin-wide warming or cooling in sea surface temperature (SST) during the decay year of El Ni{\~{n}}o-Southern Oscillation (ENSO) events. This warming or cooling is called the tropical Indian Ocean Basin Mode (IOBM). Recent studies showed that the IOBM dominates the interannual variability of the TIO SST and has impacts on the tropical climate from the TIO to the western Pacific. Analyses on a 148-year-long monthly coral $\delta$18O record from the Seychelles Islands demonstrate that the Seychelles coral $\delta$18O not only is associated with the local SST but also indicates the interannul variability of the basin-wide SST in the TIO. Moreover, the Seychelles coral $\delta$18O shows a dominant period of 3–7 years that well represents the variability of the IOBM, which in return is modulated by the inter-decadal climate variability. The correlation between the Seychelles coral $\delta$18O and the SST reveals that the coral $\delta$18O lags the SST in the eastern equatorial Pacific by five months and reaches its peak in the spring following the mature phase of ENSO. The spatial pattern of the first EOF mode indicates that the Seychelles Islands are located at the crucial place of the IOBM. Thus, the Seychelles coral $\delta$18O could be used as a proxy of the IOBM to investigate the ENSO teleconnection on the TIO in terms of long-time climate variability.},
author = {Du, Yan and Xiao, JinJun and Yu, KeFu},
doi = {10.1007/s11430-014-4956-7},
issn = {1869-1897},
journal = {Science China Earth Sciences},
number = {11},
pages = {2597--2605},
title = {{Tropical Indian Ocean Basin Mode recorded in coral oxygen isotope data from the Seychelles over the past 148 years}},
url = {https://doi.org/10.1007/s11430-014-4956-7},
volume = {57},
year = {2014}
}
@article{DU2021116670,
abstract = {The variability of El Ni{\~{n}}o-Southern Oscillation (ENSO) on centennial to millennial time-scales is poorly understood due to the insufficient length, continuity, or resolution of existing paleoclimate records. Here we present a new, continuous, sub-annually resolved scanning XRF Ti record from marine sediments collected from Santa Barbara Basin (SBB) to reveal interannual precipitation changes in Southern California for the past 9000 yrs. Interannual precipitation variability in Southern California is closely related to ENSO through an atmospheric teleconnection with the tropical Pacific. Thus, Southern California precipitation reconstructions provide an opportunity to explore ENSO variability through time. Wavelet analysis of the SBB Ti record demonstrates interannual (2–7 yrs) precipitation variance was relatively weak prior to 4.4 ka, and significantly increased after 4.4 ka. Our record demonstrates a relationship between Southern California precipitation and the tropical Pacific and extratropical climate. The inferred increase of ENSO variability during the late Holocene is generally consistent with the published tropical Pacific ENSO records, and could be associated with a southward shift of the Intertropical Convergence Zone (ITCZ). Meanwhile, a deeper, westward-shifted Aleutian Low after 4.4 ka may have strengthened the ENSO teleconnection between the tropical Pacific and Southern California, contributing to the amplified interannual precipitation variance in the SBB record. Community Earth System Model (CESM) simulations through the Holocene (0, 3, 6, 9 ka) support the role of both the ITCZ and the AL in the enhancement of interannual precipitation variability in Southern California.},
author = {Du, Xiaojing and Hendy, Ingrid and Hinnov, Linda and Brown, Erik and Zhu, Jiang and Poulsen, Christopher J},
doi = {10.1016/j.epsl.2020.116670},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {ENSO,Holocene,ITCZ,Santa Barbara Basin,Southern California precipitation,varve},
pages = {116670},
title = {{High-resolution interannual precipitation reconstruction of Southern California: Implications for Holocene ENSO evolution}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X20306142},
volume = {554},
year = {2021}
}
@inproceedings{DuchesneC.SmithS.L.EdnieM.Bonnaventure2015,
author = {Duchesne, C. and Smith, S. L. and Ednie, M. and Bonnaventure, P. P.},
booktitle = {68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference},
pages = {1--7},
title = {{Active layer variability and Change in the Mackenzie Valley, Northwest Territories}},
year = {2015}
}
@article{dumitru_constraints_2019,
author = {Dumitru, Oana A and Austermann, Jacqueline and Polyak, Victor J and Forn{\'{o}}s, Joan J and Asmerom, Yemane and Gin{\'{e}}s, Joaqu{\'{i}}n and Gin{\'{e}}s, Angel and Onac, Bogdan P},
doi = {10.1038/s41586-019-1543-2},
issn = {0028-0836, 1476-4687},
journal = {Nature},
month = {oct},
number = {7777},
pages = {233--236},
title = {{Constraints on global mean sea level during Pliocene warmth}},
url = {http://www.nature.com/articles/s41586-019-1543-2},
volume = {574},
year = {2019}
}
@article{Dunn2014,
author = {Dunn, R J H and Willett, K M and Morice, C P and Parker, D E},
doi = {10.5194/cp-10-1501-2014},
journal = {Climate of the Past},
number = {4},
pages = {1501--1522},
title = {{Pairwise homogeneity assessment of HadISD}},
volume = {10},
year = {2014}
}
@article{Dunn2012,
author = {Dunn, R J H and Willett, K M and Thorne, P W and Woolley, E V and Durre, I and Dai, A and Parker, D E and Vose, R S},
doi = {10.5194/cp-8-1649-2012},
journal = {Climate of the Past},
number = {5},
pages = {1649--1679},
title = {{HadISD: A Quality Controlled global synoptic report database for selected variables at long-term stations from 1973–2011}},
volume = {8},
year = {2012}
}
@article{Dunn2016b,
author = {Dunn, R J H; and Willett, K M; and Parker, D E; and Mitchell, L},
doi = {10.5194/cpd-11-4569-2015},
journal = {Geoscientific Instrumentation, Methods and Data Systems},
number = {2},
pages = {473--491},
title = {{Expanding HadISD: quality-controlled, sub-daily station data from 1931}},
volume = {5},
year = {2016}
}
@article{Dunn2020,
author = {Dunn, Robert J. H. and Alexander, Lisa V. and Donat, Markus G. and Zhang, Xuebin and Bador, Margot and Herold, Nicholas and Lippmann, Tanya and Allan, Rob and Aguilar, Enric and Barry, Abdoul Aziz and Brunet, Manola and Caesar, John and Chagnaud, Guillaume and Cheng, Vincent and Cinco, Thelma and Durre, Imke and Guzman, Rosaline and Htay, Tin Mar and {Wan Ibadullah}, Wan Maisarah and {Bin Ibrahim}, Muhammad Khairul Izzat and Khoshkam, Mahbobeh and Kruger, Andries and Kubota, Hisayuki and Leng, Tan Wee and Lim, Gerald and Li‐Sha, Lim and Marengo, Jose and Mbatha, Sifiso and McGree, Simon and Menne, Matthew and {Milagros Skansi}, Maria and Ngwenya, Sandile and Nkrumah, Francis and Oonariya, Chalump and Pabon‐Caicedo, Jose Daniel and Panthou, G{\'{e}}r{\'{e}}my and Pham, Cham and Rahimzadeh, Fatemeh and Ramos, Andrea and Salgado, Ernesto and Salinger, Jim and San{\'{e}}, Youssouph and Sopaheluwakan, Ardhasena and Srivastava, Arvind and Sun, Ying and Timbal, Bertrand and Trachow, Nichanun and Trewin, Blair and Schrier, Gerard and Vazquez‐Aguirre, Jorge and Vasquez, Ricardo and Villarroel, Claudia and Vincent, Lucie and Vischel, Theo and Vose, Russ and {Bin Hj Yussof}, Mohd Noor'Arifin},
doi = {10.1029/2019JD032263},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {aug},
number = {16},
title = {{Development of an Updated Global Land In Situ-Based Data Set of Temperature and Precipitation Extremes: HadEX3}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2019JD032263},
volume = {125},
year = {2020}
}
@article{Dunn2017b,
author = {Dunn, Robert J H and Willett, Kate M and Ciavarella, Andrew and Stott, Peter A},
doi = {10.5194/esd-8-719-2017},
journal = {Earth System Dynamics},
number = {3},
pages = {719--747},
title = {{Comparison of land surface humidity between observations and CMIP5 models}},
volume = {8},
year = {2017}
}
@article{Durack2012,
abstract = {Fundamental thermodynamics and climate models suggest that dry regions will become drier and wet regions will become wetter in response to warming. Efforts to detect this long-term response in sparse surface observations of rainfall and evaporation remain ambiguous. We show that ocean salinity patterns express an identifiable fingerprint of an intensifying water cycle. Our 50-year observed global surface salinity changes, combined with changes from global climate models, present robust evidence of an intensified global water cycle at a rate of 8 ± 5{\%} per degree of surface warming. This rate is double the response projected by current-generation climate models and suggests that a substantial (16 to 24{\%}) intensification of the global water cycle will occur in a future 2° to 3° warmer world.},
author = {Durack, Paul J. and Wijffels, Susan E. and Matear, Richard J.},
doi = {10.1126/science.1212222},
isbn = {1095-9203 (Electronic)$\backslash$n0036-8075 (Linking)},
issn = {10959203},
journal = {Science},
number = {6080},
pages = {455--458},
pmid = {22539717},
title = {{Ocean salinities reveal strong global water cycle intensification during 1950 to 2000}},
volume = {336},
year = {2012}
}
@article{doi:10.1175/2010JCLI3377.1,
abstract = {Abstract Using over 1.6 million profiles of salinity, potential temperature, and neutral density from historical archives and the international Argo Program, this study develops the three-dimensional field of multidecadal linear change for ocean-state properties. The period of analysis extends from 1950 to 2008, taking care to minimize the aliasing associated with the seasonal and major global El Ni{\~{n}}o–Southern Oscillation modes. Large, robust, and spatially coherent multidecadal linear trends in salinity to 2000-dbar depth are found. Salinity increases at the sea surface are found in evaporation-dominated regions and freshening in precipitation-dominated regions, with the spatial pattern of change strongly resembling that of the mean salinity field, consistent with an amplification of the global hydrological cycle. Subsurface salinity changes on pressure surfaces are attributable to both isopycnal heave and real water-mass modification of the temperature–salinity relationship. Subduction and circulation by the ocean's mean flow of surface salinity and temperature anomalies appear to account for most regional subsurface salinity changes on isopycnals. Broad-scale surface warming and the associated poleward migration of isopycnal outcrops drive a clear and repeating pattern of subsurface isopycnal salinity change in each independent ocean basin. Qualitatively, the observed global multidecadal salinity changes are thus consonant with both broad-scale surface warming and the amplification of the global hydrological cycle.},
author = {Durack, Paul J and Wijffels, Susan E},
doi = {10.1175/2010JCLI3377.1},
journal = {Journal of Climate},
number = {16},
pages = {4342--4362},
title = {{Fifty-Year Trends in Global Ocean Salinities and Their Relationship to Broad-Scale Warming}},
url = {https://doi.org/10.1175/2010JCLI3377.1},
volume = {23},
year = {2010}
}
@article{Durack2015a,
author = {Durack, P.J.},
doi = {10.5670/oceanog.2015.03},
journal = {Oceanography},
pages = {20--31},
title = {{Ocean salinity and the global water cycle}},
volume = {28},
year = {2015}
}
@article{Duruisseau2017,
abstract = {This study focuses on the ability of ERA-Interim to represent wind variability in the middle atmosphere. The originality of the proposed approach is that wind measurements are deduced from the trajectories of zero-pressure balloons that can reach high-stratospheric altitudes. These balloons are mainly used to carry large scientific payloads. The trajectories of balloons launched above Esrange, Sweden, and Teresina, Brazil, from 2000 to 2011 were used to deduce zonal and meridional wind components (by considering the balloon as a perfect tracer at high altitude). Collected data cover several dynamical conditions associated with the winter and summer polar seasons and west and east phases of the quasi-biennial oscillation at the equator. Systematic comparisons between measurements and ERA-Interim data were performed for the two horizontal wind components, as well as wind speed and wind direction in the [100, 2]-hPa pressure range to deduce biases between the model and balloon measurements as a function of altitude. Results show that whatever the location and the geophysical conditions considered, biases between ERA-Interim and balloon wind measurements increase as a function of altitude. The standard deviation of the model–observation wind differences can attain more than 5 m s−1 at high altitude (pressure P {\textless} 20 hPa). A systematic ERA-Interim underestimation of the wind speed is observed and large biases are highlighted, especially for equatorial flights.},
author = {Duruisseau, Fabrice and Huret, Nathalie and Andral, Alice and Camy-Peyret, Claude},
doi = {10.1175/JAS-D-16-0137.1},
issn = {0022-4928},
journal = {Journal of the Atmospheric Sciences},
number = {6},
pages = {2065--2080},
title = {{Assessment of the ERA-Interim Winds Using High-Altitude Stratospheric Balloons}},
volume = {74},
year = {2017}
}
@article{Duttonaaa4019,
abstract = {We know that the sea level will rise as climate warms. Nevertheless, accurate projections of how much sea-level rise will occur are difficult to make based solely on modern observations. Determining how ice sheets and sea level have varied in past warm periods can help us better understand how sensitive ice sheets are to higher temperatures. Dutton et al. review recent interdisciplinary progress in understanding this issue, based on data from four different warm intervals over the past 3 million years. Their synthesis provides a clear picture of the progress we have made and the hurdles that still exist.Science, this issue 10.1126/science.aaa4019BACKGROUNDAlthough thermal expansion of seawater and melting of mountain glaciers have dominated global mean sea level (GMSL) rise over the last century, mass loss from the Greenland and Antarctic ice sheets is expected to exceed other contributions to GMSL rise under future warming. To better constrain polar ice-sheet response to warmer temperatures, we draw on evidence from interglacial periods in the geologic record that experienced warmer polar temperatures and higher GMSLs than present. Coastal records of sea level from these previous warm periods demonstrate geographic variability because of the influence of several geophysical processes that operate across a range of magnitudes and time scales. Inferring GMSL and ice-volume changes from these reconstructions is nontrivial and generally requires the use of geophysical models.ADVANCESInterdisciplinary studies of geologic archives have ushered in a new era of deciphering magnitudes, rates, and sources of sea-level rise. Advances in our understanding of polar ice-sheet response to warmer climates have been made through an increase in the number and geographic distribution of sea-level reconstructions, better ice-sheet constraints, and the recognition that several geophysical processes cause spatially complex patterns in sea level. In particular, accounting for glacial isostatic processes helps to decipher spatial variability in coastal sea-level records and has reconciled a number of site-specific sea-level reconstructions for warm periods that have occurred within the past several hundred thousand years. This enables us to infer that during recent interglacial periods, small increases in global mean temperature and just a few degrees of polar warming relative to the preindustrial period resulted in {\textgreater}=6 m of GMSL rise. Mantle-driven dynamic topography introduces large uncertainties on longer time scales, affecting reconstructions for time periods such as the Pliocene ({\~{}}3 million years ago), when atmospheric CO2 was {\~{}}400 parts per million (ppm), similar to that of the present. Both modeling and field evidence suggest that polar ice sheets were smaller during this time period, but because dynamic topography can cause tens of meters of vertical displacement at Earth{\{}$\backslash$textquoteright{\}}s surface on million-year time scales and uncertainty in model predictions of this signal are large, it is currently not possible to make a precise estimate of peak GMSL during the Pliocene.OUTLOOKOur present climate is warming to a level associated with significant polar ice-sheet loss in the past, but a number of challenges remain to further constrain ice-sheet sensitivity to climate change using paleo{\{}$\backslash$textendash{\}}sea level records. Improving our understanding of rates of GMSL rise due to polar ice-mass loss is perhaps the most societally relevant information the paleorecord can provide, yet robust estimates of rates of GMSL rise associated with polar ice-sheet retreat and/or collapse remain a weakness in existing sea-level reconstructions. Improving existing magnitudes, rates, and sources of GMSL rise will require a better (global) distribution of sea-level reconstructions with high temporal resolution and precise elevations and should include sites close to present and former ice sheets. Translating such sea-level data into a robust GMSL signal demands integration with geophysical models, which in turn can be tested through improved spatial and temporal sampling of coastal records.Further development is needed to refine estimates of past sea level from geochemical proxies. In particular, paired oxygen isotope and Mg/Ca data are currently unable to provide confident, quantitative estimates of peak sea level during these past warm periods. In some GMSL reconstructions, polar ice-sheet retreat is inferred from the total GMSL budget, but identifying the specific ice-sheet sources is currently hindered by limited field evidence at high latitudes. Given the paucity of such data, emerging geochemical and geophysical techniques show promise for identifying the sectors of the ice sheets that were most vulnerable to collapse in the past and perhaps will be again in the future.Peak global mean temperature, atmospheric CO2, maximum global mean sea level (GMSL), and source(s) of meltwater.Light blue shading indicates uncertainty of GMSL maximum. Red pie charts over Greenland and Antarctica denote fraction (not location) of ice retreat.Interdisciplinary studies of geologic archives have ushered in a new era of deciphering magnitudes, rates, and sources of sea-level rise from polar ice-sheet loss during past warm periods. Accounting for glacial isostatic processes helps to reconcile spatial variability in peak sea level during marine isotope stages 5e and 11, when the global mean reached 6 to 9 meters and 6 to 13 meters higher than present, respectively. Dynamic topography introduces large uncertainties on longer time scales, precluding robust sea-level estimates for intervals such as the Pliocene. Present climate is warming to a level associated with significant polar ice-sheet loss in the past. Here, we outline advances and challenges involved in constraining ice-sheet sensitivity to climate change with use of paleo{\{}$\backslash$textendash{\}}sea level records.},
author = {Dutton, A and Carlson, A E and Long, A J and Milne, G A and Clark, P U and DeConto, R and Horton, B P and Rahmstorf, S and Raymo, M E},
doi = {10.1126/science.aaa4019},
issn = {0036-8075},
journal = {Science},
number = {6244},
publisher = {American Association for the Advancement of Science},
title = {{Sea-level rise due to polar ice-sheet mass loss during past warm periods}},
url = {https://science.sciencemag.org/content/349/6244/aaa4019},
volume = {349},
year = {2015}
}
@article{Dyez2018a,
abstract = {Abstract In the early Pleistocene, global temperature cycles predominantly varied with {\~{}}41-kyr (obliquity-scale) periodicity. Atmospheric greenhouse gas concentrations likely played a role in these climate cycles; marine sediments provide an indirect geochemical means to estimate early Pleistocene CO2. Here we present a boron isotope-based record of continuous high-resolution surface ocean pH and inferred atmospheric CO2 changes. Our results show that, within a window of time in the early Pleistocene (1.38?1.54 Ma), pCO2 varied with obliquity, confirming that, analogous to late Pleistocene conditions, the carbon cycle and climate covaried at {\~{}}1.5 Ma. Pairing the reconstructed early Pleistocene pCO2 amplitude (92 ± 13 ?atm) with a comparably smaller global surface temperature glacial/interglacial amplitude (3.0 ± 0.5 K) yields a surface temperature change to CO2 radiative forcing ratio of S[CO2]{\~{}}0.75 (±0.5) °C?1{\textperiodcentered}W?1{\textperiodcentered}m?2, as compared to the late Pleistocene S[CO2] value of {\~{}}1.75 (±0.6) °C?1{\textperiodcentered}W?1{\textperiodcentered}m?2. This direct comparison of pCO2 and temperature implicitly incorporates the large ice sheet forcing as an internal feedback and is not directly applicable to future warming. We evaluate this result with a simple climate model and show that the presumably thinner, though extensive, northern hemisphere ice sheets would increase surface temperature sensitivity to radiative forcing. Thus, the mechanism to dampen actual temperature variability in the early Pleistocene more likely lies with Southern Ocean circulation dynamics or antiphase hemispheric forcing. We also compile this new carbon dioxide record with published Plio-Pleistocene $\delta$11B records using consistent boundary conditions and explore potential reasons for the discrepancy between Pliocene pCO2 based on different planktic foraminifera.},
annote = {doi: 10.1029/2018PA003349},
author = {Dyez, Kelsey A and H{\"{o}}nisch, B{\"{a}}rbel and Schmidt, Gavin A},
doi = {10.1029/2018PA003349},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Pleistocene,Pliocene,boron isotope,paleo-pCO2},
month = {nov},
number = {11},
pages = {1270--1291},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Early Pleistocene Obliquity-Scale pCO2 Variability at {\~{}}1.5 Million Years Ago}},
url = {https://doi.org/10.1029/2018PA003349},
volume = {33},
year = {2018}
}
@article{Edinburgh2016,
abstract = {In stark contrast to the sharp decline in Arctic sea ice, there has been a steady increase in ice extent around Antarctica during the last three decades, especially in the Weddell and Ross Seas. In general, climate models do not to capture this trend and a lack of information about sea ice coverage in the pre-satellite period limits our ability to quantify the sensitivity of sea ice to climate change and robustly validate climate models. However, evidence of the presence and nature of sea ice was often recorded during early Antarctic exploration, though these sources have not previously been explored or exploited until now. We have analysed observations of the summer sea ice edge from the ship logbooks of explorers such as Robert Falcon Scott, Ernest Shackleton and their contemporaries during the Heroic Age of Exploration (1897–1917) and in this study, we compare these to satellite observations from the period 1989–2014, offering insight into the ice conditions of this period, from direct observations, for the first time. This comparison shows that the summer sea ice edge was between 1.0° and 1.7° further north in the Weddell Sea during this period but that ice conditions were surprisingly comparable to the present day in other sectors.},
author = {Edinburgh, Tom and Day, Jonathan J.},
doi = {10.5194/tc-10-2721-2016},
issn = {19940424},
journal = {Cryosphere},
number = {6},
pages = {2721--2730},
title = {{Estimating the extent of Antarctic summer sea ice during the Heroic Age of Antarctic exploration}},
volume = {10},
year = {2016}
}
@article{Edwards2004,
abstract = {Phenology, the study of annually recurring life cycle events such as the timing of migrations and flowering, can provide particularly sensitive indicators of climate change1. Changes in phenology may be important to ecosystem function because the level of response to climate change may vary across functional groups and multiple trophic levels. The decoupling of phenological relationships will have important ramifications for trophic interactions, altering food-web structures and leading to eventual ecosystem-level changes. Temperate marine environments may be particularly vulnerable to these changes because the recruitment success of higher trophic levels is highly dependent on synchronization with pulsed planktonic production2,3. Using long-term data of 66 plankton taxa during the period from 1958 to 2002, we investigated whether climate warming signals4 are emergent across all trophic levels and functional groups within an ecological community. Here we show that not only is the marine pelagic community responding to climate changes, but also that the level of response differs throughout the community and the seasonal cycle, leading to a mismatch between trophic levels and functional groups.},
author = {Edwards, Martin and Richardson, Anthony J},
doi = {10.1038/nature02808},
issn = {1476-4687},
journal = {Nature},
number = {7002},
pages = {881--884},
title = {{Impact of climate change on marine pelagic phenology and trophic mismatch}},
url = {https://doi.org/10.1038/nature02808},
volume = {430},
year = {2004}
}
@article{Edwards2020,
abstract = {Boundary-layer schemes are essential components of numerical weather-forecasting and climate models. From simple beginnings 50 years ago, they have grown in sophistication and detail. Here, we review development and discuss the key processes to be represented and how they have most commonly been parametrized. We conclude by discussing the challenges posed by ever-increasing model resolution and a growing emphasis on the forecasting of extreme events. Throughout, we emphasize the place of the boundary-layer scheme within the whole model and its interactions with other components of the model.},
author = {Edwards, John M and Beljaars, Anton C M and Holtslag, Albert A M and Lock, Adrian P},
doi = {10.1007/s10546-020-00530-z},
issn = {1573-1472},
journal = {Boundary-Layer Meteorology},
pages = {511--539},
title = {{Representation of Boundary-Layer Processes in Numerical Weather Prediction and Climate Models}},
url = {https://doi.org/10.1007/s10546-020-00530-z},
volume = {177},
year = {2020}
}
@techreport{EdwardsM.HelaouetP.AlhaijaR.A.BattenS.BeaugrandG.2016,
address = {Plymouth, UK},
author = {Edwards, M. and Helaouet, P. and Alhaija, R.A. and Batten, S. and Beaugrand, G. and Chiba, S. and Horaeb, R.R. and Hosie, G. and Mcquatters-Gollop, A. and Ostle, C. and Richardson, A.J. and Rochester, W. and Skinner, J. and Stern, R. and Takahashi, K. and Taylor, C. and Verheye, H.M. and Wootton, M.},
doi = {https://www.cprsurvey.org/publications/scientific-reports/ecostatus-reports/},
issn = {1744-0750},
pages = {32},
publisher = {Global Marine Ecological Status Report No. 11. Sir Alister Hardy Foundation for Continuous Plankton Recorder Survey},
title = {{Global Marine Ecological Status Report: results from the global CPR survey 2014/2015}},
url = {https://www.cprsurvey.org/publications/scientific-reports/ecostatus-reports/},
year = {2016}
}
@article{refId0,
abstract = {Context. There is no consensus on the amplitude of historical solar forcing. The estimated magnitude of the total solar irradiance (TSI) difference between the Maunder minimum and the present time ranges from 0.1 to 6 W m −2 making the simulation of the past and future climate uncertain. One reason for this disagreement is the applied evolution of the quiet Sun brightness in solar irradiance reconstruction models. This work addresses the role of the quiet Sun model choice and updated solar magnetic activity proxies on the solar forcing reconstruction.},
author = {Egorova, T. and Schmutz, W. and Rozanov, E. and Shapiro, A. I. and Usoskin, I. and Beer, J. and Tagirov, R. V. and Peter, T.},
doi = {10.1051/0004-6361/201731199},
issn = {0004-6361},
journal = {Astronomy {\&} Astrophysics},
month = {jul},
pages = {A85},
title = {{Revised historical solar irradiance forcing}},
url = {https://doi.org/10.1051/0004-6361/201731199 https://www.aanda.org/10.1051/0004-6361/201731199},
volume = {615},
year = {2018}
}
@article{Eguchi2015,
abstract = {The dynamical coupling process between the stratosphere and troposphere in the tropical tropopause layer (TTL) during a stratospheric sudden warming (SSW) in boreal winter was investigated using simulation data from a global non-hydrostatic model (NICAM) that does not use cumulus parameterization. The model reproduced well the observed tropical tropospheric changes during the SSW including the enhancement of convective activity following the amplification of planetary waves. Deep convective activity was enhanced in the latitude zone 20–10° S, in particular over the southwest Pacific and southwest Indian Ocean. Although the upwelling in the TTL was correlated with that in the stratosphere, the temperature tendency in the TTL was mainly controlled by diabatic heating originating from cloud formation. This result suggests that the stratospheric meridional circulation affects cloud formation in the TTL.},
author = {Eguchi, N. and Kodera, K. and Nasuno, T.},
doi = {10.5194/acp-15-297-2015},
issn = {16807324},
journal = {Atmospheric Chemistry and Physics},
number = {1},
pages = {297--304},
title = {{A global non-hydrostatic model study of a downward coupling through the tropical tropopause layer during a stratospheric sudden warming}},
volume = {15},
year = {2015}
}
@article{Elipot2018,
abstract = {Twenty-nine percent of the interannual variance of the Agulhas Current transport can be linearly related to six modes of Southern Hemisphere atmospheric variability. Agulhas Current transport is quantified by a 24-yr proxy constructed using satellite altimetry and in situ data, while atmospheric variability is represented by two reanalysis products. The two leading modes of atmospheric variability, each explaining 5{\%} of the variance of the Agulhas Current, can be described as a tropical Indo-Pacific mode, strongly correlated to ENSO, and a subtropical-subpolar mode, strongly correlated with the STwenty-nine percent of the interannual variance of the Agulhas Current transport can be linearly related to six modes of Southern Hemisphere atmospheric variability. Agulhas Current transport is quantified by a 24-yr proxy constructed using satellite altimetry and in situ data, while atmospheric variability is represented by two reanalysis products. The two leading modes of atmospheric variability, each explaining 5{\%} of the variance of the Agulhas Current, can be described as a tropical Indo-Pacific mode, strongly correlated to ENSO, and a subtropical-subpolar mode, strongly correlated with the SAM. ENSO alone can explain 11.5{\%} of Agulhas transport variance, yet SAM alone has no significant correlation. The remaining four atmospheric modes are not related to common climate indices and together they explain 19{\%} of Agulhas variance, describing decadal oscillations. In previous studies using reanalyses and climate models it has been suggested that the Agulhas Current is intensifying in response to a strengthening and poleward shift of the Westerlies, expressed by a positive trend in the SAM. Here, we find that, given its apparent weak sensitivity to the SAM, the increase in SAM over the past 24 years does not lead to a detectable trend in Agulhas Current transport.AM. ENSO alone can explain 11.5{\%} of Agulhas transport variance, yet SAM alone has no significant correlation. The remaining four atmospheric modes are not related to common climate indices and together they explain 19{\%} of Agulhas variance, describing decadal oscillations. In previous studies using reanalyses and climate models it has been suggested that the Agulhas Current is intensifying in response to a ...},
author = {Elipot, Shane and Beal, Lisa M.},
doi = {10.1175/JCLI-D-17-0597.1},
isbn = {0894-8755},
issn = {08948755},
journal = {Journal of Climate},
number = {8},
pages = {3077--3098},
title = {{Observed Agulhas Current sensitivity to interannual and long-term trend atmospheric forcings}},
volume = {31},
year = {2018}
}
@article{Elmendorf2015,
abstract = {Inference about future climate change impacts typically relies on one of three approaches: manipulative experiments, historical comparisons (broadly defined to include monitoring the response to ambient climate fluctuations using repeat sampling of plots, dendroecology, and paleoecology techniques), and space-for-time substitutions derived from sampling along environmental gradients. Potential limitations of all three approaches are recognized. Here we address the congruence among these three main approaches by comparing the degree to which tundra plant community composition changes (i) in response to in situ experimental warming, (ii) with interannual variability in summer temperature within sites, and (iii) over spatial gradients in summer temperature. We analyzed changes in plant community composition from repeat sampling (85 plant communities in 28 regions) and experimental warming studies (28 experiments in 14 regions) throughout arctic and alpine North America and Europe. Increases in the relative abundance of species with a warmer thermal niche were observed in response to warmer summer temperatures using all three methods; however, effect sizes were greater over broad-scale spatial gradients relative to either temporal variability in summer temperature within a site or summer temperature increases induced by experimental warming. The effect sizes for change over time within a site and with experimental warming were nearly identical. These results support the view that inferences based on space-for-time substitution overestimate the magnitude of responses to contemporary climate warming, because spatial gradients reflect long-term processes. In contrast, in situ experimental warming and monitoring approaches yield consistent estimates of the magnitude of response of plant communities to climate warming.},
author = {Elmendorf, Sarah C. and Henry, Gregory H. R. and Hollister, Robert D. and Fosaa, Anna Maria and Gould, William A. and Hermanutz, Luise and Hofgaard, Annika and J{\'{o}}nsd{\'{o}}ttir, Ingibj{\"{o}}rg S. and Jorgenson, Janet C. and L{\'{e}}vesque, Esther and Magnusson, Borgþ{\'{o}}r and Molau, Ulf and Myers-Smith, Isla H. and Oberbauer, Steven F. and Rixen, Christian and Tweedie, Craig E. and Walker, Marilyn D.},
doi = {10.1073/pnas.1410088112},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {2},
pages = {448--452},
title = {{Experiment, monitoring, and gradient methods used to infer climate change effects on plant communities yield consistent patterns}},
volume = {112},
year = {2015}
}
@article{Emile-Geay2016,
author = {Emile-Geay, J and Cobb, K. M. and Carr{\'{e}}, M and Braconnot, P and Leloup, J and Zhou, Y and Harrison, S. P. and Corr{\`{e}}ge, T and McGregor, H. V. and Collins, M and Driscoll, R and Elliot, M and Schneider, B and Tudhope, A},
doi = {10.1038/ngeo2608},
journal = {Nature Geoscience},
month = {dec},
pages = {168},
publisher = {Nature Publishing Group},
title = {{Links between tropical Pacific seasonal, interannual and orbital variability during the Holocene}},
url = {http://dx.doi.org/10.1038/ngeo2608 http://10.0.4.14/ngeo2608 https://www.nature.com/articles/ngeo2608{\#}supplementary-information},
volume = {9},
year = {2016}
}
@incollection{Montzka2018,
address = {Geneva, Switzerland},
author = {Engel, A. and Rigby, M. (Lead Authors) and Burkholder, J.B. and Fernandez, R.P. and Froidevaux, L. and Hall, B.D. and Hossaini, R. and Saito, T. and Vollmer, M.K. and Yao, B.},
booktitle = {Scientific Assessment of Ozone Depletion: 2018},
chapter = {1},
doi = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
isbn = {978-1-7329317-1-8},
pages = {1.1--1.87},
publisher = {World Meteorological Organization (WMO)},
series = {Global Ozone Research and Monitoring Project – Report No. 58},
title = {{Update on Ozone-Depleting Substances (ODSs) and Other Gases of Interest to the Montreal Protocol}},
url = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
year = {2018}
}
@article{England2014,
abstract = {Despite ongoing increases in atmospheric greenhouse gases, the Earth[rsquor]s global average surface air temperature has remained more or less steady since 2001. A variety of mechanisms have been proposed to account for this slowdown in surface warming. A key component of the global hiatus that has been identified is cool eastern Pacific sea surface temperature, but it is unclear how the ocean has remained relatively cool there in spite of ongoing increases in radiative forcing. Here we show that a pronounced strengthening in Pacific trade winds over the past two decades[mdash]unprecedented in observations/reanalysis data and not captured by climate models[mdash]is sufficient to account for the cooling of the tropical Pacific and a substantial slowdown in surface warming through increased subsurface ocean heat uptake. The extra uptake has come about through increased subduction in the Pacific shallow overturning cells, enhancing heat convergence in the equatorial thermocline. At the same time, the accelerated trade winds have increased equatorial upwelling in the central and eastern Pacific, lowering sea surface temperature there, which drives further cooling in other regions. The net effect of these anomalous winds is a cooling in the 2012 global average surface air temperature of 0.1-0.2 [deg]C, which can account for much of the hiatus in surface warming observed since 2001. This hiatus could persist for much of the present decade if the trade wind trends continue, however rapid warming is expected to resume once the anomalous wind trends abate.},
author = {England, Matthew H. and Mcgregor, Shayne and Spence, Paul and Meehl, Gerald A. and Timmermann, Axel and Cai, Wenju and Gupta, Alex Sen and Mcphaden, Michael J. and Purich, Ariaan and Santoso, Agus},
doi = {10.1038/nclimate2106},
isbn = {1758-678X$\backslash$r1758-6798},
issn = {17586798},
journal = {Nature Climate Change},
number = {3},
pages = {222--227},
title = {{Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus}},
volume = {4},
year = {2014}
}
@misc{Erb2017,
abstract = {In the light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human-induced changes in terrestrial ecosystems that do not result in land-cover conversions. Here, we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process understanding and data availability. Our review shows that ca. one-tenth of the ice-free land surface is under intense human management, half under medium and one-fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (i) management activities for which data sets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (ii) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global data sets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N fertilization); and (iii) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in, for example, Earth system or dynamic vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling.},
author = {Erb, Karl Heinz and Luyssaert, Sebastiaan and Meyfroidt, Patrick and Pongratz, Julia and Don, Axel and Kloster, Silvia and Kuemmerle, Tobias and Fetzel, Tamara and Fuchs, Richard and Herold, Martin and Haberl, Helmut and Jones, Chris D. and Mar{\'{i}}n-Spiotta, Erika and McCallum, Ian and Robertson, Eddy and Seufert, Verena and Fritz, Steffen and Valade, Aude and Wiltshire, Andrew and Dolman, Albertus J.},
booktitle = {Global Change Biology},
doi = {10.1111/gcb.13443},
issn = {13652486},
number = {2},
title = {{Land management: data availability and process understanding for global change studies}},
volume = {23},
year = {2017}
}
@article{Eriksen2018,
abstract = {Recent acceleration of rock glaciers is well recognized in the European Alps, but similar behavior is hardly documented elsewhere. Also, the controlling factors are not fully understood. Here, we provide evidence for acceleration of a rock glacier complex in Northern Norway, from 62 years of remote sensing data. Average annual horizontal velocity measured by aerial feature tracking increased from {\~{}}0.5 myr‐1 (1954–1977) to {\~{}}3.6 myr‐1 (2006–2014). Measured by satellite radar Offset‐Tracking, averages increased from {\~{}}4.9 myr‐1 to {\~{}}9.8 myr‐1 (2009‐2016) and maximum velocities from {\~{}}12 myr‐1 to {\~{}}69 myr‐1. Kinematic analysis reveal different spatial‐temporal trends in the upper and the lower parts of the rock glacier complex, suggesting progressive detachment of the faster front. We suggest that permafrost warming, topographic controls and increased water access to deeper permafrost layers and internal shear zones can explain the kinematic behavior.},
author = {Eriksen, H. {\O}. and Rouyet, L. and Lauknes, T. R. and Berthling, I. and Isaksen, K. and Hindberg, H. and Larsen, Y. and Corner, G. D.},
doi = {10.1029/2018GL077605},
issn = {00948276},
journal = {Geophysical Research Letters},
number = {16},
pages = {8314--8323},
title = {{Recent Acceleration of a Rock Glacier Complex, {\'{A}}djet, Norway, Documented by 62 Years of Remote Sensing Observations}},
volume = {45},
year = {2018}
}
@article{Estilow2015,
abstract = {This paper describes the long-term, satellite-based visible snow cover extent National Oceanic and Atmospheric Administration (NOAA) climate data record (CDR) currently available for climate studies, monitoring, and model validation. This environmental data product is developed from weekly Northern Hemisphere snow cover extent data that have been digitized from snow cover maps onto a Cartesian grid draped over a polar stereographic projection. The data have a spatial resolution of 190.6 km at 60° latitude, are updated monthly, and span the period from 4 October 1966 to the present. The data comprise the longest satellite-based CDR of any environmental variable. Access to the data is provided in Network Common Data Form (netCDF) and archived by NOAA's National Climatic Data Center (NCDC) under the satellite Climate Data Record Program (doi:10.7289/V5N014G9). The basic characteristics, history, and evolution of the data set are presented herein. In general, the CDR provides similar spatial and temporal variability to its widely used predecessor product. Key refinements included in the CDR improve the product's grid accuracy and documentation and bring metadata into compliance with current standards for climate data records.},
author = {Estilow, T. W. and Young, A. H. and Robinson, D. A.},
doi = {10.5194/essd-7-137-2015},
isbn = {1866-3516},
issn = {18663516},
journal = {Earth System Science Data},
number = {1},
pages = {137--142},
title = {{A long-term Northern Hemisphere snow cover extent data record for climate studies and monitoring}},
volume = {7},
year = {2015}
}
@article{Evan2015a,
abstract = {{\textcopyright} 2015 Royal Meteorological Society. Extremely low water vapour concentrations (as low as 1.5 ppmv) in the tropical tropopause layer (TTL) were observed by in situ measurements during the Airborne Tropical TRopopause Experiment (ATTREX) winter 2013 deployment in February 2013. The January 2013 tropical (15°N-15°S) mean value of Microwave Limb Sounder (MLS) water vapour satellite data at 82 hPa (2.3 ppmv) was one of the lowest during the instrument record (2004-2013). The relationship between a cooling of the tropical tropopause, a sudden stratospheric warming (SSW) event and convective activity in the western Pacific is investigated using satellite data and reanalysis meteorological products to elucidate the likely origin of those extremely low water vapour concentrations. A major midwinter SSW developed on 6 January 2013. Stratospheric polar temperatures increased by {\~{}}30 K in a matter of days and temperatures in the tropical upper troposphere and lower stratosphere (UTLS) dropped at the same time. As a result of the easterly shear phase of the Quasi-Biennial Oscillation and the SSW, the tropical tropopause in January 2013 was anomalously cold (zonal mean of 187 K) and elevated (85 hPa). The tropical cold point tropopause (CPT) temperature and water vapour concentration at 82 hPa decreased by about 2 K and 1.5 ppmv respectively within the first 15 days of January; the water vapour change was likely a result of dehydration associated with the rapid cooling of the tropical CPT during that period.},
author = {Evan, Stephanie and Rosenlof, K. H. and Thornberry, Troy and Rollins, Andrew and Khaykin, Sergey},
doi = {10.1002/qj.2587},
issn = {1477870X},
journal = {Quarterly Journal of the Royal Meteorological Society},
number = {693},
pages = {3030--3039},
title = {{TTL cooling and drying during the January 2013 stratospheric sudden warming}},
volume = {141},
year = {2015}
}
@article{Evans2017,
abstract = {A warming global climate will elicit changes in the distribution of plant species around the planet, and this will become most apparent where biomes converge. Climate exerts the strongest control over the geographic location of ecotones at the continental scale and many, including the boreal forest-temperate forest ecotone (BTE), are expected to shift to higher latitudes under climate change. Fine-scale drivers that define biome boundaries at the sub-continental scale are less well understood for many ecotones. We assembled studies addressing whether a modern distributional shift is occurring at the BTE and what biotic and abiotic factors are driving such a shift. Current research su ggests a northward shift is occurring; yet, scant data are available to identify the processes involved. Abiotic and biotic factors are repeatedly identified as key drivers of change, though not all claims are evidence-supported and the interacting effects of these non-climatic factors are poorly understood.},
author = {Evans, Piers and Brown, Carissa D.},
doi = {10.1139/er-2017-0009},
issn = {1181-8700},
journal = {Environmental Reviews},
number = {4},
pages = {423--431},
title = {{The boreal–temperate forest ecotone response to climate change}},
volume = {25},
year = {2017}
}
@article{Evans2019,
abstract = {Reliable interpretation of annual-resolution climate proxies for wind, precipitation, and detrital influx are required for identifying the onset and periodicities of climatic events. In particular, this is essential for the evaluation of inter-annual, decadal, and centennial trends driven by shifting positions of the Southern Westerly Winds (SWW) and subsequent storm belts associated with the Southern Annular Mode (SAM) and El Ni{\~{n}}o Southern Oscillation (ENSO). Here we present a quasi-annual data set of $\mu$-XRF time series spanning ca. 2230 years from lake sediment cores from Lake Kanono, Northland, New Zealand. The $\mu$-XRF time series were interpreted using a combination of principal component analysis (PCA) and cluster analysis, then verified with comparison to regionally averaged empirical rainfall and wind climate station data. Our results show that the wavelet patterns align with the PCA results allowing the $\mu$-XRF time series to be classified into: Group I (detrital) and Group II (biological productivity and normalized climate proxies). The normalized Group II $\mu$-XRF time series wavelet analyses displayed periodicities in the 2–16 year frequency, likely associated with ENSO, from ca. 237 BCE – 1330 CE. The data show clear evidence of both Polynesian and European settlement phases in this part of northern New Zealand, and that Polynesian settlement impact was coeval with changes in ENSO intensity and a phase shift in SAM ca. 1350 CE. The Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA) appear in the $\mu$-XRF time series data as separate clusters. This data suggests that the MCA is associated with windy/dry conditions with intermittent storminess. During the LIA, the 2–16 year periodicity associated with ENSO decreased and centennial to multi-decadal length periodicities increase, which may be an indication of an underlying SAM signal within the data. European settlement also had a direct impact on the lake basin via increased detrital influx, likely from farming activities and intensification of local forestry operations.},
author = {Evans, Gianna and Augustinus, Paul and Gadd, Patricia and Zawadzki, Atun and Ditchfield, Amber},
doi = {10.1016/j.quascirev.2019.106000},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Dune lake sediments,Holocene,Itrax},
pages = {106000},
title = {{A multi-proxy $\mu$-XRF inferred lake sediment record of environmental change spanning the last ca. 2230 years from Lake Kanono, Northland, New Zealand}},
volume = {225},
year = {2019}
}
@article{Evtushevsky2018,
abstract = {Decadal changes in the teleconnection between the central tropical Pacific and the Southern Hemisphere extratropics are studied using the NCEP--NCAR reanalysis data. Concurrent and lagged relationships show that teleconnection strength in austral spring was weak (strong) before (after) 1996/1997. This decadal change coincides in time with the climate regime shift in the Pacific in the 1990s known from many studies. We show that, after the regime shift, the concurrent and delayed teleconnection with the Southern Hemisphere extratropics is insignificant in September and abruptly increases in October. Penetration of the stratospheric anomaly into the troposphere in October can indicate interacting tropospheric and stratospheric pathways of the teleconnection to strongly enhance the central tropical Pacific impact since the late 1990s. The results give evidence that the Southern Annular Mode seems to be connecting element between the two pathways in the recent decades. The common tendencies in the eastward shift of the tropical anomalies and zonal wave 1 phase in the Antarctic stratosphere in austral spring have been demonstrated. The difference between the central Pacific and eastern Pacific teleconnections is consistent with that known from previous studies and new tendencies in their decadal changes and delayed effects have been revealed. It has been found that the central Pacific contributions to the Pacific decadal oscillation and to the Northern Hemisphere stratosphere have also increased significantly after the 1990s. This characterizes the central tropical Pacific as one of the key regions impacting climate and teleconnection not only in the Southern Hemisphere, but also in the Northern Hemisphere. Our findings are consistent with and further develop the recent studies of the stratosphere--troposphere coupling in austral spring, and emphasize significant contribution of the delayed tropical signals to the climate variability in austral spring in both hemispheres.},
author = {Evtushevsky, O M and Grytsai, A V and Milinevsky, G P},
doi = {10.1007/s00382-018-4354-5},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {jul},
pages = {4027--4055},
title = {{Decadal changes in the central tropical Pacific teleconnection to the Southern Hemisphere extratropics}},
url = {https://doi.org/10.1007/s00382-018-4354-5},
volume = {52},
year = {2018}
}
@article{Ezat2017,
abstract = {Antarctic ice cores document glacial-interglacial and millennial-scale variability in atmospheric pCO2 over the past 800 kyr. The ocean, as the largest active carbon reservoir on this timescale, is thought to have played a dominant role in these pCO2 fluctuations, but it remains unclear how and where in the ocean CO2 was stored during glaciations and released during (de)glacial millennial-scale climate events. The evolution of surface ocean pCO2 in key locations can therefore provide important clues for understanding the ocean's role in Pleistocene carbon cycling. Here we present a 135-kyr record of shallow subsurface pCO2 and nutrient levels from the Norwegian Sea, an area of intense CO2 uptake from the atmosphere today. Our results suggest that the Norwegian Sea probably acted as a CO2 source towards the end of Heinrich stadials HS1, HS4 and HS11, and may have contributed to the increase in atmospheric pCO2 at these times.},
author = {Ezat, Mohamed M and Rasmussen, Tine L and H{\"{o}}nisch, B{\"{a}}rbel and Groeneveld, Jeroen and DeMenocal, Peter},
doi = {10.1038/ncomms14498},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {14498},
title = {{Episodic release of CO2 from the high-latitude North Atlantic Ocean during the last 135 kyr}},
url = {https://doi.org/10.1038/ncomms14498},
volume = {8},
year = {2017}
}
@article{Ezer2013,
author = {Ezer, Tal},
doi = {10.1002/2013GL057952},
journal = {Geophysical Research Letters},
number = {20},
pages = {5439--5444},
publisher = {Wiley Online Library},
title = {{Sea level rise, spatially uneven and temporally unsteady: why the US east coast, the global tide gauge record and the global altimeter data show different trends}},
volume = {40},
year = {2013}
}
@article{Famiglietti2018a,
abstract = {Abstract This analysis is the first global validation of the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived near-surface air temperature and dew point estimates, which both serve as crucial input data in models of energy, water, and carbon exchange between terrestrial ecosystems and the atmosphere. By hypsometrically interpolating the MOD07 Level-2 atmospheric profile product to surface pressure level, we obtained near-surface air temperature and dew point observations at 5 km pixel resolution. We compared these daily data, retrieved over a 14-year record, to corresponding measurements from 109 ground meteorological stations (FLUXNET). Our results show strong agreement between satellite and in situ near-surface air temperature measurements (R2 = 0.89, root-mean-square error = 3.47°C, and bias = −0.19°C) and dew point observations (R2 = 0.76, root-mean-square error = 5.04°C, and bias = 0.79°C) with insignificant differences in error across climate zones. This validation is among the earliest assessments of the reprocessed, crosstalk-corrected Collection 6.1 Terra MODIS data and provides support for widespread applications of near-surface atmospheric data.},
author = {Famiglietti, Caroline A and Fisher, Joshua B and Halverson, Gregory and Borbas, Eva E},
doi = {10.1029/2018GL077813},
journal = {Geophysical Research Letters},
number = {15},
pages = {7772--7780},
title = {{Global Validation of MODIS Near-Surface Air and Dew Point Temperatures}},
volume = {45},
year = {2018}
}
@article{Fan2016a,
abstract = {AbstractThis study identifies several modes of coevolution of various types of El Ni{\~{n}}o?Southern Oscillation (ENSO) and Indian Ocean dipole (IOD) by performing rotated season-reliant empirical orthogonal function (S-EOF) analysis with consideration of ENSO asymmetry. The first two modes reveal that early-onset ENSO is associated with subsequent strong IOD development, whereas late-onset ENSO forces an obscure IOD pattern with marginal SST anomalies in the western Indian Ocean. Further studies show that El Ni{\~{n}}o starting before early summer can more easily force an IOD event than that starting in late summer or fall, even when they are of equivalent magnitudes. This is because the atmospheric responses over the Indian Ocean to the eastern Pacific warming are in sharp contrast between early and late summer. Early-onset (late onset) El Ni{\~{n}}o can (cannot) cause favorable atmospheric circulation conditions over the Indian Ocean for inducing the western Indian Ocean warming, which facilitates the subsequent IOD development. In addition, the different propagations of ocean dynamic Rossby waves during the early- or late-onset types of ENSO are also accountable for the different IOD development. For the higher-order modes, the rotated S-EOF of ?Ni{\~{n}}o only? cases shows a coevolution between a negative IOD mode and a date line Pacific El Ni{\~{n}}o, with warm sea surface temperature anomalies originating from the northern Pacific meridional mode.},
annote = {doi: 10.1175/JCLI-D-16-0426.1},
author = {Fan, Lei and Liu, Qinyu and Wang, Chunzai and Guo, Feiyan},
doi = {10.1175/JCLI-D-16-0426.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {dec},
number = {6},
pages = {2233--2249},
publisher = {American Meteorological Society},
title = {{Indian Ocean Dipole Modes Associated with Different Types of ENSO Development}},
url = {https://doi.org/10.1175/JCLI-D-16-0426.1},
volume = {30},
year = {2016}
}
@article{Farinotti2019,
abstract = {Knowledge of the ice thickness distribution of the world's glaciers is a fundamental prerequisite for a range of studies. Projections of future glacier change, estimates of the available freshwater resources or assessments of potential sea-level rise all need glacier ice thickness to be accurately constrained. Previous estimates of global glacier volumes are mostly based on scaling relations between glacier area and volume, and only one study provides global-scale information on the ice thickness distribution of individual glaciers. Here we use an ensemble of up to five models to provide a consensus estimate for the ice thickness distribution of all the about 215,000 glaciers outside the Greenland and Antarctic ice sheets. The models use principles of ice flow dynamics to invert for ice thickness from surface characteristics. We find a total volume of 158 ± 41 × 103 km3, which is equivalent to 0.32 ± 0.08 m of sea-level change when the fraction of ice located below present-day sea level (roughly 15{\%}) is subtracted. Our results indicate that High Mountain Asia hosts about 27{\%} less glacier ice than previously suggested, and imply that the timing by which the region is expected to lose half of its present-day glacier area has to be moved forward by about one decade.},
author = {Farinotti, Daniel and Huss, Matthias and F{\"{u}}rst, Johannes J. and Landmann, Johannes and Machguth, Horst and Maussion, Fabien and Pandit, Ankur},
doi = {10.1038/s41561-019-0300-3},
issn = {1752-0894},
journal = {Nature Geoscience},
keywords = {Climate change,Cryospheric science,Hydrology},
pages = {168--173},
title = {{A consensus estimate for the ice thickness distribution of all glaciers on Earth}},
volume = {12},
year = {2019}
}
@article{Farquharson2019,
author = {Farquharson, Louise M. and Romanovsky, Vladimir E. and Cable, William L. and Walker, Donald A. and Kokelj, Steven V. and Nicolsky, Dmitry},
doi = {10.1029/2019GL082187},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {jun},
number = {12},
pages = {6681--6689},
title = {{Climate Change Drives Widespread and Rapid Thermokarst Development in Very Cold Permafrost in the Canadian High Arctic}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082187},
volume = {46},
year = {2019}
}
@article{Faust2016a,
author = {Faust, Johan C and Fabian, Karl and Milzer, Gesa and Giraudeau, Jacques and Knies, Jochen},
doi = {10.1016/j.epsl.2015.12.003},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
pages = {84--93},
publisher = {Elsevier B.V.},
title = {{Norwegian fjord sediments reveal NAO related winter temperature and precipitation changes of the past 2800 years}},
volume = {435},
year = {2016}
}
@article{fedorov_pliocene_2006,
author = {Fedorov, A V},
doi = {10.1126/science.1122666},
issn = {0036-8075, 1095-9203},
journal = {Science},
month = {jun},
number = {5779},
pages = {1485--1489},
title = {{The Pliocene Paradox (Mechanisms for a Permanent El Nino)}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1122666},
volume = {312},
year = {2006}
}
@article{doi:10.1029/2010GL043572,
abstract = {The Pacific Decadal Oscillation (PDO), the leading mode of sea surface temperature (SST) anomalies in the extratropical North Pacific Ocean, has widespread impacts on precipitation in the Americas and marine fisheries in the North Pacific. However, marine proxy records with a temporal resolution that resolves interannual to interdecadal SST variability in the extratropical North Pacific are extremely rare. Here we demonstrate that the winter Sr/Ca and U/Ca records of an annually-banded reef coral from the Ogasawara Islands in the western subtropical North Pacific are significantly correlated with the instrumental winter PDO index over the last century. The reconstruction of the PDO is further improved by combining the coral data with an existing eastern mid-latitude North Pacific growth ring record of geoduck clams. The spatial correlations of this combined index with global climate fields suggest that SST proxy records from these locations provide potential for PDO reconstructions further back in time.},
author = {Felis, Thomas and Suzuki, Atsushi and Kuhnert, Henning and Rimbu, Norel and Kawahata, Hodaka},
doi = {10.1029/2010GL043572},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Coral record,Pacific Decadal Oscillation},
month = {jul},
number = {14},
title = {{Pacific Decadal Oscillation documented in a coral record of North Pacific winter temperature since 1873}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010GL043572 http://doi.wiley.com/10.1029/2010GL043572},
volume = {37},
year = {2010}
}
@article{Feng2013a,
author = {Feng, Xue and Porporato, Amilcare and Rodriguez-Iturbe, Ignacio},
doi = {10.1038/nclimate1907},
issn = {1758-678X},
journal = {Nature Climate Change},
number = {6},
pages = {1--5},
publisher = {Nature Publishing Group},
title = {{Changes in rainfall seasonality in the tropics}},
volume = {3},
year = {2013}
}
@article{feng_contributions_2019,
author = {Feng, Ran and Otto‐Bliesner, Bette L and Xu, Yangyang and Brady, Esther and Fletcher, Tamara and Ballantyne, Ashley},
doi = {10.1029/2019GL083960},
issn = {0094-8276, 1944-8007},
journal = {Geophysical Research Letters},
month = {aug},
number = {16},
pages = {9920--9929},
title = {{Contributions of aerosol‐cloud interactions to mid‐Piacenzian seasonally sea ice‐free Arctic Ocean}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL083960},
volume = {46},
year = {2019}
}
@article{Feng2018,
abstract = {The Indonesian Throughflow (ITF) is an important component of the upper cell of the global overturning circulation that provides a low-latitude pathway for warm, fresh waters from the Pacific to enter the Indian Ocean. Variability and changes of the ITF have significant impacts on Indo-Pacific oceanography and global climate. In this paper, the observed features of the ITF and its interannual to decadal variability are reviewed, and processes that influence the centennial change of the ITF under the influence of the global warming are discussed. The ITF flows across a region that comprises the intersection of two ocean waveguides—those of the equatorial Pacific and equatorial Indian Ocean. The ITF geostrophic transport is stronger during La Ni{\~{n}}as and weaker during El Ni{\~{n}}os due to the influences through the Pacific waveguide. The Indian Ocean wind variability associated with the Indian Ocean Dipole (IOD) in many years offsets the Pacific ENSO influences on the ITF geostrophic transport during the developing and mature phases of El Ni{\~{n}}o and La Ni{\~{n}}a through the Indian Ocean waveguide, due to the co-varying IOD variability with ENSO. Decadal and multi-decadal changes of the geostrophic ITF transport have been revealed: there was a weakening change from the mid-1970s climate regime shift followed by a strengthening trend of about 1Sv every 10 year during 1984–2013. These decadal changes are mostly due to the ITF responses to decadal variations of the trade winds in the Pacific. Thus, Godfrey's Island Rule, as well as other ITF proxies, appears to be able to quantify decadal variations of the ITF. Climate models project a weakening trend of the ITF under the global warming. Both climate models and downscaled ocean model show that this ITF weakening is not directly associated with the changes of the trade winds in the Pacific into the future, and the reduction of deep upwelling in the Pacific basin is mainly responsible for the ITF weakening. There is a need to amend the Island Rule to take into account the contributions from the overturning circulation which the current ITF proxies fail to capture. The implication of a weakened ITF on the Indo-Pacific Ocean circulation still needs to be assessed.},
author = {Feng, Ming and Zhang, Ningning and Liu, Qinyan and Wijffels, Susan},
doi = {10.1186/s40562-018-0102-2},
issn = {2196-4092},
journal = {Geoscience Letters},
number = {1},
pages = {3},
title = {{The Indonesian throughflow, its variability and centennial change}},
url = {https://doi.org/10.1186/s40562-018-0102-2},
volume = {5},
year = {2018}
}
@article{Feng2017c,
abstract = {Abstract The Indonesian Throughflow (ITF) is an important component of the global overturning circulation. In this study, we amend Godfrey's Island Rule to estimate the ITF transport by including contributions from deep ocean vertical transport. Simulations using a near-global 1/10° ocean general circulation model are used to verify the amended Island Rule. We show that deep ocean circulation is as important as wind-driven processes to the ITF transport and variability. The centennial weakening of the ITF by 32{\%} during the 21st century, under the high greenhouse gas emission scenario, is primarily associated with reductions in net deep ocean upwelling in the tropical and South Pacific. Deep ocean circulation of the Pacific may become less connected with the ITF transport in a warm climate.},
annote = {doi: 10.1002/2017GL072577},
author = {Feng, Ming and Zhang, Xuebin and Sloyan, Bernadette and Chamberlain, Matthew},
doi = {10.1002/2017GL072577},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {ITF,climate projection,decadal variation,ocean modeling,overturning circulation,upwelling},
month = {mar},
number = {6},
pages = {2859--2867},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Contribution of the deep ocean to the centennial changes of the Indonesian Throughflow}},
url = {https://doi.org/10.1002/2017GL072577},
volume = {44},
year = {2017}
}
@article{https://doi.org/10.1029/2019MS002033,
annote = {e2019MS002033 2019MS002033},
author = {Feng, Ran and Otto-Bliesner, Bette L and Brady, Esther C and Rosenbloom, Nan},
doi = {10.1029/2019MS002033},
journal = {Journal of Advances in Modeling Earth Systems},
keywords = {AMOC,Earth System Sensitivity,PMIP4,PlioMIP2,mid-Pliocene,tropical circulation},
number = {8},
pages = {e2019MS002033},
title = {{Increased Climate Response and Earth System Sensitivity From CCSM4 to CESM2 in Mid-Pliocene Simulations}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019MS002033},
volume = {12},
year = {2020}
}
@article{Filonchyk2019,
abstract = {Aerosol optical depth (AOD) is one of essential atmosphere parameters for climate change assessment as well as for total ecological situation study. This study presents long-term data (2000–2017) on time-space distribution and trends in AOD over various ecological regions of China, received from Moderate Resolution Imaging Spectroradiometer (MODIS) (combined Dark Target and Deep Blue) and Multi-angle Imaging Spectroradiometer (MISR), based on satellite Terra. Ground-based stations Aerosol Robotic Network (AERONET) were used to validate the data obtained. AOD data, obtained from two spectroradiometers, demonstrate the significant positive correlation relationships (r = 0.747), indicating that 55{\%} of all data illustrate relationship among the parameters under study. Comparison of results, obtained with MODIS/MISR Terra and AERONET, demonstrate high relation (r = 0.869 - 0.905), while over 60{\%} of the entire sampling fall within the range of the expected tolerance, established by MODIS and MISR over earth (±0.05 ± 0.15 × AODAERONET and 0.05 ± 0.2 × AODAERONET) with root-mean-square error (RMSE) of 0.097–0.302 and 0.067–0.149, as well as low mean absolute error (MAE) of 0.068–0.18 and 0.067–0.149, respectively. The MODIS search results were overestimated for AERONET stations with an average overestimation ranging from 14 to 17{\%}, while there was an underestimate of the search results using MISR from 8 to 22{\%}.},
author = {Filonchyk, Mikalai and Yan, Haowen and Zhang, Zhongrong and Yang, Shuwen and Li, Wei and Li, Yanming},
doi = {10.1038/s41598-019-42466-6},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {6174},
title = {{Combined use of satellite and surface observations to study aerosol optical depth in different regions of China}},
url = {https://doi.org/10.1038/s41598-019-42466-6},
volume = {9},
year = {2019}
}
@article{Finsinger2017,
abstract = {Plant communities are not stable over time and biological novelty is predicted to emerge due to climate change, the introduction of exotic species and land-use change. However, the rate at which this novelty may arise over longer time periods has so far received little attention. We reconstruct the emergence of novelty in Europe for a set of baseline conditions over the past 15 000 years to assess past rates of emergence and investigate underlying causes. The emergence of novelty is baseline specific and, during the early-Holocene, was mitigated by the rapid spread of plant taxa. Although novelty generally increases as a function of time, climate and human-induced landscape changes contributed to a non-linear post-glacial trajectory of novelty with jumps corresponding to periods of rapid changes. Emergence of novelty accelerated during the past 1000 years. Historical cultural landscapes experienced a faster novelty development due to the contribution from anthropogenic land-cover changes. {\textcopyright} 2017 John Wiley {\&} Sons Ltd/CNRS},
author = {Finsinger, Walter and Giesecke, Thomas and Brewer, Simon and Leydet, Michelle},
doi = {10.1111/ele.12731},
issn = {14610248},
journal = {Ecology Letters},
keywords = {Biological novelty,EPD,Europe,pollen,post-glacial},
pages = {336--346},
title = {{Emergence patterns of novelty in European vegetation assemblages over the past 15 000 years}},
volume = {20},
year = {2017}
}
@article{Fischer2018,
abstract = {Over the past 3.5 million years, there have been several intervals when climate conditions were warmer than during the pre-industrial Holocene. Although past intervals of warming were forced differently than future anthropogenic change, such periods can provide insights into potential future climate impacts and ecosystem feedbacks, especially over centennial-to-millennial timescales that are often not covered by climate model simulations. Our observation-based synthesis of the understanding of past intervals with temperatures within the range of projected future warming suggests that there is a low risk of runaway greenhouse gas feedbacks for global warming of no more than 2 °C. However, substantial regional environmental impacts can occur. A global average warming of 1–2 °C with strong polar amplification has, in the past, been accompanied by significant shifts in climate zones and the spatial distribution of land and ocean ecosystems. Sustained warming at this level has also led to substantial reductions of the Greenland and Antarctic ice sheets, with sea-level increases of at least several metres on millennial timescales. Comparison of palaeo observations with climate model results suggests that, due to the lack of certain feedback processes, model-based climate projections may underestimate long-term warming in response to future radiative forcing by as much as a factor of two, and thus may also underestimate centennial-to-millennial-scale sea-level rise.},
author = {Fischer, Hubertus and Meissner, Katrin J and Mix, Alan C and Abram, Nerilie J and Austermann, Jacqueline and Brovkin, Victor and Capron, Emilie and Colombaroli, Daniele and Daniau, Anne-Laure and Dyez, Kelsey A and Felis, Thomas and Finkelstein, Sarah A and Jaccard, Samuel L and McClymont, Erin L and Rovere, Alessio and Sutter, Johannes and Wolff, Eric W and Affolter, St{\'{e}}phane and Bakker, Pepijn and Ballesteros-C{\'{a}}novas, Juan Antonio and Barbante, Carlo and Caley, Thibaut and Carlson, Anders E and {Churakova (Sidorova)}, Olga and Cortese, Giuseppe and Cumming, Brian F and Davis, Basil A S and de Vernal, Anne and Emile-Geay, Julien and Fritz, Sherilyn C and Gierz, Paul and Gottschalk, Julia and Holloway, Max D and Joos, Fortunat and Kucera, Michal and Loutre, Marie-France and Lunt, Daniel J and Marcisz, Katarzyna and Marlon, Jennifer R and Martinez, Philippe and Masson-Delmotte, Valerie and Nehrbass-Ahles, Christoph and Otto-Bliesner, Bette L and Raible, Christoph C and Risebrobakken, Bj{\o}rg and {S{\'{a}}nchez Go{\~{n}}i}, Mar{\'{i}}a F and Arrigo, Jennifer Saleem and Sarnthein, Michael and Sjolte, Jesper and Stocker, Thomas F and {Velasquez Alv{\'{a}}rez}, Patricio A and Tinner, Willy and Valdes, Paul J and Vogel, Hendrik and Wanner, Heinz and Yan, Qing and Yu, Zicheng and Ziegler, Martin and Zhou, Liping},
doi = {10.1038/s41561-018-0146-0},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {7},
pages = {474--485},
title = {{Palaeoclimate constraints on the impact of 2 °C anthropogenic warming and beyond}},
url = {https://doi.org/10.1038/s41561-018-0146-0},
volume = {11},
year = {2018}
}
@article{Fitzsimmons2015,
abstract = {The Willandra Lakes complex is one of the few locations in semi-arid Australia to preserve both paleoenvironmental and Paleolithic archeological archives at high resolution. The stratigraphy of transverse lunette dunes on the lakes' downwind margins record a late Quaternary sequence of wetting and drying. Within the Willandra system, the Lake Mungo lunette is best known for its preservation of the world's oldest known ritual burials, and high densities of archeological traces documenting human adaptation to changing environmental conditions over the last 45 ka. Here we identify evidence at Lake Mungo for a previously unrecognised short-lived, very high lake filling phase at 24 ka, just prior to the Last Glacial Maximum. Mega-lake Mungo was up to 5 m deeper than preceding or subsequent lake full events and represented a lake volume increase of almost 250{\%}. Lake Mungo was linked with neighboring Lake Leaghur at two overflow points, creating an island from the northern part of the Mungo lunette. This event was most likely caused by a pulse of high catchment rainfall and runoff, combined with neotectonic activity which may have warped the lake basin. It indicates a non-linear transition to more arid ice age conditions. The mega-lake restricted mobility for people living in the area, yet archeological traces indicate that humans rapidly adapted to the new conditions. People repeatedly visited the island, transporting stone tools across water and exploiting food resources stranded there. They either swam or used watercraft to facilitate access to the island and across the lake. Since there is no evidence for watercraft use in Australia between initial colonization of the continent prior to 45 ka and the mid-Holocene, repeated visits to the island may represent a resurrection of waterfaring technologies following a hiatus of at least 20 ky.},
author = {Fitzsimmons, Kathryn E. and Stern, Nicola and Murray-Wallace, Colin V. and Truscott, William and Pop, Cornel},
doi = {10.1371/journal.pone.0127008},
issn = {19326203},
journal = {PLOS ONE},
number = {6},
pages = {1--19},
pmid = {26083665},
title = {{The Mungo mega-lake event, semi-arid Australia: Non-linear descent into the last ice age, implications for human behaviour}},
volume = {10},
year = {2015}
}
@article{Fluckiger1999,
abstract = {Nitrous oxide (N2O) is an important greenhouse gas that is presently increasing at a rate of 0.25 percent per year. Records measured along two ice cores from Summit in Central Greenland provide information about variations in atmospheric N2O concentration in the past. The record covering the past millennium reduces the uncertainty regarding the preindustrial concentration. Records covering the last glacial-interglacial transition and a fast climatic change during the last ice age show that the N2O concentration changed in parallel with fast temperature variations in the Northern Hemisphere. This provides important information about the response of the environment to global climatic changes.},
author = {Fl{\"{u}}ckiger, J. and D{\"{a}}llenbach, A. and Blunier, T. and Stauffer, B. and Stocker, T. F. and Raynaud, D. and Barnola, J. M.},
doi = {10.1126/science.285.5425.227},
issn = {00368075},
journal = {Science},
number = {5425},
pages = {227--230},
title = {{Variations in atmospheric N2O concentration during abrupt climatic changes}},
volume = {285},
year = {1999}
}
@article{doi:10.1029/2001GB001417,
abstract = {Nitrous oxide (N2O) concentration records exist for the last 1000 years and for time periods of rapid climatic changes like the transition from the last glacial to today's interglacial and for one of the fast climate variations during the last ice age. Little is known, however, about possible N2O variations during the more stable climate of the present interglacial (Holocene) spanning the last 11 thousand years. Here we fill this gap with a high-resolution N2O record measured along the European Project for Ice Coring in Antarctica (EPICA) Dome C Antarctic ice core. On the same ice we obtained high-resolution methane and carbon dioxide records. This provides the unique opportunity to compare variations of the three most important greenhouse gases (after water vapor) without any uncertainty in their relative timing. The CO2 and CH4 records are in good agreement with previous measurements on other ice cores. The N2O concentration started to decrease in the early Holocene and reached minimum values around 8 ka ({\textless}260 ppbv) before a slow increase to its preindustrial concentration of ∼265 ppbv.},
author = {Fl{\"{u}}ckiger, Jacqueline and Monnin, Eric and Stauffer, Bernhard and Schwander, Jakob and Stocker, Thomas F and Chappellaz, J{\'{e}}r{\^{o}}me and Raynaud, Dominique and Barnola, Jean-Marc},
doi = {10.1029/2001GB001417},
journal = {Global Biogeochemical Cycles},
keywords = {CH4,CO2,Holocene,N2O,greenhouse gases,nitrous oxide},
number = {1},
pages = {10--18},
title = {{High-resolution Holocene N2O ice core record and its relationship with CH4 and CO2}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2001GB001417},
volume = {16},
year = {2002}
}
@article{Fletcher2012a,
author = {Fletcher, M.-S. and Moreno, P. I.},
doi = {10.1016/j.quaint.2011.04.042},
journal = {Quaternary International},
pages = {32--46},
title = {{Have the Southern Westerlies changed in a zonally symmetric manner over the last 14,000 years? A hemisphere-wide take on a controversial problem}},
volume = {253},
year = {2012}
}
@article{Fletcher2018,
author = {Fletcher, Michael-Shawn and Benson, Alexa and Bowman, David M.J.S. and Gadd, Patricia S and Heijnis, Hendrik and Mariani, Michela and Saunders, Krystyna M and Wolfe, Brent B and Zawadzki, Atun},
doi = {10.1130/G39661.1},
issn = {0091-7613},
journal = {Geology},
month = {apr},
number = {4},
pages = {363--366},
title = {{Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years}},
url = {https://pubs.geoscienceworld.org/gsa/geology/article/46/4/363/528308/Centennialscale-trends-in-the-Southern-Annular},
volume = {46},
year = {2018}
}
@article{10.3389/fevo.2017.00019,
abstract = {A recurring goal in ecological and paleoclimatic studies is to either forecast how ecosystems will respond to future climate or hindcast climate from past ecosystem assemblages. The Pliocene is a useful deep-time laboratory for understanding an equilibrium climate state under modern atmospheric CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}, and has been a focus for climate modelers. Accurate estimates of proxy data-model mismatch are hindered by the scarcity of well-constrained observations from well-dated sites in the High Arctic. Using a recently developed community-based approach (Climate Reconstruction Analysis using Coexistence Likelihood Estimation: CRACLE) compared with an established method (The Coexistence Approach: CA), and applied to extraordinary, permafrost-driven preservation of floras, we explore the climate and community assemblages at five Pliocene sites in the Canadian Arctic Archipelago. The results suggest that climatic differences at this scale do not simply correlate to differences in community assemblage between sites. The threshold temperature for tree line is one important component, but other factors in the environment (e.g., soil characteristics) may drive dissimilarity of communities where the taxa could share the same climate space. Estimates from CRACLE agree with previous estimates where available, and generally fall within the ranges of CA. Mean annual temperatures were {\~{}}22°C hotter (ranging from 0.8 to 6.2°C by species across sites) and mean annual precipitation {\~{}}500 mm wetter (ranging from 530 to 860 mm by species across sites) during the Early to “mid”-Pliocene ({\~{}}3.6 Ma) when compared with modern climate station data in the Canadian Arctic Archipelago. Comparison of estimates for three levels of taxonomic input suggest judicious interpretation is needed when generic level identifications are used, especially in the Polar Regions. The results herein are a reminder of the large impact of non-climatic abiotic and biotic factors to be accounted for when predicting future ranges of communities under different climate conditions from the present, and when hindcasting climate from past ecosystem assemblages.},
author = {Fletcher, Tamara and Feng, Ran and Telka, Alice M and Matthews, John V and Ballantyne, Ashley},
doi = {10.3389/fevo.2017.00019},
issn = {2296-701X},
journal = {Frontiers in Ecology and Evolution},
pages = {19},
title = {{Floral Dissimilarity and the Influence of Climate in the Pliocene High Arctic: Biotic and Abiotic Influences on Five Sites on the Canadian Arctic Archipelago}},
url = {https://www.frontiersin.org/article/10.3389/fevo.2017.00019},
volume = {5},
year = {2017}
}
@article{Flores-Aqueveque2020,
abstract = {The South Pacific Subtropical High (SPSH) is a predominant feature of the South American climate. The variability of this high-pressure center induces changes in the intensity of coastal alongshore winds and precipitation, among others, over southwestern South America. In recent decades, strengthening and expansion of the SPSH have been observed and attributed to the current global warming. These changes have led to an intensification of the southerly winds along the coast of northern to central Chile and a decrease in precipitation from central to southern Chile. Motivated by improving our understanding about the regional impacts of climate change in this part of the Southern Hemisphere, we analyzed SPSH changes during the two most extreme climate events of the last millennium, the Little Ice Age (LIA) and the Current Warm Period (CWP: 1970-2000), based on paleoclimate records and CMIP5/PMIP3 model simulations. In order to assess the level of agreement of general circulation models, we also compare them with ERA-Interim reanalysis data for the 1979-2009 period as a complementary analysis. Finally, with the aim of evaluating future SPSH behavior, we include 21st century projections under a Representative Concentration Pathway (RCP8.5) scenario in our analyses. Our results indicate that during the relative warm (cold) period, the SPSH expands (contracts). Together with this change, alongshore winds intensify (weaken) south (north) of ∼ 35° S; also, southern westerly winds become stronger (weaker) and shift southward (northward). Model results generally underestimate reanalysis data. These changes are in good agreement with paleoclimate records, which suggest that these variations could be related to tropical climate dynamics but also to extratropical phenomena. However, although models adequately represent most of the South American climate changes, they fail to represent the Intertropical Convergence Zone-Hadley cell system dynamics, emphasizing the importance of improving tropical system dynamics in simulations for a better understanding of its effects on South America. Climate model projections indicate that changes recently observed will continue during the next decades, highlighting the need to establish effective mitigation and adaptation strategies against their environmental and socioeconomic impacts.},
author = {Flores-Aqueveque, Valentina and Rojas, Maisa and Aguirre, Catalina and Arias, Paola A. and Gonz{\'{a}}lez, Charles},
doi = {10.5194/cp-16-79-2020},
issn = {18149332},
journal = {Climate of the Past},
number = {1},
pages = {79--99},
title = {{South Pacific Subtropical High from the late Holocene to the end of the 21st century: insights from climate proxies and general circulation models}},
volume = {16},
year = {2020}
}
@article{Fogt2020a,
abstract = {The Southern Annular Mode (SAM) is the leading mode of extratropical Southern Hemisphere climate variability, associated with changes in the strength and position of the polar jet around Antarctica. This variability in the polar jet drives large fluctuations in the Southern Hemisphere climate, from the lower stratosphere into the troposphere, and stretching from the midlatitudes across the Southern Ocean to Antarctica. Notably, the SAM index has displayed marked positive trends in the austral summer season (stronger and poleward shifted westerlies), associated with stratospheric ozone loss. Historical reconstructions demonstrate that these recent positive SAM index values are unprecedented in the last millennia, and fall outside the range of natural climate variability. Despite these advances in the understanding of the SAM behavior, several areas of active research are identified that highlight gaps in our present knowledge. This article is categorized under: Paleoclimates and Current Trends {\textgreater} Earth System Behavior.},
author = {Fogt, Ryan L. and Marshall, Gareth J.},
doi = {10.1002/wcc.652},
issn = {17577799},
journal = {WIREs Climate Change},
number = {4},
pages = {1--24},
title = {{The Southern Annular Mode: Variability, trends, and climate impacts across the Southern Hemisphere}},
volume = {11},
year = {2020}
}
@misc{foley_community_2019,
author = {Foley, K M and Dowsett, H J},
doi = {10.5066/P9YP3DTV},
publisher = {U.S. Geological Survey data release},
title = {{Community sourced mid-Piacenzian sea surface temperature (SST) data}},
type = {data set},
year = {2019}
}
@article{Foltz2010b,
abstract = {Between May and August 2009 sea surface temperatures (SSTs) in the eastern equatorial Atlantic dropped 5°C, from 1°C above normal to 1°C below normal. The magnitude of this cooling is unprecedented since satellite SST measurements began in 1982. In this study, observations and a linear equatorial wave model are used to examine the causes of the sharp decrease in SST. It is found that the anomalous cooling along the equator can be traced to an anomalous meridional gradient of SST and associated northwesterly anomalous winds that developed in the equatorial Atlantic the preceding spring. The anomalous winds forced upwelling equatorial Rossby waves that propagated westward during boreal spring and reflected at the western boundary into upwelling Kelvin waves during late spring and summer. The upwelling Kelvin waves propagated eastward along the equator, anomalously decreasing sea level and SST during May?August.},
annote = {doi: 10.1029/2010GL045522},
author = {Foltz, Gregory R and McPhaden, Michael J},
doi = {10.1029/2010GL045522},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Atlantic Ni{\~{n}}o,Atlantic cold tongue,equatorial waves,interannual variability},
month = {dec},
number = {24},
pages = {L24605},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Abrupt equatorial wave-induced cooling of the Atlantic cold tongue in 2009}},
url = {https://doi.org/10.1029/2010GL045522},
volume = {37},
year = {2010}
}
@article{doi:10.1175/JCLI-D-11-00150.1,
abstract = { AbstractIn the first half of 2009, anomalous cooling of sea surface temperatures (SSTs) in the equatorial North Atlantic (ENA; 2°–12°N) triggered a strong Atlantic meridional mode event. During its peak in April–May, SSTs in the ENA were 1°C colder than normal and SSTs in the equatorial South Atlantic (5°S–0°) were 0.5°C warmer than normal. Associated with the SST gradient were anomalous northerly winds, an anomalous southward shift of the intertropical convergence zone, and severe flooding in Northeast Brazil. This study uses in situ and satellite observations to examine the mechanisms responsible for the anomalous cooling in the ENA during boreal winter and spring of 2009. It is found that the cooling was initiated by stronger than normal trade winds during January and February 2009 associated with an anomalous strengthening of the subtropical North Atlantic high pressure system. Between 6° and 12°N, unusually strong trade winds cooled the ocean through wind-induced evaporation and deepened the mixed layer anomalously by 5–20 m. Closer to the equator, surface equatorial winds responded to the anomalous interhemispheric SST gradient, becoming northwesterly between the equator and 6°N. The anomalous winds drove upwelling of 0.5–1 m day−1 during March–April, a period when there is normally weak downwelling. The associated vertical turbulent heat flux at the base of the mixed layer led to unusually cool SSTs in the central basin, further strengthening the anomalous interhemispheric SST gradient. These results emphasize the importance of mixed layer dynamics in the evolution of the meridional mode event of 2009 and the potential for positive coupled feedbacks between wind-induced upwelling and SST in the ENA. },
author = {Foltz, Gregory R and McPhaden, Michael J and Lumpkin, Rick},
doi = {10.1175/JCLI-D-11-00150.1},
journal = {Journal of Climate},
number = {1},
pages = {363--380},
title = {{A Strong Atlantic Meridional Mode Event in 2009: The Role of Mixed Layer Dynamics}},
url = {https://doi.org/10.1175/JCLI-D-11-00150.1},
volume = {25},
year = {2012}
}
@article{Foltz2019a,
abstract = {The tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southern and northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world's largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate. Past success of the tropical Atlantic observing system is the result of an international commitment to sustained observations and scientific cooperation, a willingness to evolve with changing research and monitoring needs, and a desire to share data openly with the scientific community and operational centers. The observing system must continue to evolve in order to meet an expanding set of research priorities and operational challenges. This paper discusses the tropical Atlantic observing system, including emerging scientific questions that demand sustained ocean observations, the potential for further integration of the observing system, and the requirements for sustaining and enhancing the tropical Atlantic observing system.},
author = {Foltz, G R and Brandt, P and Richter, I and Rodr{\'{i}}guez-Fonseca, B and Hernandez, F and Dengler, M and Rodrigues, R R and Schmidt, J O and Yu, L and Lefevre, N and {Da Cunha}, L Cotrim and McPhaden, M J and Araujo, M and Karstensen, J and Hahn, J and Mart{\'{i}}n-Rey, M and Patricola, C M and Poli, P and Zuidema, P and Hummels, R and Perez, R C and Hatje, V and L{\"{u}}bbecke, J F and Polo, I and Lumpkin, R and Bourl{\`{e}}s, B and Asuquo, F E and Lehodey, P and Conchon, A and Chang, P and Dandin, P and Schmid, C and Sutton, A and Giordani, H and Xue, Y and Illig, S and Losada, T and Grodsky, S A and Gasparin, F and Lee, T and Mohino, E and Nobre, P and Wanninkhof, R and Keenlyside, N and Garcon, V and S{\'{a}}nchez-G{\'{o}}mez, E and Nnamchi, H C and Dr{\'{e}}villon, M and Storto, A and Remy, E and Lazar, A and Speich, S and Goes, M and Dorrington, T and Johns, W E and Moum, J N and Robinson, C and Perruche, C and de Souza, R B and Gaye, A T and L{\'{o}}pez-Parages, J and Monerie, P.-A. and Castellanos, P and Benson, N U and Hounkonnou, M N and Duh{\'{a}}, J Trotte and Laxenaire, R and Reul, N},
doi = {10.3389/fmars.2019.00206},
journal = {Frontiers in Marine Science},
pages = {206},
title = {{The Tropical Atlantic Observing System}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00206},
volume = {6},
year = {2019}
}
@article{Ford2015,
abstract = {El Ni{\~{n}}o-Southern Oscillation (ENSO) is a major source of global interannual variability, but its response to climate change is uncertain. Paleoclimate records from the Last Glacial Maximum (LGM) provide insight into ENSO behavior when global boundary conditions (ice sheet extent, atmospheric partial pressure of CO2) were different from those today. In this work, we reconstruct LGM temperature variability at equatorial Pacific sites using measurements of individual planktonic foraminifera shells. A deep equatorial thermocline altered the dynamics in the eastern equatorial cold tongue, resulting in reduced ENSO variability during the LGM compared to the Late Holocene. These results suggest that ENSO was not tied directly to the east-west temperature gradient, as previously suggested. Rather, the thermocline of the eastern equatorial Pacific played a decisive role in the ENSO response to LGM climate.},
author = {Ford, Heather L. and Ravelo, A. Christina and Polissar, Pratigya J.},
doi = {10.1126/science.1258437},
issn = {10959203},
journal = {Science},
number = {6219},
pages = {255--258},
title = {{Reduced El Ni{\~{n}}o-Southern Oscillation during the last glacial maximum}},
volume = {347},
year = {2015}
}
@article{Ford2018,
abstract = {Abstract The mean state and variability of the tropical Pacific is influenced by the depth of the thermocline. During the Last Glacial Maximum ({\~{}}21,000 years ago), the zonal sea surface temperature gradient across the equatorial Pacific was reduced and productivity was generally lower than modern. To understand the thermocline depth's role in determining the Last Glacial Maximum tropical mean state, we reconstruct the upper ocean $\delta$18O profile from multiple species of planktic foraminifera. We synthesize existing records of surface and subsurface dwelling foraminifera to reconstruct the vertical $\delta$18O gradient throughout the eastern equatorial Pacific. We find the thermocline was deeper during the Last Glacial Maximum than the Holocene throughout the eastern equatorial Pacific region. The thermocline depth's role in the dynamic forcing of the cold tongue contributed to the reduced zonal SST gradient across the equatorial Pacific, decreased productivity, and presumably impacted El Ni{\~{n}}o-Southern Oscillation variability relative to the Holocene.},
author = {Ford, H L and McChesney, C L and Hertzberg, J E and McManus, J F},
doi = {10.1029/2018GL079710},
journal = {Geophysical Research Letters},
number = {21},
pages = {11806--11816},
title = {{A Deep Eastern Equatorial Pacific Thermocline During the Last Glacial Maximum}},
volume = {45},
year = {2018}
}
@misc{Fordham2020,
abstract = {Strategies for 21st-century environmental management and conservation under global change require a strong understanding of the biological mechanisms that mediate responses to climate- and human-driven change to successfully mitigate range contractions, extinctions, and the degradation of ecosystem services. Biodiversity responses to past rapid warming events can be followed in situ and over extended periods, using cross-disciplinary approaches that provide cost-effective and scalable information for species' conservation and the maintenance of resilient ecosystems in many bioregions. Beyond the intrinsic knowledge gain such integrative research will increasingly provide the context, tools, and relevant case studies to assist in mitigating climate-driven biodiversity losses in the 21st century and beyond.},
author = {Fordham, Damien A. and Jackson, Stephen T. and Brown, Stuart C. and Huntley, Brian and Brook, Barry W. and Dahl-Jensen, Dorthe and {Thomas Gilbert}, M. P. and Otto-Bliesner, Bette L. and Svensson, Anders and Theodoridis, Spyros and Wilmshurst, Janet M. and Buettel, Jessie C. and Canteri, Elisabetta and McDowell, Matthew and Orlando, Ludovic and Pilowsky, Julia and Rahbek, Carsten and Nogues-Bravo, David},
booktitle = {Science},
doi = {10.1126/science.abc5654},
issn = {10959203},
number = {6507},
pages = {eabc5654},
title = {{Using paleo-archives to safeguard biodiversity under climate change}},
volume = {369},
year = {2020}
}
@article{Forkel2014,
abstract = {Existing dynamic global vegetation models (DGVMs) have a limited ability in reproducing phenology and decadal dynamics of vegetation greenness as observed by satellites. These limitations in reproducing observations reflect a poor understanding and description of the environmental controls on phenology, which strongly influence the ability to simulate longer-term vegetation dynamics, e.g. carbon allocation. Combining DGVMs with observational data sets can potentially help to revise current modelling approaches and thus enhance the understanding of processes that control seasonal to long-term vegetation greenness dynamics. Here we implemented a new phenology model within the LPJmL (Lund Potsdam Jena managed lands) DGVM and integrated several observational data sets to improve the ability of the model in reproducing satellite-derived time series of vegetation greenness. Specifically, we optimized LPJmL parameters against observational time series of the fraction of absorbed photosynthetic active radiation (FAPAR), albedo and gross primary production to identify the main environmental controls for seasonal vegetation greenness dynamics. We demonstrated that LPJmL with new phenology and optimized parameters better reproduces seasonality, inter-annual variability and trends of vegetation greenness. Our results indicate that soil water availability is an important control on vegetation phenology not only in water-limited biomes but also in boreal forests and the Arctic tundra. Whereas water availability controls phenology in water-limited ecosystems during the entire growing season, water availability co-modulates jointly with temperature the beginning of the growing season in boreal and Arctic regions. Additionally, water availability contributes to better explain decadal greening trends in the Sahel and browning trends in boreal forests. These results emphasize the importance of considering water availability in a new generation of phenology modules in DGVMs in order to correctly reproduce observed seasonal-to-decadal dynamics of vegetation greenness.},
author = {Forkel, M. and Carvalhais, N. and Schaphoff, S. and Bloh, W. V. and Migliavacca, M. and Thurner, M. and Thonicke, K.},
doi = {10.5194/bg-11-7025-2014},
isbn = {1110917201},
issn = {17264189},
journal = {Biogeosciences},
number = {23},
pages = {7025--7050},
title = {{Identifying environmental controls on vegetation greenness phenology through model-data integration}},
volume = {11},
year = {2014}
}
@article{Forkel2016,
abstract = {Atmospheric monitoring of high northern latitudes (above 40°N) has shown an enhanced seasonal cycle of carbon dioxide (CO2) since the 1960s, but the underlying mechanisms are not yet fully understood. The much stronger increase in high latitudes relative to low ones suggests that northern ecosystems are experiencing large changes in vegetation and carbon cycle dynamics. We found that the latitudinal gradient of the increasing CO2 amplitude is mainly driven by positive trends in photosynthetic carbon uptake caused by recent climate change and mediated by changing vegetation cover in northern ecosystems. Our results underscore the importance of climate-vegetation-carbon cycle feedbacks at high latitudes; moreover, they indicate that in recent decades, photosynthetic carbon uptake has reacted much more strongly to warming than have carbon release processes.},
author = {Forkel, Matthias and Carvalhais, Nuno and R{\"{o}}denbeck, Christian and Keeling, Ralph and Heimann, Martin and Thonicke, Kirsten and Zaehle, S{\"{o}}nke and Reichstein, Markus},
doi = {10.1126/science.aac4971},
issn = {10959203},
journal = {Science},
number = {6274},
pages = {696--699},
title = {{Enhanced seasonal CO2 exchange caused by amplified plant productivity in northern ecosystems}},
volume = {351},
year = {2016}
}
@article{Forzieri2017,
abstract = {Forzieri et al . (Reports, 16 June 2017, p. 1180) used satellite data to show that boreal greening caused regional warming. We show that this positive sensitivity of temperature to the greening can be derived from the positive response of vegetation to boreal warming, which indicates that results from a statistical regression with satellite data should be carefully interpreted.},
author = {Forzieri, Giovanni and Alkama, Ramdane and Miralles, Diego G. and Cescatti, Alessandro},
doi = {10.1126/science.aal1727},
isbn = {978-3-662-49900-9},
issn = {10959203},
journal = {Science},
number = {6343},
pages = {1180--1184},
pmid = {29903940},
title = {{Satellites reveal contrasting responses of regional climate to the widespread greening of Earth}},
volume = {356},
year = {2017}
}
@article{Foster2017,
abstract = {Despite an increase in solar output, the Earth's climate has apparently remained relatively stable over geological time. Here, the authors compile atmospheric CO2 data for the past 420 million years and show that this climatic response is due to the long-term decline in this powerful greenhouse gas.},
author = {Foster, Gavin L. and Royer, Dana L. and Lunt, Daniel J.},
doi = {10.1038/ncomms14845},
isbn = {2041-1723},
issn = {20411723},
journal = {Nature Communications},
number = {14845},
pmid = {28375201},
title = {{Future climate forcing potentially without precedent in the last 420 million years}},
volume = {8},
year = {2017}
}
@article{Foster2016,
abstract = {In order to better understand the effect of CO2 on the Earth system in the future, geologists may look to CO2-induced environmental change in Earth's past. Here we describe how CO2 can be reconstructed using the boron isotopic composition ($\delta$11B) of marine calcium carbonate. We review the chemical principles that underlie the proxy, summarize the available calibration data, and detail how boron isotopes can be used to estimate ocean pH and ultimately atmospheric CO2 in the past. $\delta$11B in a variety of marine carbonates shows a coherent relationship with seawater pH, in broad agreement with simple models for this proxy. Offsets between measured and predicted $\delta$11B may in part be explained by physiological influences, though the exact mechanisms of boron incorporation into carbonate remain unknown. Despite these uncertainties, we demonstrate that $\delta$11B may provide crucial constraints on past ocean acidification and atmospheric CO2.},
author = {Foster, Gavin L. and Rae, James W.B.},
doi = {10.1146/annurev-earth-060115-012226},
isbn = {0084-6597},
issn = {0084-6597},
journal = {Annual Review of Earth and Planetary Sciences},
month = {may},
number = {1},
pages = {207--237},
publisher = {Annual Reviews},
title = {{Reconstructing Ocean pH with Boron Isotopes in Foraminifera}},
volume = {44},
year = {2016}
}
@article{Foster2008,
abstract = {Here a new analytical methodology is described for measuring the isotopic composition of boron in foraminifera using multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). This new approach is fast (∼10 samples analysed in duplicate per analytical session) and accurate (to better than 0.25‰ at 95{\%} confidence) with acceptable sample size requirements (1–3 mg of carbonate). A core top calibration of several common planktic and two benthic species from geographically widespread localities shows a very close agreement between the isotopic composition measured by MC-ICPMS and the isotopic composition of B(OH)−4 in seawater (as predicted using the recently measured isotopic equilibrium factor of 1.0272) at the depth of habitat. A down core and core top investigation of boron concentration (B/Ca ratio) shows that the partition coefficient is influenced by [CO2−3] complicating the application of this proxy. Nevertheless, it is demonstrated that these two proxies can be used to fully constrain the carbonate system of surface water in the Caribbean Sea (ODP Site 999A) over the last 130 kyr. This reconstruction shows that during much of the Holocene and the last interglacial period surface water at Site 999A was in equilibrium with the atmosphere with respect to CO2. During the intervening colder periods although the surface water pCO2 was lower than the Holocene, it was a minor to significant source of CO2 to the atmosphere possibly due to either an expansion of the eastern equatorial Atlantic upwelling zone, or a more local expansion of coastal upwelling in the southern Caribbean. Such reorganisation of the oceanic carbonate system in favour of a larger source of CO2 to the atmosphere from the equatorial ocean may require mechanisms responsible for lowering atmospheric CO2 during glacial periods to be more efficient than previously supposed.},
author = {Foster, G L},
doi = {10.1016/j.epsl.2008.04.015},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Boron isotopes,Caribbean Sea,calibration,carbonate ion concentration,pCO,pH,proxy},
number = {1},
pages = {254--266},
title = {{Seawater pH, pCO2 and [CO32−] variations in the Caribbean Sea over the last 130 kyr: A boron isotope and B/Ca study of planktic foraminifera}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X08002549},
volume = {271},
year = {2008}
}
@article{cp-16-503-2020,
abstract = {Abstract. We measured the methane mixing ratios of enclosed air in five ice core sections drilled on the East Antarctic Plateau. Our work aims to study two effects that alter the recorded gas concentrations in ice cores: layered gas trapping artifacts and firn smoothing. Layered gas trapping artifacts are due to the heterogeneous nature of polar firn, where some strata might close early and trap abnormally old gases that appear as spurious values during measurements. The smoothing is due to the combined effects of diffusive mixing in the firn and the progressive closure of bubbles at the bottom of the firn. Consequently, the gases trapped in a given ice layer span a distribution of ages. This means that the gas concentration in an ice layer is the average value over a certain period of time, which removes the fast variability from the record. Here, we focus on the study of East Antarctic Plateau ice cores, as these low-accumulation ice cores are particularly affected by both layering and smoothing. We use high-resolution methane data to test a simple trapping model reproducing the layered gas trapping artifacts for different accumulation conditions typical of the East Antarctic Plateau. We also use the high-resolution methane measurements to estimate the gas age distributions of the enclosed air in the five newly measured ice core sections. It appears that for accumulations below 2 cm ice equivalent yr−1 the gas records experience nearly the same degree of smoothing. We therefore propose to use a single gas age distribution to represent the firn smoothing observed in the glacial ice cores of the East Antarctic Plateau. Finally, we used the layered gas trapping model and the estimation of glacial firn smoothing to quantify their potential impacts on a hypothetical 1.5-million-year-old ice core from the East Antarctic Plateau. Our results indicate that layering artifacts are no longer individually resolved in the case of very thinned ice near the bedrock. They nonetheless contribute to slight biases of the measured signal (less than 10 ppbv and 0.5 ppmv in the case of methane using our currently established continuous CH4 analysis and carbon dioxide, respectively). However, these biases are small compared to the dampening experienced by the record due to firn smoothing.},
author = {Fourteau, K{\'{e}}vin and Martinerie, Patricia and Fa{\"{i}}n, Xavier and Ekaykin, Alexey A and Chappellaz, J{\'{e}}r{\^{o}}me and Lipenkov, Vladimir},
doi = {10.5194/cp-16-503-2020},
issn = {1814-9332},
journal = {Climate of the Past},
month = {mar},
number = {2},
pages = {503--522},
title = {{Estimation of gas record alteration in very low-accumulation ice cores}},
url = {https://cp.copernicus.org/articles/16/503/2020/},
volume = {16},
year = {2020}
}
@article{Frajka-Williams2015,
abstract = {Abstract Climate simulations predict a slowing of the Atlantic meridional overturning circulation (MOC), a key oceanic component of the climate system, while continuous observations of the MOC from boundary arrays demonstrate substantial variability on weekly to interannual time scales. These arrays are necessarily limited to individual latitudes. A potential proxy for the MOC covering longer time scales and larger spatial scales is desirable. Here we use sea surface height data from satellites to estimate the interannual variability of transbasin ocean transports at 26°N. Combining this estimate with surface Ekman transport and cable measurements of the Florida Current, we construct a time series of the MOC from 1993 to 2014. This satellite-based estimate recovers over 90{\%} of the interannual variability of the MOC measured by the RAPID 26°N array. This analysis complements in situ observational efforts to measure the MOC at multiple latitudes and opens the door to a broader spatial understanding of the Atlantic circulation variability.},
annote = {doi: 10.1002/2015GL063220},
author = {Frajka-Williams, E},
doi = {10.1002/2015GL063220},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {interannual variability,meridional overturning circulation,ocean climate,ocean transports,satellite oceanography},
month = {may},
number = {9},
pages = {3458--3464},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Estimating the Atlantic overturning at 26°N using satellite altimetry and cable measurements}},
url = {https://doi.org/10.1002/2015GL063220},
volume = {42},
year = {2015}
}
@article{Francis2012,
author = {Francis, Jennifer A and Vavrus, Stephen J},
doi = {10.1029/2012GL051000},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {mar},
number = {6},
title = {{Evidence linking Arctic amplification to extreme weather in mid-latitudes}},
url = {http://doi.wiley.com/10.1029/2012GL051000},
volume = {39},
year = {2012}
}
@article{Francis2015,
abstract = {New metrics and evidence are presented that support a linkage between rapid Arctic warming, relative to Northern hemisphere mid-latitudes, and more frequent high-amplitude (wavy) jet-stream configurations that favor persistent weather patterns. We find robust relationships among seasonal and regional patterns of weaker poleward thickness gradients, weaker zonal upper-level winds, and a more meridional flow direction. These results suggest that as the Arctic continues to warm faster than elsewhere in response to rising greenhouse-gas concentrations, the frequency of extreme weather events caused by persistent jet-stream patterns will increase.},
author = {Francis, Jennifer A. and Vavrus, Stephen J.},
doi = {10.1088/1748-9326/10/1/014005},
isbn = {1748-9326},
issn = {17489326},
journal = {Environmental Research Letters},
number = {1},
publisher = {IOP Publishing},
title = {{Evidence for a wavier jet stream in response to rapid Arctic warming}},
volume = {10},
year = {2015}
}
@article{FRANK2006274,
abstract = {On the Am{\'{e}}d{\'{e}}e islet, 4 drill cores were recovered from the barrier reef of Western New Caledonia. The coral reef is slowly subsiding and is thus percolated by sea water during sea level highstands. The cores sample a ∼10 m thick Holocene reef overlying a 24 m thick reef of marine isotope stage (MIS) 5.5, which in turn overlies older reef material from MIS 7.5 and beyond. (234U/238U) and (230Th/238U) ratios and 232Th were determined by thermal ionization mass spectrometry on aragonitic coral samples that were carefully investigated using X-ray diffraction and scanning electron microscopy. The petrographic study shows an increasing coral weathering with growing coral age that causes different degree of U-series open system behavior and 232Th accumulation. Holocene corals exhibit a small degree of early diagenesis and yield 230Th/238U ages according to the Holocene sea level rise from ∼8200 years to 5000 years BP. Corals from the last Interglacial section have experienced more frequent replacement of aragonite fibers and minor dissolution, and U-series open system behavior is evident. To estimate the impact of recoil processes and alteration on the U-series system two models by Villemant and Feuillet [B. Villemant, N. Feuillet, Dating open systems by the 238U–234U–230Th method: application to Quaternary reef terraces, Earth and Planetary Science Letters 210(2003) 105–118.] and Thompson et al. [W. G. Thompson, M. W. Spiegelman, S. L. Goldstein, R. C. Speed, An open-system model for U-series age determinations of fossil corals, Earth and Planetary Science Letters 210(2003) 365–381.] have been tested. These models yield identical ages within uncertainty, which are in agreement to the sea level history of the past 250,000 years, as long as physico-chemical alteration and re-crystallization is small. Consequently, we were able to estimate the subsidence rate from the subsidence observed between the end of MIS 5.5 and the early Holocene, which is ∼0.16±0.04 m per 1000 years. In addition, by using this subsidence rate and the sea level highstand of +6±3 m during MIS 5.5 we can estimate the sea level highstand at 244,000 (MIS 7.5) to be between +2 m to −2 m, respectively. Corals from underneath the marine isotope stage 7.5 sequence show more significant dissolution, increasing re-crystallization, elevated 232Th, and excess 234U and 230Th. Here the Villemant and Feuillet [B. Villemant, N. Feuillet, Dating open systems by the 238U–234U–230Th method: application to Quaternary reef terraces, Earth and Planetary Science Letters 210(2003) 105–118.] model fails to predict ages, but the Thompson et al. [W.G. Thompson, M. W. Spiegelman, S. L. Goldstein, R. C. Speed, An open-system model for U-series age determinations of fossil corals, Earth and Planetary Science Letters 210(2003) 365–381.] model was applicable predicting ages between 355,000 to {\textgreater}430,000 years, i.e. coral growth potentially during MIS 9 or 11.},
author = {Frank, N and Turpin, L and Cabioch, G and Blamart, D and Tressens-Fedou, M and Colin, C and Jean-Baptiste, P},
doi = {10.1016/j.epsl.2006.07.029},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Holocene,New Caledonia,Th/U dating,U-series open system dating,coral,sea level,subsidence rate},
number = {3},
pages = {274--289},
title = {{Open system U-series ages of corals from a subsiding reef in New Caledonia: Implications for sea level changes, and subsidence rate}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X06005206},
volume = {249},
year = {2006}
}
@article{Franklin2016a,
abstract = {Anthropogenic drivers of global change include rising atmospheric concentrations of carbon dioxide and other greenhouse gasses and resulting changes in the climate, as well as nitrogen deposition, biotic invasions, altered disturbance regimes, and land-use change. Predicting the effects of global change on terrestrial plant communities is crucial because of the ecosystem services vegetation provides, from climate regulation to forest products. In this paper, we present a framework for detecting vegetation changes and attributing them to global change drivers that incorporates multiple lines of evidence from spatially extensive monitoring networks, distributed experiments, remotely sensed data, and historical records. Based on a literature review, we summarize observed changes and then describe modeling tools that can forecast the impacts of multiple drivers on plant communities in an era of rapid change. Observed responses to changes in temperature, water, nutrients, land use, and disturbance show strong sensitivity of ecosystem productivity and plant population dynamics to water balance and long-lasting effects of disturbance on plant community dynamics. Persistent effects of land-use change and human-altered fire regimes on vegetation can overshadow or interact with climate change impacts. Models forecasting plant community responses to global change incorporate shifting ecological niches, population dynamics, species interactions, spatially explicit disturbance, ecosystem processes, and plant functional responses. Monitoring, experiments, and models evaluating multiple change drivers are needed to detect and predict vegetation changes in response to 21st century global change.},
author = {Franklin, Janet and Serra-Diaz, Josep M. and Syphard, Alexandra D. and Regan, Helen M.},
doi = {10.1073/pnas.1519911113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {14},
pages = {3725--3734},
title = {{Global change and terrestrial plant community dynamics}},
volume = {113},
year = {2016}
}
@article{Frederikse2020,
author = {Frederikse, Thomas and Landerer, Felix and Caron, Lambert and Adhikari, Surendra and Parkes, David and Humphrey, Vincent W and Dangendorf, S{\"{o}}nke and Hogarth, Peter and Zanna, Laure and Cheng, Lijing and Wu, Yun Hao},
doi = {10.1038/s41586-020-2591-3},
isbn = {4158602025},
issn = {14764687},
journal = {Nature},
number = {7821},
pages = {393--397},
publisher = {Springer US},
title = {{The causes of sea-level rise since 1900}},
volume = {584},
year = {2020}
}
@article{doi:10.1002/joc.4775,
abstract = {ABSTRACT We highlight improvements to the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) in the latest Release 3.0 (R3.0; covering 1662–2014). ICOADS is the most widely used freely available collection of surface marine observations, providing data for the construction of gridded analyses of sea surface temperature, estimates of air–sea interaction and other meteorological variables. ICOADS observations are assimilated into all major atmospheric, oceanic and coupled reanalyses, further widening its impact. R3.0 therefore includes changes designed to enable effective exchange of information describing data quality between ICOADS, reanalysis centres, data set developers, scientists and the public. These user-driven innovations include the assignment of a unique identifier (UID) to each marine report – to enable tracing of observations, linking with reports and improved data sharing. Other revisions and extensions of the ICOADS' International Maritime Meteorological Archive common data format incorporate new near-surface oceanographic data elements and cloud parameters. Many new input data sources have been assembled, and updates and improvements to existing data sources, or removal of erroneous data, made. Coupled with enhanced ‘preliminary' monthly data and product extensions past 2014, R3.0 provides improved support of climate assessment and monitoring, reanalyses and near-real-time applications.},
author = {Freeman, Eric and Woodruff, Scott D and Worley, Steven J and Lubker, Sandra J and Kent, Elizabeth C and Angel, William E and Berry, David I and Brohan, Philip and Eastman, Ryan and Gates, Lydia and Gloeden, Wolfgang and Ji, Zaihua and Lawrimore, Jay and Rayner, Nick A and Rosenhagen, Gudrun and Smith, Shawn R},
doi = {10.1002/joc.4775},
journal = {International Journal of Climatology},
keywords = {buoy data,humidity,marine meteorological data,metadata,ocean,sea-level pressure,sea-surface temperature,ship data},
number = {5},
pages = {2211--2232},
title = {{ICOADS Release 3.0: a major update to the historical marine climate record}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.4775},
volume = {37},
year = {2017}
}
@article{10.3389/fmars.2019.00435,
abstract = {The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a collection and archive of in situ marine observations, which has been developed over several decades as an international project and recently guided by formal international partnerships and the ICOADS Steering Committee. ICOADS contains observations from many different observing systems encompassing the evolution of measurement technology since the 18th century. ICOADS provides an integrated source of observations for a range of applications including research and climate monitoring, and forms the main marine in situ surface data source, e.g., near-surface ocean observations and lower atmospheric marine-meteorological observations from buoys, ships, coastal stations, and oceanographic sensors, for oceanic and atmospheric research and reanalysis. ICOADS has developed ways to incorporate user and reanalyses feedback information associated with permanent unique identifiers and is also the main repository for data that have been rescued from ships' logbooks and other marine data digitization activities. ICOADS has been adopted widely because it provides convenient access to a range of observation types, globally, and through the entire marine instrumental record. ICOADS has provided a secure home for such observations for decades. Because of the increased volume of observations, particularly those available in near-real-time, and an expansion of their diversity, the ICOADS processing system now requires extensive modernization. Based on user feedback, we will outline the improvements that are required, the challenges to their implementation, and the benefits of upgrading this important and diverse marine archive and distribution activity.},
author = {Freeman, Eric and Kent, Elizabeth C and Brohan, Philip and Cram, Thomas and Gates, Lydia and Huang, Boyin and Liu, Chunying and Smith, Shawn R and Worley, Steven J and Zhang, Huai-Min},
doi = {10.3389/fmars.2019.00435},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
pages = {435},
title = {{The International Comprehensive Ocean-Atmosphere Data Set – Meeting Users Needs and Future Priorities}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00435},
volume = {6},
year = {2019}
}
@article{French2014,
author = {French, Hugh M. and Millar, Susan W. S.},
doi = {10.1111/bor.12036},
issn = {03009483},
journal = {Boreas},
month = {jul},
number = {3},
pages = {667--677},
title = {{Permafrost at the time of the Last Glacial Maximum (LGM) in North America}},
volume = {43},
year = {2014}
}
@article{Freund,
author = {Freund, Mandy B and Henley, Benjamin J and Karoly, David J and McGregor, Helen V and Abram, Nerilie J and Dommenget, Dietmar},
doi = {10.1038/s41561-019-0353-3},
journal = {Nature Geoscience},
number = {6},
pages = {450--455},
title = {{Higher frequency of Central Pacific El Ni{\~{n}}o events in recent decades relative to past centuries}},
volume = {12},
year = {2019}
}
@article{Frezzotti2013,
abstract = {Abstract. Global climate models suggest that Antarctic snowfall should increase in a warming climate and mitigate rises in the sea level. Several processes affect surface mass balance (SMB), introducing large uncertainties in past, present and future ice sheet mass balance. To provide an extended perspective on the past SMB of Antarctica, we used 67 firn/ice core records to reconstruct the temporal variability in the SMB over the past 800 yr and, in greater detail, over the last 200 yr. Our SMB reconstructions indicate that the SMB changes over most of Antarctica are statistically negligible and that the current SMB is not exceptionally high compared to the last 800 yr. High-accumulation periods have occurred in the past, specifically during the 1370s and 1610s. However, a clear increase in accumulation of more than 10{\%} has occurred in high SMB coastal regions and over the highest part of the East Antarctic ice divide since the 1960s. To explain the differences in behaviour between the coastal/ice divide sites and the rest of Antarctica, we suggest that a higher frequency of blocking anticyclones increases the precipitation at coastal sites, leading to the advection of moist air in the highest areas, whereas blowing snow and/or erosion have significant negative impacts on the SMB at windy sites. Eight hundred years of stacked records of the SMB mimic the total solar irradiance during the 13th and 18th centuries. The link between those two variables is probably indirect and linked to a teleconnection in atmospheric circulation that forces complex feedback between the tropical Pacific and Antarctica via the generation and propagation of a large-scale atmospheric wave train.},
author = {Frezzotti, M. and Scarchilli, C. and Becagli, S. and Proposito, M. and Urbini, S.},
doi = {10.5194/tc-7-303-2013},
issn = {19940416},
journal = {Cryosphere},
number = {1},
pages = {303--319},
title = {{A synthesis of the Antarctic surface mass balance during the last 800 yr}},
volume = {7},
year = {2013}
}
@article{doi:10.1002/2017GL072582,
abstract = {Abstract Sea surface salinity (SSS) is a major ocean circulation component and indicator of the hydrological cycle. Here we investigate an unprecedented Atlantic SSS compilation from 1896 to 2013 and analyze the main modes of SSS decadal variability. Using principal component analysis, we find that the low-latitude (tropical and subtropical) Atlantic and the subpolar Atlantic have distinct variability. Subpolar and low-latitude SSS are negatively correlated, with subpolar anomalies leading low-latitude anomalies by about a decade. Subpolar SSS varies in phase with the Atlantic Multidecadal Oscillation (AMO), whereas low-latitude SSS varies in phase with the North Atlantic Oscillation (NAO). Additionally, northern tropical SSS is anticorrelated with Sahel rainfall, suggesting that SSS reflects the Intertropical Convergence Zone latitude. The 1896–2013 SSS trend shows amplification of the mean SSS field, with subpolar freshening and low-latitude salinification. The AMO and NAO have little effect on the long-term trend but contribute to the trend since 1970.},
author = {Friedman, Andrew R and Reverdin, Gilles and Khodri, Myriam and Gastineau, Guillaume},
doi = {10.1002/2017GL072582},
journal = {Geophysical Research Letters},
keywords = {Atlantic Ocean,Sahel rainfall,climate variability,historical trends,hydrological cycle,surface salinity},
number = {4},
pages = {1866--1876},
title = {{A new record of Atlantic sea surface salinity from 1896 to 2013 reveals the signatures of climate variability and long-term trends}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL072582},
volume = {44},
year = {2017}
}
@article{Friedrich2016,
abstract = {Global mean surface temperatures are rising in response to anthropogenic greenhouse gas emissions. The magnitude of this warming at equilibrium for a given radiative forcing—referred to as specific equilibrium climate sensitivity (S)—is still subject to uncertainties. We estimate global mean temperature variations and S using a 784,000-year-long field reconstruction of sea surface temperatures and a transient paleoclimate model simulation. Our results reveal that S is strongly dependent on the climate background state, with significantly larger values attained during warm phases. Using the Representative Concentration Pathway 8.5 for future greenhouse radiative forcing, we find that the range of paleo-based estimates of Earth's future warming by 2100 CE overlaps with the upper range of climate simulations conducted as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Furthermore, we find that within the 21st century, global mean temperatures will very likely exceed maximum levels reconstructed for the last 784,000 years. On the basis of temperature data from eight glacial cycles, our results provide an independent validation of the magnitude of current CMIP5 warming projections.},
author = {Friedrich, Tobias and Timmermann, Axel and Tigchelaar, Michelle and {Elison Timm}, Oliver and Ganopolski, Andrey},
doi = {10.1126/sciadv.1501923},
journal = {Science Advances},
month = {nov},
number = {11},
pages = {e1501923},
title = {{Nonlinear climate sensitivity and its implications for future greenhouse warming}},
url = {http://advances.sciencemag.org/content/2/11/e1501923.abstract},
volume = {2},
year = {2016}
}
@article{Friedrich2020,
author = {Friedrich, Tobias and Timmermann, Axel},
doi = {10.1016/j.epsl.2019.115911},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {jan},
pages = {115911},
title = {{Using Late Pleistocene sea surface temperature reconstructions to constrain future greenhouse warming}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X1930603X},
volume = {530},
year = {2020}
}
@article{Frieling2016a,
abstract = {The Paleocene–Eocene Thermal Maximum (PETM) was a period of global warming associated with rapid massive 13C-depleted carbon input, often mentioned as a paleoanalog for future climate change and associated feedbacks. One hypothesized carbon source is intrusive volcanism in the North Atlantic region, but rigid dating lacks. We date thermogenic methane release from a hydrothermal vent and find that it postdates the onset of the PETM but correlates to a period of additional carbon injection within the PETM. This study provides evidence of carbon release during the PETM from a reservoir (i.e., organic matter in sedimentary rocks) and implies that carbon release from the vent systems should be included in all future considerations regarding PETM carbon cycling.The Paleocene–Eocene Thermal Maximum (PETM) (∼56 Ma) was a ∼170,000-y (∼170-kyr) period of global warming associated with rapid and massive injections of 13C-depleted carbon into the ocean–atmosphere system, reflected in sedimentary components as a negative carbon isotope excursion (CIE). Carbon cycle modeling has indicated that the shape and magnitude of this CIE are generally explained by a large and rapid initial pulse, followed by ∼50 kyr of 13C-depleted carbon injection. Suggested sources include submarine methane hydrates, terrigenous organic matter, and thermogenic methane and CO2 from hydrothermal vent complexes. Here, we test for the contribution of carbon release associated with volcanic intrusions in the North Atlantic Igneous Province. We use dinoflagellate cyst and stable carbon isotope stratigraphy to date the active phase of a hydrothermal vent system and find it to postdate massive carbon release at the onset of the PETM. Crucially, however, it correlates to the period within the PETM of longer-term 13C-depleted carbon release. This finding represents actual proof of PETM carbon release from a particular reservoir. Based on carbon cycle box model [i.e., Long-Term Ocean–Atmosphere–Sediment Carbon Cycle Reservoir (LOSCAR) model] experiments, we show that 4–12 pulses of carbon input from vent systems over 60 kyr with a total mass of 1,500 Pg of C, consistent with the vent literature, match the shape of the CIE and pattern of deep ocean carbonate dissolution as recorded in sediment records. We therefore conclude that CH4 from the Norwegian Sea vent complexes was likely the main source of carbon during the PETM, following its dramatic onset.},
author = {Frieling, Joost and Svensen, Henrik H and Planke, Sverre and Cramwinckel, Margot J and Selnes, Haavard and Sluijs, Appy},
doi = {10.1073/pnas.1603348113},
journal = {Proceedings of the National Academy of Sciences},
month = {oct},
number = {43},
pages = {201603348},
title = {{Thermogenic methane release as a cause for the long duration of the PETM}},
url = {http://www.pnas.org/content/early/2016/10/06/1603348113.abstract},
volume = {113},
year = {2016}
}
@article{Froidevaux2015,
author = {Froidevaux, L and Anderson, J and Wang, H.-J. and Fuller, R A and Schwartz, M J and Santee, M L and Livesey, N J and Pumphrey, H C and Bernath, P F and {Russell III}, J M and McCormick, M P},
doi = {10.5194/acp-15-10471-2015},
journal = {Atmospheric Chemistry and Physics},
number = {18},
pages = {10471--10507},
title = {{Global OZone Chemistry And Related trace gas Data records for the Stratosphere (GOZCARDS): methodology and sample results with a focus on HCl, H2O, and O3}},
volume = {15},
year = {2015}
}
@article{Fu2011,
abstract = {AbstractOne pronounced feature in observed latitudinal dependence of lower-stratospheric temperature trends is the enhanced cooling near 30° latitude in both hemispheres. The observed phenomenon has not, to date, been explained in the literature. This study shows that the enhanced cooling is a direct response of the lower-stratospheric temperature to the poleward shift of subtropical jets. Furthermore, this enhanced lower-stratospheric cooling can be used to quantify the poleward shift of subtropical jets. Using the lower-stratospheric temperatures observed by satellite-borne microwave sounding units, it is shown that the subtropical jets have shifted poleward by 0.6° ± 0.1° and 1.0° ± 0.3° latitude in the Southern and Northern Hemispheres, respectively, in last 30 years since 1979, indicating a widening of tropical belt by 1.6° ± 0.4° latitude.},
author = {Fu, Qiang and Lin, Pu},
doi = {10.1175/JCLI-D-11-00027.1},
isbn = {1520-0442},
issn = {08948755},
journal = {Journal of Climate},
number = {21},
pages = {5597--5603},
title = {{Poleward shift of subtropical jets inferred from satellite-observed lower-stratospheric temperatures}},
volume = {24},
year = {2011}
}
@article{Fueabc7836,
author = {Fu, Yao and Li, Feili and Karstensen, Johannes and Wang, Chunzai},
doi = {10.1126/sciadv.abc7836},
journal = {Science Advances},
number = {48},
pages = {eabc7836},
publisher = {American Association for the Advancement of Science},
title = {{A stable Atlantic Meridional Overturning Circulation in a changing North Atlantic Ocean since the 1990s}},
url = {https://advances.sciencemag.org/content/6/48/eabc7836},
volume = {6},
year = {2020}
}
@article{Fuchs2020,
abstract = {Ocean warming has predictably driven some marine species to migrate polewards or to deeper water, matching rates of environmental temperature change (climate velocity) to remain at tolerable temperatures. Most species conforming to expectations are fish and other strong swimmers that can respond to temperature change by migrating as adults. On the Northwest Atlantic continental shelf, however, many benthic invertebrates' ranges have instead shifted southwards and into shallower, warmer water. We tested whether these ‘wrong-way' migrations could arise from warming-induced changes in the timing of spawning (phenology) and transport of drifting larvae. The results showed that larvae spawned earlier in the year encounter more downwelling-favourable winds and river discharge that drive transport onshore and southwards. Phenology and transport explained most observed range shifts, whereas climate velocity was a poor predictor. This study reveals a physical mechanism that counterintuitively pushes benthic species, including commercial shellfish, into warmer regions with higher mortality.},
author = {Fuchs, Heidi L and Chant, Robert J and Hunter, Elias J and Curchitser, Enrique N and Gerbi, Gregory P and Chen, Emily Y},
doi = {10.1038/s41558-020-0894-x},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {11},
pages = {1052--1056},
title = {{Wrong-way migrations of benthic species driven by ocean warming and larval transport}},
url = {https://doi.org/10.1038/s41558-020-0894-x},
volume = {10},
year = {2020}
}
@article{Funk2015a,
author = {Funk, Chris and Peterson, Pete and Landsfeld, Martin and Pedreros, Diego and Verdin, James and Shukla, Shraddhanand and Husak, Gregory and Rowland, James and Harrison, Laura and Hoell, Andrew and Michaelsen, Joel},
doi = {10.1038/sdata.2015.66},
issn = {2052-4463},
journal = {Scientific Data},
month = {dec},
number = {1},
pages = {150066},
title = {{The climate hazards infrared precipitation with stations – a new environmental record for monitoring extremes}},
url = {http://www.nature.com/articles/sdata201566},
volume = {2},
year = {2015}
}
@article{Funk2019,
abstract = {AbstractUnderstanding the dynamics and physics of climate extremes will be a critical challenge for twenty-first-century climate science. Increasing temperatures and saturation vapor pressures may exacerbate heat waves, droughts, and precipitation extremes. Yet our ability to monitor temperature variations is limited and declining. Between 1983 and 2016, the number of observations in the University of East Anglia Climatic Research Unit (CRU) Tmax product declined precipitously (5900 ? 1000); 1000 poorly distributed measurements are insufficient to resolve regional Tmax variations. Here, we show that combining long (1983 to the near present), high-resolution (0.05°), cloud-screened archives of geostationary satellite thermal infrared (TIR) observations with a dense set of {\~{}}15 000 station observations explains 23{\%}, 40{\%}, 30{\%}, 41{\%}, and 1{\%} more variance than the CRU globally and for South America, Africa, India, and areas north of 50°N, respectively; even greater levels of improvement are shown for the 2011?16 period (28{\%}, 45{\%}, 39{\%}, 52{\%}, and 28{\%}, respectively). Described here for the first time, the TIR Tmax algorithm uses subdaily TIR distributions to screen out cloud-contaminated observations, providing accurate (correlation ≈0.8) gridded emission Tmax estimates. Blending these gridded fields with {\~{}}15 000 station observations provides a seamless, high-resolution source of accurate Tmax estimates that performs well in areas lacking dense in situ observations and even better where in situ observations are available. Cross-validation results indicate that the satellite-only, station-only, and combined products all perform accurately (R ≈ 0.8?0.9, mean absolute errors ≈ 0.8?1.0). Hence, the Climate Hazards Center Infrared Temperature with Stations (CHIRTSmax) dataset should provide a valuable resource for climate change studies, climate extreme analyses, and early warning applications.},
annote = {doi: 10.1175/JCLI-D-18-0698.1},
author = {Funk, Chris and Peterson, Pete and Peterson, Seth and Shukla, Shraddhanand and Davenport, Frank and Michaelsen, Joel and Knapp, Kenneth R and Landsfeld, Martin and Husak, Gregory and Harrison, Laura and Rowland, James and Budde, Michael and Meiburg, Alex and Dinku, Tufa and Pedreros, Diego and Mata, Nicholas},
doi = {10.1175/JCLI-D-18-0698.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jun},
number = {17},
pages = {5639--5658},
publisher = {American Meteorological Society},
title = {{A High-Resolution 1983–2016 Tmax Climate Data Record Based on Infrared Temperatures and Stations by the Climate Hazard Center}},
url = {https://doi.org/10.1175/JCLI-D-18-0698.1},
volume = {32},
year = {2019}
}
@article{Fyfe2015,
abstract = {Maps of continental-scale land cover are utilized by a range of diverse users but whilst a range of products exist that describe present and recent land cover in Europe, there are currently no datasets that describe past variations over long time-scales. User groups with an interest in past land cover include the climate modelling community, socio-ecological historians and earth system scientists. Europe is one of the continents with the longest histories of land conversion from forest to farmland, thus understanding land cover change in this area is globally significant. This study applies the pseudobiomization method (PBM) to 982 pollen records from across Europe, taken from the European Pollen Database (EPD) to produce a first synthesis of pan-European land cover change for the period 9000 bp to present, in contiguous 200 year time intervals. The PBM transforms pollen proportions from each site to one of eight land cover classes (LCCs) that are directly comparable to the CORINE land cover classification. The proportion of LCCs represented in each time window provides a spatially aggregated record of land cover change for temperate and northern Europe, and for a series of case study regions (western France, the western Alps, and the Czech Republic and Slovakia). At the European scale, the impact of Neolithic food producing economies appear to be detectable from 6000 bp through reduction in broad-leaf forests resulting from human land use activities such as forest clearance. Total forest cover at a pan-European scale moved outside the range of previous background variability from 4000 bp onwards. From 2200 bp land cover change intensified, and the broad pattern of land cover for preindustrial Europe was established by 1000 bp. Recognizing the timing of anthropogenic land cover change in Europe will further the understanding of land cover-climate interactions, and the origins of the modern cultural landscape.},
author = {Fyfe, Ralph M. and Woodbridge, Jessie and Roberts, Neil},
doi = {10.1111/gcb.12776},
issn = {13652486},
journal = {Global Change Biology},
keywords = {Europe,Holocene,Human impacts,Land cover,Pollen,Pseudobiomization,Vegetation},
number = {3},
pages = {1197--1212},
title = {{From forest to farmland: Pollen-inferred land cover change across Europe using the pseudobiomization approach}},
volume = {21},
year = {2015}
}
@article{Galaasen2014,
abstract = {Deep ocean circulation is thought to be stable during warm, interglacial periods. Galaasen et al. (p. 1129, published online 20 February) constructed a highly resolved record of North Atlantic Deep Water production during the last interglacial period, around 128,000 to 116,000 years ago. The findings reveal large, centennial-scale reductions—in contrast to the prevailing paradigm. These changes occurred in an ocean warmer than that of today, but in a temperature regime similar to that expected because of global warming, raising the possibility that future ocean circulation, regional climate, and CO2 sequestration pathways could be impacted.Deep ocean circulation has been considered relatively stable during interglacial periods, yet little is known about its behavior on submillennial time scales. Using a subcentennially resolved epibenthic foraminiferal $\delta$13C record, we show that the influence of North Atlantic Deep Water (NADW) was strong at the onset of the last interglacial period and was then interrupted by several prominent centennial-scale reductions. These NADW transients occurred during periods of increased ice rafting and southward expansions of polar water influence, suggesting that a buoyancy threshold for convective instability was triggered by freshwater and circum-Arctic cryosphere changes. The deep Atlantic chemical changes were similar in magnitude to those associated with glaciations, implying that the canonical view of a relatively stable interglacial circulation may not hold for conditions warmer and fresher than at present.},
author = {Galaasen, Eirik Vinje and Ninnemann, Ulysses S and Irvalı, Nil and Kleiven, Helga (Kikki) F and Rosenthal, Yair and Kissel, Catherine and Hodell, David A},
doi = {10.1126/science.1248667},
journal = {Science},
month = {mar},
number = {6175},
pages = {1129},
title = {{Rapid Reductions in North Atlantic Deep Water During the Peak of the Last Interglacial Period}},
url = {http://science.sciencemag.org/content/343/6175/1129.abstract},
volume = {343},
year = {2014}
}
@article{Galaasen2020,
abstract = {Atlantic Meridional Overturning Circulation (AMOC) and the related process of North Atlantic Deep Water (NADW) have been thought to be stable during warm, interglacial periods. Galaasen et al. report that episodes of reduced NADW over the past 500,000 years actually have been relatively common and occasionally long-lasting features of interglacials and that they can occur independently of the catastrophic freshwater outburst floods normally thought to be their cause (see the Perspective by Stocker). This discovery implies that large NADW disruptions might be more likely than we have assumed in the warmer climate of the future.Science, this issue p. 1485; see also p. 1425Disrupting North Atlantic Deep Water (NADW) ventilation is a key concern in climate projections. We use (sub)centennially resolved bottom water $\delta$13C records that span the interglacials of the last 0.5 million years to assess the frequency of and the climatic backgrounds capable of triggering large NADW reductions. Episodes of reduced NADW in the deep Atlantic, similar in magnitude to glacial events, have been relatively common and occasionally long-lasting features of interglacials. NADW reductions were triggered across the range of recent interglacial climate backgrounds, which demonstrates that catastrophic freshwater outburst floods were not a prerequisite for large perturbations. Our results argue that large NADW disruptions are more easily achieved than previously appreciated and that they occurred in past climate conditions similar to those we may soon face.},
author = {Galaasen, Eirik Vinje and Ninnemann, Ulysses S and Kessler, Augustin and Irvalı, Nil and Rosenthal, Yair and Tjiputra, Jerry and Bouttes, Natha{\"{e}}lle and Roche, Didier M and Kleiven, Helga (Kikki) F and Hodell, David A},
doi = {10.1126/science.aay6381},
journal = {Science},
month = {mar},
number = {6485},
pages = {1485},
title = {{Interglacial instability of North Atlantic Deep Water ventilation}},
url = {http://science.sciencemag.org/content/367/6485/1485.abstract},
volume = {367},
year = {2020}
}
@article{Galbraith2015,
abstract = {Among the many potential explanations for the 80ppm rise of atmospheric CO2 concentrations at the end of the last ice age, most involve a weakening of the oceanic soft tissue pump. Here we use global data compilations of sedimentary nitrogen isotopes and benthic oxygenation proxies to provide a synoptic global perspective on the deglacial soft tissue pump weakening. The net change between the Last Glacial Maximum and Holocene shows a removal of respired carbon everywhere that proxy data is available, with the exception of the upper 1.5km of the North Pacific, while excess nitrate accumulated in polar oceans. These observations could be explained by intensifying iron limitation, a shoaling of organic matter remineralization, and/or a change in ocean circulation, but are inconsistent with a change in the magnitude or position of the Southern mid-latitude westerlies. The net soft tissue pump weakening was front-loaded in the early deglaciation ({\~{}}17.5-{\~{}}14ka), when atmospheric $\delta$13C and $\delta$14C were changing rapidly, and appears to have contributed little net change thereafter. Superimposed on the overall deglacial trend were pronounced transient changes that coincided with variability in the Atlantic Meridional Overturning Circulation (AMOC) and bipolar seesaw. The seesaw variability is most clearly expressed as anti-phased oxygenation changes between the upper 1.5km of the North Pacific and the deep North Atlantic, consistent with an Atlantic-Pacific ventilation seesaw, but it dominated transient variability in records throughout the world. Although the soft tissue pump seesaw made little contribution to the contrast between the glacial and interglacial states, it could have contributed to deglacial variability in atmospheric CO2 and might have catalyzed the deglaciation.},
author = {Galbraith, Eric D. and Jaccard, Samuel L.},
doi = {10.1016/j.quascirev.2014.11.012},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Biological pump,Carbon dioxide,Dissolved oxygen,Ice ages,Iron fertilization,Marine sediments,Nitrogen isotopes,Ocean circulation},
month = {feb},
pages = {38--48},
publisher = {Elsevier Ltd},
title = {{Deglacial weakening of the oceanic soft tissue pump: Global constraints from sedimentary nitrogen isotopes and oxygenation proxies}},
volume = {109},
year = {2015}
}
@article{Gallagher2015,
abstract = {The Kuroshio Current is a major western boundary current controlled by the North Pacific Gyre. It brings warm subtropical waters from the Indo-Pacific Warm Pool to Japan exerting a major control on Asian climate. The Tsushima Current is a Kuroshio offshoot transporting warm water into the Japan Sea. Various proxies are used to determine the paleohistory of these currents. Sedimentological proxies such as reefs, bedforms, sediment source and sorting reveal paleocurrent strength and latitude. Proxies such as coral and mollusc assemblages reveal past shelfal current activity. Microfossil assemblages and organic/inorganic geochemical analyses determine paleo- sea surface temperature and salinity histories. Transportation of tropical palynomorphs and migrations of Indo-Pacific species to Japanese waters also reveal paleocurrent activity. The stratigraphic distribution of these proxies suggests the Kuroshio Current reached its present latitude (35 °N) by {\~{}}3 Ma when temperatures were 1 to 2 °C lower than present. At this time a weak Tsushima Current broke through Tsushima Strait entering the Japan Sea. Similar oceanic conditions persisted until {\~{}}2 Ma when crustal stretching deepened the Tsushima Strait allowing inflow during every interglacial. The onset of stronger interglacial/glacial cycles {\~{}}1 Ma was associated with increased North Pacific Gyre and Kuroshio Current intensity. This triggered Ryukyu Reef expansion when reefs reached their present latitude ({\~{}}31 °N), thereafter the reef front advanced ({\~{}}31 °N) and retreated ({\~{}}25 °N) with each cycle. Foraminiferal proxy data suggests eastward deflection of the Kuroshio Current from its present path at 24 °N into the Pacific Ocean due to East Taiwan Channel restriction during the Last Glacial Maximum. Subsequently Kuroshio flow resumed its present trajectory during the Holocene. Ocean modeling and geochemical proxies show that the Kuroshio Current path may have been similar during glacials and interglacials, however the glacial mode of this current remains controversial. Paleohistorical studies form important analogues for current behavior with future climate change, however, there are insufficient studies at present in the region that may be used for this purpose. Modeling of the response of the Kuroshio Current to future global warming reveals that current velocity may increase by up to 0.3 m/sec associated with a northward migration of the Kuroshio Extension.},
author = {Gallagher, Stephen J and Kitamura, Akihisa and Iryu, Yasufumi and Itaki, Takuya and Koizumi, Itaru and Hoiles, Peter W},
doi = {10.1186/s40645-015-0045-6},
issn = {2197-4284},
journal = {Progress in Earth and Planetary Science},
number = {1},
pages = {17},
title = {{The Pliocene to recent history of the Kuroshio and Tsushima Currents: a multi-proxy approach}},
url = {https://doi.org/10.1186/s40645-015-0045-6},
volume = {2},
year = {2015}
}
@article{Gallaher2014,
author = {Gallaher, David W. and Campbell, G. Garrett and Meier, Walter N.},
doi = {10.1109/JSTARS.2013.2264391},
issn = {21511535},
journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
keywords = {Antarctic sea ice,Historic data,Nimbus},
number = {3},
pages = {881--887},
title = {{Anomalous variability in Antarctic sea ice extents during the 1960s with the use of Nimbus data}},
volume = {7},
year = {2014}
}
@article{doi:10.1175/JCLI-D-12-00338.1,
abstract = {AbstractThe stationarity of relationships between local and remote climates is a necessary, yet implicit, assumption underlying many paleoclimate reconstructions. However, the assumption is tenuous for many seasonal relationships between interannual variations in the El Ni{\~{n}}o–Southern Oscillation (ENSO) and the southern annular mode (SAM) and Australasian precipitation and mean temperatures. Nonstationary statistical relationships between local and remote climates on the 31–71-yr time scale, defined as a change in their strength and/or phase outside that expected from local climate noise, are detected on near-centennial time scales from instrumental data, climate model simulations, and paleoclimate proxies.The relationships between ENSO and SAM and Australasian precipitation were nonstationary at 21{\%}–37{\%} of Australasian stations from 1900 to 2009 and strongly covaried, suggesting common modulation. Control simulations from three coupled climate models produce ENSO-like and SAM-like patterns of variability, but differ in detail to the observed patterns in Australasia. However, the model teleconnections also display nonstationarity, in some cases for over 50{\%} of the domain. Therefore, nonstationary local–remote climatic relationships are inherent in environments regulated by internal variability. The assessments using paleoclimate reconstructions are not robust because of extraneous noise associated with the paleoclimate proxies.Instrumental records provide the only means of calibrating and evaluating regional paleoclimate reconstructions. However, the length of Australasian instrumental observations may be too short to capture the near-centennial-scale variations in local–remote climatic relationships, potentially compromising these reconstructions. The uncertainty surrounding nonstationary teleconnections must be acknowledged and quantified. This should include interpreting nonstationarities in paleoclimate reconstructions using physically based frameworks.},
author = {Gallant, Ailie J E and Phipps, Steven J and Karoly, David J and Mullan, A Brett and Lorrey, Andrew M},
doi = {10.1175/JCLI-D-12-00338.1},
journal = {Journal of Climate},
number = {22},
pages = {8827--8849},
title = {{Nonstationary Australasian Teleconnections and Implications for Paleoclimate Reconstructions}},
url = {https://doi.org/10.1175/JCLI-D-12-00338.1},
volume = {26},
year = {2013}
}
@article{Gao2015,
author = {Gao, Pan and Xu, Xiaohua and Zhang, Xiaohong},
doi = {10.1109/TGRS.2015.2449338},
issn = {0196-2892},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
month = {dec},
number = {12},
pages = {6813--6822},
title = {{Characteristics of the Trends in the Global Tropopause Estimated From COSMIC Radio Occultation Data}},
url = {http://ieeexplore.ieee.org/document/7156128/},
volume = {53},
year = {2015}
}
@article{Gao2019,
abstract = {The global vegetation greening trend in the past three decades has been detected from satellite observations, but few studies focused on agricultural greening. We used two long-term satellite LAI datasets and statistical methods to verify a significant greening trend in global cropland from 1982 to 2015. Agricultural greening trends [6.55 ± 1.38 (10−3 m2 m−2yr−1)] are more than twice that of natural vegetation [3.15 ± 0.89 (10−3 m2 m−2yr−1)] within the key agricultural zone in the Northern Hemisphere (10 °N–50 °N). Agricultural greening contributes near one-third (27.4{\%} ± 4.3{\%}) of Northern Hemisphere greening. In less developed regions (Asia, South America, and Africa), the primary reasons for agricultural greening are cropland expansion and cropping systems reforming in a way that extends growing seasons, whereas in developed regions (North America, Australia and Europe) these are agricultural intensification (Green Revolution). Agricultural greening trends in less developed regions are greater than in developed regions. Agricultural intensification is accompanied by cropland decreases within developed regions, whereas this is accompanied by cropland expansion in less developed regions, which is different from previous conclusions that “agricultural intensification was not generally accompanied by decline or stasis in cropland area.” Our results suggest that global cropland is experiencing significant eco-environmental changes. The roles that agricultural greening plays in global environmental and climatic changes are worthy of further research.},
author = {Gao, Xueyuan and Liang, Shunlin and He, Bin},
doi = {10.1016/j.agrformet.2019.107652},
issn = {01681923},
journal = {Agricultural and Forest Meteorology},
month = {oct},
pages = {107652},
title = {{Detected global agricultural greening from satellite data}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192319302606},
volume = {276-277},
year = {2019}
}
@article{Garfinkel2015,
abstract = {Comprehensive chemistry-climate model experiments and observational data are used to show that up to half of the satellite era early springtime cooling trend in the Arctic lower stratosphere was caused by changing sea surface temperatures (SSTs). An ensemble of experiments forced only by changing SSTs is compared to an ensemble of experiments in which both the observed SSTs and chemically and radiatively active trace species are changing. By comparing the two ensembles, it is shown that warming of Indian Ocean, North Pacific, and North Atlantic SSTs and cooling of the tropical Pacific have strongly contributed to recent polar stratospheric cooling in late winter and early spring.When concentrations of ozone-depleting substances and greenhouse gases are fixed, polar ozone concentrations show a small but robust decline due to changing SSTs. Ozone loss is larger in the presence of changing concentrations of ozone-depleting substances and greenhouse gases. The stratospheric changes can be understood by examining the tropospheric height and heat flux anomalies generated by the anomalous SSTs. Finally, recent SST changes have},
author = {Garfinkel, C. I. and Hurwitz, M. M. and Oman, L. D.},
doi = {10.1002/2015JD023284},
isbn = {2169-897x},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jun},
number = {11},
pages = {5404--5416},
title = {{Effect of recent sea surface temperature trends on the Arctic stratospheric vortex}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015JD023284},
volume = {120},
year = {2015}
}
@article{Garfinkel2017,
abstract = {The recent hiatus in global-mean surface temperature warming was characterized by a Eurasian winter cooling trend, and the cause(s) for this cooling is unclear. Here we show that the observed hiatus in Eurasian warming was associated with a recent trend toward weakened stratospheric polar vortices. Specifically, by calculating the change in Eurasian surface air temperature associated with a given vortex weakening, we demonstrate that the recent trend toward weakened polar vortices reduced the anticipated Eurasian warming due to increasing greenhouse gas concentrations. Those model integrations whose stratospheric vortex evolution most closely matches that in reanalysis data also simulate a hiatus. While it is unclear whether the recent weakening of the midwinter stratospheric polar vortex was forced, a properly configured model can simulate substantial deviations of the polar vortex on decadal timescales and hence such hiatus events, implying that similar hiatus events may recur even as greenhouse gas concentrations rise.},
author = {Garfinkel, Chaim I. and Son, Seok Woo and Song, Kanghyun and Aquila, Valentina and Oman, Luke D.},
doi = {10.1002/2016GL072035},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {1},
pages = {374--382},
title = {{Stratospheric variability contributed to and sustained the recent hiatus in Eurasian winter warming}},
volume = {44},
year = {2017}
}
@article{Garfinkel2018,
author = {Garfinkel, C I and Gordon, A and Oman, L D and Li, F and Davis, S and Pawson, S},
doi = {10.5194/acp-18-4597-2018},
journal = {Atmospheric Chemistry and Physics},
number = {7},
pages = {4597--4615},
title = {{Nonlinear response of tropical lower-stratospheric temperature and water vapor to ENSO}},
volume = {18},
year = {2018}
}
@article{Garfinkel2015e,
author = {Garfinkel, Chaim I and Waugh, Darryn W and Polvani, Lorenzo M},
doi = {10.1002/2015GL066942},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {10.1002/2015GL066942 and Hadley Cell,chemistry-climate interactions,climate change},
month = {dec},
number = {24},
pages = {10824--10831},
title = {{Recent Hadley cell expansion: The role of internal atmospheric variability in reconciling modeled and observed trends}},
url = {http://doi.wiley.com/10.1002/2015GL066942},
volume = {42},
year = {2015}
}
@article{Garonna2014,
abstract = {Land Surface Phenology (LSP) is the most direct representation of intra-annual dynamics of vegetated land surfaces as observed from satellite imagery. LSP plays a key role in characterizing land-surface fluxes, and is central to accurately parameterizing terrestrial biosphere-atmosphere interactions, as well as climate models. In this paper we present an evaluation of Pan-European LSP and its changes over the past 30 years, using the longest continuous record of Normalized Difference Vegetation Index (NDVI) available to date in combination with a landscape-based aggregation scheme. We used indicators of Start-Of-Season, End-Of-Season and Growing Season Length (SOS, EOS and GSL, respectively) for the period 1982-2011 to test for temporal trends in activity of terrestrial vegetation and their spatial distribution. We aggregated pixels into ecologically representative spatial units using the European Landscape Classification (LANMAP) and assessed the relative contribution of spring and autumn phenology. GSL increased significantly by 18-24 days/decade over 18-30{\%} of the land area of Europe, depending on methodology. This trend varied extensively within and between climatic zones and landscape classes. The areas of greatest growing-season lengthening were the Continental and Boreal zones, with hotspots concentrated in southern Fennoscandia, Western Russia and pockets of continental Europe. For the Atlantic and Steppic zones, we found an average shortening of the growing season with hotspots in Western France, the Po valley, and around the Caspian Sea. In many zones, changes in the NDVI-derived end-of-season contributed more to the GSL trend than changes in spring green-up, resulting in asymmetric trends. This underlines the importance of investigating senescence and its underlying processes more closely as a driver of LSP and global change. This article is protected by copyright. All rights reserved.},
author = {Garonna, Irene and de Jong, Rogier and de Wit, Allard J.W. and M{\"{u}}cher, Caspar A. and Schmid, Bernhard and Schaepman, Michael E.},
doi = {10.1111/gcb.12625},
isbn = {1365-2486},
issn = {13652486},
journal = {Global Change Biology},
keywords = {Asymmetric trends,GIMMS,Growing season length,Land surface phenology,Spring vs. autumn phenology,Vegetation activity},
number = {11},
pages = {3457--3470},
pmid = {24797086},
title = {{Strong contribution of autumn phenology to changes in satellite-derived growing season length estimates across Europe (1982–2011)}},
volume = {20},
year = {2014}
}
@article{Garonna2016,
abstract = {Monitoring land surface phenology (LSP) is important for understanding both the responses and feedbacks of ecosystems to the climate system, and for representing these accurately in terrestrial biosphere models. Moreover, by shedding light on phenological trends at a variety of scales, LSP provides the potential to fill the gap between traditional phenological (field) observations and the large-scale view of global models. In this study, we review and evaluate the variability and evolution of satellite-derived growing season length (GSL) globally and over the past three decades. We used the longest continuous record of Normalized Difference Vegetation Index data available to date at global scale to derive LSP metrics consistently over all vegetated land areas and for the period 1982-2012. We tested GSL, start- and end-of-season metrics (SOS and EOS, respectively) for linear trends as well as for significant trend shifts over the study period. We evaluated trends using global environmental stratification information in place of commonly used land cover maps to avoid circular findings. Our results confirmed an average lengthening of the growing season globally during 1982-2012 - averaging 0.22-0.34 days yr(-1) , but with spatially heterogeneous trends. About 13-19{\%} of global land areas displayed significant GSL change, and over 30{\%} of trends occurred in the boreal/alpine biome of the Northern Hemisphere, which showed diverging GSL evolution over the past three decades. Within this biome, the 'Cold and Mesic' environmental zone appeared as an LSP change hotspot. We also examined the relative contribution of SOS and EOS to the overall changes, finding that EOS trends were generally stronger and more prevalent than SOS trends. These findings constitute a step towards the identification of large-scale phenological drivers of vegetated land surfaces, necessary for improving phenological representation in terrestrial biosphere models.},
author = {Garonna, Irene and de Jong, Rogier and Schaepman, Michael E.},
doi = {10.1111/gcb.13168},
issn = {13652486},
journal = {Global Change Biology},
keywords = {GIMMS 3g,Growing season length,Land surface phenology,Spring and autumn phenology,Vegetation activity},
number = {4},
pages = {1456--1468},
title = {{Variability and evolution of global land surface phenology over the past three decades (1982–2012)}},
volume = {22},
year = {2016}
}
@article{doi:10.1029/2018JC014225,
abstract = {Abstract We construct a novel framework to investigate the uncertainties and biases associated with estimates of deep ocean temperature change from hydrographic sections and demonstrate this framework in an eddy-permitting ocean model. Biases in estimates from observations arise due to sparse spatial coverage (few sections in a basin), low frequency of occupations (typically 5–10 years apart), mismatches between the time period of interest and span of occupations, and from seasonal biases relating to the practicalities of sampling during certain times of year. Between the years 1990 and 2010, the modeled global abyssal ocean biases are small, although regionally some biases (expressed as a heat flux into the 4,000- to 6,000-m layer) can be up to 0.05 W/m2. In this model, biases in the heat flux into the deep 2,000- to 4,000-m layer, due to either temporal or spatial sampling uncertainties, are typically much larger and can be over 0.1 W/m2 across an ocean. Overall, 82{\%} of the warming trend deeper than 2,000 m is captured by hydrographic section-style sampling in the model. At 2,000 m, only half the model global warming trend is obtained from observational-style sampling, with large biases in the Atlantic, Southern, and Indian Oceans. Biases due to different sources of uncertainty can have opposing signs and differ in relative importance both regionally and with depth, revealing the importance of reducing temporal and spatial uncertainties in future deep ocean observing design.},
author = {Garry, F K and McDonagh, E L and Blaker, A T and Roberts, C D and Desbruy{\`{e}}res, D G and Frajka-Williams, E and King, B A},
doi = {10.1029/2018JC014225},
journal = {Journal of Geophysical Research: Oceans},
keywords = {decadal variability,deep oceans,observational uncertainties,ocean heat content,ocean modeling,temperature trends},
number = {2},
pages = {1155--1169},
title = {{Model-Derived Uncertainties in Deep Ocean Temperature Trends Between 1990 and 2010}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC014225},
volume = {124},
year = {2019}
}
@article{Gaudel2020,
author = {Gaudel, A. and Cooper, O. R. and Chang, K.-L. and Bourgeois, Ilann and Ziemke, Jerry R. and Strode, Sarah A. and Oman, L. D. and Sellitto, P. and Nedelec, Philippe and Blot, Romain and Thouret, Valerie and Granier, Claire},
doi = {10.1126/sciadv.aba8272},
journal = {Science Advances},
number = {34},
pages = {eaba8272},
title = {{Aircraft observations since the 1990s reveal increases of tropospheric ozone at multiple locations across the Northern Hemisphere}},
volume = {6},
year = {2020}
}
@article{Gautier2019,
abstract = {High quality records of stratospheric volcanic eruptions, required to model past climate variability, have been constructed by identifying synchronous (bipolar) volcanic sulfate horizons in Greenland and Antarctic ice cores. Here we present a new 2600-year chronology of stratospheric volcanic events using an independent approach that relies on isotopic signatures ($\Delta$33S and in some cases $\Delta$17O) of ice core sulfate from five closely-located ice cores from Dome C, Antarctica. The Dome C stratospheric reconstruction provides independent validation of prior reconstructions. The isotopic approach documents several high-latitude stratospheric events that are not bipolar, but climatically-relevant, and diverges deeper in the record revealing tropospheric signals for some previously assigned bipolar events. Our record also displays a collapse of the $\Delta$17O anomaly of sulfate for the largest volcanic eruptions, showing a further change in atmospheric chemistry induced by large emissions. Thus, the refinement added by considering both isotopic and bipolar correlation methods provides additional levels of insight for climate-volcano connections and improves ice core volcanic reconstructions.},
author = {Gautier, E and Savarino, J and Hoek, J and Erbland, J and Caillon, N and Hattori, S and Yoshida, N and Albalat, E and Albarede, F and Farquhar, J},
doi = {10.1038/s41467-019-08357-0},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {466},
title = {2600-years of stratospheric volcanism through sulfate isotopes},
url = {https://doi.org/10.1038/s41467-019-08357-0},
volume = {10},
year = {2019}
}
@article{Gebbie70,
abstract = {Earth{\{}$\backslash$textquoteright{\}}s climate cooled considerably across the transition from the Medieval Warm Period to the Little Ice Age about 700 years ago. Theoretically, owing to how the ocean circulates, this cooling should be recorded in Pacific deep-ocean temperatures, where water that was on the surface then is found today. Gebbie and Huybers used an ocean circulation model and observations from both the end of the 19th century and the end of the 20th century to detect and quantify this trend. The ongoing deep Pacific is cooling, which revises Earth{\{}$\backslash$textquoteright{\}}s overall heat budget since 1750 downward by 35{\%}.Science, this issue p. 70Proxy records show that before the onset of modern anthropogenic warming, globally coherent cooling occurred from the Medieval Warm Period to the Little Ice Age. The long memory of the ocean suggests that these historical surface anomalies are associated with ongoing deep-ocean temperature adjustments. Combining an ocean model with modern and paleoceanographic data leads to a prediction that the deep Pacific is still adjusting to the cooling going into the Little Ice Age, whereas temperature trends in the surface ocean and deep Atlantic reflect modern warming. This prediction is corroborated by temperature changes identified between the HMS Challenger expedition of the 1870s and modern hydrography. The implied heat loss in the deep ocean since 1750 CE offsets one-fourth of the global heat gain in the upper ocean.},
author = {Gebbie, G and Huybers, P},
doi = {10.1126/science.aar8413},
issn = {0036-8075},
journal = {Science},
number = {6422},
pages = {70--74},
publisher = {American Association for the Advancement of Science},
title = {{The Little Ice Age and 20th-century deep Pacific cooling}},
url = {https://science.sciencemag.org/content/363/6422/70},
volume = {363},
year = {2019}
}
@article{Gebbie2014,
abstract = {Observations of $\delta$13C and Cd/Ca from benthic foraminifera have been interpreted to reflect a shoaling of northern source waters by about 1000 m during the Last Glacial Maximum, with the degree of shoaling being significant enough for the water mass to be renamed Glacial North Atlantic Intermediate Water. These nutrient tracers, however, may not solely reflect changes in water mass distributions. To quantify the distribution of Glacial North Atlantic Water, we perform a glacial water mass decomposition where the sparsity of data, geometrical constraints, and nonconservative tracer effects are taken into account, and the extrapolation for the unknown water mass end-members is guided by the modern-day circulation. Under the assumption that the glacial sources of remineralized material are similar to that of the modern day, we find a steady solution consistent with 241 $\delta$13C, 87 Cd/Ca, and 174 $\delta$18O observations and their respective uncertainties. The water mass decomposition indicates that the core of Glacial North Atlantic Water shoals and southern source water extends in greater quantities into the abyssal North Atlantic, as previously inferred. The depth of the deep northern-southern water mass interface and the volume of North Atlantic Water, however, are not grossly different from that of the modern day. Under this scenario, the vertical structure of glacial $\delta$13C and Cd/Ca is primarily due to the greater accumulation of nutrients in lower North Atlantic Water, which may be a signal of the hoarding of excess carbon from the atmosphere by the glacial Atlantic.},
annote = {doi: 10.1002/2013PA002557},
author = {Gebbie, Geoffrey},
doi = {10.1002/2013PA002557},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {Last Glacial Maximum,circulation variability,inverse methods,remineralization,tracer distributions,water mass geometry},
month = {mar},
number = {3},
pages = {190--209},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{How much did Glacial North Atlantic Water shoal?}},
url = {https://doi.org/10.1002/2013PA002557},
volume = {29},
year = {2014}
}
@article{doi:10.1146/annurev-marine-010419-010844,
abstract = { Monitoring Earth's energy imbalance requires monitoring changes in the heat content of the ocean. Recent observational estimates indicate that ocean heat uptake is accelerating in the twenty-first century. Examination of estimates of ocean heat uptake over the industrial era, the Common Era of the last 2,000 years, and the period since the Last Glacial Maximum, 20,000 years ago, permits a wide perspective on modern-day warming rates. In addition, this longer-term focus illustrates how the dynamics of the deep ocean and the cryosphere were active in the past and are still active today. The large climatic shifts that started with the melting of the great ice sheets have involved significant ocean heat uptake that was sustained over centuries and millennia, and modern-ocean heat content changes are small by comparison. },
annote = {PMID: 32928022},
author = {Gebbie, Geoffrey},
doi = {10.1146/annurev-marine-010419-010844},
journal = {Annual Review of Marine Science},
number = {1},
pages = {255--281},
title = {{Combining Modern and Paleoceanographic Perspectives on Ocean Heat Uptake}},
url = {https://doi.org/10.1146/annurev-marine-010419-010844},
volume = {13},
year = {2021}
}
@article{DOI: 10.1080/1755876X.2020.1785097,
author = {Gehlen, Marion and Chau, Thi Tuyet Trang and Conchon, Anna and Denvil-Sommer, Anna and Chevallier, Fr{\'{e}}d{\'{e}}ric and Vrac, Mathieu and Mejia, Carlos},
doi = {10.1080/1755876X.2020.1785097},
journal = {Journal of Operational Oceanography},
number = {sup1},
pages = {S64--S67},
title = {{Ocean acidification [in “Copernicus Marine Service Ocean State Report, Issue 4”]}},
volume = {13},
year = {2020}
}
@article{doi:10.1175/JCLI-D-16-0758.1,
abstract = {AbstractThe Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), is the latest atmospheric reanalysis of the modern satellite era produced by NASA's Global Modeling and Assimilation Office (GMAO). MERRA-2 assimilates observation types not available to its predecessor, MERRA, and includes updates to the Goddard Earth Observing System (GEOS) model and analysis scheme so as to provide a viable ongoing climate analysis beyond MERRA's terminus. While addressing known limitations of MERRA, MERRA-2 is also intended to be a development milestone for a future integrated Earth system analysis (IESA) currently under development at GMAO. This paper provides an overview of the MERRA-2 system and various performance metrics. Among the advances in MERRA-2 relevant to IESA are the assimilation of aerosol observations, several improvements to the representation of the stratosphere including ozone, and improved representations of cryospheric processes. Other improvements in the quality of MERRA-2 compared with MERRA include the reduction of some spurious trends and jumps related to changes in the observing system and reduced biases and imbalances in aspects of the water cycle. Remaining deficiencies are also identified. Production of MERRA-2 began in June 2014 in four processing streams and converged to a single near-real-time stream in mid-2015. MERRA-2 products are accessible online through the NASA Goddard Earth Sciences Data Information Services Center (GES DISC).},
author = {Gelaro, Ronald and McCarty, Will and Su{\'{a}}rez, Max J and Todling, Ricardo and Molod, Andrea and Takacs, Lawrence and Randles, Cynthia A and Darmenov, Anton and Bosilovich, Michael G and Reichle, Rolf and Wargan, Krzysztof and Coy, Lawrence and Cullather, Richard and Draper, Clara and Akella, Santha and Buchard, Virginie and Conaty, Austin and da Silva, Arlindo M and Gu, Wei and Kim, Gi-Kong and Koster, Randal and Lucchesi, Robert and Merkova, Dagmar and Nielsen, Jon Eric and Partyka, Gary and Pawson, Steven and Putman, William and Rienecker, Michele and Schubert, Siegfried D and Sienkiewicz, Meta and Zhao, Bin},
doi = {10.1175/JCLI-D-16-0758.1},
journal = {Journal of Climate},
number = {14},
pages = {5419--5454},
title = {{The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)}},
url = {https://doi.org/10.1175/JCLI-D-16-0758.1},
volume = {30},
year = {2017}
}
@article{Georgoulias2016,
abstract = {Abstract. This study characterizes the spatiotemporal variability and relative contribution of different types of aerosols to the aerosol optical depth (AOD) over the Eastern Mediterranean as derived from MODIS (Moderate Resolution Imaging Spectroradiometer) Terra (March 2000–December 2012) and Aqua (July 2002–December 2012) satellite instruments. For this purpose, a 0.1° × 0.1° gridded MODIS dataset was compiled and validated against sun photometric observations from the AErosol RObotic NETwork (AERONET). The high spatial resolution and long temporal coverage of the dataset allows for the determination of local hot spots like megacities, medium-sized cities, industrial zones and power plant complexes, seasonal variabilities and decadal averages. The average AOD at 550 nm (AOD550) for the entire region is ∼ 0.22 ± 0.19, with maximum values in summer and seasonal variabilities that can be attributed to precipitation, photochemical production of secondary organic aerosols, transport of pollution and smoke from biomass burning in central and eastern Europe and transport of dust from the Sahara and the Middle East. The MODIS data were analyzed together with data from other satellite sensors, reanalysis projects and a chemistry–aerosol-transport model using an optimized algorithm tailored for the region and capable of estimating the contribution of different aerosol types to the total AOD550. The spatial and temporal variability of anthropogenic, dust and fine-mode natural aerosols over land and anthropogenic, dust and marine aerosols over the sea is examined. The relative contribution of the different aerosol types to the total AOD550 exhibits a low/high seasonal variability over land/sea areas, respectively. Overall, anthropogenic aerosols, dust and fine-mode natural aerosols account for ∼ 51, ∼ 34 and ∼ 15 {\%} of the total AOD550 over land, while, anthropogenic aerosols, dust and marine aerosols account ∼ 40, ∼ 34 and ∼ 26 {\%} of the total AOD550 over the sea, based on MODIS Terra and Aqua observations.},
author = {Georgoulias, Aristeidis K. and Alexandri, Georgia and Kourtidis, Konstantinos A. and Lelieveld, Jos and Zanis, Prodromos and P{\"{o}}schl, Ulrich and Levy, Robert and Amiridis, Vassilis and Marinou, Eleni and Tsikerdekis, Athanasios},
doi = {10.5194/acp-16-13853-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {nov},
number = {21},
pages = {13853--13884},
title = {{Spatiotemporal variability and contribution of different aerosol types to the aerosol optical depth over the Eastern Mediterranean}},
url = {https://www.atmos-chem-phys.net/16/13853/2016/},
volume = {16},
year = {2016}
}
@article{Gergis2009,
abstract = {Reconstructions of past climate are important for providing a historical context for evaluating the nature of 20th century climate change. Here, a number of percentile-based palaeoclimate reconstructions were used to isolate signals of both phases of El Ni{\~{n}}o--Southern Oscillation (ENSO). A total of 92 (82) El Ni{\~{n}}o (La Ni{\~{n}}a) events were reconstructed since A.D. 1525. Significantly, we introduce the most comprehensive La Ni{\~{n}}a event record compiled to date. This annual record of ENSO events can now be used for independent verification of climate model simulations, reconstructions of ENSO indices and as a chronological control for archaeologists/social scientists interested in human responses to past climate events. Although extreme ENSO events are seen throughout the 478-year ENSO reconstruction, approximately 43{\%} of extreme and 28{\%} of all protracted ENSO events (i.e. both El Ni{\~{n}}o and La Ni{\~{n}}a phase) occur in the 20th century. The post-1940 period alone accounts for 30{\%} of extreme ENSO years observed since A.D. 1525. These results suggest that ENSO may operate differently under natural (pre-industrial) and anthropogenic background states. As evidence of stresses on water supply, agriculture and natural ecosystems caused by climate change strengthens, studies into how ENSO will operate under global warming should be a global research priority.},
author = {Gergis, Jo{\"{e}}lle L and Fowler, Anthony M},
doi = {10.1007/s10584-008-9476-z},
issn = {1573-1480},
journal = {Climatic Change},
month = {feb},
number = {3},
pages = {343--387},
title = {{A history of ENSO events since A.D. 1525: implications for future climate change}},
url = {https://doi.org/10.1007/s10584-008-9476-z},
volume = {92},
year = {2009}
}
@article{Gertler2019,
abstract = {The circulation of the Northern Hemisphere extratropical troposphere has changed over recent decades, with marked decreases in extratropical cyclone activity and eddy kinetic energy (EKE) in summer and increases in the fraction of precipitation that is convective in all seasons. Decreasing EKE in summer is partly explained by a weakening meridional temperature gradient, but changes in vertical temperature gradients and increasing moisture also affect the mean available potential energy (MAPE), which is the energetic reservoir from which extratropical cyclones draw. Furthermore, the relation of changes in mean thermal structure and moisture to changes in convection associated with extratropical cyclones is poorly understood. Here we calculate trends in MAPE for the Northern extratropics in summer over the years 1979–2017, and we decompose MAPE into both convective and nonconvective components. Nonconvective MAPE decreased over this period, consistent with decreases in EKE and extratropical cyclone activity, but convective MAPE increased, implying an increase in the energy available to convection. Calculations with idealized atmospheres indicate that nonconvective and convective MAPE both increase with increasing mean surface temperature and decrease with decreasing meridional surface temperature gradient, but convective MAPE is relatively more sensitive to the increase in mean surface temperature. These results connect changes in the atmospheric mean state with changes in both large-scale and convective circulations, and they suggest that extratropical cyclones can weaken even as their associated convection becomes more energetic.},
author = {Gertler, Charles G and O'Gorman, Paul A.},
doi = {10.1073/pnas.1812312116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {10},
pages = {4105--4110},
title = {{Changing available energy for extratropical cyclones and associated convection in Northern Hemisphere summer}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1812312116},
volume = {116},
year = {2019}
}
@article{Ghiggi2019a,
abstract = {Abstract. Freshwater resources are of high societal relevance and understanding their past variability is vital to water management in the context of current and future climatic change. This study introduces a global gridded monthly reconstruction of runoff covering the period from 1902 to 2014. In-situ streamflow observations are used to train a machine learning algorithm that predicts monthly runoff rates based on antecedent precipitation and temperature from an atmospheric reanalysis. The accuracy of this reconstruction is assessed with cross-validation and compared with an independent set of discharge observations for large river basins. The presented dataset agrees on average better with the streamflow observations than an ensemble of 13 state-of-the art global hydrological model runoff simulations. We estimate a global long-term mean runoff of 37{\&}thinsp;419{\&}thinsp;km3{\&}thinsp;yr{\&}minus;1 in agreement with previous assessments. The temporal coverage of the reconstruction offers an unprecedented view on large-scale features of runoff variability also in regions with limited data coverage, making it an ideal candidate for large-scale hydro-climatic process studies, water resources assessments and for evaluating and refining existing hydrological models. The paper closes with example applications fostering the understanding of global freshwater dynamics, interannual variability, drought propagation and the response of runoff to atmospheric teleconnections. The GRUN dataset is available from the ETHZ Research Collection at https://doi.org/10.3929/ethz-b-000324386 (Ghiggi et al., 2019).},
author = {Ghiggi, Gionata and Humphrey, Vincent and Seneviratne, Sonia I. and Gudmundsson, Lukas},
doi = {10.5194/essd-2019-32},
isbn = {1116552019},
issn = {1866-3591},
journal = {Earth System Science Data},
pages = {1655--1674},
title = {{GRUN: An observations-based global gridded runoff dataset from 1902 to 2014}},
volume = {11},
year = {2019}
}
@article{Ghimire2014,
abstract = {Widespread anthropogenic land-cover change over the last five centuries has influenced the global climate system through both biogeochemical and biophysical processes. Models indicate that warming from carbon emissions associated with land-cover conversion have been partially offset by cooling from elevated albedo, but considerable uncertainty remains partly because of uncertainty in model treatments of albedo. This study incorporates a new spatially and temporally explicit, land-cover specific albedo product derived from MODIS with a historical land-use dataset (Land Use Harmonization product) to provide more precise, observationally derived estimates of albedo impacts from anthropogenic land-cover change with a complete range of dataset specific uncertainty. The mean annual global albedo increase due to land-cover change during 1700–2005 was estimated as 0.00106 ± 0.00008 (mean ± standard deviation), mainly driven by snow exposure due to land-cover transitions from natural vegetation to agriculture. This translates to a top-of-atmosphere (TOA) radiative cooling of −0.15 ± 0.1 W m−2 (mean ± standard deviation). Our estimate was in the middle of the IPCC AR5 range of −0.05 to −0.25 W m−2, and incorporates variability in albedo within land-cover classes.},
author = {Ghimire, Bardan and Williams, Christopher A. and Masek, Jeffrey and Gao, Feng and Wang, Zhuosen and Schaaf, Crystal and He, Tao},
doi = {10.1002/2014GL061671},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {MODIS,albedo,global climate system,land cover change,radiative forcing},
number = {24},
pages = {9087--9096},
title = {{Global albedo change and radiative cooling from anthropogenic land cover change, 1700 to 2005 based on MODIS, land use harmonization, radiative kernels, and reanalysis}},
volume = {41},
year = {2014}
}
@article{Gibson-Reinemer2015,
abstract = {Climate in part determines species' distributions, and species' distributions are shifting in response to climate change. Strong correlations between the magnitude of temperature changes and the extent of range shifts point to warming temperatures as the single most influential factor causing shifts in species' distributions species. However, other abiotic and biotic factors may alter or even reverse these patterns. The importance of temperature relative to these other factors can be evaluated by examining range shifts of the same species in different geographic areas. When the same species experience warming in different geographic areas, the extent to which they show range shifts that are similar in direction and magnitude is a measure of temperature's importance. We analyzed published studies to identify species that have documented range shifts in separate areas. For 273 species of plants, birds, mammals, and marine invertebrates with range shifts measured in multiple geographic areas, 42-50{\%} show inconsistency in the direction of their range shifts, despite experiencing similar warming trends. Inconsistency of within-species range shifts highlights how biotic interactions and local, non-thermal abiotic conditions may often supersede the direct physiological effects of temperature. Assemblages show consistent responses to climate change, but this predictability does not appear to extend to species considered individually.},
author = {Gibson-Reinemer, Daniel K. and Rahel, Frank J.},
doi = {10.1371/journal.pone.0132103},
issn = {19326203},
journal = {PLOS ONE},
number = {7},
pages = {e0132103},
title = {{Inconsistent range shifts within species highlight idiosyncratic responses to climate warming}},
volume = {10},
year = {2015}
}
@article{Gibson-Reinemer2015a,
abstract = {Recent decades have seen substantial changes in patterns of biodiversity worldwide. Simultaneously, climate change is producing a widespread pattern of species' range shifts to higher latitudes and higher elevations, potentially creating novel assemblages as species shift at different rates. However, the direct link between species' turnover as a result of climate-induced range shifts has not yet been empirically evaluated. We measured rates of species turnover associated with species' range shifts in relatively undisturbed montane areas in Asia, Europe, North America, South America, and the Indo-Pacific. We show that species turnover is rapidly creating novel assemblages, and this can be explained by variable changes in species' range limits following warming. Across all the areas we analyzed, mean species' turnover was 12{\%} per decade, which was nearly balanced between the loss of existing co-occurrences and the gain of novel co-occurrences. Turnover appears to be more rapid among ectothermic assemblages, and some evidence suggests tropical assemblages may be responding at more rapid rates than temperate assemblages.},
author = {Gibson-Reinemer, Daniel K. and Sheldon, Kimberly S. and Rahel, Frank J.},
doi = {10.1002/ece3.1518},
issn = {20457758},
journal = {Ecology and Evolution},
keywords = {Climate change,Disassembly,Range shift,Species' distributions,Species' turnover},
number = {12},
pages = {2340--2347},
title = {{Climate change creates rapid species turnover in montane communities}},
volume = {5},
year = {2015}
}
@article{doi:10.1029/2010JC006695,
abstract = {A new ocean reanalysis that covers the period from 1871 to 2008 is used to explore the time-evolving characteristics of El Ni{\~{n}}o. The new reanalysis assimilates all available hydrographic and sea surface temperature data into a model of the global ocean forced with surface boundary conditions from an atmospheric reanalysis that also covers the period from 1871 through 2008. Using traditional measures of El Ni{\~{n}}o, our reanalysis shows that the timing of El Ni{\~{n}}o events is in agreement with sea surface temperature reconstructions, but El Ni{\~{n}}o in the reanalysis is stronger, particularly from 1871 to 1920. A new index based on the first moment of the temperature anomaly is introduced. The new index is used to characterize the strength and location of El Ni{\~{n}}o events and has the advantage that it is independent of the location of El Ni{\~{n}}o. Using the new index, El Ni{\~{n}}o in the reanalysis shows prominent decadal variability of strength but relatively little long-term trend. El Ni{\~{n}}o events were strong in the last part of the 19th century and first part of the 20th century and again in the latter part of the 20th century, with weak El Ni{\~{n}}o events in the middle of the 20th century. The location of El Ni{\~{n}}o also varies considerably, ranging from the western to the eastern Pacific near the coast of South America. However, the null hypothesis that the location of El Ni{\~{n}}o can be represented as a random distribution about a central longitude of about 140°W cannot be rejected.},
author = {Giese, Benjamin S and Ray, Sulagna},
doi = {10.1029/2010JC006695},
journal = {Journal of Geophysical Research: Oceans},
keywords = {El Ni{\~{n}}o,decadal variability,ocean reanalysis},
number = {C2},
title = {{El Ni{\~{n}}o variability in simple ocean data assimilation (SODA), 1871–2008}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010JC006695},
volume = {116},
year = {2011}
}
@article{Gillett2021b,
abstract = {Parties to the Paris Agreement agreed to holding global average temperature increases “well below 2 °C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 °C above pre-industrial levels”. Monitoring the contributions of human-induced climate forcings to warming so far is key to understanding progress towards these goals. Here we use climate model simulations from the Detection and Attribution Model Intercomparison Project, as well as regularized optimal fingerprinting, to show that anthropogenic forcings caused 0.9 to 1.3 °C of warming in global mean near-surface air temperature in 2010–2019 relative to 1850–1900, compared with an observed warming of 1.1 °C. Greenhouse gases and aerosols contributed changes of 1.2 to 1.9 °C and −0.7 to −0.1 °C, respectively, and natural forcings contributed negligibly. These results demonstrate the substantial human influence on climate so far and the urgency of action needed to meet the Paris Agreement goals.},
author = {Gillett, Nathan P and Kirchmeier-Young, Megan and Ribes, Aur{\'{e}}lien and Shiogama, Hideo and Hegerl, Gabriele C and Knutti, Reto and Gastineau, Guillaume and John, Jasmin G and Li, Lijuan and Nazarenko, Larissa and Rosenbloom, Nan and Seland, {\O}yvind and Wu, Tongwen and Yukimoto, Seiji and Ziehn, Tilo},
doi = {10.1038/s41558-020-00965-9},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {mar},
number = {3},
pages = {207--212},
title = {{Constraining human contributions to observed warming since the pre-industrial period}},
url = {https://doi.org/10.1038/s41558-020-00965-9 http://www.nature.com/articles/s41558-020-00965-9},
volume = {11},
year = {2021}
}
@article{doi:10.1029/2018PA003379,
abstract = {Abstract The Paleocene-Eocene thermal maximum (PETM) was caused by a massive release of carbon to the atmosphere. This is a benchmark global greenhouse warming event that raised temperatures to their warmest since extinction of the dinosaurs. Rates of carbon emission today can be compared to those during onset of the PETM in two ways: (1) projection of long-term PETM rates for comparison on an annual time scale; and (2) projection of short-term modern rates for comparison on a PETM time scale. Both require temporal scaling and extrapolation for comparison on the same time scale. PETM rates are few and projection to a short time scale is poorly constrained. Modern rates are many and projection to a longer PETM time scale is tightly constrained — modern rates are some 9–10 times higher than those during onset of the PETM. If the present trend of anthropogenic emissions continues, we can expect to reach a PETM-scale accumulation of atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human generations).},
author = {Gingerich, Philip D},
doi = {10.1029/2018PA003379},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Carbon emissions,PETM,Temporal scaling},
number = {3},
pages = {329--335},
title = {{Temporal Scaling of Carbon Emission and Accumulation Rates: Modern Anthropogenic Emissions Compared to Estimates of PETM-Onset Accumulation}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018PA003379},
volume = {34},
year = {2019}
}
@article{Gladyshev2016,
abstract = {The anomalous thermohaline properties of the core of the Labrador Sea water (LSW), a product of winter convection resulted from the ocean–winter interaction, which were recorded in the Irminger Sea in 2014 and 2015, are discussed. It is found that, in the summer of 2015, the LSW filled the entire deepwater basin in the south of the sea down to a depth of 1300 m over the periphery of the Irminger gyral, and down to a depth of 1800 m, in the anticyclone eddy formed in early June of 2015. The maximum density of the LSW core here was 27.75 $\sigma$$\theta$. Such deep and intense winter convection in the Irminger Sea was last recorded 20 years ago. As a result, the temperature of the LSW dropped to values observed in the years 2002 and 2007, but its average salinity remained high. The LSW that have been formed in recent years are reported to have great amplitude and nonmonotonic variability of the properties.},
author = {Gladyshev, S V and Gladyshev, V S and Gulev, S K and Sokov, A V},
doi = {10.1134/S1028334X16070229},
issn = {1531-8354},
journal = {Doklady Earth Sciences},
number = {1},
pages = {766--770},
title = {{Anomalously deep convection in the Irminger Sea during the winter of 2014–2015}},
url = {https://doi.org/10.1134/S1028334X16070229},
volume = {469},
year = {2016}
}
@article{Gobron2018a,
author = {Gobron, N.},
doi = {10.1175/2018BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
pages = {S62--S63},
title = {{Terrestrial Vegetation Activity [in “State of the Climate in 2017”]}},
volume = {99},
year = {2018}
}
@article{Goelzer2016,
abstract = {As the most recent warm period in Earth's history with a sea-level stand higher than present, the Last Interglacial period ({\~{}}130 to 115 kyr BP) is often considered a prime example to study the impact of a warmer climate on the two polar ice sheets remaining today. Here we simulate the Last Interglacial climate, ice sheet and sea-level evolution with the Earth system model of intermediate complexity LOVECLIM v.1.3, which includes dynamic and fully-coupled components representing the atmosphere, the ocean and sea ice, the terrestrial biosphere and the Greenland and Antarctic ice sheets. In this set-up, sea-level evolution and climate-ice sheet interactions are modelled in a consistent framework. Surface mass balance changes are the dominant forcing for the Greenland ice sheet, which shows a peak sea-level contribution of 1.4 m at 123 kyr BP in the reference experiment. Our results indicate that ice sheet-climate feedbacks play an important role to amplify climate and sea-level changes in the Northern Hemisphere. The sensitivity of the Greenland ice sheet to surface temperature changes considerably increases when interactive albedo changes are considered. Southern Hemisphere polar and sub-polar ocean warming is limited throughout the Last Interglacial and surface and sub-shelf melting exerts only a minor control on the Antarctic sea-level contribution with a peak of 4.4 m at 125 kyr BP. Retreat of the Antarctic ice sheet at the onset of the LIG is mainly forced by rising sea-level and reduced ice shelf viscosity as the surface temperature increases. Global sea level shows a peak of 5.3 m at 124.5 kyr BP, which includes a minor contribution of 0.35 m from oceanic thermal expansion. Neither the individual contributions nor the total modelled sea-level stand show multi millennial time scale variations as indicated by some reconstructions},
author = {Goelzer, Heiko and Huybrechts, Philippe and Loutre, Marie-France and Fichefet, Thierry},
doi = {10.5194/cp-12-2195-2016},
issn = {1814-9332},
journal = {Climate of the Past},
month = {dec},
number = {12},
pages = {2195--2213},
publisher = {Copernicus Publications},
title = {{Last Interglacial climate and sea-level evolution from a coupled ice sheet-climate model}},
url = {https://www.clim-past.net/12/2195/2016/ https://www.clim-past.net/12/2195/2016/cp-12-2195-2016.pdf},
volume = {12},
year = {2016}
}
@article{cp-10-523-2014,
author = {Goldner, A and Herold, N and Huber, M},
doi = {10.5194/cp-10-523-2014},
journal = {Climate of the Past},
number = {2},
pages = {523--536},
title = {{The challenge of simulating the warmth of the mid-Miocene climatic optimum in CESM1}},
url = {https://cp.copernicus.org/articles/10/523/2014/},
volume = {10},
year = {2014}
}
@article{https://doi.org/10.1002/wcc.634,
abstract = {Abstract Under future climate change scenarios it is virtually certain that global mean sea level will continue to rise. But the rate at which this occurs, and the height and time at which it might stabilize, are uncertain. The largest potential contributors to sea level are the Greenland and Antarctic ice sheets, but these may take thousands of years to fully adjust to environmental changes. Modeled projections of how these ice masses will evolve in the future are numerous, but vary both in complexity and projection timescale. Typically, there is greater agreement between models in the present century than over the next millennium. This reflects uncertainty in the physical processes that dominate ice-sheet change and also feedbacks in the ice–atmosphere–ocean system, and how these might lead to nonlinear behavior. Satellite observations help constrain short-term projections of ice-sheet change but these records are still too short to capture the full ice-sheet response. Conversely, geological records can be used to inform long-term ice-sheet simulations but are prone to large uncertainties, meaning that they are often unable to adequately confirm or refute the operation of particular processes. Because of these limitations there is a clear need to more accurately reconstruct sea level changes during periods of the past, to improve the spatial and temporal extent of current ice sheet observations, and to robustly attribute observed changes to driving mechanisms. Improved future projections will require models that capture a more extensive suite of physical processes than are presently incorporated, and which better quantify the associated uncertainties. This article is categorized under: Climate Models and Modeling {\textgreater} Knowledge Generation with Models},
author = {Golledge, Nicholas R},
doi = {10.1002/wcc.634},
journal = {WIREs Climate Change},
keywords = {Antarctic,Greenland,climate change,commitment,ice sheet},
number = {2},
pages = {e634},
title = {{Long-term projections of sea-level rise from ice sheets}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/wcc.634},
volume = {11},
year = {2020}
}
@article{Golledge2014,
abstract = {{\textcopyright} 2014 Macmillan Publishers Limited. All rights reserved. During the last glacial termination, the upwelling strength of the southern polar limb of the Atlantic Meridional Overturning Circulation varied, changing the ventilation and stratification of the high-latitude Southern Ocean. During the same period, at least two phases of abrupt global sea-level rise - meltwater pulses - took place. Although the timing and magnitude of these events have become better constrained, a causal link between ocean stratification, the meltwater pulses and accelerated ice loss from Antarctica has not been proven. Here we simulate Antarctic ice sheet evolution over the last 25-kyr using a data-constrained ice-sheet model forced by changes in Southern Ocean temperature from an Earth system model. Results reveal several episodes of accelerated ice-sheet recession, the largest being coincident with meltwater pulse 1A. This resulted from reduced Southern Ocean overturning following Heinrich Event 1, when warmer subsurface water thermally eroded grounded marine-based ice and instigated a positive feedback that further accelerated ice-sheet retreat.},
author = {Golledge, N. R. and Menviel, L. and Carter, L. and Fogwill, C. J. and England, M. H. and Cortese, G. and Levy, R. H.},
doi = {10.1038/ncomms6107},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {5107},
title = {{Antarctic contribution to meltwater pulse 1A from reduced Southern Ocean overturning}},
url = {http://www.nature.com/articles/ncomms6107},
volume = {5},
year = {2014}
}
@article{Gong2018,
abstract = {AbstractThe multidecadal fluctuations in the patterns and teleconnections of the winter mean Arctic Oscillation (AO) are investigated based on observational and reanalysis datasets. Results show that the Atlantic center of the AO pattern remains unchanged throughout the period 1920–2010, whereas the Pacific center of the AO is strong during 1920–59 and 1986–2010 and weak during 1960–85. Consequently, the link between the AO and the surface air temperature over western North America is strong during 1920–59 and 1986–2010 and weak during 1960–85. The time-varying Pacific center of the AO motivates a revisit to the nature of the AO from the perspective of decadal change. It reveals that the North Pacific mode (NPM) and North Atlantic Oscillation (NAO) are the inherent regional atmospheric modes over the North Pacific and North Atlantic, respectively. Their patterns over the North Pacific and North Atlantic remain stable and change little with time during 1920–2010. The Atlantic center of the AO always resembles the NAO over the North Atlantic, but the Pacific center of the AO only resembles the NPM over the North Pacific when the NPM–NAO coupling is strong. These results suggest that the AO seems to be fundamentally rooted in the variability over the North Atlantic and that the annular structure of the AO very likely arises from the coupling of the atmospheric modes between the North Pacific and North Atlantic.},
author = {Gong, Hainan and Wang, Lin and Chen, Wen and Nath, Debashis},
doi = {10.1175/JCLI-D-17-0530.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Arctic Oscillation,Multidecadal variability,North Atlantic Oscillation,Surface temperature},
number = {14},
pages = {5595--5608},
title = {{Multidecadal fluctuation of the wintertime Arctic Oscillation pattern and its implication}},
volume = {31},
year = {2018}
}
@article{doi:10.1002/joc.4654,
abstract = {ABSTRACT The limited historical observational sampling of the ocean gives rise to uncertainty in time series of global ocean temperature anomalies calculated from those observations. Without knowledge of the true global state of the oceans, it is difficult to characterize the errors caused by these sampling issues. One way to quantify them is to use climate model data. Pseudo observational time series can be constructed from the model data using knowledge of where observations occurred. Comparison of these with time series constructed from the full model fields yields information about how observational sampling impacts time series of the temperature change in the modelled world. This can then be related back to the time series generated from the real observations. In this study, climate model data were used to investigate sampling errors in 0–700 m global average ocean temperature anomaly time series calculated using a straightforward gridding approach. The sampling had two impacts. First, sampling causes issues with constructing a climatology that is representative of the long-term average state of the ocean. Climatology errors were shown to have the potential to cause systematically changing errors in anomaly time series. Second, some regions of the ocean were poorly observed prior to improvements brought about by the Argo project. This was found to cause spurious variability, both year to year and over multi-year time scales. The latter had similar magnitude to the actual multi-year variability seen in the model data but was smaller than the model's long-term temperature change. The features of these errors depend on the ocean state and therefore varied between climate model runs. More sophisticated methods used to calculate ocean temperature time series are expected to be less impacted by sampling. Nevertheless, sampling errors will still occur and therefore this type of study is recommended even for those techniques.},
author = {Good, Simon A},
doi = {10.1002/joc.4654},
journal = {International Journal of Climatology},
keywords = {observations,ocean heat content,ocean temperature,sampling,time series,uncertainty},
number = {5},
pages = {2260--2268},
title = {{The impact of observational sampling on time series of global 0–700 m ocean average temperature: a case study}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.4654},
volume = {37},
year = {2017}
}
@article{doi:10.1002/2013JC009067,
abstract = {We present version 4 of the Met Office Hadley Centre “EN” series of data sets of global quality controlled ocean temperature and salinity profiles and monthly objective analyses, which covers the period 1900 to present. We briefly describe the EN4 data sources, processing, quality control procedures, and the method of generating the analyses. In particular, we highlight improvements relative to previous versions, which include a new duplicate profile removal procedure and the inclusion of three new quality control checks. We discuss in detail a novel method for providing uncertainty estimates for the objective analyses and improving the background error variance estimates used by the analysis system. These were calculated using an iterative method that is relatively robust to initial misspecification of background error variances. We also show how the method can be used to identify issues with the analyses such as those caused by misspecification of error variances and demonstrate the impact of changes in the observing system on the uncertainty in the analyses.},
author = {Good, Simon A and Martin, Matthew J and Rayner, Nick A},
doi = {10.1002/2013JC009067},
journal = {Journal of Geophysical Research: Oceans},
keywords = {objective analysis,ocean observations,quality control,uncertainty estimation},
number = {12},
pages = {6704--6716},
title = {{EN4: Quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013JC009067},
volume = {118},
year = {2013}
}
@article{Goodwin2014,
author = {Goodwin, I. D. and Browning, S. and Lorrey, A. M. and Mayewski, P. A. and Phipps, S. J. and Bertler, N. A. N. and Stager, J. C},
doi = {10.1007/s00382-013-1899-1},
journal = {Climate Dynamics},
number = {5-6},
pages = {1197--1219},
title = {{A reconstruction of extratropical Indo-Pacific sea-level pressure patterns during the Medieval Climate Anomaly}},
volume = {43},
year = {2014}
}
@article{Goring2016a,
abstract = {Background EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km) reconstructions of pre-settlement (1800s) forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan), using 19th Century Public Land Survey System (PLSS), with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection. Changes in Forest Structure We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA) data to show the prevalence of lost forests (pre-settlement forests with no current analog), and novel forests (modern forests with no past analogs). Differences between pre-settlement and modern forests are spatially structured owing to differences in land-use impacts and accompanying ecological responses. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 28{\%} of all FIA cells, and 28{\%} of pre-settlement forests no longer exist in a modern context. Lost forests include tamarack forests in northeastern Minnesota, hemlock and cedar dominated forests in north-central Wisconsin and along the Upper Peninsula of Michigan, and elm, oak, basswood and ironwood forests along the forest-prairie boundary in south central Minnesota and eastern Wisconsin. Novel FIA forest assemblages are distributed evenly across the region, but novelty shows a strong relationship to spatial distance from remnant forests in the upper Midwest, with novelty predicted at between 20 to 60km from remnants, depending on historical forest type. The spatial relationships between remnant and novel forests, shifts in ecotone structure and the loss of historic forest types point to significant challenges for land managers if landscape restoration is a priority. The spatial signals of novelty and ecological change also point to potential challenges in using modern spatial distributions of species and communities and their relationship to underlying geophysical and climatic attributes in understanding potential responses to changing climate. The signal of human settlement on modern forests is broad, spatially varying and acts to homogenize modern forests relative to their historic counterparts, with significant implications for future management.},
author = {Goring, Simon J. and Mladenoff, David J. and Cogbill, Charles V. and Record, Sydne and Paciorek, Christopher J. and Jackson, Stephen T. and Dietze, Michael C. and Dawson, Andria and Matthes, Jaclyn Hatala and McLachlan, Jason S. and Williams, John W.},
doi = {10.1371/journal.pone.0151935},
issn = {19326203},
journal = {PLOS ONE},
number = {12},
pages = {e0151935},
title = {{Novel and lost forests in the upper Midwestern United States, from new estimates of settlement-era composition, stem density, and biomass}},
volume = {11},
year = {2016}
}
@article{Gottschalk2016a,
abstract = {Millennial-scale climate changes during the last glacial period and deglaciation were accompanied by rapid changes in atmospheric CO2 that remain unexplained. While the role of the Southern Ocean as a 'control valve' on ocean-atmosphere CO2 exchange has been emphasized, the exact nature of this role, in particular the relative contributions of physical (for example, ocean dynamics and air-sea gas exchange) versus biological processes (for example, export productivity), remains poorly constrained. Here we combine reconstructions of bottom-water [O2], export production and (14)C ventilation ages in the sub-Antarctic Atlantic, and show that atmospheric CO2 pulses during the last glacial- and deglacial periods were consistently accompanied by decreases in the biological export of carbon and increases in deep-ocean ventilation via southern-sourced water masses. These findings demonstrate how the Southern Ocean's 'organic carbon pump' has exerted a tight control on atmospheric CO2, and thus global climate, specifically via a synergy of both physical and biological processes.},
author = {Gottschalk, Julia and Skinner, Luke C. and Lippold, J{\"{o}}rg and Vogel, Hendrik and Frank, Norbert and Jaccard, Samuel L. and Waelbroeck, Claire},
doi = {10.1038/ncomms11539},
issn = {2041-1723},
journal = {Nature Communications},
month = {sep},
number = {1},
pages = {11539},
publisher = {Nature Publishing Group},
title = {{Biological and physical controls in the Southern Ocean on past millennial-scale atmospheric CO2 changes}},
url = {http://www.nature.com/articles/ncomms11539},
volume = {7},
year = {2016}
}
@article{Gottschalk2020a,
abstract = {Past millennial-scale changes in atmospheric CO2 (CO2,atm) concentrations have often been attributed to variations in the overturning timescale of the ocean that result in changes in the marine carbon inventory. Yet, there remains a paucity of proxy evidence that documents changes in marine carbon storage globally, and that links them to abrupt climate variability in the northern hemisphere associated with perturbations of the Atlantic Meridional Overturning Circulation (AMOC). The last two glacial periods were suggested to differ in the spatial extent of the AMOC and its sensitivity to perturbations. This provides an opportunity to compare the nature of marine carbon cycle-climate feedbacks between them. Here, we reconstruct variations in respired carbon storage (via oxygenation) and the AMOC “geometry” (via carbonate ion saturation) in the deep South Atlantic. We infer decreases in deep South Atlantic respired carbon levels at times of weakened AMOC and rising CO2,atm concentrations during both glacial periods. These findings suggest a consistent pattern of increased Southern Ocean convection and/or air-sea CO2 fluxes during northern-hemisphere stadials accompanying AMOC perturbations and promoting a rise in CO2,atm levels. We find that net ocean carbon loss, and hence the magnitude of CO2,atm rise, is largely determined by the stadial duration. North Atlantic climate anomalies therefore affect Southern Ocean carbon cycling in a consistent manner, through oceanic (e.g., ventilation seesaw) and/or atmospheric processes (e.g., Ekman pumping).},
author = {Gottschalk, Julia and Skinner, Luke C and Jaccard, Samuel L and Menviel, Laurie and Nehrbass-Ahles, Christoph and Waelbroeck, Claire},
doi = {10.1016/j.quascirev.2019.106067},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Atmospheric CO variations,Carbon cycle,Dansgaard-Oeschger cycles,Foraminifera,Glacials,Interstadials,Palaeoclimatology,Redox-sensitive elements,Southern Ocean,Stadials},
pages = {106067},
title = {{Southern Ocean link between changes in atmospheric CO2 levels and northern-hemisphere climate anomalies during the last two glacial periods}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379118310461},
volume = {230},
year = {2020}
}
@article{Gouretski2012a,
abstract = {We compare historical global temperature time series, based on bias-adjusted sea-surface temperatures with independent temperature time series, for the upper 20 meter layer of the ocean based on the latest update of an historical hydrographic profile data set. Despite the two underlying data sets being different in number of data points, instrumentation and applied adjustments, both of the time series are consistent in showing an overall warming since 1900. We also extend records of temperature change in the upper 400 m back to 1900. Noting that the geographic coverage is limited prior to 1950, the temperature change in the 0–400 m layer is characterized by two periods of temperature increase between 1900 and 1940–45 and between 1970 and 2003, separated by a period of little change.},
author = {Gouretski, Viktor and Kennedy, John and Boyer, Tim and K{\"{o}}hl, Armin},
doi = {10.1029/2012GL052975},
journal = {Geophysical Research Letters},
number = {19},
pages = {L19606},
title = {{Consistent near-surface ocean warming since 1900 in two largely independent observing networks}},
volume = {39},
year = {2012}
}
@article{CorrectionforSystematicErrorsintheGlobalDatasetofTemperatureProfilesfromMechanicalBathythermographs,
address = {Boston MA, USA},
author = {Gouretski, Viktor and Cheng, Lijing},
doi = {10.1175/JTECH-D-19-0205.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {5},
pages = {841--855},
publisher = {American Meteorological Society},
title = {{Correction for Systematic Errors in the Global Dataset of Temperature Profiles from Mechanical Bathythermographs}},
url = {https://journals.ametsoc.org/view/journals/atot/37/5/jtech-d-19-0205.1.xml},
volume = {37},
year = {2020}
}
@article{grant_amplitude_2019,
author = {Grant, G R and Naish, T R and Dunbar, G B and Stocchi, P and Kominz, M A and Kamp, P J J and Tapia, C A and McKay, R M and Levy, R H and Patterson, M O},
doi = {10.1038/s41586-019-1619-z},
issn = {0028-0836, 1476-4687},
journal = {Nature},
month = {oct},
number = {7777},
pages = {237--241},
title = {{The amplitude and origin of sea-level variability during the Pliocene epoch}},
url = {http://www.nature.com/articles/s41586-019-1619-z},
volume = {574},
year = {2019}
}
@article{Grant2014,
abstract = {Research on global ice-volume changes during Pleistocene glacial cycles is hindered by a lack of detailed sea-level records for time intervals older than the last interglacial. Here we present the first robustly dated, continuous and highly resolved records of Red Sea sea level and rates of sea-level change over the last 500,000 years, based on tight synchronization to an Asian monsoon record. We observe maximum ‘natural' (pre-anthropogenic forcing) sea-level rise rates below 2 m per century following periods with up to twice present-day ice volumes, and substantially higher rise rates for greater ice volumes. We also find that maximum sea-level rise rates were attained within 2 kyr of the onset of deglaciations, for 85{\%} of such events. Finally, multivariate regressions of orbital parameters, sea-level and monsoon records suggest that major meltwater pulses account for millennial-scale variability and insolation-lagged responses in Asian monsoon records.},
author = {Grant, K M and Rohling, E J and Ramsey, C Bronk and Cheng, H and Edwards, R L and Florindo, F and Heslop, D and Marra, F and Roberts, A P and Tamisiea, M E and Williams, F},
doi = {10.1038/ncomms6076},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {5076},
title = {{Sea-level variability over five glacial cycles}},
url = {https://doi.org/10.1038/ncomms6076},
volume = {5},
year = {2014}
}
@article{Graven2013a,
abstract = {Seasonal variations of atmospheric carbon dioxide (CO 2 ) in the Northern Hemisphere have increased since the 1950s, but sparse observations have prevented a clear assessment of the patterns of long-term change and the underlying mechanisms. We compare recent aircraft-based observations of CO 2 above the North Pacific and Arctic Oceans to earlier data from 1958 to 1961 and find that the seasonal amplitude at altitudes of 3 to 6 km increased by 50{\%} for 45° to 90°N but by less than 25{\%} for 10° to 45°N. An increase of 30 to 60{\%} in the seasonal exchange of CO 2 by northern extratropical land ecosystems, focused on boreal forests, is implicated, substantially more than simulated by current land ecosystem models. The observations appear to signal large ecological changes in northern forests and a major shift in the global carbon cycle.},
author = {Graven, H. D. and Keeling, R. F. and Piper, S. C. and Patra, P. K. and Stephens, B. B. and Wofsy, S. C. and Welp, L. R. and Sweeney, C. and Tans, P. P. and Kelley, J. J. and Daube, B. C. and Kort, E. A. and Santoni, G. W. and Bent, J. D.},
doi = {10.1126/science.1239207},
issn = {0036-8075},
journal = {Science},
month = {sep},
number = {6150},
pages = {1085--1089},
title = {{Enhanced Seasonal Exchange of CO2 by Northern Ecosystems Since 1960}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1239207},
volume = {341},
year = {2013}
}
@article{Gray2018,
abstract = {Although the Southern Ocean is thought to account for a significant portion of the contemporary oceanic uptake of carbon dioxide (CO2), flux estimates in this region are based on sparse observations that are strongly biased toward summer. Here we present new estimates of Southern Ocean air-sea CO2 fluxes calculated with measurements from biogeochemical profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling project during 2014–2017. Compared to ship-based CO2 flux estimates, the float-based fluxes find significantly stronger outgassing in the zone around Antarctica where carbon-rich deep waters upwell to the surface ocean. Although interannual variability contributes, this difference principally stems from the lack of autumn and winter ship-based observations in this high-latitude region. These results suggest that our current understanding of the distribution of oceanic CO2 sources and sinks may need revision and underscore the need for sustained year-round biogeochemical observations in the Southern Ocean.},
author = {Gray, Alison R. and Johnson, Kenneth S. and Bushinsky, Seth M. and Riser, Stephen C. and Russell, Joellen L. and Talley, Lynne D. and Wanninkhof, Rik and Williams, Nancy L. and Sarmiento, Jorge L.},
doi = {10.1029/2018GL078013},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {SOCCOM,air-sea carbon flux},
number = {17},
pages = {9049--9057},
title = {{Autonomous Biogeochemical Floats Detect Significant Carbon Dioxide Outgassing in the High-Latitude Southern Ocean}},
volume = {45},
year = {2018}
}
@article{Gregg_2019,
abstract = {Ocean primary production (PP), representing the uptake of inorganic carbon through photosynthesis, supports marine life and affects carbon exchange with the atmosphere. It is difficult to ascertain its magnitude, variability, and trends due to our inability to measure it directly at large scales. Yet it is paramount for understanding changes in marine health, fisheries, and the global carbon cycle. Using assimilation of ocean color satellite data into an ocean biogeochemical model, we estimate that global net ocean PP has experienced a small but significant decline −0.8 PgC y−1 (−2.1{\%}) decade−1 (P {\textless} 0.05) in the 18-year satellite record from 1998 to 2015. This decline is associated with shallowing surface mixed layer depth (−2.4{\%} decade−1) and decreasing nitrate concentrations (−3.2{\%} decade−1). Relative contributions to PP by various types of ocean phytoplankton have changed, with decreases in production by intermediate-sized phytoplankton represented by chlorophytes (−14.3{\%} decade−1). This is partially compensated by increases from the unique, more nutrient-efficient, coccolithophores (8.4{\%} decade−1). Geographically, the North and Equatorial Indian Oceans are responsible for much of the decline in PP, falling 0.16 and 0.69 PgC y−1 decade−1, respectively. Reduced production by large, fast-growing diatoms along with chlorophytes characterizes the decline here. In contrast, increases in PP are found in the North and North Central Pacific. The increases here are led by chlorophytes in the North Pacific and the small cyanobacteria in the North Central Pacific. These results suggest that the multi-decadal satellite observational record, coupled with an underlying representation of marine biodiversity in a model, can monitor the uptake of carbon by phytoplankton and that changes, although small, are occurring in the global oceans.},
author = {Gregg, Watson W and Rousseaux, Cecile S},
doi = {10.1088/1748-9326/ab4667},
journal = {Environmental Research Letters},
month = {nov},
number = {12},
pages = {124011},
publisher = {{\{}IOP{\}} Publishing},
title = {{Global ocean primary production trends in the modern ocean color satellite record (1998–2015)}},
url = {https://doi.org/10.1088/1748-9326/ab4667},
volume = {14},
year = {2019}
}
@article{GregorL.2021,
abstract = {Abstract. Ocean acidification has profoundly altered the ocean's carbonate chemistry since preindustrial times, with potentially serious consequences for marine life. Yet, no long-term, global observation-based data set exists that allows us to study changes in ocean acidification for all carbonate system parameters over the last few decades. Here, we fill this gap and present a methodologically consistent global data set of all relevant surface ocean parameters, i.e., dissolved inorganic carbon (DIC), total alkalinity (TA), partial pressure of CO2 (pCO2), pH, and the saturation state with respect to mineral CaCO3 ($\Omega$) at a monthly resolution over the period 1985 through 2018 at a spatial resolution of 1∘×1∘. This data set, named OceanSODA-ETHZ, was created by extrapolating in time and space the surface ocean observations of pCO2 (from the Surface Ocean CO2 Atlas, SOCAT) and total alkalinity (TA; from the Global Ocean Data Analysis Project, GLODAP) using the newly developed Geospatial Random Cluster Ensemble Regression (GRaCER) method (code available at https://doi.org/10.5281/zenodo.4455354, Gregor, 2021). This method is based on a two-step (cluster-regression) approach but extends it by considering an ensemble of such cluster regressions, leading to improved robustness. Surface ocean DIC, pH, and $\Omega$ were then computed from the globally mapped pCO2 and TA using the thermodynamic equations of the carbonate system. For the open ocean, the cluster-regression method estimates pCO2 and TA with global near-zero biases and root mean squared errors of 12 µatm and 13 µmol kg−1, respectively. Taking into account also the measurement and representation errors, the total uncertainty increases to 14 µatm and 21 µmol kg−1, respectively. We assess the fidelity of the computed parameters by comparing them to direct observations from GLODAP, finding surface ocean pH and DIC global biases of near zero, as well as root mean squared errors of 0.023 and 16 µmol kg−1, respectively. These uncertainties are very comparable to those expected by propagating the total uncertainty from pCO2 and TA through the thermodynamic computations, indicating a robust and conservative assessment of the uncertainties. We illustrate the potential of this new data set by analyzing the climatological mean seasonal cycles of the different parameters of the surface ocean carbonate system, highlighting their commonalities and differences. Further, this data set provides a novel constraint on the global- and basin-scale trends in ocean acidification for all parameters. Concretely, we find for the period 1990 through 2018 global mean trends of 8.6 ± 0.1 µmol kg−1 per decade for DIC, −0.016 ± 0.000 per decade for pH, 16.5 ± 0.1 µatm per decade for pCO2, and −0.07 ± 0.00 per decade for $\Omega$. The OceanSODA-ETHZ data can be downloaded from https://doi.org/10.25921/m5wx-ja34 (Gregor and Gruber, 2020).},
author = {Gregor, L. and Gruber, N.},
doi = {10.5194/essd-13-777-2021},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {mar},
number = {2},
pages = {777--808},
title = {{OceanSODA-ETHZ: a global gridded data set of the surface ocean carbonate system for seasonal to decadal studies of ocean acidification}},
url = {https://essd.copernicus.org/articles/13/777/2021/},
volume = {13},
year = {2021}
}
@article{Greve2014,
abstract = {Changes in the hydrological conditions of the land surface have substantial impacts on society. Yet assessments of observed continental dryness trends yield contradicting results. The concept that dry regions dry out further, whereas wet regions become wetter as the climate warms has been proposed as a simplified summary of expected as well as observed changes over land, although this concept is mostly based on oceanic data. Here we present an analysis of more than 300 combinations of various hydrological data sets of historical land dryness changes covering the period from 1948 to 2005. Each combination of data sets is benchmarked against an empirical relationship between evaporation, precipitation and aridity. Those combinations that perform well are used for trend analysis. We find that over about three-quarters of the global land area, robust dryness changes cannot be detected. Only 10.8{\%} of the global land area shows a robust ‘dry gets drier, wet gets wetter' pattern, compared to 9.5{\%} of global land area with the opposite pattern, that is, dry gets wetter, and wet gets drier. We conclude that aridity changes over land, where the potential for direct socio-economic consequences is highest, have not followed a simple intensification of existing patterns.},
author = {Greve, Peter and Orlowsky, Boris and Mueller, Brigitte and Sheffield, Justin and Reichstein, Markus and Seneviratne, Sonia I.},
doi = {10.1038/NGEO2247},
isbn = {1752-0894},
issn = {17520908},
journal = {Nature Geoscience},
number = {10},
pages = {716--721},
title = {{Global assessment of trends in wetting and drying over land}},
volume = {7},
year = {2014}
}
@article{Grieger2018a,
author = {Grieger, J and Leckebusch, G C and Raible, C C and Rudeva, I and Simmonds, I},
doi = {10.1080/16000870.2018.1454808},
journal = {Tellus A: Dynamic Meteorology and Oceanography},
number = {1},
pages = {1454808},
title = {{Subantarctic cyclones identified by 14 tracking methods, and their role for moisture transports into the continent}},
volume = {70},
year = {2018}
}
@article{Griffiths2016,
abstract = {Interdecadal modes of tropical Pacific ocean-Atmosphere circulation have a strong influence on global temperature, yet the extent to which these phenomena influence global climate on multicentury timescales is still poorly known. Here we present a 2,000-year, multiproxy reconstruction of western Pacific hydroclimate from two speleothem records for southeastern Indonesia. The composite record shows pronounced shifts in monsoon rainfall that are antiphased with precipitation records for East Asia and the central-eastern equatorial Pacific. These meridional and zonal patterns are best explained by a poleward expansion of the Australasian Intertropical Convergence Zone and weakening of the Pacific Walker circulation (PWC) between {\^{a}} 1/41000 and 1500 CE Conversely, an equatorward contraction of the Intertropical Convergence Zone and strengthened PWC occurred between {\^{a}} 1/41500 and 1900 CE. Our findings, together with climate model simulations, highlight the likelihood that century-scale variations in tropical Pacific climate modes can significantly modulate radiatively forced shifts in global temperature.},
author = {Griffiths, Michael L. and Kimbrough, Alena K. and Gagan, Michael K. and Drysdale, Russell N. and Cole, Julia E. and Johnson, Kathleen R. and Zhao, Jian Xin and Cook, Benjamin I. and Hellstrom, John C. and Hantoro, Wahyoe S.},
doi = {10.1038/ncomms11719},
issn = {20411723},
journal = {Nature Communications},
pages = {1--9},
publisher = {Nature Publishing Group},
title = {{Western Pacific hydroclimate linked to global climate variability over the past two millennia}},
volume = {7},
year = {2016}
}
@article{Griffiths2020,
abstract = {Between 5 and 4 thousand years ago, crippling megadroughts led to the disruption of ancient civilizations across parts of Africa and Asia, yet the extent of these climate extremes in mainland Southeast Asia (MSEA) has never been defined. This is despite archeological evidence showing a shift in human settlement patterns across the region during this period. We report evidence from stalagmite climate records indicating a major decrease of monsoon rainfall in MSEA during the mid- to late Holocene, coincident with African monsoon failure during the end of the Green Sahara. Through a set of modeling experiments, we show that reduced vegetation and increased dust loads during the Green Sahara termination shifted the Walker circulation eastward and cooled the Indian Ocean, causing a reduction in monsoon rainfall in MSEA. Our results indicate that vegetation-dust climate feedbacks from Sahara drying may have been the catalyst for societal shifts in MSEA via ocean-atmospheric teleconnections.},
author = {Griffiths, Michael L. and Johnson, Kathleen R. and Pausata, Francesco S. R. and White, Joyce C. and Henderson, Gideon M. and Wood, Christopher T. and Yang, Hongying and Ersek, Vasile and Conrad, Cyler and Sekhon, Natasha},
doi = {10.1038/s41467-020-17927-6},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {4204},
pmid = {32826905},
title = {{End of Green Sahara amplified mid- to late Holocene megadroughts in mainland Southeast Asia}},
url = {http://www.nature.com/articles/s41467-020-17927-6},
volume = {11},
year = {2020}
}
@article{Grise2018,
abstract = {In recent decades, the subtropical edges of Earth's Hadley circulation have shifted poleward. Some studies have concluded that this observed tropical expansion is occurring more rapidly than predicted by global climate models. However, recent modeling studies have shown that internal variability can account for a large fraction of the observed circulation trends, at least in an annual-mean, zonal-mean framework. This study extends these previous results by examining the seasonal and regional characteristics of the recent poleward expansion of the Hadley circulation using seven reanalysis datasets, sea level pressure observations, and surface wind observations. The circulation has expanded the most poleward during summer and fall in both hemispheres, with more zonally asymmetric circulation trends occurring in the Northern Hemisphere (NH). The seasonal and regional characteristics of these observed trends generally fall within the range of trends predicted by climate models for the late twentieth and early twenty-first centuries, and in most cases, the magnitude of the observed trends does not exceed the range of interdecadal trends in the models' control runs, which arise exclusively from internal variability. One exception occurs during NH fall when large observed poleward shifts in the atmospheric circulation over the North Atlantic sector exceed nearly all trends projected by models. While most recent NH circulation trends are consistent with a change in phase of the Pacific decadal oscillation (PDO), the observed circulation trends over the North Atlantic instead reflect 1) large natural variability unrelated to the PDO and/or 2) a climate forcing (or the circulation response to that forcing) that is not properly captured by models.},
author = {Grise, Kevin M. and Davis, Sean M. and Staten, Paul W. and Adam, Ori},
doi = {10.1175/JCLI-D-18-0060.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {sep},
number = {17},
pages = {6839--6856},
title = {{Regional and Seasonal Characteristics of the Recent Expansion of the Tropics}},
url = {https://journals.ametsoc.org/doi/10.1175/JCLI-D-18-0060.1},
volume = {31},
year = {2018}
}
@article{Grise2019a,
abstract = {{\textcopyright} 2019, American Meteorological Society. Previous studies have documented a poleward shift in the subsiding branches of Earth's Hadley circulation since 1979 but have disagreed on the causes of these observed changes and the ability of global climate models to capture them. This synthesis paper reexamines a number of contradictory claims in the past literature and finds that the tropical expansion indicated by modern reanalyses is within the bounds of models' historical simulations for the period 1979-2005. Earlier conclusions that models were underestimating the observed trends relied on defining the Hadley circulation using the mass streamfunction from older reanalyses. The recent observed tropical expansion has similar magnitudes in the annual mean in the Northern Hemisphere (NH) and Southern Hemisphere (SH), but models suggest that the factors driving the expansion differ between the hemispheres. In the SH, increasing greenhouse gases (GHGs) and stratospheric ozone depletion contributed to tropical expansion over the late twentieth century, and if GHGs continue increasing, the SH tropical edge is projected to shift further poleward over the twenty-first century, even as stratospheric ozone concentrations recover. In the NH, the contribution of GHGs to tropical expansion is much smaller and will remain difficult to detect in a background of large natural variability, even by the end of the twenty-first century. To explain similar recent tropical expansion rates in the two hemispheres, natural variability must be taken into account. Recent coupled atmosphere-ocean variability, including the Pacific decadal oscillation, has contributed to tropical expansion. However, in models forced with observed sea surface temperatures, tropical expansion rates still vary widely because of internal atmospheric variability.},
author = {Grise, Kevin M. and Davis, Sean M. and Simpson, Isla R. and Waugh, Darryn W. and Fu, Qiang and Allen, Robert J. and Rosenlof, Karen H. and Ummenhofer, Caroline C. and Karnauskas, Kristopher B. and Maycock, Amanda C. and Quan, Xiao Wei and Birner, Thomas and Staten, Paul W.},
doi = {10.1175/JCLI-D-18-0444.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Climate models,Hadley circulation,Multidecadal variability,Pacific decadal oscillation,Reanalysis data,Trends},
number = {5},
pages = {1551--1571},
title = {{Recent tropical expansion: Natural variability or forced response?}},
volume = {32},
year = {2019}
}
@article{Grise2020a,
abstract = {In response to increasing greenhouse gases, the subtropical edges of Earth's Hadley circulation shift poleward in global climate models. Recent studies have found that reanalysis trends in the Hadley cell edge over the past 30-40 years are within the range of trends simulated by Coupled Model Intercomparison Project Phase 5 (CMIP5) models and have documented seasonal and hemispheric asymmetries in these trends. In this study, we evaluate whether these conclusions hold for the newest generation of models (CMIP6). Overall, we find similar characteristics of Hadley cell expansion in CMIP5 and CMIP6 models. In both CMIP5 and CMIP6 models, the poleward shift of the Hadley cell edge in response to increasing greenhouse gases is 2-3 times larger in the Southern Hemisphere (SH), except during September-November. The trends from CMIP5 and CMIP6 models agree well with reanalyses, although prescribing observed coupled atmosphere-ocean variability allows the models to better capture reanalysis trends in the Northern Hemisphere (NH). We find two notable differences between CMIP5 and CMIP6 models. First, while both CMIP5 and CMIP6 models contract the NH summertime Hadley circulation equatorward (particularly over the Pacific sector), this contraction is larger in CMIP6 models due to their higher average climate sensitivity. Second, in recent decades, the poleward shift of the NH annual-mean Hadley cell edge is slightly larger in CMIP6 models. Increasing greenhouse gases drive similar trends in CMIP5 and CMIP6 models, so the larger recent NH trends in CMIP6 models point to the role of other forcings, such as aerosols.},
author = {Grise, Kevin M. and Davis, Sean M.},
doi = {10.5194/acp-20-5249-2020},
issn = {16807324},
journal = {Atmospheric Chemistry and Physics},
number = {9},
pages = {5249--5268},
title = {{Hadley cell expansion in CMIP6 models}},
volume = {20},
year = {2020}
}
@article{doi:10.1002/2016JC012091,
abstract = {Abstract A novel assessment of recent changes in air-sea freshwater fluxes has been conducted using a surface temperature-salinity framework applied to four atmospheric reanalyses. Viewed in the T-S space of the ocean surface, the complex pattern of the longitude-latitude space mean global Precipitation minus Evaporation (PME) reduces to three distinct regions. The analysis is conducted for the period 1979–2007 for which there is most evidence for a broadening of the (atmospheric) tropical belt. All four of the reanalyses display an increase in strength of the water cycle. The range of increase is between 2{\%} and 30{\%} over the period analyzed, with an average of 14{\%}. Considering the average across the reanalyses, the water cycle changes are dominated by changes in tropical as opposed to mid-high latitude precipitation. The increases in the water cycle strength, are consistent in sign, but larger than in a 1{\%} greenhouse gas run of the HadGEM3 climate model. In the model a shift of the precipitation/evaporation cells to higher temperatures is more evident, due to the much stronger global warming signal. The observed changes in freshwater fluxes appear to be reflected in changes in the T-S distribution of the Global Ocean. Specifically, across the diverse range of atmospheric reanalyses considered here, there was an acceleration of the hydrological cycle during 1979–2007 which led to a broadening of the ocean's salinity distribution. Finally, although the reanalyses indicate that the warm temperature tropical precipitation dominated water cycle change, ocean observations suggest that ocean processes redistributed the freshening to lower ocean temperatures.},
author = {Grist, Jeremy P and Josey, Simon A and Zika, Jan D and Evans, Dafydd Gwyn and Skliris, Nikolaos},
doi = {10.1002/2016JC012091},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Global Ocean,atmospheric reanalysis,evaporation,precipitation,temperature-salinity},
number = {12},
pages = {8787--8806},
title = {{Assessing recent air-sea freshwater flux changes using a surface temperature-salinity space framework}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012091},
volume = {121},
year = {2016}
}
@article{10.1002/essoar.10503569.1,
abstract = {In Arctic winter and spring 2020, the stratospheric temperatures{\&}{\#}xD; were exceptionally low for a long time period and the polar vortex{\&}{\#}xD; was very stable. As a consequence, significant ozone depletion{\&}{\#}xD; occurred in Northern polar regions in spring 2020. Here, we present{\&}{\#}xD; simulations by the Chemical Lagrangian Model of the Stratosphere{\&}{\#}xD; (CLaMS) that addresses the development of chlorine compounds and{\&}{\#}xD; ozone in the polar stratosphere in 2020. The simulation is able to{\&}{\#}xD; reproduce relevant observations which is shown by comparisons with{\&}{\#}xD; MLS, ACE-FTS and OMI data. Although the concentration of chlorine{\&}{\#}xD; and bromine compounds in the polar stratosphere has decreased by{\&}{\#}xD; more than 10{\%} compared to the peak values around the year 2000, the{\&}{\#}xD; meteorological conditions in winter and spring 2020 caused an{\&}{\#}xD; unprecedented ozone depletion. The simulated lowest ozone mixing{\&}{\#}xD; ratio was around 0.05 ppmv and the ozone depletion in the vortex{\&}{\#}xD; core in the lower stratosphere reached 133 Dobson Units, which is{\&}{\#}xD; more than the loss in the years 2011 and 2016 that had the largest{\&}{\#}xD; Arctic ozone depletion so far.},
author = {Groo{\ss}, Jens-Uwe and M{\"{u}}ller, Rolf},
doi = {10.1029/2020JD033339},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jun},
number = {12},
pages = {17},
title = {{Simulation of Record Arctic Stratospheric Ozone Depletion in 2020}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020JD033339},
volume = {126},
year = {2021}
}
@article{doi:10.1029/2019GL083906,
abstract = {Abstract The El Ni{\~{n}}o-Southern Oscillation (ENSO) represents the largest source of year-to-year global climate variability. While earth system models suggest a range of possible shifts in ENSO properties under continued greenhouse gas forcing, many centuries of preindustrial climate data are required to detect a potential shift in the properties of recent ENSO extremes. Here, we reconstruct the strength of ENSO variations over the last 7,000 years with a new ensemble of fossil coral oxygen isotope records from the Line Islands, located in the central equatorial Pacific. The corals document a significant decrease in ENSO variance of {\~{}}20{\%} from 3,000 to 5,000 years ago, coinciding with changes in spring/fall precessional insolation. We find that ENSO variability over the last five decades is {\~{}}25{\%} stronger than during the preindustrial. Our results provide empirical support for recent climate model projections showing an intensification of ENSO extremes under greenhouse forcing.},
author = {Grothe, Pamela R and Cobb, Kim M and Liguori, Giovanni and {Di Lorenzo}, Emanuele and Capotondi, Antonietta and Lu, Yanbin and Cheng, Hai and Edwards, R Lawrence and Southon, John R and Santos, Guaciara M and Deocampo, Daniel M and Lynch-Stieglitz, Jean and Chen, Tianran and Sayani, Hussein R and Thompson, Diane M and Conroy, Jessica L and Moore, Andrea L and Townsend, Kayla and Hagos, Melat and O'Connor, Gemma and Toth, Lauren T},
doi = {10.1029/2019GL083906},
journal = {Geophysical Research Letters},
keywords = {Anthropogenic Climate Change,Coral Paleoclimate,El-Nino Southern Oscillation,Holocene Climate Change,Mid-Holocene},
number = {7},
pages = {e2019GL083906},
title = {{Enhanced El Ni{\~{n}}o-Southern Oscillation variability in recent decades}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL083906},
volume = {46},
year = {2019}
}
@article{Gu2015,
abstract = {AbstractThis study examines global precipitation changes/variations during 1901–2010 by using the long-record GPCC land precipitation analysis, the NOAA/Cooperative Institute for Climate and Satellites (CICS) reconstructed (RECONS) precipitation analysis, and the CMIP5 outputs. In particular, spatial features of long-term precipitation changes and trends and decadal/interdecadal precipitation variations are explored by focusing on the effects of various physical mechanisms such as the anthropogenic greenhouse gas (GHG) and aerosol forcings and certain internal oscillations including the Pacific decadal variability (PDV) and Atlantic multidecadal oscillation (AMO).Precipitation increases in the Northern Hemisphere (NH) mid- to high-latitude lands observed in GPCC can also be found in RECONS and model simulations. Over tropical/subtropical land areas, precipitation reductions generally appear in all products, but with large discrepancies on regional scales. Over ocean, consistent spatial structures of preci...},
author = {Gu, Guojun and Adler, Robert F.},
doi = {10.1175/JCLI-D-14-00201.1},
isbn = {0894-8755$\backslash$r1520-0442},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Climate variability,Interdecadal variability,Multidecadal variability,Pacific decadal oscillation,Precipitation,Trends},
number = {11},
pages = {4431--4453},
title = {{Spatial patterns of global precipitation change and variability during 1901–2010}},
volume = {28},
year = {2015}
}
@article{Gu2013,
abstract = {This study explores how global precipitation and tropospheric water vapor content vary on the interdecadal/long-term time scale during past three decades (1988–2010 for water vapor), in particular to what extent the spatial structures of their variations relate to changes in surface temperature. EOF analyses of satellite-based products indicate that the first two modes of global precipitation and columnar water vapor content anomalies are in general related to the El Ni{\~{n}}o-Southern oscillation. The spatial patterns of their third modes resemble the corresponding linear fits/trends estimated at each grid point, which roughly represent the interdecadal/long-term changes happening during the same time period. Global mean sea surface temperature (SST) and land surface temperature have increased during the past three decades. However, the water vapor and precipitation patterns of change do not reflect the pattern of warming, in particular in the tropical Pacific basin. Therefore, other mechanisms in addition to global warming likely exist to account for the spatial structures of global precipitation changes during this time period. An EOF analysis of longer-record (1949–2010) SST anomalies within the Pacific basin (60oN–60oS) indicates the existence of a strong climate regime shift around 1998/1999, which might be associated with the Pacific decadal variability (PDV) as suggested in past studies. Analyses indicate that the observed linear changes/trends in both precipitation and tropospheric water vapor during 1988–2010 seem to result from a combined impact of global mean surface warming and the PDV shift. In particular, in the tropical central-eastern Pacific, a band of increases along the equator in both precipitation and water vapor sandwiched by strong decreases south and north of it are likely caused by the opposite effects from global-mean surface warming and PDV-related, La Ni{\~{n}}a-like cooling in the tropical central-eastern Pacific. This narrow band of precipitation increase could also be considered an evidence for the influence of global mean surface warming.},
author = {Gu, Guojun and Adler, Robert F.},
doi = {10.1007/s00382-012-1443-8},
isbn = {1432-0894},
issn = {09307575},
journal = {Climate Dynamics},
number = {11-12},
pages = {3009--3022},
title = {{Interdecadal variability/long-term changes in global precipitation patterns during the past three decades: Global warming and/or pacific decadal variability?}},
volume = {40},
year = {2013}
}
@article{Gudmundsson2018,
abstract = {This is Part 2 of a two-paper series presenting the Global Streamflow Indices and Metadata Archive (GSIM), which is a collection of daily streamflow observations at more than 30000 stations around the world. While Part 1 describes the data collection process as well as the generation of auxiliary catchment data (e.g. catchment boundary, land-cover, mean climate), Part 2 introduces a set of quality controlled time series indices representing (i) the water balance, (ii) the seasonal cycle, (iii) low-flows and (iv) floods. To this end we first consider the quality of individual daily records using a combination of quality flags of the data providers and automated screening methods. Subsequently streamflow time series indices are computed for yearly, seasonal and monthly resolution. The paper closes with a generalized assessment of the homogeneity of all generated streamflow time series indices, which can be used to select time series that are suitable for a specific task. The presented global set of streamflow time series indices is made freely available at https://iacweb.ethz.ch/staff/lukasgu/GSIM/GSIM{\_}indices.zip and is expected to foster global freshwater research, by acting as a ground-truth for model validation or as a basis for assessing the role of human impacts on the terrestrial water cycle.},
author = {Gudmundsson, Lukas and Do, Hong Xuan and Leonard, Michael and Westra, Seth},
doi = {10.5194/essd-10-787-2018},
issn = {18663516},
journal = {Earth System Science Data},
number = {2},
pages = {787--804},
title = {{The Global Streamflow Indices and Metadata Archive (GSIM) – Part 2: Quality control, time-series indices and homogeneity assessment}},
volume = {10},
year = {2018}
}
@article{Gudmundsson2019,
author = {Gudmundsson, Lukas and Leonard, M. and Do, H.X. and Westra, S. and Seneviratne, S.I.},
doi = {10.1029/2018GL079725},
journal = {Geophysical Research Letters},
number = {2},
pages = {756--766},
title = {{Observed Trends in Global Indicators of Mean and Extreme Streamflow}},
volume = {46},
year = {2019}
}
@article{Gulev2013,
author = {Gulev, Sergey K and Latif, Mojib and Keenlyside, Noel and Park, Wonsun and Koltermann, Klaus Peter},
doi = {10.1038/nature12268},
journal = {Nature},
month = {jul},
pages = {464},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{North Atlantic Ocean control on surface heat flux on multidecadal timescales}},
url = {http://dx.doi.org/10.1038/nature12268 http://10.0.4.14/nature12268 https://www.nature.com/articles/nature12268{\#}supplementary-information},
volume = {499},
year = {2013}
}
@article{Guo2015,
abstract = {AbstractUsing observational data and phase 5 of the Coupled Model Intercomparison Project (CMIP5) model outputs [the preindustrial (PI) control run of the Community Climate System Model, version 4 (CCSM4) and historical simulations of 17 CMIP5 models], Indian Ocean dipoles (IODs) with a peak in fall are categorized into three types. The first type is closely related to the development phase of El Ni{\~{n}}o/La Ni{\~{n}}a. The second type evolves from the basinwide warming (cooling) in the tropical Indian Ocean (IO), usually occurring in the year following El Ni{\~{n}}o (La Ni{\~{n}}a). The third type is independent of El Ni{\~{n}}o and La Ni{\~{n}}a. The dominant trigger condition for the first (third) type of IOD is the anomalous Walker circulation (anomalous cross-equatorial flow); the anomalous zonal sea surface temperature (SST) gradient in the tropical IO is the trigger condition for the second type. The occurrence of anomalous ocean Rossby waves during the forming stage of IO basinwide mode and their effect on SST in the southwestern IO during winter and spring are critical for early development of the second type of IOD. Although most models simulate a stronger El Ni{\~{n}}o?Southern Oscillation and IOD compared to the observations, this does not influence the phase-locking and classification of the IOD peaking in the fall.},
annote = {doi: 10.1175/JCLI-D-14-00507.1},
author = {Guo, Feiyan and Liu, Qinyu and Sun, S and Yang, Jianling},
doi = {10.1175/JCLI-D-14-00507.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {feb},
number = {8},
pages = {3073--3092},
publisher = {American Meteorological Society},
title = {{Three Types of Indian Ocean Dipoles}},
url = {https://doi.org/10.1175/JCLI-D-14-00507.1},
volume = {28},
year = {2015}
}
@article{Gutjahr2017a,
author = {Gutjahr, Marcus and Ridgwell, Andy and Sexton, Philip F and Anagnostou, Eleni and Pearson, Paul N. and P{\"{a}}like, Heiko and Norris, Richard D. and Thomas, Ellen and Foster, Gavin L.},
doi = {10.1038/nature23646},
isbn = {0028-0836},
issn = {14764687},
journal = {Nature},
month = {aug},
number = {7669},
pages = {573--577},
pmid = {28858305},
publisher = {Nature Publishing Group},
title = {{Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum}},
volume = {548},
year = {2017}
}
@article{doi:10.1002/2014JD022985,
abstract = {Abstract Ocean-atmosphere interactions represent a key component of the hydrological cycle in tropical regions and their variability has profound influences on low-latitude climate. In order to evaluate how climate models represent these fluxes while taking into account the observational uncertainties, we assemble a comprehensive database of 14 climatological surface flux products, including in situ-based, satellite, hybrid, and reanalysis data sets. We find that the large observational uncertainties are reflected in the climatological magnitudes, as well as in the spatial patterns and seasonal variations and that, for the most part, they do not carry specific signatures of product type. This data ensemble allows us to draw several conclusions on the current representation of the intertropical turbulent air-sea fluxes in the atmospheric component of the Intitut Pierre Simon Laplace-Coupled Model 5A, when forced by observed sea surface temperatures. Despite significantly underestimated near-surface wind speeds over the entire tropical oceans domain, the atmospheric model produces generally well represented zonal and meridional wind stress values, and only weak biases in the spatial patterns and seasonality. The simulated latent heat flux develops a bias pattern matching that of the wind speed, but with no systematic underestimation. Compared to the same reference, the sensible heat flux is overestimated over the entire region of interest, in response to a significant overestimation of the sea-air temperature contrast. The observational ensemble and analyses presented in this paper offer a good framework for large-scale model surface flux evaluation.},
author = {Găinuşă-Bogdan, Alina and Braconnot, Pascale and Servonnat, J{\'{e}}r{\^{o}}me},
doi = {10.1002/2014JD022985},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {IPSL model,air-sea fluxes,model evaluation,observational ensemble,observational spread,significant model biases},
number = {10},
pages = {4483--4505},
title = {{Using an ensemble data set of turbulent air-sea fluxes to evaluate the IPSL climate model in tropical regions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JD022985},
volume = {120},
year = {2015}
}
@article{HONISCH2005305,
abstract = {Knowledge of past atmospheric pCO2 is important for evaluating the role of greenhouse gases in climate forcing. Ice core records show the tight correlation between climate change and pCO2, but records are limited to the past ∼900 kyr. We present surface ocean pH and PCO2 data, reconstructed from boron isotopes in planktonic foraminifera over two full glacial cycles (0–140 and 300–420 kyr). The data co-vary strongly with the Vostok pCO2-record and demonstrate that the coupling between surface ocean chemistry and the atmosphere is recorded in marine archives, allowing for quantitative estimation of atmospheric pCO2 beyond the reach of ice cores.},
author = {H{\"{o}}nisch, B{\"{a}}rbel and Hemming, N Gary},
doi = {10.1016/j.epsl.2005.04.027},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {boron isotopes,pCO,pH,planktonic foraminifera},
number = {1},
pages = {305--314},
title = {{Surface ocean pH response to variations in pCO2 through two full glacial cycles}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X05002803},
volume = {236},
year = {2005}
}
@article{Honisch2009a,
abstract = {The dominant period of Pleistocene glacial cycles changed during the mid-Pleistocene from 40,000 years to 100,000 years, for as yet unknown reasons. Here we present a 2.1-million-year record of sea surface partial pressure of CO2 (PCO2), based on boron isotopes in planktic foraminifer shells, which suggests that the atmospheric partial pressure of CO2 (pCO2) was relatively stable before the mid-Pleistocene climate transition. Glacial PCO2 was {\~{}}31 microatmospheres higher before the transition (more than 1 million years ago), but interglacial PCO2 was similar to that of late Pleistocene interglacial cycles ({\textless}450,000 years ago). These estimates are consistent with a close linkage between atmospheric CO2 concentration and global climate, but the lack of a gradual decrease in interglacial PCO2 does not support the suggestion that a long-term drawdown of atmospheric CO2 was the main cause of the climate transition.},
author = {H{\"{o}}nisch, B. and Hemming, N. Gary and Archer, David and Siddall, Mark and McManus, Jerry F.},
doi = {10.1126/science.1171477},
isbn = {0036-8075},
issn = {0036-8075},
journal = {Science},
month = {jun},
number = {5934},
pages = {1551--1554},
pmid = {19541994},
title = {{Atmospheric Carbon Dioxide Concentration Across the Mid-Pleistocene Transition}},
url = {http://science.sciencemag.org/content/324/5934/1551.abstract https://www.sciencemag.org/lookup/doi/10.1126/science.1171477},
volume = {324},
year = {2009}
}
@article{acp-15-7017-2015,
author = {H{\"{o}}pfner, M and Boone, C D and Funke, B and Glatthor, N and Grabowski, U and G{\"{u}}nther, A and Kellmann, S and Kiefer, M and Linden, A and Lossow, S and Pumphrey, H C and Read, W G and Roiger, A and Stiller, G and Schlager, H and von Clarmann, T and Wissm{\"{u}}ller, K},
doi = {10.5194/acp-15-7017-2015},
journal = {Atmospheric Chemistry and Physics},
number = {12},
pages = {7017--7037},
title = {{Sulfur dioxide SO2 from MIPAS in the upper troposphere and lower stratosphere 2002–2012}},
url = {https://www.atmos-chem-phys.net/15/7017/2015/},
volume = {15},
year = {2015}
}
@article{article,
author = {H{\o}gda, Kjell and T{\o}mmervik, Hans and Karlsen, Stein},
doi = {10.3390/rs5094304},
issn = {2072-4292},
journal = {Remote Sensing},
month = {sep},
number = {9},
pages = {4304--4318},
title = {{Trends in the Start of the Growing Season in Fennoscandia 1982–2011}},
url = {http://www.mdpi.com/2072-4292/5/9/4304},
volume = {5},
year = {2013}
}
@article{doi:10.1002/2017GL075434,
abstract = {Abstract In April 2017, we collected unique, extensive in situ data of sea ice and snow thickness. At 10 sampling sites, located under a CryoSat-2 overpass, between Ellesmere Island and 87.1°N mean and modal total ice thicknesses ranged between 2 to 3.4 m and 1.8 to 2.9 m, respectively. Coincident snow thicknesses ranged between 0.3 to 0.47 m (mean) and 0.1 to 0.5 m (mode). The profile spanned the complete multiyear ice zone in the Lincoln Sea, into the first-year ice zone farther north. Complementary snow thickness measurements near the North Pole showed a mean thickness of 0.31 m. Compared with scarce measurements from other years, multiyear ice was up to 0.75 m thinner than in 2004, but not significantly different from 2011 and 2014. We found excellent agreement with a commonly used snow climatology and with published long-term ice thinning rates. There was reasonable agreement with CryoSat-2 thickness retrievals.},
author = {Haas, Christian and Beckers, Justin and King, Josh and Silis, Arvids and Stroeve, Julienne and Wilkinson, Jeremy and Notenboom, Bernice and Schweiger, Axel and Hendricks, Stefan},
doi = {10.1002/2017GL075434},
journal = {Geophysical Research Letters},
keywords = {Arctic,CryoSat,sea ice,snow on sea ice,thickness},
number = {20},
pages = {10,410--462,469},
title = {{Ice and Snow Thickness Variability and Change in the High Arctic Ocean Observed by In Situ Measurements}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL075434},
volume = {44},
year = {2017}
}
@article{Haimberger2017,
author = {Haimberger, L and Mayer, M},
doi = {10.1175/2017BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S39--S41},
title = {{Upper air winds [in “State of the Climate in 2016”]}},
volume = {98},
year = {2017}
}
@article{doi:10.1175/JCLI-D-11-00668.1,
abstract = {AbstractThis article describes progress in the homogenization of global radiosonde temperatures with updated versions of the Radiosonde Observation Correction Using Reanalyses (RAOBCORE) and Radiosonde Innovation Composite Homogenization (RICH) software packages. These are automated methods to homogenize the global radiosonde temperature dataset back to 1958. The break dates are determined from analysis of time series of differences between radiosonde temperatures (obs) and background forecasts (bg) of climate data assimilation systems used for the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and the ongoing interim ECMWF Re-Analysis (ERA-Interim).RAOBCORE uses the obs−bg time series also for estimating the break sizes. RICH determines the break sizes either by comparing the observations of a tested time series with observations of neighboring radiosonde time series (RICH-obs) or by comparing their background departures (RICH-$\tau$). Consequently RAOBCORE results may be influenced by inhomogeneities in the bg, whereas break size estimation with RICH-obs is independent of the bg. The adjustment quality of RICH-obs, on the other hand, may suffer from large interpolation errors at remote stations. RICH-$\tau$ is a compromise that substantially reduces interpolation errors at the cost of slight dependence on the bg.Adjustment uncertainty is estimated by comparing the three methods and also by varying parameters in RICH. The adjusted radiosonde time series are compared with recent temperature datasets based on (Advanced) Microwave Sounding Unit [(A)MSU] radiances. The overall spatiotemporal consistency of the homogenized dataset has improved compared to earlier versions, particularly in the presatellite era. Vertical profiles of temperature trends are more consistent with satellite data as well.},
author = {Haimberger, Leopold and Tavolato, Christina and Sperka, Stefan},
doi = {10.1175/JCLI-D-11-00668.1},
journal = {Journal of Climate},
number = {23},
pages = {8108--8131},
title = {{Homogenization of the Global Radiosonde Temperature Dataset through Combined Comparison with Reanalysis Background Series and Neighboring Stations}},
url = {https://doi.org/10.1175/JCLI-D-11-00668.1},
volume = {25},
year = {2012}
}
@article{Hain2018,
abstract = {Abstract The atmospheric concentration of the greenhouse gas carbon dioxide, CO2, is intimately coupled to the carbon chemistry of seawater, such that the radiative climate forcing from CO2 can be changed by an array of physical, geochemical, and biological ocean processes. For instance, biological carbon sequestration, seawater cooling, and net CaCO3 dissolution are commonly invoked as the primary drivers of CO2 change that amplify the orbitally paced ice age cycles of the late Pleistocene. Based on first-principle arguments with regard to ocean chemistry, we demonstrate that seawater pH change (?pH) is the dominant control that effectively sets CO2 radiative forcing (?F) on orbital timescales, as is evident from independent late Pleistocene reconstructions of pH and CO2. In short, all processes relevant for CO2on orbital timescales, including temperature change, cause pH to change to bring about fractional CO2 change so as to yield a linear relationship of ?pH to CO2 climate forcing. Further, we show that ?pH and CO2 climate forcing can be reconstructed using the boron isotope pH proxy more accurately than absolute pH or CO2, even if seawater boron isotope composition is poorly constrained and without information on a second carbonate system parameter. Thus, our formalism relaxes otherwise necessary assumptions to allow the accurate determination of orbital timescale CO2 radiative forcing from boron isotope pH reconstructions alone, thereby eliminating a major limitation of current methods to estimate our planet's climate sensitivity from the geologic record.},
annote = {doi: 10.1029/2018PA003362},
author = {Hain, M P and Foster, G L and Chalk, T},
doi = {10.1029/2018PA003362},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {boron isotope proxy,carbon dioxide,climate forcing,pH,paleoclimate},
month = {oct},
number = {10},
pages = {1099--1115},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Robust Constraints on Past CO2 Climate Forcing From the Boron Isotope Proxy}},
url = {https://doi.org/10.1029/2018PA003362},
volume = {33},
year = {2018}
}
@article{doi:10.1029/2008GL034791,
abstract = {Sea ice drift data (from Russian North Pole stations, various ice camps, and the International Arctic Buoy Program) and surface wind stress data from the NCAR/NCEP Reanalysis are analyzed to determine their long-term trends and causality. The study finds that both parameters (ice drift and wind stress) show gradual acceleration over last 50 years. Significant positive trends are present in both winter and summer data. The major cause of observed positive trends is increasing Arctic storm activity over the Transpolar Drift Stream caused by a shift of storm tracks toward higher latitudes. It is speculated, with some observational evidence, that the increased stirring of the ocean by winds could hasten the transition of the Arctic toward a weakly stratified ocean with a potential for deep convection and a new sink for atmospheric CO2.},
author = {Hakkinen, Sirpa and Proshutinsky, Andrey and Ashik, Igor},
doi = {10.1029/2008GL034791},
journal = {Geophysical Research Letters},
keywords = {Arctic and Antarctic oceanography,climate variability,ice mechanics and air/sea/ice exchange processes},
number = {19},
pages = {L19704},
title = {{Sea ice drift in the Arctic since the 1950s}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2008GL034791},
volume = {35},
year = {2008}
}
@article{Hammer2018,
abstract = {Abstract. Observations of aerosol scattering and absorption offer valuable information about aerosol composition. We apply a simulation of the Ultraviolet Aerosol Index (UVAI), a method of detecting aerosol absorption from satellite observations, to interpret UVAI values observed by the Ozone Monitoring Instrument (OMI) from 2005 to 2015 to understand global trends in aerosol composition. We conduct our simulation using the vector radiative transfer model VLIDORT with aerosol fields from the global chemical transport model GEOS-Chem. We examine the 2005–2015 trends in individual aerosol species from GEOS-Chem and apply these trends to the UVAI simulation to calculate the change in simulated UVAI due to the trends in individual aerosol species. We find that global trends in the UVAI are largely explained by trends in absorption by mineral dust, absorption by brown carbon, and scattering by secondary inorganic aerosol. Trends in absorption by mineral dust dominate the simulated UVAI trends over North Africa, the Middle East, East Asia, and Australia. The UVAI simulation resolves observed negative UVAI trends well over Australia, but underestimates positive UVAI trends over North Africa and Central Asia near the Aral Sea and underestimates negative UVAI trends over East Asia. We find evidence of an increasing dust source from the desiccating Aral Sea that may not be well represented by the current generation of models. Trends in absorption by brown carbon dominate the simulated UVAI trends over biomass burning regions. The UVAI simulation reproduces observed negative trends over central South America and West Africa, but underestimates observed UVAI trends over boreal forests. Trends in scattering by secondary inorganic aerosol dominate the simulated UVAI trends over the eastern United States and eastern India. The UVAI simulation slightly overestimates the observed positive UVAI trends over the eastern United States and underestimates the observed negative UVAI trends over India. Quantitative simulation of the OMI UVAI offers new insight into global trends in aerosol composition.},
author = {Hammer, Melanie S. and Martin, Randall V. and Li, Chi and Torres, Omar and Manning, Max and Boys, Brian L.},
doi = {10.5194/acp-18-8097-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jun},
number = {11},
pages = {8097--8112},
title = {{Insight into global trends in aerosol composition from 2005 to 2015 inferred from the OMI Ultraviolet Aerosol Index}},
url = {https://www.atmos-chem-phys.net/18/8097/2018/},
volume = {18},
year = {2018}
}
@article{Hammond2018a,
author = {Hammond, John C. and Saavedra, Freddy A. and Kampf, Stephanie K.},
doi = {10.1002/joc.5674},
issn = {08998418},
journal = {International Journal of Climatology},
month = {oct},
number = {12},
pages = {4369--4383},
title = {{Global snow zone maps and trends in snow persistence 2001–2016}},
url = {http://doi.wiley.com/10.1002/joc.5674},
volume = {38},
year = {2018}
}
@article{Han2019b,
author = {Han, Zixuan and Su, Tao and Huang, Bicheng and Feng, Taichen and Qu, Shulin and Feng, Guolin},
doi = {10.1002/joc.5896},
journal = {International Journal of Climatology},
number = {3},
pages = {1490--1503},
title = {{Changes in global monsoon precipitation and the related dynamic and thermodynamic mechanisms in recent decades}},
volume = {39},
year = {2019}
}
@article{Han2013,
author = {Han, Weiqing and Meehl, Gerald A and Hu, Aixue and Alexander, Michael A and Yamagata, Toshio and Yuan, Dongliang and Ishii, Masayoshi and Pegion, Philip and Zheng, Jian and Hamlington, Benjamin D. and Quan, Xiao-Wei and Leben, Robert R.},
doi = {10.1007/s00382-013-1951-1},
issn = {0930-7575},
journal = {Climate Dynamics},
keywords = {decadal {\'{a}} multidecadal {\'{a}},department of atmospheric and,han,indian ocean warming,oceanic sciences,pacific decadal variability {\'{a}},sea level {\'{a}},university of,w,zheng,{\'{a}} j},
month = {sep},
number = {5-6},
pages = {1357--1379},
title = {{Intensification of decadal and multi-decadal sea level variability in the western tropical Pacific during recent decades}},
url = {http://link.springer.com/10.1007/s00382-013-1951-1},
volume = {43},
year = {2014}
}
@article{Hanna2015,
author = {Hanna, Edward and Cropper, Thomas E and Jones, Philip D and Scaife, Adam A and Allan, Rob},
doi = {10.1002/joc.4157},
issn = {08998418},
journal = {International Journal of Climatology},
month = {jul},
number = {9},
pages = {2540--2554},
title = {{Recent seasonal asymmetric changes in the NAO (a marked summer decline and increased winter variability) and associated changes in the AO and Greenland Blocking Index}},
url = {http://doi.wiley.com/10.1002/joc.4157},
volume = {35},
year = {2015}
}
@article{Hanna2018a,
abstract = {We present a homogenized Greenland blocking index (GBI) daily record from 1851 to 2015, therefore significantly extending our previously published monthly/seasonal GBI analysis. This new time series is analysed for evidence of changes in extreme events, and we investigate the underlying thermodynamic and dynamic precursors. We compare occurrences and changes in extreme events between our GBI record and a recently published, temporally similar daily North Atlantic Oscillation (NAO) series, and use this comparison to test dynamic meteorology hypotheses relating negative NAO to Greenland blocking. We also compare daily GBI changes and extreme events with long?running indices of England and Wales temperature and precipitation, to assess potential downstream effects of Greenland blocking on UK extreme weather events and climate change. In this extended analysis we show that there have been sustained periods of positive GBI during 1870?1900 and from the late 1990s to present. A clustering of extreme high GBI events since 2000 is not consistently reflected by a similar grouping of extreme low NAO events. Case studies of North Atlantic atmospheric circulation changes linked with extreme high and low daily GBI episodes are used to shed light on potential linkages between Greenland blocking and jet?stream changes. Particularly noteworthy is a clustering of extreme high GBI events during mid?October in 4 out of 5 years during 2002?2006, which we investigate from both cryospheric and dynamic meteorology perspectives. Supporting evidence suggests that these autumn extreme GBI episodes may have been influenced by regional sea?ice anomalies off west Greenland but were probably largely forced by increases in Rossby?wave train activity originating from the tropical Pacific. However, more generally our results indicate that high GBI winter anomalies are co?located with sea?ice anomalies, while there seems to be minimal influence of sea?ice anomalies on the recent significant increase in summer GBI.},
author = {Hanna, E and Hall, R J and Cropper, T E and Ballinger, T J and Wake, L and Mote, T and Cappelen, J},
doi = {10.1002/joc.5516},
issn = {10970088},
journal = {International Journal of Climatology},
number = {9},
pages = {3546--3564},
title = {{Greenland blocking index daily series 1851–2015: Analysis of changes in extremes and links with North Atlantic and UK climate variability and change}},
volume = {38},
year = {2018}
}
@article{Hanna2016,
author = {Hanna, Edward and Cropper, Thomas E and Hall, Richard J and Cappelen, John},
doi = {10.1002/joc.4673},
issn = {0899-8418},
journal = {International Journal of Climatology},
month = {dec},
number = {15},
pages = {4847--4861},
title = {{Greenland Blocking Index 1851–2015: a regional climate change signal}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.4673},
volume = {36},
year = {2016}
}
@article{Hansen2013a,
abstract = {Time series (1990-2011) of sea ice thickness observed by moored sonars in the Transpolar Drift in Fram Strait are examined. Contrasting the post-2007 years against the 1990s, three remarkable changes in the monthly ice thickness distributions are highlighted: (1) The thickness of old level ice (modal thickness) is reduced by 32{\%}, (2) the old ice modal peak width is reduced by 25{\%}, and (3) the fraction of (ridged) ice thicker than 5 m is reduced by 50{\%}. The combined effect on the mean ice thickness is a reduction from an annual average of 3.0 m during the 1990s to 2.2 m during 2008-2011. Most of the thinning took place after 2005-2006. While the old ice modal thickness and peak width show signs of recovery after 2008, the decreasing trend in fraction of ridged ice and mean ice thickness persists until the end of the record in 2011. The ice observed in Fram Strait carries an integrated signal of Arctic change due to the advection of ice from many sites in the Arctic. Based on concurrence in timing, we conclude that much of the thinning quantified here is reflecting recent change in the age composition of the Arctic ice cover toward younger ice. The old level ice remains thin, and as such the ice cover remains preconditioned for new summers of very low sea ice extent.},
author = {Hansen, E. and Gerland, S. and Granskog, M. A. and Pavlova, O. and Renner, A. H. H. and Haapala, J. and L{\o}yning, T. B. and Tschudi, M.},
doi = {10.1002/jgrc.20393},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {sea ice change},
month = {oct},
number = {10},
pages = {5202--5221},
title = {{Thinning of Arctic sea ice observed in Fram Strait: 1990–2011}},
url = {http://doi.wiley.com/10.1002/jgrc.20393},
volume = {118},
year = {2013}
}
@article{Hansen,
abstract = {Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3±1(°)C for a 4 W m(-2) CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3-4(°)C for a 4 W m(-2) CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.},
author = {Hansen, James and Sato, Makiko and Russell, Gary and Kharecha, Pushker},
doi = {10.1098/rsta.2012.0294},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
number = {2001},
pages = {20120294},
publisher = {The Royal Society Publishing},
title = {{Climate sensitivity, sea level and atmospheric carbon dioxide}},
volume = {371},
year = {2013}
}
@article{Hansen2015a,
author = {Hansen, B and Larsen, K M H and H{\'{a}}t{\'{u}}n, H and Kristiansen, R and Mortensen, E and {\O}sterhus, S},
doi = {10.5194/os-11-743-2015},
issn = {1812-0792},
journal = {Ocean Science},
month = {sep},
number = {5},
pages = {743--757},
publisher = {Copernicus Publications},
title = {{Transport of volume, heat, and salt towards the Arctic in the Faroe Current 1993–2013}},
url = {https://os.copernicus.org/articles/11/743/2015/ https://os.copernicus.org/articles/11/743/2015/os-11-743-2015.pdf},
volume = {11},
year = {2015}
}
@article{2018QSRv..189...31H,
author = {Harning, David J and Geirsd{\'{o}}ttir, {\'{A}}slaug and Miller, Gifford H},
doi = {10.1016/j.quascirev.2018.04.009},
journal = {Quaternary Science Reviews},
keywords = {8.2 ka event,Dead vegetation,Glaciers,Holocene,Iceland,Lake sediment,Little Ice Age,Neoglaciation,North Atlantic,Paleoclimate},
month = {jun},
pages = {31--42},
title = {{Punctuated Holocene climate of Vestfirðir, Iceland, linked to internal/external variables and oceanographic conditions}},
volume = {189},
year = {2018}
}
@article{2016QSRv..152..118H,
author = {Harning, David J and Geirsd{\'{o}}ttir, {\'{A}}slaug and Miller, Gifford H and Anderson, Leif},
doi = {10.1016/j.quascirev.2016.10.001},
journal = {Quaternary Science Reviews},
keywords = {Dead vegetation,Drangaj{\"{o}}kull,Glaciers,Iceland,Lake sediment,Little Ice Age,Moraines,Paleoclimate,Sea ice},
month = {nov},
pages = {118--131},
title = {{Episodic expansion of Drangaj{\"{o}}kull, Vestfirdir, Iceland, over the last 3 ka culminating in its maximum dimension during the Little Ice Age}},
volume = {152},
year = {2016}
}
@article{Harper2020,
abstract = {Abstract Eocene Thermal Maximum 2 (ETM-2; 54.1 Ma) was the second largest Eocene hyperthermal. Like the Paleocene-Eocene Thermal Maximum (PETM), ETM-2 was characterized by massive carbon emissions and several degrees of global warming and thus can serve as a case study for assessing the impacts of rapid CO2 emissions on ocean carbonate chemistry, biota, and climate. Marine carbonate records of ETM-2 are better preserved than those of the PETM due to more subdued carbonate dissolution. As yet, however, the magnitude of this carbon cycle perturbation has not been well constrained. Here, we present the first records of surface ocean acidification for ETM-2, based on stable boron isotope records in mixed-layer planktic foraminifera from two midlatitude ODP sites (1210 in the North Pacific and 1265 in the SE Atlantic), which indicate conservative minimum global sea surface acidification of ?0.20 +0.12/?0.13 pH units. Using these estimates of pH and temperature as constraints on carbon cycle model simulations, we conclude that the total mass of C, released over a period of 15 to 25 kyr during ETM-2, likely ranged from 2,600 to 3,800 Gt C, which is greater than previously estimated on the basis of other observations (i.e., stable carbon isotopes and carbonate compensation depth) alone.},
annote = {doi: 10.1029/2019PA003699},
author = {Harper, D T and H{\"{o}}nisch, B and Zeebe, R E and Shaffer, G and Haynes, L L and Thomas, E and Zachos, J C},
doi = {10.1029/2019PA003699},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {ETM-2,PETM,boron isotope,carbon isotope,hyperthermal,ocean acidification},
month = {feb},
number = {2},
pages = {e2019PA003699},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{The Magnitude of Surface Ocean Acidification and Carbon Release During Eocene Thermal Maximum 2 (ETM-2) and the Paleocene–Eocene Thermal Maximum (PETM)}},
url = {https://doi.org/10.1029/2019PA003699},
volume = {35},
year = {2020}
}
@article{Harris2014,
abstract = {This paper describes the construction of an updated gridded climate dataset (referred to as CRU TS3.10) from monthly observations at meteorological stations across the world's land areas. Station anomalies (from 1961 to 1990 means) were interpolated into 0.5° latitude/longitude grid cells covering the global land surface (excluding Antarctica), and combined with an existing climatology to obtain absolute monthly values. The dataset includes six mostly independent climate variables (mean temperature, diurnal temperature range, precipitation, wet-day frequency, vapour pressure and cloud cover). Maximum and minimum temperatures have been arithmetically derived from these. Secondary variables (frost day frequency and potential evapotranspiration) have been estimated from the six primary variables using well-known formulae. Time series for hemispheric averages and 20 large sub-continental scale regions were calculated (for mean, maximum and minimum temperature and precipitation totals) and compared to a number of similar gridded products. The new dataset compares very favourably, with the major deviations mostly in regions and/or time periods with sparser observational data. CRU TS3.10 includes diagnostics associated with each interpolated value that indicates the number of stations used in the interpolation, allowing determination of the reliability of values in an objective way. This gridded product will be publicly available, including the input station series (http://www.cru.uea.ac.uk/ and http://badc.nerc.ac.uk/data/cru/). {\textcopyright} 2013 Royal Meteorological Society},
author = {Harris, I. and Jones, P. D. and Osborn, T. J. and Lister, D. H.},
doi = {10.1002/joc.3711},
isbn = {1097-0088},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {Gridded climate data,High resolution,Precipitation,Temperature},
number = {3},
pages = {623--642},
title = {{Updated high-resolution grids of monthly climatic observations – the CRU TS3.10 Dataset}},
volume = {34},
year = {2014}
}
@article{Harrison2014,
abstract = {Past climates provide a test of models' ability to predict climate change. We present a comprehensive evaluation of state-of-the-art models against Last Glacial Maximum and mid-Holocene climates, using reconstructions of land and ocean climates and simulations from the Palaeoclimate Modelling and Coupled Modelling Intercomparison Projects. Newer models do not perform better than earlier versions despite higher resolution and complexity. Differences in climate sensitivity only weakly account for differences in model performance. In the glacial, models consistently underestimate land cooling (especially in winter) and overestimate ocean surface cooling (especially in the tropics). In the mid-Holocene, models generally underestimate the precipitation increase in the northern monsoon regions, and overestimate summer warming in central Eurasia. Models generally capture large-scale gradients of climate change but have more limited ability to reproduce spatial patterns. Despite these common biases, some models perform better than others.},
author = {Harrison, S P and Bartlein, P J and Brewer, S and Prentice, I C and Boyd, M and Hessler, I and Holmgren, K and Izumi, K and Willis, K},
doi = {10.1007/s00382-013-1922-6},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {aug},
number = {3},
pages = {671--688},
title = {{Climate model benchmarking with glacial and mid-Holocene climates}},
url = {https://doi.org/10.1007/s00382-013-1922-6},
volume = {43},
year = {2014}
}
@article{Harrison2015,
author = {Harrison, S P and Bartlein, P J and Izumi, K and Li, G and Annan, J and Hargreaves, J and Braconnot, P and Kageyama, M},
doi = {10.1038/nclimate2649},
journal = {Nature Climate Change},
month = {jul},
pages = {735},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Evaluation of CMIP5 palaeo-simulations to improve climate projections}},
url = {http://dx.doi.org/10.1038/nclimate2649 http://10.0.4.14/nclimate2649 https://www.nature.com/articles/nclimate2649{\#}supplementary-information},
volume = {5},
year = {2015}
}
@article{Harrison2016,
author = {Harrison, S.P. and Bartlein, P.J. and Prentice, I.C.},
doi = {10.1002/jqs.2842},
journal = {Journal of Quaternary Science},
number = {4},
pages = {363--385},
title = {{What have we learnt from palaeoclimate simulations?}},
volume = {31},
year = {2016}
}
@article{gmd-13-805-2020,
abstract = {Paper under review},
author = {Harrison, S P and Gaillard, M.-J. and Stocker, B D and {Vander Linden}, M and {Klein Goldewijk}, K and Boles, O and Braconnot, P and Dawson, A and Fluet-Chouinard, E and Kaplan, J O and Kastner, T and Pausata, F S R and Robinson, E and Whitehouse, N J and Madella, M and Morrison, K D},
doi = {10.5194/gmd-13-805-2020},
journal = {Geoscientific Model Development},
number = {2},
pages = {805--824},
title = {{Development and testing scenarios for implementing land use and land cover changes during the Holocene in Earth system model experiments}},
url = {https://gmd.copernicus.org/articles/13/805/2020/},
volume = {13},
year = {2020}
}
@article{Harsch2009,
abstract = {Treelines are temperature sensitive transition zones that are expected to respond to climate warming by advancing beyond their current position. Response to climate warming over the last century, however, has been mixed, with some treelines showing evidence of recruitment at higher altitudes and/or latitudes (advance) whereas others reveal no marked change in the upper limit of tree establishment. To explore this variation, we analysed a global dataset of 166 sites for which treeline dynamics had been recorded since 1900 AD. Advance was recorded at 52{\%} of sites with only 1{\%} reporting treeline recession. Treelines that experienced strong winter warming were more likely to have advanced, and treelines with a diffuse form were more likely to have advanced than those with an abrupt or krummholz form. Diffuse treelines may be more responsive to warming because they are more strongly growth limited, whereas other treeline forms may be subject to additional constraints.},
author = {Harsch, Melanie A. and Hulme, Philip E. and McGlone, Matt S. and Duncan, Richard P.},
doi = {10.1111/j.1461-0248.2009.01355.x},
isbn = {1461-023X},
issn = {1461023X},
journal = {Ecology Letters},
keywords = {Abrupt,Advance,Climate change,Diffuse,Forest dynamics,Global meta-analysis,Krummholz,Temperature,Treeline},
month = {oct},
number = {10},
pages = {1040--1049},
pmid = {19682007},
title = {{Are treelines advancing? A global meta-analysis of treeline response to climate warming}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/j.1461-0248.2009.01355.x},
volume = {12},
year = {2009}
}
@incollection{Hartmann2013159,
address = {Cambridge, United Kingdom and New York, NY, USA},
annote = {cited By 986},
author = {Hartmann, D L and {Klein Tank}, A M G and Rusticucci, M and Alexander, L V and Br{\"{o}}nnimann, S and Charabi, Y.A.-R. and Dentener, F J and Dlugokencky, E J and Easterling, D R and Kaplan, A and Soden, B J and Thorne, P W and Wild, M and Zhai, P},
booktitle = {Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
doi = {10.1017/CBO9781107415324.008},
editor = {Stocker, T F and Qin, D and Plattner, G K and Tignor, M and Allen, S K and Boschung, J and Nauels, A and Xia, Y and Bex, V and Midgley, P M},
pages = {159--254},
publisher = {Cambridge University Press},
title = {{Observations: Atmosphere and surface}},
year = {2013}
}
@article{Hassanzadeh2014,
author = {Hassanzadeh, P and Kuang, Z and Farrell, B F},
doi = {10.1002/2014GL060764},
journal = {Geophysical Research Letters},
number = {14},
pages = {5223--5232},
title = {{Responses of midlatitude blocks and wave amplitude to changes in the meridional temperature gradient in an idealized dry GCM}},
volume = {41},
year = {2014}
}
@article{HAUG201738,
abstract = {Global warming drives changes in oceanographic conditions in the Arctic Ocean and the adjacent continental slopes. This may result in favourable conditions for increased biological production in waters at the northern continental shelves. However, production in the central Arctic Ocean will continue to be limited by the amount of light and by vertical stratification reducing nutrient availability. Upwelling conditions due to topography and inflowing warm and nutrient rich Atlantic Water may result in high production in areas along the shelf breaks. This may particularly influence distribution and abundance of sea mammals, as can be seen from analysis of historical records of hunting. The species composition and biomass of plankton, fish and shellfish may be influenced by acidification due to increased carbon dioxide uptake in the water, thereby reducing the survival of some species. Northwards shift in the distribution of commercial species of fish and shellfish is observed in the Barents Sea, especially in the summer period, and is related to increased inflow of Atlantic Water and reduced ice cover. This implies a northward extension of boreal species and potential displacement of lipid-rich Arctic zooplankton, altering the distribution of organisms that depend on such prey. However, euphausiid stocks expanding northward into the Arctic Ocean may be a valuable food resource as they may benefit from increases in Arctic phytoplankton production and rising water temperatures. Even though no scenario modelling or other prediction analyses have been made, both scientific ecosystem surveys in the northern areas, as well as the fisheries show indications of a recent northern expansion of mackerel (Scomber scombrus), cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and capelin (Mallotus villosus). These stocks are found as far north as the shelf-break north of Svalbard. Greenland halibut (Reinhardtius hippoglossoides), redfish (Sebastes spp.) and shrimp (Pandalus borealis) are also present in the slope waters between the Barents Sea and the Arctic Ocean. It is assumed that cod and haddock have reached their northernmost limit, whereas capelin and redfish have potential to expand their distribution further into the Arctic Ocean. Common minke whales (Balaenoptera acutorostrata) and harp seals (Pagophilus groenlandicus) may also be able to expand their distribution into the Arctic Ocean. The abundance and distribution of other species may change as well – to what degree is unknown.},
author = {Haug, Tore and Bogstad, Bjarte and Chierici, Melissa and Gj{\o}s{\ae}ter, Harald and Hallfredsson, Elvar H and H{\o}ines, {\AA}ge S and Hoel, Alf H{\aa}kon and Ingvaldsen, Randi B and J{\o}rgensen, Lis Lindal and Knutsen, Tor and Loeng, Harald and Naustvoll, Lars-Johan and R{\o}ttingen, Ingolf and Sunnan{\aa}, Knut},
doi = {10.1016/j.fishres.2016.12.002},
issn = {0165-7836},
journal = {Fisheries Research},
keywords = {Biological production,Climate change,Fish,Mammals,Oceanography},
pages = {38--57},
title = {{Future harvest of living resources in the Arctic Ocean north of the Nordic and Barents Seas: A review of possibilities and constraints}},
url = {http://www.sciencedirect.com/science/article/pii/S0165783616304131},
volume = {188},
year = {2017}
}
@article{Hausfathere1601207,
abstract = {Sea surface temperature (SST) records are subject to potential biases due to changing instrumentation and measurement practices. Significant differences exist between commonly used composite SST reconstructions from the National Oceanic and Atmospheric Administration{\{}$\backslash$textquoteright{\}}s Extended Reconstruction Sea Surface Temperature (ERSST), the Hadley Centre SST data set (HadSST3), and the Japanese Meteorological Agency{\{}$\backslash$textquoteright{\}}s Centennial Observation-Based Estimates of SSTs (COBE-SST) from 2003 to the present. The update from ERSST version 3b to version 4 resulted in an increase in the operational SST trend estimate during the last 19 years from 0.07{\{}$\backslash$textdegree{\}} to 0.12{\{}$\backslash$textdegree{\}}C per decade, indicating a higher rate of warming in recent years. We show that ERSST version 4 trends generally agree with largely independent, near-global, and instrumentally homogeneous SST measurements from floating buoys, Argo floats, and radiometer-based satellite measurements that have been developed and deployed during the past two decades. We find a large cooling bias in ERSST version 3b and smaller but significant cooling biases in HadSST3 and COBE-SST from 2003 to the present, with respect to most series examined. These results suggest that reported rates of SST warming in recent years have been underestimated in these three data sets.},
author = {Hausfather, Zeke and Cowtan, Kevin and Clarke, David C and Jacobs, Peter and Richardson, Mark and Rohde, Robert},
doi = {10.1126/sciadv.1601207},
journal = {Science Advances},
number = {1},
pages = {e1601207},
publisher = {American Association for the Advancement of Science},
title = {{Assessing recent warming using instrumentally homogeneous sea surface temperature records}},
url = {http://advances.sciencemag.org/content/3/1/e1601207},
volume = {3},
year = {2017}
}
@article{Hay2015,
abstract = {Estimating and accounting for twentieth-century global mean sea-level (GMSL) rise is critical to characterizing current and future human-induced sea-level change. Several previous analyses of tide gauge records1, 2, 3, 4, 5, 6—employing different methods to accommodate the spatial sparsity and temporal incompleteness of the data and to constrain the geometry of long-term sea-level change—have concluded that GMSL rose over the twentieth century at a mean rate of 1.6 to 1.9 millimetres per year. Efforts to account for this rate by summing estimates of individual contributions from glacier and ice-sheet mass loss, ocean thermal expansion, and changes in land water storage fall significantly short in the period before 19907. The failure to close the budget of GMSL during this period has led to suggestions that several contributions may have been systematically underestimated8. However, the extent to which the limitations of tide gauge analyses have affected estimates of the GMSL rate of change is unclear. Here we revisit estimates of twentieth-century GMSL rise using probabilistic techniques9, 10 and find a rate of GMSL rise from 1901 to 1990 of 1.2 ± 0.2 millimetres per year (90{\%} confidence interval). Based on individual contributions tabulated in the Fifth Assessment Report7 of the Intergovernmental Panel on Climate Change, this estimate closes the twentieth-century sea-level budget. Our analysis, which combines tide gauge records with physics-based and model-derived geometries of the various contributing signals, also indicates that GMSL rose at a rate of 3.0 ± 0.7 millimetres per year between 1993 and 2010, consistent with prior estimates from tide gauge records4. The increase in rate relative to the 1901–90 trend is accordingly larger than previously thought; this revision may affect some projections11 of future sea-level rise.},
author = {Hay, Carling C. and Morrow, Eric and Kopp, Robert E. and Mitrovica, Jerry X.},
doi = {10.1038/nature14093},
isbn = {1476-4687},
issn = {14764687},
journal = {Nature},
number = {7535},
pages = {481--484},
pmid = {25629092},
title = {{Probabilistic reanalysis of twentieth-century sea-level rise}},
volume = {517},
year = {2015}
}
@article{Hayes2014,
abstract = {During the last interglacial period, global temperatures were {\~{}}2°C warmer than at present and sea level was 6 to 8 meters higher. Southern Ocean sediments reveal a spike in authigenic uranium 127,000 years ago, within the last interglacial, reflecting decreased oxygenation of deep water by Antarctic Bottom Water (AABW). Unlike ice age reductions in AABW, the interglacial stagnation event appears decoupled from open ocean conditions and may have resulted from coastal freshening due to mass loss from the Antarctic ice sheet. AABW reduction coincided with increased North Atlantic Deep Water (NADW) formation, and the subsequent reinvigoration in AABW coincided with reduced NADW formation. Thus, alternation of deep water formation between the Antarctic and the North Atlantic, believed to characterize ice ages, apparently also occurs in warm climates. During the last interglacial period, Antarctic Bottom Water (AABW) formation slowed markedly. This densest ocean water sinks to the bottom of the sea, and its production helps to flush the oceans and eventually to recycle the carbon dioxide (CO2) that forms from sinking organic matter back into the atmosphere. If the AABW production rate decreases, then CO2 accumulates at depth, potentially causing a corresponding drop in atmospheric CO2 concentration. Hayes et al. found evidence, in the form of a uranium spike, in deep sea sediments that such a slowdown in AABW formation occurred ∼127,000 years ago, which may have caused the atmospheric CO2 minimum observed at that time. Science, this issue p. 1514},
author = {Hayes, Christopher T and Mart{\'{i}}nez-Garc{\'{i}}a, Alfredo and Hasenfratz, Adam P and Jaccard, Samuel L and Hodell, David A and Sigman, Daniel M and Haug, Gerald H and Anderson, Robert F},
doi = {10.1126/science.1256620},
journal = {Science},
month = {dec},
number = {6216},
pages = {1514},
title = {{A stagnation event in the deep South Atlantic during the last interglacial period}},
url = {http://science.sciencemag.org/content/346/6216/1514.abstract},
volume = {346},
year = {2014}
}
@article{haywood_identification_2013,
abstract = {The characteristics of the mid-Pliocene warm period (mPWP: 3.264–3.025 Ma BP) have been examined using geological proxies and climate models. While there is agreement between models and data, details of regional climate differ. Uncertainties in prescribed forcings and in proxy data limit the utility of the interval to understand the dynamics of a warmer than present climate or evaluate models. This uncertainty comes, in part, from the reconstruction of a time slab rather than a time slice , where forcings required by climate models can be more adequately constrained. Here, we describe the rationale and approach for identifying a time slice(s) for Pliocene environmental reconstruction. A time slice centred on 3.205 Ma BP (3.204–3.207 Ma BP) has been identified as a priority for investigation. It is a warm interval characterized by a negative benthic oxygen isotope excursion (0.21–0.23‰) centred on marine isotope stage KM5c (KM5.3). It occurred during a period of orbital forcing that was very similar to present day. Climate model simulations indicate that proxy temperature estimates are unlikely to be significantly affected by orbital forcing for at least a precession cycle centred on the time slice, with the North Atlantic potentially being an important exception.},
author = {Haywood, Alan M. and Dolan, Aisling M. and Pickering, Steven J. and Dowsett, Harry J. and McClymont, Erin L. and Prescott, Caroline L. and Salzmann, Ulrich and Hill, Daniel J. and Hunter, Stephen J. and Lunt, Daniel J. and Pope, James O. and Valdes, Paul J.},
doi = {10.1098/rsta.2012.0515},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Climate models,Climate sensitivity,Earth system sensitivity,Pliocene},
month = {oct},
number = {2001},
pages = {20120515},
title = {{On the identification of a Pliocene time slice for data–model comparison}},
url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2012.0515},
volume = {371},
year = {2013}
}
@article{cp-16-2095-2020,
author = {Haywood, A M and Tindall, J C and Dowsett, H J and Dolan, A M and Foley, K M and Hunter, S J and Hill, D J and Chan, W.-L. and Abe-Ouchi, A and Stepanek, C and Lohmann, G and Chandan, D and Peltier, W R and Tan, N and Contoux, C and Ramstein, G and Li, X and Zhang, Z and Guo, C and Nisancioglu, K H and Zhang, Q and Li, Q and Kamae, Y and Chandler, M A and Sohl, L E and Otto-Bliesner, B L and Feng, R and Brady, E C and von der Heydt, A S and Baatsen, M L J and Lunt, D J},
doi = {10.5194/cp-16-2095-2020},
journal = {Climate of the Past},
number = {6},
pages = {2095--2123},
title = {{The Pliocene Model Intercomparison Project Phase 2: large-scale climate features and climate sensitivity}},
url = {https://cp.copernicus.org/articles/16/2095/2020/},
volume = {16},
year = {2020}
}
@article{Haywood2016a,
author = {Haywood, Alan M and Dowsett, Harry J and Dolan, Aisling M},
doi = {10.1038/ncomms10646},
journal = {Nature Communications},
month = {feb},
pages = {10646},
publisher = {The Author(s)},
title = {{Integrating geological archives and climate models for the mid-Pliocene warm period}},
url = {https://doi.org/10.1038/ncomms10646 http://10.0.4.14/ncomms10646},
volume = {7},
year = {2016}
}
@article{He2014,
abstract = {Surface albedo changes from anthropogenic land cover change (ALCC) represent the second largest negative radiative forcing behind aerosol during the industrial era. Using a new reconstruction of ALCC during the Holocene era by Kaplan et al. (2011), we quantify the local and global temperature response induced by Holocene ALCC in the Community Climate System Model, version 4. We find that Holocene ALCC causes a global cooling of 0.17°C due to the biogeophysical effects of land-atmosphere exchange of momentum, moisture, and radiative and heat fluxes. On the global scale, the biogeochemical effects of Holocene ALCC from carbon emissions dominate the biogeophysical effects by causing 0.9°C global warming. The net effects of Holocene ALCC amount to a global warming of 0.73°C during the preindustrial era, which is comparable to the {\~{}}0.8°C warming during industrial times. On local to regional scales, such as parts of Europe, North America, and Asia, the biogeophysical effects of Holocene ALCC are significant and comparable to the biogeochemical effect.},
author = {He, Feng and Vavrus, Steve J. and Kutzbach, John E. and Ruddiman, William F. and Kaplan, Jed O. and Krumhardt, Kristen M.},
doi = {10.1002/2013GL058085},
isbn = {00948276},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {Holocene,anthropogenic effects,climate sensitivity,land cover change,radiative forcing},
number = {2},
pages = {623--631},
title = {{Simulating global and local surface temperature changes due to Holocene anthropogenic land cover change}},
volume = {41},
year = {2014}
}
@article{doi:10.1175/JCLI-D-12-00355.1,
abstract = {AbstractInterdecadal changes in the relationship between El Ni{\~{n}}o–Southern Oscillation (ENSO) and midlatitude atmospheric circulation are investigated in this study. Comparison of associations between ENSO and midlatitude atmospheric circulation anomalies between 1958–76 and 1977–2010 suggest that during 1958–76, ENSO exerted a strong impact on the East Asian winter monsoon (EAWM) and the associated atmospheric circulation pattern was similar to the positive North Pacific Oscillation (NPO). In contrast, during 1977–2010, the NPO-like atmospheric pattern disappeared. Instead, ENSO exerted a strong impact on the eastern North Pacific Ocean (NP) and North America, and the associated atmospheric circulation pattern resembled the Pacific–North America (PNA) teleconnection. Also, significant correlations between ENSO and sea surface temperature anomalies (SSTAs) over the western subtropical NP during 1958–76 became insignificant during 1977–2010, whereas negative correlations between ENSO and SSTAs in the central and northeastern subtropical NP became more significant since the mid-1970s. Further analyses suggest that the interdecadal shift of the Aleutian low, which occurred around the mid-1970s, might be responsible for the identified changes. Before the mid-1970s, warm ENSO events generated an anomalous anticyclone over the western NP, which is a key system bridging ENSO and EAWM-related atmospheric circulation. After the mid-1970s, the Aleutian low intensified and shifted eastward, leading to the impact of ENSO prevailing over the eastern NP. In addition, the weakened (strengthened) ENSO–NPO/EAWM (ENSO–PNA) relationship likely contributed to the weakened (strengthened) relationship between ENSO and SSTAs over the western (central and eastern) subtropical NP.},
author = {He, Shengping and Wang, Huijun and Liu, Jiping},
doi = {10.1175/JCLI-D-12-00355.1},
journal = {Journal of Climate},
number = {10},
pages = {3377--3393},
title = {{Changes in the Relationship between ENSO and Asia–Pacific Midlatitude Winter Atmospheric Circulation}},
url = {https://doi.org/10.1175/JCLI-D-12-00355.1},
volume = {26},
year = {2013}
}
@article{https://doi.org/10.1029/2019PA003835,
abstract = {Abstract The Mid-Pliocene Warm Period (MPWP, 2.9 to 3.3 Ma), along with older Pliocene (3.2 to 5.3 Ma) records, offers potential past analogues for our 400-ppmv world. The coastal geology of western and southern coasts of the Republic of South Africa exposes an abundance of marine deposits of Pliocene and Pleistocene age. In this study, we report differential GPS elevations, detailed stratigraphic descriptions, standardized interpretations, and dating of relative sea-level indicators measured across {\~{}}700 km from the western and southern coasts of the Cape Provinces. Wave abrasion surfaces on bedrock, intertidal sedimentary structures, and in situ marine invertebrates including oysters and barnacles provide precise indicators of past sea levels. Multiple sea-level highstands imprinted at different elevations along South African coastlines were identified. Zone I sites average +32 ± 5 m (six sites). A lower topographic Zone II of sea stands were measured at several sites around +17 ± 5 m. Middle and late Pleistocene sites are included in Zone III. Shoreline chronologies using 87Sr/86Sr ages on shells from these zones yield ages from Zone I at 4.6 and 3.0 Ma and Zone II at 1.04 Ma. Our results show that polar ice sheets during the Plio-Pleistocene were dynamic and subject to significant melting under modestly warmer global temperatures. These processes occurred during a period when CO2 concentrations were comparable to our current and rapidly rising values above 400 ppmv.},
annote = {e2019PA003835 2019PA003835},
author = {Hearty, P J and Rovere, A and Sandstrom, M R and O'Leary, M J and Roberts, D and Raymo, M E},
doi = {10.1029/2019PA003835},
journal = {Paleoceanography and Paleoclimatology},
keywords = {CO2,Pliocene,climate change,sea level,stratigraphy,strontium dating},
number = {7},
pages = {e2019PA003835},
title = {{Pliocene–Pleistocene Stratigraphy and Sea-Level Estimates, Republic of South Africa With Implications for a 400 ppmv CO2 World}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019PA003835},
volume = {35},
year = {2020}
}
@article{Hegerl2015,
author = {Hegerl, Gabriele C. and Black, Emily and Allan, Richard P and Ingram, W. J and Polson, D and Trenberth, Kevin E. and Chadwick, Robin and Arkin, Phillip A. and Sarojini, B. B. and Becker, Andreas and Dai, A and Durack, Paul J and Easterling, David R and Fowler, Hayley J and Kendon, E. and Huffman, George J. and Liu, C and Marsh, Robert and New, Mark and Osborn, Timothy J. and Skliris, Nikolaos and Stott, P A and Vidale, P.-L. and Wijffels, Susan E and Wilcox, L.J. and Willett, K M and Zhang, Xuebin},
doi = {10.1175/BAMS-D-13-00212.1},
journal = {Bulletin of the American Meteorological Society},
number = {7},
pages = {1097--1116},
title = {{Challenges in quantifying changes in the global water cycle}},
volume = {96},
year = {2015}
}
@article{Hegerl2006,
abstract = {The scale of any future global warming will depend on the sensitivity of the climate system to changes in greenhouse gas concentrations. Past climate is a useful guide to future events and now a new estimate of climate sensitivity, based on reconstructions of Northern Hemisphere temperature in the pre-industrial period 1270–1850, provides the best guide yet. It was thought that the upper limit of climate sensitivity (global mean temperature change due to CO2 doubling) was between 7.7 °C and above 9 °C. But the new model suggests a small probability that climate sensitivity will exceed 6.2 °C.},
author = {Hegerl, Gabriele C and Crowley, Thomas J and Hyde, William T and Frame, David J},
doi = {10.1038/nature04679},
issn = {1476-4687},
journal = {Nature},
number = {7087},
pages = {1029--1032},
title = {{Climate sensitivity constrained by temperature reconstructions over the past seven centuries}},
url = {https://doi.org/10.1038/nature04679},
volume = {440},
year = {2006}
}
@article{Hegglin2014,
author = {Hegglin, M I and Plummer, D A and Shepherd, T G and Scinocca, J F and Anderson, J and Froidevaux, L and Funke, B and Hurst, D and Rozanov, A and Urban, J and von Clarmann, T and Walker, K A and Wang, H J and Tegtmeier, S and Weigel, K},
doi = {10.1038/ngeo2236},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {oct},
number = {10},
pages = {768--776},
publisher = {Nature Publishing Group},
title = {{Vertical structure of stratospheric water vapour trends derived from merged satellite data}},
url = {http://www.nature.com/articles/ngeo2236},
volume = {7},
year = {2014}
}
@article{Hein2016,
abstract = {Establishing the trajectory of thinning of the West Antarctic ice sheet (WAIS) since the last glacial maximum (LGM) is important for addressing questions concerning ice sheet (in)stability and changes in global sea level. Here we present detailed geomorphological and cosmogenic nuclide data from the southern Ellsworth Mountains in the heart of the Weddell Sea embayment that suggest the ice sheet, nourished by increased snowfall until the early Holocene, was close to its LGM thickness at 10 ka. A pulse of rapid thinning caused the ice elevation to fall 1/4400 m to the present level at 6.5-3.5 ka, and could have contributed 1.4-2 m to global sea-level rise. These results imply that the Weddell Sea sector of the WAIS contributed little to late-glacial pulses in sea-level rise but was involved in mid-Holocene rises. The stepped decline is argued to reflect marine downdraw triggered by grounding line retreat into Hercules Inlet.},
author = {Hein, Andrew S. and Marrero, Shasta M. and Woodward, John and Dunning, Stuart A. and Winter, Kate and Westoby, Matthew J. and Freeman, Stewart P.H.T. and Shanks, Richard P. and Sugden, David E.},
doi = {10.1038/ncomms12511},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {12511},
title = {{Mid-Holocene pulse of thinning in the Weddell Sea sector of the West Antarctic ice sheet}},
volume = {7},
year = {2016}
}
@article{Helsen2013,
author = {Helsen, M M and van de Berg, W J and van de Wal, R S W and van den Broeke, M R and Oerlemans, J},
doi = {10.5194/cp-9-1773-2013},
issn = {1814-9332},
journal = {Climate of the Past},
month = {aug},
number = {4},
pages = {1773--1788},
publisher = {Copernicus Publications},
title = {{Coupled regional climate-ice-sheet simulation shows limited Greenland ice loss during the Eemian}},
url = {https://www.clim-past.net/9/1773/2013/ https://www.clim-past.net/9/1773/2013/cp-9-1773-2013.pdf},
volume = {9},
year = {2013}
}
@article{Henehan2013,
abstract = {The boron isotope-pH proxy, applied to mixed-layer planktic foraminifera, has great potential for estimating past CO2 levels, which in turn is crucial to advance our understanding of how this greenhouse gas influences Earth's climate. Previous culture experiments have shown that, although the boron isotopic compositions of various planktic foraminifera are pH dependent, they do not agree with the aqueous geochemical basis of the proxy. Here we outline the results of culture experiments on Globigerinoides ruber (white) across a range of pH (∼7.5–8.2) and analysed via multicollector inductively-coupled plasma mass spectrometry (MC-ICPMS), and compare these data to core-top and sediment-trap samples to derive a robust new species-specific boron isotope-pH calibration. Consistent with earlier culture studies, we show a reduced pH dependency of the boron isotopic composition of symbiont-bearing planktonic foraminifera compared to borate ion in seawater. We also present evidence for a size fraction effect in the $\delta$11B of G. ruber. Finally, we reconstruct atmospheric CO2 concentrations over the last deglacial using our new calibration at two equatorial sites, ODP Site 999A and Site GeoB1523-1. These data provide further grounding for the application of the boron isotope-pH proxy in reconstructions of past atmospheric CO2 levels.},
author = {Henehan, Michael J and Rae, James W B and Foster, Gavin L and Erez, Jonathan and Prentice, Katherine C and Kucera, Michal and Bostock, Helen C and Mart{\'{i}}nez-Bot{\'{i}}, Miguel A and Milton, J Andy and Wilson, Paul A and Marshall, Brittney J and Elliott, Tim},
doi = {10.1016/j.epsl.2012.12.029},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {MC-ICPMS,boron isotopes,culture calibration,pCO reconstruction,planktic foraminifera},
pages = {111--122},
title = {{Calibration of the boron isotope proxy in the planktonic foraminifera Globigerinoides ruber for use in palaeo-CO2 reconstruction}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X12007157},
volume = {364},
year = {2013}
}
@article{Henehan2019,
abstract = {Debate lingers over what caused the last mass extinction 66 million years ago, with intense volcanism and extraterrestrial impact the most widely supported hypotheses. However, without empirical evidence for either's exact environmental effects, it is difficult to discern which was most important in driving extinction. It is also unclear why recovery of biodiversity and carbon cycling in the oceans was so slow after an apparently sudden extinction event. In this paper, we show (using boron isotopes and Earth system modeling) that the impact caused rapid ocean acidification, and that the resulting ecological collapse in the oceans had long-lasting effects for global carbon cycling and climate. Our data suggest that impact, not volcanism, was key in driving end-Cretaceous mass extinction.Mass extinction at the Cretaceous–Paleogene (K-Pg) boundary coincides with the Chicxulub bolide impact and also falls within the broader time frame of Deccan trap emplacement. Critically, though, empirical evidence as to how either of these factors could have driven observed extinction patterns and carbon cycle perturbations is still lacking. Here, using boron isotopes in foraminifera, we document a geologically rapid surface-ocean pH drop following the Chicxulub impact, supporting impact-induced ocean acidification as a mechanism for ecological collapse in the marine realm. Subsequently, surface water pH rebounded sharply with the extinction of marine calcifiers and the associated imbalance in the global carbon cycle. Our reconstructed water-column pH gradients, combined with Earth system modeling, indicate that a partial ∼50{\%} reduction in global marine primary productivity is sufficient to explain observed marine carbon isotope patterns at the K-Pg, due to the underlying action of the solubility pump. While primary productivity recovered within a few tens of thousands of years, inefficiency in carbon export to the deep sea lasted much longer. This phased recovery scenario reconciles competing hypotheses previously put forward to explain the K-Pg carbon isotope records, and explains both spatially variable patterns of change in marine productivity across the event and a lack of extinction at the deep sea floor. In sum, we provide insights into the drivers of the last mass extinction, the recovery of marine carbon cycling in a postextinction world, and the way in which marine life imprints its isotopic signal onto the geological record.},
author = {Henehan, Michael J and Ridgwell, Andy and Thomas, Ellen and Zhang, Shuang and Alegret, Laia and Schmidt, Daniela N and Rae, James W B and Witts, James D and Landman, Neil H and Greene, Sarah E and Huber, Brian T and Super, James R and Planavsky, Noah J and Hull, Pincelli M},
doi = {10.1073/pnas.1905989116},
journal = {Proceedings of the National Academy of Sciences},
month = {nov},
number = {45},
pages = {22500},
title = {{Rapid ocean acidification and protracted Earth system recovery followed the end-Cretaceous Chicxulub impact}},
url = {http://www.pnas.org/content/116/45/22500.abstract},
volume = {116},
year = {2019}
}
@article{article,
author = {Henehan, Michael J. and Edgar, Kirsty and Foster, Gavin and Penman, Donald and Hull, Pincelli and Greenop, Rosanna and Anagnostou, Eleni and Pearson, Paul},
doi = {10.1029/2019PA003713},
journal = {Paleoceanography and Paleoclimatology},
pages = {e2019PA003713},
title = {{Revisiting the Middle Eocene Climatic Optimum “Carbon Cycle Conundrum” With New Estimates of Atmospheric pCO2 From Boron Isotopes}},
volume = {35},
year = {2020}
}
@article{Henley2017,
author = {Henley, Benjamin J},
doi = {10.1016/j.gloplacha.2017.06.004},
journal = {Global and Planetary Change},
keywords = {interdecadal paci fi c,oscillation},
number = {October 2016},
pages = {42--55},
title = {{Pacific decadal climate variability: Indices, patterns and tropical-extratropical interactions}},
volume = {155},
year = {2017}
}
@article{Henry2016,
abstract = {Large decreases in Atlantic meridional overturning circulation accompanied every one of the cold Northern Hemispheric stadial events that occurred during the heart of the last glacial period. These events, lasting on average around 1000 years each, have long been thought to result from changes in deep ocean circulation. Henry et al. used a suite of geochemical proxies from marine sediments to show that reductions in the export of northern deep waters occurred before and during stadial periods (see the Perspective by Schmittner). This observation firmly establishes the role of ocean circulation as a cause of abrupt glacial climate change during that interval.Science, this issue p. 470; see also p. 445The most recent ice age was characterized by rapid and hemispherically asynchronous climate oscillations, whose origin remains unresolved. Variations in oceanic meridional heat transport may contribute to these repeated climate changes, which were most pronounced during marine isotope stage 3, the glacial interval 25 thousand to 60 thousand years ago. We examined climate and ocean circulation proxies throughout this interval at high resolution in a deep North Atlantic sediment core, combining the kinematic tracer protactinium/thorium (Pa/Th) with the deep water-mass tracer, epibenthic $\delta$13C. These indicators suggest reduced Atlantic overturning circulation during every cool northern stadial, with the greatest reductions during episodic Hudson Strait iceberg discharges, while sharp northern warming followed reinvigorated overturning. These results provide direct evidence for the oceans persistent, central role in abrupt glacial climate change.},
author = {Henry, L G and McManus, J F and Curry, W B and Roberts, N L and Piotrowski, A M and Keigwin, L D},
doi = {10.1126/science.aaf5529},
issn = {0036-8075},
journal = {Science},
number = {6298},
pages = {470--474},
publisher = {American Association for the Advancement of Science},
title = {{North Atlantic ocean circulation and abrupt climate change during the last glaciation}},
url = {https://science.sciencemag.org/content/353/6298/470},
volume = {353},
year = {2016}
}
@article{Hermann2018,
author = {Hermann, N. W. and Oster, J. L. and Ibarra, D. E.},
doi = {10.1002/jqs.3023},
journal = {Journal of Quaternary Science},
number = {4},
pages = {421--434},
title = {{Spatial patterns and driving mechanisms of mid-Holocene hydroclimate in western North America}},
volume = {33},
year = {2018}
}
@article{Hernandez2020a,
abstract = {Modes of climate variability affect global and regional climates on different spatio-temporal scales, and they have important impacts on human activities and ecosystems. As these modes are a useful tool for simplifying the understanding of the climate system, it is crucial that we gain improved knowledge of their long-term past evolution and interactions over time to contextualise their present and future behaviour. We review the literature focused on proxy-based reconstructions of modes of climate variability during the Holocene (i.e., the last 11.7 thousand years) with a special emphasis on i) proxy-based reconstruction methods; ii) available proxy- based reconstructions of the main modes of variability, i.e., El Ni{\~{n}}o Southern Oscillation, Pacific Decadal Variability, Atlantic Multidecadal Variability, the North Atlantic Oscillation, the Southern Annular Mode and the Indian Ocean Dipole; iii) major interactions between these modes; and iv) external forcing mechanisms related to the evolution of these modes. This review shows that modes of variability can be reconstructed using proxy-based records from a wide range of natural archives, but these reconstructions are scarce beyond the last millennium, partly due to the lack of robust chronologies with reduced dating uncertainties, technical issues related to proxy calibration, and difficulty elucidating their stationary impact (or not) on regional climates over time. While for each mode the available reconstructions tend to agree at mutidecadal timescales, they show notable disagreement on shorter timescales beyond the instrumental period. The reviewed evidence suggests that the intrinsic variability of modes can be modulated by external forcing, such as orbital, solar, volcanic, and anthropogenic forcing. The review also highlights some modes experience higher variability over the instrumental period, which is partly ascribed to anthropogenic forcing. These features stress the paramount importance of further studying their past variations using long climate-proxy records for the progress of climate science. Journal},
author = {Hern{\'{a}}ndez, Armand and Martin-Puertas, Celia and Moffa-S{\'{a}}nchez, Paola and Moreno-Chamarro, Eduardo and Ortega, Pablo and Blockley, Simon and Cobb, Kim M. and Comas-Bru, Laia and Giralt, Santiago and Goosse, Hugues and Luterbacher, J{\"{u}}rg and Martrat, Belen and Muscheler, Raimund and Parnell, Andrew and Pla-Rabes, Sergi and Sjolte, Jesper and Scaife, Adam A. and Swingedouw, Didier and Wise, Erika and Xu, Guobao},
doi = {10.1016/j.earscirev.2020.103286},
issn = {00128252},
journal = {Earth-Science Reviews},
month = {oct},
number = {103286},
pages = {103286},
publisher = {Elsevier B.V},
title = {{Modes of climate variability: Synthesis and review of proxy-based reconstructions through the Holocene}},
url = {https://doi.org/10.1016/j.earscirev.2020.103286 https://linkinghub.elsevier.com/retrieve/pii/S0012825220303329},
volume = {209},
year = {2020}
}
@article{Hernandez-Henriquez2015,
abstract = {Recent years (i.e., 2007–2014) have exhibited large declines in snow cover extent (SCE) in the Northern Hemisphere (NH), marked by earlier snowmelt in the springtime. In Northern latitudes, the snow-albedo feedback (SAF) is most pronounced in the spring and may be contributing to these decreasing trends in SCE. Rising surface air temperatures and changes in precipitation patterns could also vary the declining trends in SCE depending on latitude and elevation. Previous trend analyses of NH SCE are extended here to cover the period 1 October 1971 to 30 September 2014 using observed data from the National Oceanic and Atmospheric Administration snow chart climate data record. Trends in snow coverage (significant when p {\textless} 0.05) with latitude and elevation are investigated using the Mann–Kendall test. Over the 43 year period, strong polar amplification of negative trends in snow cover are observed. The majority of statistically significant negative trends are found in the mid- to high-latitudes, reaching a maximum reduction at 75.5°N. There is also elevation dependence of SCE over time as statistically significant negative trends occur at most elevations, with the strongest observed at 3950 m a.s.l. These significant negative trends exhibited in the mid- to high-latitudes and mid- to high-elevations provide evidence of polar amplification and elevation dependence of trends in snow cover in a warming climate, suggesting a leading role of the SAF on the recent retreat of NH snow cover.},
author = {Hern{\'{a}}ndez-Henr{\'{i}}quez, Marco A. and D{\'{e}}ry, Stephen J. and Derksen, Chris},
doi = {10.1088/1748-9326/10/4/044010},
isbn = {1748-9326},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {Northern Hemisphere,climate change,polar amplification,snow cover extent,snow-albedo feedback},
number = {044010},
title = {{Polar amplification and elevation-dependence in trends of Northern Hemisphere snow cover extent, 1971-2014}},
volume = {10},
year = {2015}
}
@article{Hersbach2020b,
abstract = {Within the Copernicus Climate Change Service (C3S), ECMWF is producing the ERA5 reanalysis which, once completed, will embody a detailed record of the global atmosphere, land surface and ocean waves from 1950 onwards. This new reanalysis replaces the ERA-Interim reanalysis (spanning 1979 onwards) which was started in 2006. ERA5 is based on the Integrated Forecasting System (IFS) Cy41r2 which was operational in 2016. ERA5 thus benefits from a decade of developments in model physics, core dynamics and data assimilation. In addition to a significantly enhanced horizontal resolution of 31 km, compared to 80 km for ERA-Interim, ERA5 has hourly output throughout, and an uncertainty estimate from an ensemble (3-hourly at half the horizontal resolution). This paper describes the general set-up of ERA5, as well as a basic evaluation of characteristics and performance, with a focus on the dataset from 1979 onwards which is currently publicly available. Re-forecasts from ERA5 analyses show a gain of up to one day in skill with respect to ERA-Interim. Comparison with radiosonde and PILOT data prior to assimilation shows an improved fit for temperature, wind and humidity in the troposphere, but not the stratosphere. A comparison with independent buoy data shows a much improved fit for ocean wave height. The uncertainty estimate reflects the evolution of the observing systems used in ERA5. The enhanced temporal and spatial resolution allows for a detailed evolution of weather systems. For precipitation, global-mean correlation with monthly-mean GPCP data is increased from 67{\%} to 77{\%}. In general, low-frequency variability is found to be well represented and from 10 hPa downwards general patterns of anomalies in temperature match those from the ERA-Interim, MERRA-2 and JRA-55 reanalyses.},
author = {Hersbach, Hans and Bell, Bill and Berrisford, Paul and Hirahara, Shoji and Hor{\'{a}}nyi, Andr{\'{a}}s and Mu{\~{n}}oz-Sabater, Joaqu{\'{i}}n and Nicolas, Julien and Peubey, Carole and Radu, Raluca and Schepers, Dinand and Simmons, Adrian and Soci, Cornel and Abdalla, Saleh and Abellan, Xavier and Balsamo, Gianpaolo and Bechtold, Peter and Biavati, Gionata and Bidlot, Jean and Bonavita, Massimo and {De Chiara}, Giovanna and Dahlgren, Per and Dee, Dick and Diamantakis, Michail and Dragani, Rossana and Flemming, Johannes and Forbes, Richard and Fuentes, Manuel and Geer, Alan and Haimberger, Leo and Healy, Sean and Hogan, Robin J. and H{\'{o}}lm, El{\'{i}}as and Janiskov{\'{a}}, Marta and Keeley, Sarah and Laloyaux, Patrick and Lopez, Philippe and Lupu, Cristina and Radnoti, Gabor and de Rosnay, Patricia and Rozum, Iryna and Vamborg, Freja and Villaume, Sebastien and Th{\'{e}}paut, Jean No{\"{e}}l},
doi = {10.1002/qj.3803},
issn = {1477870X},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {Copernicus Climate Change Service,ERA5,climate reanalysis,data assimilation,historical observations},
pages = {1999--2049},
title = {{The ERA5 global reanalysis}},
volume = {146},
year = {2020}
}
@article{Herzschuh2016,
author = {Herzschuh, Ulrike and Birks, H. John B. and Laepple, Thomas and Andreev, Andrei and Melles, Martin and Brigham-Grette, Julie},
doi = {10.1038/ncomms11967},
issn = {2041-1723},
journal = {Nature Communications},
month = {sep},
number = {1},
pages = {11967},
title = {{Glacial legacies on interglacial vegetation at the Pliocene-Pleistocene transition in NE Asia}},
url = {http://www.nature.com/articles/ncomms11967},
volume = {7},
year = {2016}
}
@article{Hessl2017,
abstract = {The leading mode of atmospheric variability in the Southern Hemisphere is the Southern Annular Mode (SAM), which affects the atmosphere and ocean from the mid-latitudes to the Antarctic. However, the short instrumental record of the SAM does not adequately represent its multi-decadal to centennial-scale variability. Long palaeoclimatic reconstructions of the SAM would improve our understanding of its low frequency behavior and its effects on regional temperature, rainfall, sea ice, and ecosystem processes. In this progress report, we review three published palaeoclimatic reconstructions available for understanding multi-decadal to centennial-scale variability of the SAM. Reconstructions reviewed here show similar patterns of decadal SAM variability during the last two centuries, but earlier centuries are less coherent. Reconstructions clearly maintain similar trends towards more positive SAM states since the onset of significant anthropogenic climate forcing from rising greenhouse gas (GHG) concentrations...},
author = {Hessl, Amy and Allen, Kathryn J. and Vance, Tessa and Abram, Nerilie J. and Saunders, Krystyna M.},
doi = {10.1177/0309133317743165},
issn = {03091333},
journal = {Progress in Physical Geography},
keywords = {Ice cores,Southern Hemisphere climate,climate modes,climate reconstruction,corals,lake sediments,tree rings},
number = {6},
pages = {834--849},
title = {{Reconstructions of the southern annular mode (SAM) during the last millennium}},
volume = {41},
year = {2017}
}
@article{Hibbert2018,
abstract = {The last deglacial was an interval of rapid climate and sea-level change, including the collapse of large continental ice sheets. This database collates carefully assessed sea-level data from peer-reviewed sources for the interval 0 to 25 thousand years ago (ka), from the Last Glacial Maximum to the present interglacial. In addition to facilitating site-specific reconstructions of past sea levels, the database provides a suite of data beyond the range of modern/instrumental variability that may help hone future sea-level projections. The database is global in scope, internally consistent, and contains U-series and radiocarbon dated indicators from both biological and geomorpohological archives. We focus on far-field data (i.e., away from the sites of the former continental ice sheets), but some key intermediate (i.e., from the Caribbean) data are also included. All primary fields (i.e., sample location, elevation, age and context) possess quantified uncertainties, which—in conjunction with available metadata—allows the reconstructed sea levels to be interpreted within both their uncertainties and geological context.},
author = {Hibbert, F D and Williams, F H and Fallon, S J and Rohling, E J},
doi = {10.1038/sdata.2018.88},
issn = {2052-4463},
journal = {Scientific Data},
number = {1},
pages = {180088},
title = {{A database of biological and geomorphological sea-level markers from the Last Glacial Maximum to present}},
url = {https://doi.org/10.1038/sdata.2018.88},
volume = {5},
year = {2018}
}
@article{Hiemstra2018,
author = {Hiemstra, John F.},
doi = {10.1177/0959683618785835},
issn = {14770911},
journal = {Holocene},
number = {8},
pages = {1201--1204},
title = {{Permafrost and environmental dynamics: A virtual issue of The Holocene}},
volume = {28},
year = {2018}
}
@article{Higgins2015a,
abstract = {Here, we present direct measurements of atmospheric composition and Antarctic climate from the mid-Pleistocene (∼1 Ma) from ice cores drilled in the Allan Hills blue ice area, Antarctica. The 1-Ma ice is dated from the deficit in 40Ar relative to the modern atmosphere and is present as a stratigraphically disturbed 12-m section at the base of a 126-m ice core. The 1-Ma ice appears to represent most of the amplitude of contemporaneous climate cycles and CO2 and CH4 concentrations in the ice range from 221 to 277 ppm and 411 to 569 parts per billion (ppb), respectively. These concentrations, together with measured $\delta$D of the ice, are at the warm end of the field for glacial–interglacial cycles of the last 800 ky and span only about one-half of the range. The highest CO2 values in the 1-Ma ice fall within the range of interglacial values of the last 400 ka but are up to 7 ppm higher than any interglacial values between 450 and 800 ka. The lowest CO2 values are 30 ppm higher than during any glacial period between 450 and 800 ka. This study shows that the coupling of Antarctic temperature and atmospheric CO2 extended into the mid-Pleistocene and demonstrates the feasibility of discontinuously extending the current ice core record beyond 800 ka by shallow coring in Antarctic blue ice areas.},
author = {Higgins, John A. and Kurbatov, Andrei V. and Spaulding, Nicole E. and Brook, Ed and Introne, Douglas S. and Chimiak, Laura M. and Yan, Yuzhen and Mayewski, Paul A. and Bender, Michael L.},
doi = {10.1073/pnas.1420232112},
isbn = {1091-6490},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {22},
pages = {6887--6891},
pmid = {25964367},
title = {{Atmospheric composition 1 million years ago from blue ice in the Allan Hills, Antarctica}},
volume = {112},
year = {2015}
}
@article{Hirahara2014,
abstract = {AbstractA new sea surface temperature (SST) analysis on a centennial time scale is presented. In this analysis, a daily SST field is constructed as a sum of a trend, interannual variations, and daily changes, using in situ SST and sea ice concentration observations. All SST values are accompanied with theory-based analysis errors as a measure of reliability. An improved equation is introduced to represent the ice–SST relationship, which is used to produce SST data from observed sea ice concentrations. Prior to the analysis, biases of individual SST measurement types are estimated for a homogenized long-term time series of global mean SST. Because metadata necessary for the bias correction are unavailable for many historical observational reports, the biases are determined so as to ensure consistency among existing SST and nighttime air temperature observations. The global mean SSTs with bias-corrected observations are in agreement with those of a previously published study, which adopted a different approach. Satellite observations are newly introduced for the purpose of reconstruction of SST variability over data-sparse regions. Moreover, uncertainty in areal means of the present and previous SST analyses is investigated using the theoretical analysis errors and estimated sampling errors. The result confirms the advantages of the present analysis, and it is helpful in understanding the reliability of SST for a specific area and time period.},
author = {Hirahara, Shoji and Ishii, Masayoshi and Fukuda, Yoshikazu},
doi = {10.1175/JCLI-D-12-00837.1},
journal = {Journal of Climate},
number = {1},
pages = {57--75},
title = {{Centennial-Scale Sea Surface Temperature Analysis and Its Uncertainty}},
volume = {27},
year = {2014}
}
@article{acp-17-4493-2017,
author = {Ho, S.-P. and Peng, L and V{\"{o}}mel, H},
doi = {10.5194/acp-17-4493-2017},
journal = {Atmospheric Chemistry and Physics},
number = {7},
pages = {4493--4511},
title = {{Characterization of the long-term radiosonde temperature biases in the upper troposphere and lower stratosphere using COSMIC and Metop-A/GRAS data from 2006 to 2014}},
url = {https://www.atmos-chem-phys.net/17/4493/2017/},
volume = {17},
year = {2017}
}
@article{doi:10.1029/2012JD017665,
abstract = {To examine the claim that Global Positioning System (GPS) radio occultation (RO) data are useful as a benchmark data set for climate monitoring, the structural uncertainties of retrieved profiles that result from different processing methods are quantified. Profile-to-profile comparisons of CHAMP (CHAllenging Minisatellite Payload) data from January 2002 to August 2008 retrieved by six RO processing centers are presented. Differences and standard deviations of the individual centers relative to the inter-center mean are used to quantify the structural uncertainty. Uncertainties accumulate in derived variables due to propagation through the RO retrieval chain. This is reflected in the inter-center differences, which are small for bending angle and refractivity increasing to dry temperature, dry pressure, and dry geopotential height. The mean differences of the time series in the 8 km to 30 km layer range from −0.08{\%} to 0.12{\%} for bending angle, −0.03{\%} to 0.02{\%} for refractivity, −0.27 K to 0.15 K for dry temperature, −0.04{\%} to 0.04{\%} for dry pressure, and −7.6 m to 6.8 m for dry geopotential height. The corresponding standard deviations are within 0.02{\%}, 0.01{\%}, 0.06 K, 0.02{\%}, and 2.0 m, respectively. The mean trend differences from 8 km to 30 km for bending angle, refractivity, dry temperature, dry pressure, and dry geopotential height are within ±0.02{\%}/5 yrs, ±0.02{\%}/5 yrs, ±0.06 K/5 yrs, ±0.02{\%}/5 yrs, and ±2.3 m/5 yrs, respectively. Although the RO-derived variables are not readily traceable to the international system of units, the high precision nature of the raw RO observables is preserved in the inversion chain.},
author = {Ho, Shu-Peng and Hunt, Doug and Steiner, Andrea K and Mannucci, Anthony J and Kirchengast, Gottfried and Gleisner, Hans and Heise, Stefan and von Engeln, Axel and Marquardt, Christian and Sokolovskiy, Sergey and Schreiner, William and Scherllin-Pirscher, Barbara and Ao, Chi and Wickert, Jens and Syndergaard, Stig and Lauritsen, Kent B and Leroy, Stephen and Kursinski, Emil R and Kuo, Ying-Hwa and Foelsche, Ulrich and Schmidt, Torsten and Gorbunov, Michael},
doi = {10.1029/2012JD017665},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {GPS,radio occultation,reproducibility},
number = {D18},
pages = {D18111},
title = {{Reproducibility of GPS radio occultation data for climate monitoring: Profile-to-profile inter-comparison of CHAMP climate records 2002 to 2008 from six data centers}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012JD017665},
volume = {117},
year = {2012}
}
@article{doi:10.1175/BAMS-D-18-0290.1,
abstract = {Capsule SummaryContributions and the remaining challenges of COSMIC and other RO observations to weather, climate, and space weather since 2011 and potential contributions to research and operations of COSMIC-2 are summarized.},
author = {Ho, Shu-Peng and Anthes, Richard A and Ao, Chi O and Healy, Sean and Horanyi, Andras and Hunt, Douglas and Mannucci, Anthony J and Pedatella, Nicholas and Randel, William J and Simmons, Adrian and Steiner, Andrea and Xie, Feiqin and Yue, Xinan and Zeng, Zhen},
doi = {10.1175/BAMS-D-18-0290.1},
journal = {Bulletin of the American Meteorological Society},
pages = {E1107--E1136},
title = {{The COSMIC/FORMOSAT-3 Radio Occultation Mission after 12 years: Accomplishments, Remaining Challenges, and Potential Impacts of COSMIC-2}},
url = {https://doi.org/10.1175/BAMS-D-18-0290.1},
volume = {101},
year = {2020}
}
@article{Hobbs2016,
abstract = {Since 1979 when continuous satellite observations began, Southern Ocean sea ice cover has increased, whilst global coupled climate models simulate a decrease over the same period. It is uncertain whether the observed trends are anthropogenically forced or due to internal variability, or whether the apparent discrepancy between models and observations can be explained by internal variability. The shortness of the satellite record is one source of this uncertainty, and a possible solution is to use proxy reconstructions, which extend the analysis period but at the expense of higher observational uncertainty. In this work, we evaluate the utility for change detection of 20th century Southern Ocean sea ice proxies. We find that there are reliable proxies for the East Antarctic, Amundsen, Bellingshausen and Weddell sectors in late winter, and for the Weddell Sea in late autumn. Models and reconstructions agree that sea ice extent in the East Antarctic, Amundsen and Bellingshausen Seas has decreased since the early 1970s, consistent with an anthropogenic response. However, the decrease is small compared to internal variability, and the change is not robustly detectable. We also find that optimal fingerprinting filters out much of the uncertainty in proxy reconstructions. The Ross Sea is a confounding factor, with a significant increase in sea ice since 1979 that is not captured by climate models; however, existing proxy reconstructions of this region are not yet sufficiently reliable for formal change detection.},
author = {Hobbs, Will R. and Curran, Mark and Abram, Nerilie and Thomas, Elizabeth R.},
doi = {10.1002/2016JC012111},
isbn = {2169-9291},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Southern Ocean,attribution,detection,proxies,sea ice},
number = {10},
pages = {7804--7818},
title = {{Century-scale perspectives on observed and simulated Southern Ocean sea ice trends from proxy reconstructions}},
volume = {121},
year = {2016}
}
@article{Hobbs2016a,
abstract = {Over the past 37 years, satellite records show an increase in Antarctic sea ice cover that is most pronounced in the period of sea ice growth. This trend is dominated by increased sea ice coverage in the western Ross Sea, and is mitigated by a strong decrease in the Bellingshausen and Amundsen seas. The trends in sea ice areal coverage are accompanied by related trends in yearly duration. These changes have implications for ecosystems, as well as global and regional climate. In this review, we summarise the research to date on observing these trends, identifying their drivers, and assessing the role of anthropogenic climate change. Whilst the atmosphere is thought to be the primary driver, the ocean is also essential in explaining the seasonality of the trend patterns. Detecting an anthropogenic signal in Antarctic sea ice is particularly challenging for a number of reasons: the expected response is small compared to the very high natural variability of the system; the observational record is relatively short; and the ability of global coupled climate models to faithfully represent the complex Antarctic climate system is in doubt.},
author = {Hobbs, William R. and Massom, Rob and Stammerjohn, Sharon and Reid, Phillip and Williams, Guy and Meier, Walter},
doi = {10.1016/j.gloplacha.2016.06.008},
isbn = {0921-8181},
issn = {09218181},
journal = {Global and Planetary Change},
pages = {228--250},
title = {{A review of recent changes in Southern Ocean sea ice, their drivers and forcings}},
volume = {143},
year = {2016}
}
@article{Hobbs2009a,
abstract = {Many ecosystems are rapidly being transformed into new, non-historical configurations owing to a variety of local and global changes. We discuss how new systems can arise in the face of primarily biotic change (extinction and/or invasion), primarily abiotic change (e.g. land use or climate change) and a combination of both. Some changes will result in hybrid systems retaining some original characteristics as well as novel elements, whereas larger changes will result in novel systems, which comprise different species, interactions and functions. We suggest that these novel systems will require significant revision of conservation and restoration norms and practices away from the traditional place-based focus on existing or historical assemblages. {\textcopyright} 2009 Elsevier Ltd. All rights reserved.},
author = {Hobbs, Richard J. and Higgs, Eric and Harris, James A.},
doi = {10.1016/j.tree.2009.05.012},
isbn = {0169-5347},
issn = {01695347},
journal = {Trends in Ecology and Evolution},
number = {11},
pages = {599--605},
pmid = {19683830},
title = {{Novel ecosystems: implications for conservation and restoration}},
volume = {24},
year = {2009}
}
@article{Hoelzmann1998a,
abstract = {P. Hoelzmann, 1'2 D. Jolly, 3 S. P. Harrison, • F. Laarif, • R. Bonnefille, 4' • and H.-J. Pachur 6 Abstract. Large changes in the extent of northern subtropical arid regions during the Holocene are attributed to orbitally forced variations in monsoon strength and have been implicated in the regulation of atmospheric trace gas concentrations on millenial times-cales. Models that omit biogeophysical feedback, however, are unable to account for the full magnitude of African monsoon amplification and extension during the early to middle Holocene (• 9500-5000 years B.P.). A data set describing land-surface conditions 6000 years B.P. on a 1 o x 1 o grid across northern Africa and the Arabian Peninsula has been prepared from published maps and other sources of palaeoenvironmental data, with the primary aim of providing a realistic lower boundary condition for atmospheric general circulation model experiments similar to those performed in the Palaeoclimate Modelling Intercomparison Project. The data set includes information on the percentage of each grid cell occupied by specific vegetation types (steppe, savanna, xerophytic woods/scrub, tropical deciduous forest, and tropical montane evergreen forest), open water (lakes), and wetlands, plus information on the flow direction of major drainage channels for use in large-scale palaeohydrological modeling. The data set is available in digital form by anonymous ftp.},
author = {Hoelzmann, P. and Jolly, D. and Harrison, S. P. and Laarif, F. and Bonnefille, R. and Pachur, H. J.},
doi = {10.1029/97GB02733},
issn = {19449224},
journal = {Global Biogeochemical Cycles},
number = {1},
pages = {35--51},
title = {{Mid-Holocene land-surface conditions in northern Africa and the Arabian peninsula: A data set for the analysis of biogeophysical feedbacks in the climate system}},
volume = {12},
year = {1998}
}
@article{Hoffman2017,
abstract = {Understanding how warm intervals affected sea level in the past is vital for projecting how human activities will affect it in the future. Hoffman et al. compiled estimates of sea surface temperatures during the last interglacial period, which lasted from about 129,000 to 116,000 years ago. The global mean annual values were ∼0.5°C warmer than they were 150 years ago and indistinguishable from the 1995–2014 mean. This is a sobering point, because sea levels during the last interglacial period were 6 to 9 m higher than they are now.Science, this issue p. 276The last interglaciation (LIG, 129 to 116 thousand years ago) was the most recent time in Earth's history when global mean sea level was substantially higher than it is at present. However, reconstructions of LIG global temperature remain uncertain, with estimates ranging from no significant difference to nearly 2°C warmer than present-day temperatures. Here we use a network of sea-surface temperature (SST) records to reconstruct spatiotemporal variability in regional and global SSTs during the LIG. Our results indicate that peak LIG global mean annual SSTs were 0.5 ± 0.3°C warmer than the climatological mean from 1870 to 1889 and indistinguishable from the 1995 to 2014 mean. LIG warming in the extratropical latitudes occurred in response to boreal insolation and the bipolar seesaw, whereas tropical SSTs were slightly cooler than the 1870 to 1889 mean in response to reduced mean annual insolation.},
author = {Hoffman, Jeremy S and Clark, Peter U and Parnell, Andrew C and He, Feng},
doi = {10.1126/science.aai8464},
issn = {0036-8075},
journal = {Science},
month = {jan},
number = {6322},
pages = {276--279},
title = {{Regional and global sea-surface temperatures during the last interglaciation}},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aai8464},
volume = {355},
year = {2017}
}
@article{Hoffmann2018,
abstract = {Abstract While substantial changes in thermohaline circulation related to deglacial climate variability are well established, the role of this circulation in Holocene climate variability remains uncertain. Here we use two dynamical proxies, 231Pa/230Th ratios and mean sortable silt size ( ), to reconstruct Holocene bottom water circulation at the intermediate-depth Carolina Slope. We find no substantial change in deep current speed or 231Pa export at this site during the Holocene, suggesting consistent 231Pa export via the Deep Western Boundary Current. shows increasing millennial-scale variability in the middle-late Holocene, which may reflect Labrador Sea Water contribution to current speed. We conclude that deepwater export from the North Atlantic has remained remarkably stable during the Holocene, decoupled from changing rates of specific water masses, while production of these water masses varied at millennial to centennial time scales. The persistence of the large-scale overturning may reflect the ocean's stabilizing influence on Holocene climate.},
annote = {doi: 10.1029/2018GL080187},
author = {Hoffmann, Sharon S and McManus, Jerry F and Swank, Emerson},
doi = {10.1029/2018GL080187},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {geochemical tracers,interglacial,radioactivity and radioisotopes,sedimentation (1861),thermohaline},
month = {dec},
number = {24},
pages = {13427--13436},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Evidence for Stable Holocene Basin-Scale Overturning Circulation Despite Variable Currents Along the Deep Western Boundary of the North Atlantic Ocean}},
url = {https://doi.org/10.1029/2018GL080187},
volume = {45},
year = {2018}
}
@article{Holland2014,
abstract = {Antarctic sea ice is experiencing a weak overall increase in area that is the residual of opposing regional trends. This study considers their seasonal pattern. In addition to traditional ice concentration and total ice area, temporal derivatives of these quantities are investigated (“intensification” and “expansion,” respectively). This is crucial to the attribution of trends, since changes in forcing directly affect ice areal change (rather than ice area). Diverse regional trends all contribute significantly to the overall increase. Trends in the Weddell and Amundsen-Bellingshausen regions compensate in magnitude and seasonality. The largest concentration trends, in autumn, are actually caused by intensification trends during spring. Autumn intensification trends directly oppose autumn concentration trends in most places, seemingly as a result of ice and ocean feedbacks. Springtime trends are reconcilable with wind trends, but further study of changes during the spring melting season is required to unravel the Antarctic sea ice increase.},
author = {Holland, Paul R.},
doi = {10.1002/2014GL060172},
isbn = {1944-8007},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {12},
pages = {4230--4237},
title = {{The seasonality of Antarctic sea ice trends}},
volume = {41},
year = {2014}
}
@article{Hollis2019,
author = {Hollis, Christopher J and {Dunkley Jones}, Tom and Anagnostou, Eleni and Bijl, Peter K and Cramwinckel, Margot J and Cui, Ying and Dickens, Gerald R and Edgar, Kirsty M and Eley, Yvette and Evans, David and Foster, Gavin L and Frieling, Joost and Inglis, Gordon N and Kennedy, Elizabeth M and Kozdon, Reinhard and Lauretano, Vittoria and Lear, Caroline H and Littler, Kate and Lourens, Lucas and Meckler, A. Nele and Naafs, B David A and P{\"{a}}like, Heiko and Pancost, Richard D and Pearson, Paul N. and R{\"{o}}hl, Ursula and Royer, Dana L and Salzmann, Ulrich and Schubert, Brian A. and Seebeck, Hannu and Sluijs, Appy and Speijer, Robert P. and Stassen, Peter and Tierney, Jessica and Tripati, Aradhna and Wade, Bridget and Westerhold, Thomas and Witkowski, Caitlyn and Zachos, James C and Zhang, Yi Ge and Huber, Matthew and Lunt, Daniel J},
doi = {10.5194/gmd-12-3149-2019},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {jul},
number = {7},
pages = {3149--3206},
title = {{The DeepMIP contribution to PMIP4: methodologies for selection, compilation and analysis of latest Paleocene and early Eocene climate proxy data, incorporating version 0.1 of the DeepMIP database}},
url = {https://gmd.copernicus.org/articles/12/3149/2019/},
volume = {12},
year = {2019}
}
@article{Holloway2020,
author = {Holloway, Jean E. and Lewkowicz, Antoni G.},
doi = {10.1002/ppp.2017},
issn = {1045-6740},
journal = {Permafrost and Periglacial Processes},
month = {jan},
number = {1},
pages = {85--96},
title = {{Half a century of discontinuous permafrost persistence and degradation in western Canada}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ppp.2017},
volume = {31},
year = {2020}
}
@article{Holloway2016,
abstract = {Several studies have suggested that sea-level rise during the last interglacial implies retreat of the West Antarctic Ice Sheet (WAIS). The prevalent hypothesis is that the retreat coincided with the peak Antarctic temperature and stable water isotope values from 128,000 years ago (128 ka); very early in the last interglacial. Here, by analysing climate model simulations of last interglacial WAIS loss featuring water isotopes, we show instead that the isotopic response to WAIS loss is in opposition to the isotopic evidence at 128 ka. Instead, a reduction in winter sea ice area of 65±7{\%} fully explains the 128 ka ice core evidence. Our finding of a marked retreat of the sea ice at 128 ka demonstrates the sensitivity of Antarctic sea ice extent to climate warming.},
author = {Holloway, Max D and Sime, Louise C and Singarayer, Joy S and Tindall, Julia C and Bunch, Pete and Valdes, Paul J},
doi = {10.1038/ncomms12293},
issn = {20411723},
journal = {Nature Communications},
pages = {1--9},
publisher = {Nature Publishing Group},
title = {{Antarctic last interglacial isotope peak in response to sea ice retreat not ice-sheet collapse}},
volume = {7},
year = {2016}
}
@misc{Hoogakker2018,
abstract = {Increased storage of carbon in the oceans has been proposed as a mechanism to explain lower concentrations of atmospheric carbon dioxide during ice ages; however, unequivocal signatures of this storage have not been found1. In seawater, the dissolved gases oxygen and carbon dioxide are linked via the production and decay of organic material, with reconstructions of low oxygen concentrations in the past indicating an increase in biologically mediated carbon storage. Marine sediment proxy records have suggested that oxygen concentrations in the deep ocean were indeed lower during the last ice age, but that near-surface and intermediate waters of the Pacific Ocean—a large fraction of which are poorly oxygenated at present—were generally better oxygenated during the glacial1–3. This vertical opposition could suggest a minimal net basin-integrated change in carbon storage. Here we apply a dual-proxy approach, incorporating qualitative upper-water-column and quantitative bottom-water oxygen reconstructions4,5, to constrain changes in the vertical extent of low-oxygen waters in the eastern tropical Pacific since the last ice age. Our tandem proxy reconstructions provide evidence of a downward expansion of oxygen depletion in the eastern Pacific during the last glacial, with no indication of greater oxygenation in the upper reaches of the water column. We extrapolate our quantitative deep-water oxygen reconstructions to show that the respired carbon reservoir of the glacial Pacific was substantially increased, establishing it as an important component of the coupled mechanism that led to low levels of atmospheric carbon dioxide during the glacial.},
author = {Hoogakker, Babette A.A. and Lu, Zunli and Umling, Natalie and Jones, Luke and Zhou, Xiaoli and Rickaby, Rosalind E.M. and Thunell, Robert and Cartapanis, Olivier and Galbraith, Eric},
booktitle = {Nature},
doi = {10.1038/s41586-018-0589-x},
issn = {14764687},
month = {oct},
number = {7727},
pages = {410--413},
publisher = {Nature Publishing Group},
title = {{Glacial expansion of oxygen-depleted seawater in the eastern tropical Pacific}},
volume = {562},
year = {2018}
}
@article{Hoogakker2015a,
abstract = {During the last and penultimate glacial maxima, atmospheric CO2 concentrations were lower than present, possibly in part because of increased storage of respired carbon in the deep oceans1. The amount of respired carbon present in a water mass can be calculated from its oxygen content through apparent oxygen utilization; the oxygen content can in turn be calculated from the carbon isotope gradient within the sediment column2. Here we analyse the shells of benthic foraminifera occurring at the sediment surface and the oxic/anoxic interface on the Portuguese Margin to reconstruct the carbon isotope gradient and hence bottom-water oxygenation over the past 150,000 years. We find that bottom-water oxygen concentrations were 45 and 65 $\mu$mol kg−1 lower than present during the last and penultimate glacial maxima, respectively. We calculate that concentrations of remineralized organic carbon were at least twice as high as today during the glacial maxima. We attribute these changes to decreased ventilation linked to a reorganization of ocean circulation3 and a strengthened global biological pump4. If the respired carbon pool was of a similar size throughout the entire glacial deep Atlantic basin, then this sink could account for 15 and 20 per cent of the glacial PCO2 drawdown during the last and penultimate glacial maxima.},
author = {Hoogakker, Babette A.A. and Elderfield, Henry and Schmiedl, Gerhard and McCave, I. Nick and Rickaby, Rosalind E.M.},
doi = {10.1038/ngeo2317},
issn = {17520908},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {40--43},
publisher = {Nature Publishing Group},
title = {{Glacial-interglacial changes in bottom-water oxygen content on the Portuguese margin}},
volume = {8},
year = {2015}
}
@article{Hoogakker2016,
abstract = {Abstract. A new global synthesis and biomization of long ({\textgreater} 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial–interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C.},
author = {Hoogakker, B. A. A. and Smith, R. S. and Singarayer, J. S. and Marchant, R. and Prentice, I. C. and Allen, J. R. M. and Anderson, R. S. and Bhagwat, S. A. and Behling, H. and Borisova, O. and Bush, M. and Correa-Metrio, A. and de Vernal, A. and Finch, J. M. and Fr{\'{e}}chette, B. and Lozano-Garcia, S. and Gosling, W. D. and Granoszewski, W. and Grimm, E. C. and Gr{\"{u}}ger, E. and Hanselman, J. and Harrison, S. P. and Hill, T. R. and Huntley, B. and Jim{\'{e}}nez-Moreno, G. and Kershaw, P. and Ledru, M.-P. and Magri, D. and McKenzie, M. and M{\"{u}}ller, U. and Nakagawa, T. and Novenko, E. and Penny, D. and Sadori, L. and Scott, L. and Stevenson, J. and Valdes, P. J. and Vandergoes, M. and Velichko, A. and Whitlock, C. and Tzedakis, C.},
doi = {10.5194/cp-12-51-2016},
issn = {1814-9332},
journal = {Climate of the Past},
month = {jan},
number = {1},
pages = {51--73},
title = {{Terrestrial biosphere changes over the last 120 kyr}},
url = {https://cp.copernicus.org/articles/12/51/2016/},
volume = {12},
year = {2016}
}
@article{Hope2017,
abstract = {The characteristics of El Nino–Southern Oscillation (ENSO) spectra over the Last Millennium are examined to characterise variability over past centuries. Seven published palaeo-ENSO reconstructions and Nino3.4 from six Coupled Model Intercomparison Project-Phase 5 and Paleoclimate Modelling Intercomparison Project-Phase 3 (CMIP5–PMIP3) Last Millennium simulations were analysed. The corresponding Historical and pre-industrial Control CMIP5–PMIP3 simulations were also considered. The post-1850 spectrum of each modelled or reconstructed ENSO series captures aspects of the observed spectrum to varying degrees. We note that no single model or ENSO reconstruction completely reproduces the instrumental spectral characteristics. The spectral power across the 2–3 years (near biennial), 3–8 years (classical ENSO) and 8–25 years (decadal) periodicity bands was calculated in a sliding 50 year window, revealing temporal variability in the spectra. There was strong temporal variability in the spectral power of each periodicity band in observed Nino3.4 and SOI and for all reconstructions and simulations of ENSO. Significant peaks in spectral power such as observed in recent decades also occur in some of the reconstructed palaeo-ENSO (around 1600, the early 1700s and 1900) and modelled series (around the major volcanic eruptions of 1258 and 1452). While the recent increase in spectral power might be in response to enhanced greenhouse gas levels, the increase lies within the range of variability across the suite of ENSO reconstructions and simulations examined here. This study demonstrates that the analysis of a suite of ENSO reconstructions and model simulations can build a broader understanding of the time-varying nature of ENSO spectra, and how the nature of the past spectra of ENSO is to some extent dependant on the climate model or palaeo-ENSO reconstruction chosen.},
author = {Hope, Pandora and Henley, Benjamin J. and Gergis, Joelle and Brown, Josephine and Ye, Hua},
doi = {10.1007/s00382-016-3393-z},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {CMIP5,Climate model simulations,Decadal variability,ENSO,El Ni{\~{n}}o–Southern Oscillation,Last Millennium,Nino3.4,PMIP,SOI,Spectra},
number = {5-6},
pages = {1705--1727},
publisher = {Springer Berlin Heidelberg},
title = {{Time-varying spectral characteristics of ENSO over the Last Millennium}},
volume = {49},
year = {2017}
}
@article{Hori2017,
abstract = {A long-term Northern Hemisphere (NH) daily 5-km snow cover extent (SCE) product (JASMES) was developed by the application of a consistent objective snow cover mapping algorithm to data from historical optical sensors on polar orbiting satellites from 1978 to 2015. A conventional decision tree algorithm with multiple threshold tests was employed to analyze radiances for the five spectral bands available across the full analysis period. The accuracies of the analyzed SCE maps were evaluated against in-situ snow data measured at ground stations along with the SCE maps from the National Oceanic and Atmospheric Administration Climate Data Record (NOAA-CDR) product. The evaluation showed the JASMES product to have a more temporally stable producer's accuracy (PA; 1–omission error) than NOAA, which is a key factor in the analysis of long-term SCE trends. Comparison of seasonal NH SCE trends from the two products showed NOAA to have opposite trends to those of JASMES in the fall and winter seasons, and to have overestimated SCE decreasing trends in the spring and summer. These tendencies are consistent with the increasing spatial and temporal resolutions of information over time, which were used in generating the NOAA snow analysis. An estimation of unbiased SCEs based on the accuracies of SCE maps also endorses the long-term trends of the JASMES product. The JASMES NH seasonal SCE exhibited negative slopes in all seasons but was only statistically significant in the summer (JJA) and fall (SON). Delayed snow cover onset was observed to be the main driver of decreasing annual snow duration (SCD) trends. The spatial pattern of annual SCD trends exhibited noticeable asymmetry between continents, with the largest significant decreases observed over western Eurasia with relatively few statistically significant decreases over North America.},
author = {Hori, Masahiro and Sugiura, Konosuke and Kobayashi, Kazufumi and Aoki, Teruo and Tanikawa, Tomonori and Kuchiki, Katsuyuki and Niwano, Masashi and Enomoto, Hiroyuki},
doi = {10.1016/j.rse.2017.01.023},
isbn = {0034-4257},
issn = {00344257},
journal = {Remote Sensing of Environment},
keywords = {AVHRR,Climate,Long-term data,MODIS,Remote sensing,Snow cover duration,Snow cover extent},
pages = {402--418},
title = {{A 38-year (1978–2015) Northern Hemisphere daily snow cover extent product derived using consistent objective criteria from satellite-borne optical sensors}},
volume = {191},
year = {2017}
}
@article{Hou2018,
abstract = {The tropical Pacific Walker circulation (PWC) is fundamentally important to global atmospheric circulation, and changes in it have a vital influence on the weather and climate systems. A novel three-pattern decomposition of a global atmospheric circulation (3P-DGAC) method, which can be used to investigate atmospheric circulations including the PWC, was proposed in our previous study. Therefore, the present study aims to examine the capability of this 3P-DGAC method to acquire interdecadal variations in the PWC and its connection to inhomogeneous air temperature changes in the period from 1961-2012. Our findings reveal that interdecadal variations in the PWC, i.e., weakening (strengthening) between the periods 1961-1974 and 1979-1997 (1979-1997 and 1999-2012), can be observed using the zonal stream function (ZSF) derived from the 3P-DGAC method. Enhancement of the PWC is also associated with the strengthening and weakening of zonal circulations in the tropical Indian Ocean (IOC) and Atlantic (AOC), respectively, and vice versa, implying a connection between these zonal overturning circulations in the tropics. The interdecadal variations in the zonal circulations correspond well to inhomogeneous air temperature changes, i.e., an enhancement of the PWC is associated with a warming (cooling) of the air temperature from 1000 to 300 hPa in the western (mid-eastern) Pacific Ocean and a cooling (warming) of the air temperature in the tropopause in the western (mid-eastern) Pacific Ocean. Furthermore, a novel index for the PWC intensity based on air temperature is defined, and the capability of the novel index in representing the PWC intensity is evaluated. This novel index is potentially important for the prediction of the PWC by using dynamic equations derived from the 3P-DGAC method.},
author = {Hou, Xiaoya and Cheng, Jianbo and Hu, Shujuan and Feng, Guolin},
doi = {10.3390/atmos9120469},
issn = {20734433},
journal = {Atmosphere},
keywords = {3P-DGAC method,Inhomogeneous air temperature changes,Interdecadal variations,Novel index,Walker circulation},
number = {12},
pages = {469},
title = {{Interdecadal variations in the walker circulation and its connection to inhomogeneous air temperature changes from 1961–2012}},
volume = {9},
year = {2018}
}
@article{2019SciBu..64..565H,
author = {Hou, Juzhi and Li, Can-Ge and Lee, Shihyu},
doi = {10.1016/j.scib.2019.02.012},
journal = {Science Bulletin},
month = {may},
number = {9},
pages = {565--566},
title = {{The temperature record of the Holocene: progress and controversies}},
volume = {64},
year = {2019}
}
@article{howell_arctic_2016,
abstract = {Abstract. Eight general circulation models have simulated the mid-Pliocene warm period (mid-Pliocene, 3.264 to 3.025 Ma) as part of the Pliocene Modelling Intercomparison Project (PlioMIP). Here, we analyse and compare their simulation of Arctic sea ice for both the pre-industrial period and the mid-Pliocene. Mid-Pliocene sea ice thickness and extent is reduced, and the model spread of extent is more than twice the pre-industrial spread in some summer months. Half of the PlioMIP models simulate ice-free conditions in the mid-Pliocene. This spread amongst the ensemble is in line with the uncertainties amongst proxy reconstructions for mid-Pliocene sea ice extent. Correlations between mid-Pliocene Arctic temperatures and sea ice extents are almost twice as strong as the equivalent correlations for the pre-industrial simulations. The need for more comprehensive sea ice proxy data is highlighted, in order to better compare model performances.},
author = {Howell, Fergus W and Haywood, Alan M and Otto-Bliesner, Bette L and Bragg, Fran and Chan, Wing-Le and Chandler, Mark A and Contoux, Camille and Kamae, Youichi and Abe-Ouchi, Ayako and Rosenbloom, Nan A and Stepanek, Christian and Zhang, Zhongshi},
doi = {10.5194/cp-12-749-2016},
issn = {1814-9332},
journal = {Climate of the Past},
month = {mar},
number = {3},
pages = {749--767},
title = {{Arctic sea ice simulation in the PlioMIP ensemble}},
url = {https://www.clim-past.net/12/749/2016/},
volume = {12},
year = {2016}
}
@article{Hrbacek2018,
abstract = {{\textcopyright} 2018 Informa UK Limited, trading as Taylor {\&} Francis Group Monitoring of active layer thawing depth and active layer thickness (ALT), using mechanical pronging and continuous temperature data logging, has been undertaken under the Circumpolar Active Layer Monitoring – South (CALM-S) program at a range of sites across Antarctica. The objective of this study was to summarize key data from sites in different Antarctic regions from 2006 to 2015 to review the state of the active layer in Antarctica and the effectiveness of the CALM-S program. The data from 16 sites involving 8 CALM-S and another 8 boreholes across the Antarctic have been used in the study. Probing for thaw depth, while giving information on local spatial variability, often underestimates the maximum ALT of Antarctic soils compared to that determined using continuous temperature monitoring. The differences are likely to be caused by stones limiting probe penetration and the timing of probing not coinciding with the timing of maximum thaw, which varies between seasons. The information on the active layer depth is still sparse in many regions and the monitoring needs to be extended and continued to provide a better understanding of both spatial and temporal variability in Antarctic soil thermal properties.},
author = {Hrb{\'{a}}{\v{c}}ek, Filip and Vieira, Goncalo and Oliva, Marc and Balks, Megan and Guglielmin, Mauro and de Pablo, Miguel {\'{A}}ngel and Molina, Antonio and Ramos, Miguel and Goyanes, Gabriel and Meiklejohn, Ian and Abramov, Andrey and Demidov, Nikita and Fedorov-Davydov, Dmitry and Lupachev, Alexey and Rivkina, Elizaveta and L{\'{a}}ska, Kamil and Kňa{\v{z}}kov{\'{a}}, Michaela and N{\'{y}}vlt, Daniel and Raffi, Rossana and Strelin, Jorge and Sone, Toshio and Fukui, Kotaro and Dolgikh, Andrey and Zazovskaya, Elya and Mergelov, Nikita and Osokin, Nikolay and Miamin, Vladislav},
doi = {10.1080/1088937X.2017.1420105},
isbn = {1088-937X 1939-0513},
issn = {19390513},
journal = {Polar Geography},
keywords = {Antarctica,CALM-S,active layer monitoring,active layer thickness,climate,ground temperature},
title = {{Active layer monitoring in Antarctica: an overview of results from 2006 to 2015}},
year = {2018}
}
@article{Hsin2015,
abstract = {Based on the analyses of 59 year (1950–2008) surface geostrophic velocities, the multidecadal changes of Kuroshio from the eastern Luzon to the southern Japan are investigated. Result shows that the upstream Kuroshio from the east of Luzon to southern East China Sea suffers much more obvious multidecadal changes. Except for the decade of 1980, the Kuroshio east of Luzon possesses a multidecadal tendency opposite to that east of Taiwan. Besides 1980s, the multidecadal change of Kuroshio bordering Taiwan is mainly governed by the eddy activity off the eastern Taiwan, while the wind stress curl plays a major role in the Kuroshio in the east of Luzon and in the Luzon Strait. The wind-stress-induced Ekman transport plays a secondary role in regulating the Kuroshio east of Luzon. In addition, the multidecadal fluctuation of Kuroshio east of Luzon also modulates the westward intrusion in the Luzon Strait. Instead, the Ekman transport dominated the whole upstream Kuroshio area from the eastern Luzon to the vicinity of Taiwan during the exceptional decade of 1980. Associated changes of water properties in the northern South China Sea and southern East China Sea are also ascribed to the multidecadal changes of surface Kuroshio in the upstream area.},
author = {Hsin, Yi Chia},
doi = {10.1002/2014JC010582},
isbn = {2169-9291},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
number = {3},
pages = {1792--1808},
title = {{Multidecadal variations of the surface Kuroshio between 1950s and 2000s and its impacts on surrounding waters}},
volume = {120},
year = {2015}
}
@article{Hu2018b,
abstract = {The stratospheric Arctic vortex (SAV) plays a critical role in forecasting cold winters in northern mid-latitudes. Its influence on the tropospheric mid-and high-latitudes has attracted growing attention in recent years. However, the trend in the SAV during the recent two decades is still unknown. Here, using three reanalysis datasets, we found that the SAV intensity during 1998–2016 has a strengthening trend, in contrast to the weakening trend before that period. Approximately 25{\%} of this strengthening is contributed by the warming of sea-surface temperature (SST) over the central North Pacific (CNP). Observational analysis and model experiments show that the warmed CNP SST tends to weaken the Aleutian low, subsequently weakening the upward propagation of wavenumber-1 planetary wave flux, further strengthening the SAV. This strengthened SAV suggests important implications in understanding the Arctic warming amplification and in predicting the surface temperature changes over the northern continents. NATURE COMMUNICATIONS | (2018) 9:1697 | DOI: 10.1038/s41467-018-04138-3 | www.nature.com/naturecommunications},
author = {Hu, Dingzhu and Guan, Zhaoyong and Tian, Wenshou and Ren, Rongcai},
doi = {10.1038/s41467-018-04138-3},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1697},
publisher = {Springer US},
title = {{Recent strengthening of the stratospheric Arctic vortex response to warming in the central North Pacific}},
url = {http://www.nature.com/articles/s41467-018-04138-3},
volume = {9},
year = {2018}
}
@article{Hu2018a,
abstract = {The Hadley circulation is one of the most important atmospheric circulations. Widening of the Hadley circulation has drawn extensive studies in the past decade. The key concern is that widening of the Hadley circulation would cause poleward shift of the subtropical dry zone. Various metrics have been applied to measure the widening of the tropics. What are responsible for the observed widening trends of the Hadley circulation? How anthropogenic and natural forcings caused the widening? How the widening results in regional climatic effects? These are the major questions in studing the widening of the Hadley circulation. While both observations and simulations all show widening of the Hadley circulation in the past few decades, there are no general agreements of changes in the strength of the Hadley circulation. Although some reanalysis datasets show strengthening of the Hadley circulation, it was shown that the strengthening trend could be artificial, and simulations show weakening of the Hadley circulation for global greenhouse warming. In the present paper, we shall briefly review the major progresses of studies in trends in width and strength of the Hadley circulation. We address answers to these questions, clarify inconsistent results, and propose ideas for future studies.},
author = {Hu, Yongyun and Huang, Han and Zhou, Chen},
doi = {10.1016/j.scib.2018.04.020},
issn = {20959281},
journal = {Science Bulletin},
keywords = {ENSO,Global warming,Greenhouse gases,Hadley circulation,Ozone depletion},
number = {10},
pages = {640--644},
publisher = {Science China Press},
title = {{Widening and weakening of the Hadley circulation under global warming}},
url = {https://doi.org/10.1016/j.scib.2018.04.020},
volume = {63},
year = {2018}
}
@article{doi:10.1175/JCLI-D-12-00265.1,
abstract = {AbstractAn interdecadal shift in the variability and mean state of the tropical Pacific Ocean is investigated within the context of changes in El Ni{\~{n}}o–Southern Oscillation (ENSO). Compared with 1979–99, the interannual variability in the tropical Pacific was significantly weaker in 2000–11, and this shift can be seen by coherent changes in both the tropical atmosphere and ocean. For example, the equatorial thermocline tilt became steeper during 2000–11, which was consistent with positive (negative) sea surface temperature anomalies, increased (decreased) precipitation, and enhanced (suppressed) convection in the western (central and eastern) tropical Pacific, which reflected an intensification of the Walker circulation.The combination of a steeper thermocline slope with stronger surface trade winds is proposed to have hampered the eastward migration of the warm water along the equatorial Pacific. As a consequence, the variability of the warm water volume was reduced and thus ENSO amplitude also decreased. Sensitivity experiments with the Zebiak–Cane model confirm the link between thermocline slope, wind stress, and the amplitude of ENSO.},
author = {Hu, Zeng-Zhen and Kumar, Arun and Ren, Hong-Li and Wang, Hui and L'Heureux, Michelle and Jin, Fei-Fei},
doi = {10.1175/JCLI-D-12-00265.1},
journal = {Journal of Climate},
number = {8},
pages = {2601--2613},
title = {{Weakened Interannual Variability in the Tropical Pacific Ocean since 2000}},
url = {https://doi.org/10.1175/JCLI-D-12-00265.1},
volume = {26},
year = {2013}
}
@article{Hu2019,
abstract = {Rainfall is one of the most basic meteorological and hydrological elements. Quantitative rainfall estimation has always been a common concern in many fields of research and practice, such as meteorology, hydrology, and environment, as well as being one of the most important research hotspots in various fields nowadays. Due to the development of space observation technology and statistics, progress has been made in rainfall quantitative spatial estimation, which has continuously deepened our understanding of the water cycle across different space-time scales. In light of the information sources used in rainfall spatial estimation, this paper summarized the research progress in traditional spatial interpolation, remote sensing retrieval, atmospheric reanalysis rainfall, and multi-source rainfall merging since 2000. However, because of the extremely complex spatiotemporal variability and physical mechanism of rainfall, it is still quite challenging to obtain rainfall spatial distribution with high quality and resolution. Therefore, we present existing problems that require further exploration, including the improvement of interpolation and merging methods, the comprehensive evaluation of remote sensing, and the reanalysis of rainfall data and in-depth application of non-gauge based rainfall data.},
author = {Hu, Qingfang and Li, Zhe and Wang, Leizhi and Huang, Yong and Wang, Yintang and Li, Lingjie},
doi = {10.3390/w11030579},
issn = {20734441},
journal = {Water},
keywords = {Atmospheric reanalysis,Radar,Rainfall,Rainfall merging,Satellite,Spatial interpolation},
number = {3},
pages = {1--30},
title = {{Rainfall spatial estimations: A review from spatial interpolation to multi-source data merging}},
volume = {11},
year = {2019}
}
@article{doi:10.1175/JCLI-D-16-0836.1,
abstract = {AbstractThe monthly global 2° × 2° Extended Reconstructed Sea Surface Temperature (ERSST) has been revised and updated from version 4 to version 5. This update incorporates a new release of ICOADS release 3.0 (R3.0), a decade of near-surface data from Argo floats, and a new estimate of centennial sea ice from HadISST2. A number of choices in aspects of quality control, bias adjustment, and interpolation have been substantively revised. The resulting ERSST estimates have more realistic spatiotemporal variations, better representation of high-latitude SSTs, and ship SST biases are now calculated relative to more accurate buoy measurements, while the global long-term trend remains about the same. Progressive experiments have been undertaken to highlight the effects of each change in data source and analysis technique upon the final product. The reconstructed SST is systematically decreased by 0.077°C, as the reference data source is switched from ship SST in ERSSTv4 to modern buoy SST in ERSSTv5. Furthermore, high-latitude SSTs are decreased by 0.1°–0.2°C by using sea ice concentration from HadISST2 over HadISST1. Changes arising from remaining innovations are mostly important at small space and time scales, primarily having an impact where and when input observations are sparse. Cross validations and verifications with independent modern observations show that the updates incorporated in ERSSTv5 have improved the representation of spatial variability over the global oceans, the magnitude of El Ni{\~{n}}o and La Ni{\~{n}}a events, and the decadal nature of SST changes over 1930s–40s when observation instruments changed rapidly. Both long- (1900–2015) and short-term (2000–15) SST trends in ERSSTv5 remain significant as in ERSSTv4.},
author = {Huang, Boyin and Thorne, Peter W and Banzon, Viva F and Boyer, Tim and Chepurin, Gennady and Lawrimore, Jay H and Menne, Matthew J and Smith, Thomas M and Vose, Russell S and Zhang, Huai-Min},
doi = {10.1175/JCLI-D-16-0836.1},
journal = {Journal of Climate},
number = {20},
pages = {8179--8205},
title = {{Extended Reconstructed Sea Surface Temperature, Version 5 (ERSSTv5): Upgrades, Validations, and Intercomparisons}},
url = {https://doi.org/10.1175/JCLI-D-16-0836.1},
volume = {30},
year = {2017}
}
@article{doi:10.1175/JCLI-D-17-0824.1,
abstract = { AbstractThe difficulty in effectively evaluating sea surface temperature (SST) analyses is finding independent observations, since most available observations have been used in the SST analyses. In this study, the ocean profile measurements [from reverse thermometer, CTD, mechanical bathythermograph (MBT), and XBT] above 5-m depth over 1950–2016 from the World Ocean Database (WOD) are used (data labeled pSSTW). The biases of MBT and XBT are corrected based on currently available algorithms. The bias-corrected pSSTW over 1950–2016 and satellite-based SST from the European Space Agency (ESA) Climate Change Initiative (CCI) over 1992–2010 are used to evaluate commonly available SST analyses. These SST analyses are the Extended Reconstructed SST (ERSST), versions 5, 4, and 3b, the Met Office Hadley Centre Sea Ice and SST dataset (HadISST), and the Japan Meteorological Administration (JMA) Centennial In Situ Observation-Based Estimates of SST version 2.9.2 (COBE-SST2). Our comparisons show that the SST from COBE-SST2 is the closest to pSSTW and CCI in most of the Pacific, Atlantic, and Southern Oceans, which may result from its unique bias correction to ship observations. The SST from ERSST version 5 is more consistent with pSSTW than its previous versions over 1950–2016, and is more consistent with CCI than its previous versions over 1992–2010. The better performance of ERSST version 5 over its previous versions is attributed to its improved bias correction applied to ship observations with a baseline of buoy observations, and is seen in most of the Pacific and Atlantic. },
author = {Huang, Boyin and Angel, William and Boyer, Tim and Cheng, Lijing and Chepurin, Gennady and Freeman, Eric and Liu, Chunying and Zhang, Huai-Min},
doi = {10.1175/JCLI-D-17-0824.1},
journal = {Journal of Climate},
number = {13},
pages = {5015--5030},
title = {{Evaluating SST Analyses with Independent Ocean Profile Observations}},
url = {https://doi.org/10.1175/JCLI-D-17-0824.1},
volume = {31},
year = {2018}
}
@article{doi:10.1175/JCLI-D-15-0430.1,
abstract = { AbstractThe uncertainty in Extended Reconstructed SST (ERSST) version 4 (v4) is reassessed based upon 1) reconstruction uncertainties and 2) an extended exploration of parametric uncertainties. The reconstruction uncertainty (Ur) results from using a truncated (130) set of empirical orthogonal teleconnection functions (EOTs), which yields an inevitable loss of information content, primarily at a local level. The Ur is assessed based upon 32 ensemble ERSST.v4 analyses with the spatially complete monthly Optimum Interpolation SST product. The parametric uncertainty (Up) results from using different parameter values in quality control, bias adjustments, and EOT definition etc. The Up is assessed using a 1000-member ensemble ERSST.v4 analysis with different combinations of plausible settings of 24 identified internal parameter values. At the scale of an individual grid box, the SST uncertainty varies between 0.3° and 0.7°C and arises from both Ur and Up. On the global scale, the SST uncertainty is substantially smaller (0.03°–0.14°C) and predominantly arises from Up. The SST uncertainties are greatest in periods and locales of data sparseness in the nineteenth century and relatively small after the 1950s. The global uncertainty estimates in ERSST.v4 are broadly consistent with independent estimates arising from the Hadley Centre SST dataset version 3 (HadSST3) and Centennial Observation-Based Estimates of SST version 2 (COBE-SST2). The uncertainty in the internal parameter values in quality control and bias adjustments can impact the SST trends in both the long-term (1901–2014) and “hiatus” (2000–14) periods. },
author = {Huang, Boyin and Thorne, Peter W and Smith, Thomas M and Liu, Wei and Lawrimore, Jay and Banzon, Viva F and Zhang, Huai-Min and Peterson, Thomas C and Menne, Matthew},
doi = {10.1175/JCLI-D-15-0430.1},
journal = {Journal of Climate},
number = {9},
pages = {3119--3142},
title = {{Further Exploring and Quantifying Uncertainties for Extended Reconstructed Sea Surface Temperature (ERSST) Version 4 (v4)}},
url = {https://doi.org/10.1175/JCLI-D-15-0430.1},
volume = {29},
year = {2016}
}
@article{doi:10.1175/JCLI-D-14-00006.1,
abstract = { AbstractThe monthly Extended Reconstructed Sea Surface Temperature (ERSST) dataset, available on global 2° × 2° grids, has been revised herein to version 4 (v4) from v3b. Major revisions include updated and substantially more complete input data from the International Comprehensive Ocean–Atmosphere Data Set (ICOADS) release 2.5; revised empirical orthogonal teleconnections (EOTs) and EOT acceptance criterion; updated sea surface temperature (SST) quality control procedures; revised SST anomaly (SSTA) evaluation methods; updated bias adjustments of ship SSTs using the Hadley Centre Nighttime Marine Air Temperature dataset version 2 (HadNMAT2); and buoy SST bias adjustment not previously made in v3b.Tests show that the impacts of the revisions to ship SST bias adjustment in ERSST.v4 are dominant among all revisions and updates. The effect is to make SST 0.1°–0.2°C cooler north of 30°S but 0.1°–0.2°C warmer south of 30°S in ERSST.v4 than in ERSST.v3b before 1940. In comparison with the Met Office SST product [the Hadley Centre Sea Surface Temperature dataset, version 3 (HadSST3)], the ship SST bias adjustment in ERSST.v4 is 0.1°–0.2°C cooler in the tropics but 0.1°–0.2°C warmer in the midlatitude oceans both before 1940 and from 1945 to 1970. Comparisons highlight differences in long-term SST trends and SSTA variations at decadal time scales among ERSST.v4, ERSST.v3b, HadSST3, and Centennial Observation-Based Estimates of SST version 2 (COBE-SST2), which is largely associated with the difference of bias adjustments in these SST products. The tests also show that, when compared with v3b, SSTAs in ERSST.v4 can substantially better represent the El Ni{\~{n}}o/La Ni{\~{n}}a behavior when observations are sparse before 1940. Comparisons indicate that SSTs in ERSST.v4 are as close to satellite-based observations as other similar SST analyses. },
author = {Huang, Boyin and Banzon, Viva F and Freeman, Eric and Lawrimore, Jay and Liu, Wei and Peterson, Thomas C and Smith, Thomas M and Thorne, Peter W and Woodruff, Scott D and Zhang, Huai-Min},
doi = {10.1175/JCLI-D-14-00006.1},
journal = {Journal of Climate},
number = {3},
pages = {911--930},
title = {{Extended Reconstructed Sea Surface Temperature Version 4 (ERSST.v4). Part I: Upgrades and Intercomparisons}},
url = {https://doi.org/10.1175/JCLI-D-14-00006.1},
volume = {28},
year = {2015}
}
@article{doi:10.1175/JCLI-D-19-0395.1,
abstract = {AbstractThis analysis estimates uncertainty in the NOAA global surface temperature (GST) version 5 (NOAAGlobalTemp v5) product, which consists of sea surface temperature (SST) from the Extended Reconstructed SST version 5 (ERSSTv5) and land surface air temperature (LSAT) from the Global Historical Climatology Network monthly version 4 (GHCNm v4). Total uncertainty in SST and LSAT consists of parametric and reconstruction uncertainties. The parametric uncertainty represents the dependence of SST/LSAT reconstructions on selecting 28/6 internal parameters of SST/LSAT, and is estimated by a 1000-member ensemble from 1854 to 2016. The reconstruction uncertainty represents the residual error of using a limited number of 140/65 modes for SST/LSAT.Uncertainty is quantified at the global scale as well as the local grid scale. Uncertainties in SST and LSAT at the local grid scale are larger in the earlier period (1880s–1910s) and during the two world wars due to sparse observations, then decrease in the modern period (1950s–2010s) due to increased data coverage. Uncertainties in SST and LSAT at the global scale are much smaller than those at the local grid scale due to error cancellations by averaging. Uncertainties are smaller in SST than in LSAT due to smaller SST variabilities. Comparisons show that GST and its uncertainty in NOAAGlobalTemp v5 are comparable to those in other internationally recognized GST products. The differences between NOAAGlobalTemp v5 and other GST products are within their uncertainties at the 95{\%} confidence level.},
author = {Huang, Boyin and Menne, Matthew J and Boyer, Tim and Freeman, Eric and Gleason, Byron E and Lawrimore, Jay H and Liu, Chunying and Rennie, J Jared and Schreck, Carl J and Sun, Fengying and Vose, Russell and Williams, Claude N and Yin, Xungang and Zhang, Huai-Min},
doi = {10.1175/JCLI-D-19-0395.1},
journal = {Journal of Climate},
number = {4},
pages = {1351--1379},
title = {{Uncertainty estimates for sea surface temperature and land surface air temperature in NOAAGlobalTemp version 5}},
url = {https://doi.org/10.1175/JCLI-D-19-0395.1},
volume = {33},
year = {2019}
}
@article{Huang2019,
abstract = {The relative roles of buoy and Argo observations in two sea surface temperature (SST) analyses are studied in the global ocean and tropical Pacific Ocean over 2000-16 using monthly Extended Reconstructed SST version 5 (ERSSTv5) and Daily Optimum Interpolation SST version 2 (DOISST). Experiments show an overall higher impact by buoys than Argo floats over the global oceans and an increasing impact by Argo floats. The impact by Argo floats is generally larger in the Southern Hemisphere than in the Northern Hemisphere. The impact on trends and anomalies of globally averaged SST by either one is small when the other is used. The warming trend over 2000-16 remains significant by including either buoys or Argo floats or both. In the tropical Pacific, the impact by buoys was large over 2000-05 when the number of Argo floats was low, and became smaller over 2010-16 when the number and area coverage of Argo floats increased. The magnitude of El Ni{\~{n}}o and La Ni{\~{n}}a events decreases when the observations from buoys, Argo floats, or both are excluded. The impact by the Tropical Atmosphere Ocean (TAO) and Triangle Trans-Ocean Buoy Network (TRITON) is small in normal years and during El Ni{\~{n}}o events. The impact by TAO/TRITON buoys on La Ni{\~{n}}a events is small when Argo floats are included in the analysis systems, and large when Argo floats are not included. The reason for the different impact on El Ni{\~{n}}o and La Ni{\~{n}}a events is that the drifting buoys are more dispersed from the equatorial Pacific region by stronger trade winds during La Ni{\~{n}}a events.},
author = {Huang, Boyin and Liu, Chunying and Ren, Guoyu and Zhang, Huai Min and Zhang, Lei},
doi = {10.1175/JCLI-D-18-0368.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Buoy observations,ENSO,El Nino,In situ oceanic observations,La Nina,Sea surface temperature},
number = {9},
pages = {2517--2535},
title = {{The role of buoy and Argo observations in two SST analyses in the global and tropical Pacific Oceans}},
volume = {32},
year = {2019}
}
@article{Huang2019a,
author = {Huang, Ruping and Chen, Shangfeng and Chen, Wen and Hu, Peng and Yu, Bin},
journal = {Advances in Atmospheric Sciences},
keywords = {10,1007,11,1251,1264,2019,36,adv,and b,atmos,boreal spring,chen,circulation over the western,citation,doi,f,https,hu,huang,long-term trend,org,p,pacific during boreal spring,r,recent strengthening of the,regional hadley,regional hadley circulation,s,s00376-019-9004-2,sci,w,western pacific,yu},
number = {November},
pages = {1251--1264},
title = {{Recent Strengthening of the Regional Hadley Circulation over the Western Pacific during Boreal Spring}},
volume = {36},
year = {2019}
}
@article{Huang2019c,
abstract = {Observations are required to understand monsoon changes over time. Reanalyses are useful supplements to observations; however, their ability to reveal long-term monsoon changes remains unknown. Here, we evaluate against observations the performance of two reanalysis datasets covering the whole twentieth century, the ECMWF reanalysis of the twentieth century (ERA20C) and the Twentieth Century Reanalysis Project (20CR), in terms of reproducing the climatological averages, the centennial co-variation, and long-term trends of Northern Hemisphere land monsoon rainfall (NHLMR). Their performance is compared with three other widely used reanalyses, the NCEP–NCAR reanalysis (NCEP1), the ECMWF 40-year reanalysis (ERA40), and the Japanese 55-year Reanalysis Project (JRA55), for the period after 1955. Results show that the five reanalysis datasets reasonably reproduce the climatological NHLMR and NHLM domains. The leading co-variation mode of NHLMR, with an overall increasing tendency before 1955 and a decreasing tendency afterwards, is captured by the corresponding principal components of the two long-term datasets, with some spatial biases. For the long-term precipitation trends, both the ERA20C and 20CR reproduce the increasing trend during 1901–1955, except for parts of the North African (NAF) monsoon region. However, neither dataset captures the decreasing trend of NHLMR after 1955 because of limitations in the NAF and North American (NAM) monsoon region. The NCEP1, ERA40, and JRA55 datasets also have shortcomings in the NAM region. An overall decreasing NHLMR is only shown in the NCEP1 dataset. A moisture budget analysis reveals that the long-term trends of NHLMR are dominated by the dynamic component of moisture convergence, suggesting a prominent role for atmospheric circulation changes. The influence of residual terms related to observations assimilated in the reanalyses is also discussed.},
author = {Huang, Xin and Zhou, Tianjun and Zhang, Wenxia and Jiang, Jie and Li, Puxi and Zhao, Yin},
doi = {10.1007/s00382-019-04982-z},
isbn = {0123456789},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Long-term changes,Moisture budget analysis,Northern Hemisphere land monsoon rainfall,Reanalysis data},
number = {11},
pages = {7131--7149},
publisher = {Springer Berlin Heidelberg},
title = {{Northern Hemisphere land monsoon precipitation changes in the twentieth century revealed by multiple reanalysis datasets}},
url = {https://doi.org/10.1007/s00382-019-04982-z},
volume = {53},
year = {2019}
}
@article{Huang2020a,
abstract = {Weddell Sea-derived Antarctic Bottom Water (AABW) is one of the most important deep water masses in the Southern Hemisphere occupying large portions of the deep Southern Ocean (SO) today. While substantial changes in SO-overturning circulation were previously suggested, the state of Weddell Sea AABW export during glacial climates remains poorly understood. Here we report seawater-derived Nd and Pb isotope records that provide evidence for the absence of Weddell Sea-derived AABW in the Atlantic sector of the SO during the last two glacial maxima. Increasing delivery of Antarctic Pb to regions outside the Weddell Sea traced SO frontal displacements during both glacial terminations. The export of Weddell Sea-derived AABW resumed late during glacial terminations, coinciding with the last major atmospheric CO2 rise in the transition to the Holocene and the Eemian. Our new records lend strong support for a previously inferred AABW overturning stagnation event during the peak Eemian interglacial.},
author = {Huang, Huang and Gutjahr, Marcus and Eisenhauer, Anton and Kuhn, Gerhard},
doi = {10.1038/s41467-020-14302-3},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {424},
title = {{No detectable Weddell Sea Antarctic Bottom Water export during the Last and Penultimate Glacial Maximum}},
url = {https://doi.org/10.1038/s41467-020-14302-3},
volume = {11},
year = {2020}
}
@article{Huang2020,
abstract = {Previous research has shown that the 1877/78 El Ni{\~{n}}o resulted in great famine events around the world. However, the strength and statistical significance of this El Ni{\~{n}}o event have not been fully addressed, largely due to the lack of data. We take a closer look at the data using an ensemble analysis of the Extended Reconstructed Sea Surface Temperature version 5 (ERSSTv5). The ERSSTv5 standard run indicates a strong El Ni{\~{n}}o event with a peak monthly value of the Ni{\~{n}}o-3 index of 3.5°C during 1877/78, stronger than those during 1982/83, 1997/98, and 2015/16. However, an analysis of the ERSSTv5 ensemble runs indicates that the strength and significance (uncertainty estimates) depend on the construction of the ensembles. A 1000-member ensemble analysis shows that the ensemble mean Ni{\~{n}}o-3 index has a much weaker peak of 1.8°C, and its uncertainty is much larger during 1877/78 (2.8°C) than during 1982/83 (0.3°C), 1997/98 (0.2°C), and 2015/16 (0.1°C). Further, the large uncertainty during 1877/78 is associated with selections of a short (1 month) period of raw-data filter and a large (20{\%}) acceptance criterion of empirical orthogonal teleconnection modes in the ERSSTv5 reconstruction. By adjusting these two parameters, the uncertainty during 1877/78 decreases to 0.5°C, while the peak monthly value of the Ni{\~{n}}o-3 index in the ensemble mean increases to 2.8°C, suggesting a strong and statistically significant 1877/78 El Ni{\~{n}}o event. The adjustment of those two parameters is validated by masking the modern observations of 1981–2017 to 1861–97. Based on the estimated uncertainties, the differences among the strength of these four major El Ni{\~{n}}o events are not statistically significant.},
author = {Huang, Boyin and L'Heureux, Michelle and Hu, Zeng-Zhen and Yin, Xungang and Zhang, Huai-Min},
doi = {10.1175/JCLI-D-19-0650.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {may},
number = {11},
pages = {4853--4869},
title = {{How Significant Was the 1877/78 El Ni{\~{n}}o?}},
url = {https://doi.org/10.1175/JCLI-D-19-0650.1},
volume = {33},
year = {2020}
}
@article{https://doi.org/10.1029/2018JD028995,
author = {Huang, Xiaofang and Jiang, Dabang and Dong, Xinxin and Yang, Shiling and Su, Baohuang and Li, Xiangyu and Tang, Zihua and Wang, Yongda},
doi = {10.1029/2018JD028995},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {PlioMIP,mid-Pliocene,northern edge of the East Asian summer monsoon,western Pacific subtropical high},
number = {3},
pages = {1392--1404},
title = {{Northwestward Migration of the Northern Edge of the East Asian Summer Monsoon During the Mid-Pliocene Warm Period: Simulations and Reconstructions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD028995},
volume = {124},
year = {2019}
}
@article{Huffman2007a,
abstract = {The Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) provides a calibration-based sequential scheme for combining precipitation estimates from multiple satellites, as well as gauge analyses where feasible, at fine scales (0.25° × 0.25° and 3 hourly). TMPA is available both after and in real time, based on calibration by the TRMM Combined Instrument and TRMM Microwave Imager precipitation products, respectively. Only the after-real-time product incorporates gauge data at the present. The dataset covers the latitude band 50°N–S for the period from 1998 to the delayed present. Early validation results are as follows: the TMPA provides reasonable performance at monthly scales, although it is shown to have precipitation rate–dependent low bias due to lack of sensitivity to low precipitation rates over ocean in one of the input products [based on Advanced Microwave Sounding Unit-B (AMSU-B)]. At finer scales the TMPA is successful at approximately reproducing the surface observation–based histogram of precipitation, as well as reasonably detecting large daily events. The TMPA, however, has lower skill in correctly specifying moderate and light event amounts on short time intervals, in common with other finescale estimators. Examples are provided of a flood event and diurnal cycle determination.},
author = {Huffman, George J. and Bolvin, David T. and Nelkin, Eric J. and Wolff, David B and Adler, Robert F. and Gu, Guojun and Hong, Yang and Bowman, Kenneth P and Stocker, Erich F},
doi = {10.1175/JHM560.1},
issn = {1525-7541},
journal = {Journal of Hydrometeorology},
month = {feb},
number = {1},
pages = {38--55},
title = {{The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-Global, Multiyear, Combined-Sensor Precipitation Estimates at Fine Scales}},
url = {http://journals.ametsoc.org/doi/10.1175/JHM560.1},
volume = {8},
year = {2007}
}
@article{Hugonnet2021,
author = {Hugonnet, Romain and McNabb, Robert and Berthier, Etienne and Menounos, Brian and Nuth, Christopher and Girod, Luc and Farinotti, Daniel and Huss, Matthias and Dussaillant, Ines and Brun, Fanny and K{\"{a}}{\"{a}}b, Andreas},
doi = {10.1038/s41586-021-03436-z},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7856},
pages = {726--731},
title = {{Accelerated global glacier mass loss in the early twenty-first century}},
url = {http://www.nature.com/articles/s41586-021-03436-z},
volume = {592},
year = {2021}
}
@article{Hummels2015,
abstract = {The western boundary current system off Brazil is a key region for diagnosing variations of the Atlantic meridional overturning circulation (AMOC) and the southern subtropical cell. In July 2013 a mooring array was installed off the coast at 11°S similar to an array installed between 2000 and 2004 at the same location. Here we present results from two research cruises and the first 10.5 months of moored observations in comparison to the observations a decade ago. Average transports of the North Brazil Undercurrent and the Deep Western Boundary Current (DWBC) have not changed between the observational periods. DWBC eddies that are predicted to disappear with a weakening AMOC are still present. Upper layer changes in salinity and oxygen within the last decade are consistent with an increased Agulhas leakage, while at depths water mass changes are likely related to changes in the North Atlantic as well as tropical circulation changes.},
author = {Hummels, Rebecca and Brandt, Peter and Dengler, Marcus and Fischer, J{\"{u}}rgen and Araujo, Moacyr and Veleda, Doris and Durgadoo, Jonathan V.},
doi = {10.1002/2015GL065254},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {18},
pages = {7615--7622},
title = {{Interannual to decadal changes in the western boundary circulation in the Atlantic at 11°S}},
volume = {42},
year = {2015}
}
@article{Hurd2018a,
abstract = {Ocean acidification is a global phenomenon, but it is overlaid by pronounced regional variability modulated by local physics, chemistry and biology. Recognition of its multifaceted nature and the interplay of acidification with other ocean drivers has led to international and regional initiatives to establish observation networks and develop unifying principles for biological responses. There is growing awareness of the threat presented by ocean acidification to ecosystem services and the socio-economic consequences are becoming increasingly apparent and quantifiable. In this higher-CO2 world, future challenges involve better design and rigorous testing of adaptation, mitigation and intervention options to offset the effects of ocean acidification at scales ranging from local to regional.},
author = {Hurd, Catriona L and Lenton, Andrew and Tilbrook, Bronte and Boyd, Philip W},
doi = {10.1038/s41558-018-0211-0},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {8},
pages = {686--694},
title = {{Current understanding and challenges for oceans in a higher-CO2 world}},
url = {https://doi.org/10.1038/s41558-018-0211-0},
volume = {8},
year = {2018}
}
@article{Hyland2017,
abstract = {The early Eocene climatic optimum was a period of major climatic and environmental change that was caused by perturbations to the global carbon cycle. Recent work from terrestrial sections in the Northern Hemisphere demonstrates that the period was characterized by different responses in the terrestrial and marine realms, suggesting that traditional causal mechanisms may not adequately explain the dynamics of the early Eocene climatic optimum. Here, we present a new high-resolution multiproxy record of terrestrial climatic and environmental conditions during the early Eocene climatic optimum from the Southern Hemisphere and compare this reconstruction to other marine and terrestrial records. Similar to Northern Hemisphere terrestrial records, there is a transient peak period of atmospheric carbon isotope enrichment as well as increased temperatures and precipitation, which indicate that terrestrial environmental responses to the early Eocene climatic optimum were broadly consistent in temperate settings worldwide. This global consistency in terrestrial records demonstrates differences in peak warming time scales and carbon isotope responses between marine and terrestrial systems, which further constrain potential causes for the early Eocene climatic optimum to multiple-system or nontraditional mechanisms and highlight the importance of paired records for understanding past climate.},
author = {Hyland, Ethan G. and Sheldon, Nathan D. and Cotton, Jennifer M.},
doi = {10.1130/B31493.1},
issn = {0016-7606},
journal = {Geological Society of America Bulletin},
month = {jan},
number = {1-2},
pages = {244--252},
title = {{Constraining the early Eocene climatic optimum: A terrestrial interhemispheric comparison}},
url = {https://pubs.geoscienceworld.org/gsabulletin/article/129/1-2/244-252/185464},
volume = {129},
year = {2017}
}
@article{Ibarra2018,
author = {Ibarra, Daniel E and Oster, Jessica L and Winnick, Matthew J and {Caves Rugenstein}, Jeremy K. and Byrne, Michael P and Chamberlain, C Page},
doi = {10.1130/G39962.1},
issn = {0091-7613},
journal = {Geology},
month = {apr},
number = {4},
pages = {355--358},
title = {{Warm and cold wet states in the western United States during the Pliocene-Pleistocene}},
url = {https://pubs.geoscienceworld.org/gsa/geology/article/46/4/355/528314/Warm-and-cold-wet-states-in-the-western-United},
volume = {46},
year = {2018}
}
@article{Shepherd2018a,
abstract = {The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise. Here we combine satellite observations of its changing volume, flow and gravitational attraction with modelling of its surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation). Over this period, ocean-driven melting has caused rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. We find large variations in and among model estimates of surface mass balance and glacial isostatic adjustment for East Antarctica, with its average rate of mass gain over the period 1992–2017 (5 ± 46 billion tonnes per year) being the least certain.},
author = {{IMBIE Consortium}},
doi = {10.1038/s41586-018-0179-y},
issn = {0028-0836},
journal = {Nature},
month = {jun},
number = {7709},
pages = {219--222},
title = {{Mass balance of the Antarctic Ice Sheet from 1992 to 2017}},
url = {http://www.nature.com/articles/s41586-018-0179-y},
volume = {558},
year = {2018}
}
@article{IMBIEConsortium2020a,
author = {{IMBIE Consortium}},
doi = {10.1038/s41586-019-1855-2},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {7798},
pages = {233--239},
title = {{Mass balance of the Greenland Ice Sheet from 1992 to 2018}},
url = {http://www.nature.com/articles/s41586-019-1855-2},
volume = {579},
year = {2020}
}
@article{cp-16-1953-2020,
author = {Inglis, G.N. and Bragg, F. and Burls, N. and Evans, D. and Foster, G.L. and Huber, M. and Lunt, D.J. and Siler, N. and Steinig, S. and Wilkinson, R. and Anagnostou, E. and Camwinckel, M. and Hollis, C.J. and Pancost, R.D. and Tierney, J.E.},
doi = {10.5194/cp-16-1953-2020},
journal = {Climate of the Past},
number = {5},
pages = {1953--1968},
title = {{Global mean surface temperature and climate sensitivity of the EECO, PETM and latest Paleocene}},
url = {https://cp.copernicus.org/articles/16/1953/2020/},
volume = {16},
year = {2020}
}
@techreport{IPCC2018,
author = {IPCC},
doi = {https://www.ipcc.ch/sr15},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {616},
publisher = {In Press},
title = {{Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,}},
url = {https://www.ipcc.ch/sr15},
year = {2018}
}
@techreport{IPCC,
author = {IPCC},
editor = {P{\"{o}}rtner, Hans-Otto and Roberts, DC and Masson-Delmotte, V and Zhai, P and Tignor, M and Poloczanska, E and Mintenbeck, K and Alegr{\'{i}}a, A and Nicolai, M and Okem, A},
pages = {755},
publisher = {In Press},
title = {{IPCC Special Report on the Ocean and Cryosphere in a Changing Climate}},
url = {https://www.ipcc.ch/report/srocc},
year = {2019}
}
@incollection{IPCC2013,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {IPCC},
booktitle = {Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
doi = {10.1017/CBO9781107415324.004},
editor = {Stocker, T F and Qin, D and Plattner, G K and Tignor, M and Allen, S K and Boschung, J and Nauels, A and Xia, Y and Bex, V and Midgley, P M},
isbn = {9781107661820},
pages = {3--29},
publisher = {Cambridge University Press},
title = {{Summary for Policymakers}},
url = {https://www.ipcc.ch/report/ar5/wg1},
year = {2013}
}
@article{Irval2016,
abstract = {High-resolution lithic and sea surface climate records are used to portray the progression of North Atlantic climate, hydrography, and Greenland Ice Sheet (GIS) activity through the peak of Marine Isotope Stage (MIS) 5e into the last glacial inception. We use Eirik Drift sediment core MD03-2664 (57°26.34′N, 48°36.35′W), recovered south of Greenland, strategically located to monitor fluctuations in GIS extent and iceberg calving events. Our results show that a significant amount of ice-rafted debris (IRD) was present during the early MIS 5e, until gradually tapering off by 122 kyr BP due to a diminishing GIS. Sea surface temperatures (SSTs) in the northern subpolar gyre reached peak values early in MIS 5e coinciding with peak insolation. Regional cooling leading to the demise of the last interglacial started prior to the end of the MIS 5e benthic $\delta$18O plateau, at approximately 119 kyr BP, as summer insolation waned. This gradual cooling trend is interrupted by an abrupt and brief cooling episode at ∼117 kyr BP. Increased IRD abundance during the 117 kyr BP cooling event suggests that regional ice sheet growth occurred prior to the end of the MIS 5e benthic $\delta$18O plateau, and the major glacial inception. SSTs south of Greenland followed a two-step cooling during the glacial inception similar to the pattern observed across much of the North Atlantic and Europe. Benthic $\delta$18O increases in parallel, suggesting that this two-step cooling is linked to a two-phased intensification of Northern Hemisphere glaciation.},
author = {Irvalı, Nil and Ninnemann, Ulysses S and Kleiven, Helga (Kikki) F and Galaasen, Eirik V and Morley, Audrey and Rosenthal, Yair},
doi = {10.1016/j.quascirev.2016.08.029},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Eirik drift,Glacial inception,Greenland Ice Sheet,Last interglacial,Multi-proxy,North Atlantic},
pages = {184--199},
title = {{Evidence for regional cooling, frontal advances, and East Greenland Ice Sheet changes during the demise of the last interglacial}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379116303195},
volume = {150},
year = {2016}
}
@article{IshiiM.FakudaY.HiraharaS.YasuiS.SuzukiT.andSato2017,
author = {Ishii, Masayoshi and Fukuda, Yoshikazu and Hirahara, Shoji and Yasui, Soichiro and Suzuki, Toru and Sato, Kanako},
doi = {10.2151/sola.2017-030},
issn = {1349-6476},
journal = {SOLA},
pages = {163--167},
title = {{Accuracy of Global Upper Ocean Heat Content Estimation Expected from Present Observational Data Sets}},
url = {https://www.jstage.jst.go.jp/article/sola/13/0/13{\_}2017-030/{\_}article},
volume = {13},
year = {2017}
}
@article{ISHINO2020101895,
abstract = {Fossil diatom records from the Southern Ocean are needed to clarify the detailed conditions under warmer-than-present global climate in the Piacenzian Stage (3.60–2.588 Ma), and to provide direct evidence of simultaneity between changes in environmental conditions and diatom species turnovers. In this study, fossil diatom records between 3.5 and 2.8 Ma were investigated at two sites located along a latitudinal gradient within the Indian sector of the Southern Ocean (offshore from Prydz Bay and south-east of the Kerguelen Plateau). Paleoceanographic changes were assessed from assemblage changes of extant diatom indicators. Fluctuations of their relative percentages were compared with those of extinct diatom species. The diatom assemblage between 3.5 and 3.1 Ma consisted of open ocean species which indicate warmer-than-present SST. Notable increases in sea-ice associated species were identified at 3.3 Ma and 3.1 Ma at both sites. Our results suggest sea-ice existence during short intervals of 3.3 Ma and 3.1–2.8 Ma at the studied area. At both sites, relative abundances of species which have first occurrences during the Piacenzian, increased at 3.2–3.1 Ma, conversely, those of species which have last occurrences during the Piacenzian decreased at the same period. These diatom records show a correlation with cooling at 3.1 Ma suggested from extant indicators and compositional changes in fossil diatoms from the Southern Ocean. This comparison can provide insights into the environmental effects on diatom evolutionary acceleration, which can help identify ecologies of extinct species.},
author = {Ishino, Saki and Suto, Itsuki},
doi = {10.1016/j.marmicro.2020.101895},
issn = {0377-8398},
journal = {Marine Micropaleontology},
keywords = {Diatom,Paleoceanographic changes,Pliocene,Sea-ice,Southern Ocean,Turnover},
pages = {101895},
title = {{Late Pliocene sea-ice expansion and its influence on diatom species turnover in the Southern Ocean}},
url = {http://www.sciencedirect.com/science/article/pii/S0377839819300611},
volume = {160},
year = {2020}
}
@article{Ito2016,
abstract = {Dissolved oxygen in the mid-depth tropical Pacific Ocean has declined. Simulations with a combination of atmosphere and ocean models suggest that anthropogenic pollution can interact and amplify climate-driven impacts on ocean biogeochemistry.},
author = {Ito, T and Nenes, A and Johnson, M S and Meskhidze, N and Deutsch, C},
doi = {10.1038/ngeo2717},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {6},
pages = {443--447},
title = {{Acceleration of oxygen decline in the tropical Pacific over the past decades by aerosol pollutants}},
url = {https://doi.org/10.1038/ngeo2717},
volume = {9},
year = {2016}
}
@article{Ivanova2016a,
abstract = {Reproducing characteristics of observed sea ice extent remains an important climate modeling challenge. This study describes several approaches to improve how model biases in total sea ice distribution are quantified, and applies them to historically forced simulations contributed to phase 5 of the Coupled Model Intercomparison Project (CMIP5). The quantity of hemispheric total sea ice area, or some measure of its equatorward extent, is often used to evaluate model performance. Anew approach is introduced that investigates additional details about the structure of model errors, with an aim to reduce the potential impact of compensating errors when gauging differences between simulated and observed sea ice. Using multiple observational datasets, several new methods are applied to evaluate the climatological spatial distribution and the annual cycle of sea ice cover in 41 CMIP5 models. It is shown that in some models, error compensation can be substantial, for example resulting from too much sea ice in one region and too little in another. Error compensation tends to be larger in models that agree more closely with the observed total sea ice area, which may result from model tuning. The results herein suggest that consideration of only the total hemispheric sea ice area or extent can be misleading when quantitatively comparing how well models agree with observations. Further work is needed to fully develop robust methods to holistically evaluate the ability of models to capture the finescale structure of sea ice characteristics; however, the "sector scale'' metric used here aids in reducing the impact of compensating errors in hemispheric integrals.},
author = {Ivanova, Detelina P. and Gleckler, Peter J. and Taylor, Karl E. and Durack, Paul J. and Marvel, Kate D.},
doi = {10.1175/JCLI-D-16-0026.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Climate models,Coupled models,General circulation models,Model comparison,Model errors,Model evaluation/performance},
number = {24},
pages = {8965--8987},
title = {{Moving beyond the total sea ice extent in gauging model biases}},
volume = {29},
year = {2016}
}
@article{Ivy2017,
abstract = {AbstractMuch research has focused on trends in the Southern Hemispheric circulation in austral summer (Dec-Jan-Feb) in the troposphere and stratosphere, while changes in other seasons have received less attention. Here we examine the seasonality and structure of observed changes in tropospheric and stratospheric winds, temperature, and ozone over the Southern Hemisphere. We find that statistically significant trends similar to those of the Antarctic summer season are also observed since 1979 in austral fall, particularly May, and are strongest over the Pacific sector of the hemisphere. We provide evidence for a significant shift in the position of the jet in May over the Pacific, and show that the strengthening and shifting of the jet has rendered the latitudinal distribution of upper tropospheric zonal wind more bimodal. The Antarctic ozone hole has cooled the lower stratosphere and strengthened the polar vortex. While the mechanism and timing are not fully understood, the ozone hole has been identified ...},
author = {Ivy, Diane J. and Hilgenbrink, Casey and Kinnison, Doug and Plumb, R. Alan and Sheshadri, Aditi and Solomon, Susan and Thompson, David W.J. J},
doi = {10.1175/JCLI-D-16-0394.1},
isbn = {0894-8755},
issn = {08948755},
journal = {Journal of Climate},
number = {2},
pages = {527--536},
title = {{Observed changes in the Southern Hemispheric circulation in May}},
volume = {30},
year = {2017}
}
@article{Ivy2016,
abstract = {AbstractRadiative and dynamical heating rates control stratospheric temperatures. In this study, radiative temperature trends due to ozone depletion and increasing well-mixed greenhouse gases from 1980 to 2000 in the polar stratosphere are directly evaluated, and the dynamical contributions to temperature trends are estimated as the residual between the observed and radiative trends. The radiative trends are obtained from a seasonally evolving fixed dynamical heating calculation with the Parallel Offline Radiative Transfer model using four different ozone datasets, which provide estimates of observed ozone changes. In the spring and summer seasons, ozone depletion leads to radiative cooling in the lower stratosphere in the Arctic and Antarctic. In Arctic summer there is weak wave driving, and the radiative cooling due to ozone depletion is the dominant driver of observed trends. In late winter and early spring, dynamics dominate the changes in Arctic temperatures. In austral spring and summer in the Antar...},
author = {Ivy, Diane J. and Solomon, Susan and Rieder, Harald E.},
doi = {10.1175/JCLI-D-15-0503.1},
isbn = {0894-8755},
issn = {08948755},
journal = {Journal of Climate},
number = {13},
pages = {4927--4938},
title = {{Radiative and dynamical influences on polar stratospheric temperature trends}},
volume = {29},
year = {2016}
}
@article{Jaber2020,
abstract = {This study harnessed some of the many opportunities provided by the TRMM 3B43 data in order to generate maps illustrating the spatial and temporal distribution of significant linear rates of change of annual total precipitation for the surface of earth bounded by latitudes 50° S and 50° N for the years 1998–2018 by applying pixel-based simple linear regression. These maps are valuable for many applications and should enhance our understanding of the global precipitation patterns and trigger more research in order to explain what has not been explained. It has been found that the whole study area had a mean significant linear rate of change of − 0.4 mm/year. Nearly half of its area had significant linear rates of increase with a mean of 8.5 mm/year while the other half had significant linear rates of decrease with mean of − 7.6 mm/year. Landmass alone can be divided into nearly two halves; the first had significant linear rates of increase with a mean of 5.2 mm/year while the second had significant linear rates of decrease with mean of − 7.0 mm/year. Water areas alone also can nearly be divided into two halves; the first showed significant linear rates of increase with a mean of 9.6 mm/year while the second showed significant linear rates of decrease with mean of − 7.8 mm/year. Grouping the whole study area into six climatic zones and 21 administrative land and water regions and applying pixel-based Tukey test showed that the obtained significant linear rates of change varied significantly among these climatic and administrative regions.},
author = {Jaber, Salahuddin M. and Abu-Allaban, Mahmoud M.},
doi = {10.1007/s10661-020-08405-z},
issn = {15732959},
journal = {Environmental Monitoring and Assessment},
keywords = {Linear rates of change,Precipitation,Simple linear regression,TRMM 3B43,Tukey test},
number = {7},
pages = {437},
pmid = {32548783},
publisher = {Environmental Monitoring and Assessment},
title = {{TRMM 3B43 Product-Based Spatial and Temporal Anatomy of Precipitation Trends: Global Perspective}},
volume = {192},
year = {2020}
}
@article{Jaccard2016a,
abstract = {No single mechanism can account for the full amplitude of past atmospheric carbon dioxide (CO2) concentration variability over glacial-interglacial cycles. A build-up of carbon in the deep ocean has been shown to have occurred during the Last Glacial Maximum. However, the mechanisms responsible for the release of the deeply sequestered carbon to the atmosphere at deglaciation, and the relative importance of deep ocean sequestration in regulating millennial-timescale variations in atmospheric CO2 concentration before the Last Glacial Maximum, have remained unclear. Here we present sedimentary redox-sensitive trace-metal records from the Antarctic Zone of the Southern Ocean that provide a reconstruction of transient changes in deep ocean oxygenation and, by inference, respired carbon storage throughout the last glacial cycle. Our data suggest that respired carbon was removed from the abyssal Southern Ocean during the Northern Hemisphere cold phases of the deglaciation, when atmospheric CO2 concentration increased rapidly, reflecting--at least in part--a combination of dwindling iron fertilization by dust and enhanced deep ocean ventilation. Furthermore, our records show that the observed covariation between atmospheric CO2 concentration and abyssal Southern Ocean oxygenation was maintained throughout most of the past 80,000 years. This suggests that on millennial timescales deep ocean circulation and iron fertilization in the Southern Ocean played a consistent role in modifying atmospheric CO2 concentration.},
author = {Jaccard, Samuel L. and Galbraith, Eric D. and Mart{\'{i}}nez-Garci{\'{a}}, Alfredo and Anderson, Robert F.},
doi = {10.1038/nature16514},
issn = {14764687},
journal = {Nature},
month = {feb},
number = {7589},
pages = {207--210},
publisher = {Nature Publishing Group},
title = {{Covariation of deep Southern Ocean oxygenation and atmospheric CO2 through the last ice age}},
volume = {530},
year = {2016}
}
@article{Jaccard2012a,
abstract = {During the last glacial termination, the solubility of gases in the ocean decreased as ocean temperatures rose. However, marine sediments have not unanimously recorded ocean deoxygenation throughout this time. Some records show increasing oxygenation since the Last Glacial Maximum, particularly in the deep sea, while many document abrupt oxygenation changes, often associated with apparent changes in the formation rate of North Atlantic Deep Water. Here we present a global compilation of marine sediment proxy records that reveals remarkable coherency between regional oxygenation changes throughout deglaciation. The upper ocean generally became less oxygenated, but this general trend included pauses and even reversals, reflecting changes in nutrient supply, respiration rates and ventilation. The most pronounced deoxygenation episode in the upper ocean occurred midway through the deglaciation, associated with a reinvigoration of North Atlantic Deep Water formation. At this time, the upper Indo-Pacific Ocean was less oxygenated than today. Meanwhile, the bulk of the deep ocean became more oxygenated over the deglaciation, reflecting a transfer of respired carbon to the atmosphere. The observed divergence from a simple solubility control emphasizes the degree to which oxygen consumption patterns can be altered by changes in ocean circulation and marine ecosystems.},
author = {Jaccard, Samuel L. and Galbraith, Eric D.},
doi = {10.1038/ngeo1352},
issn = {17520894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {151--156},
title = {{Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation}},
volume = {5},
year = {2012}
}
@article{Jackson2016e,
abstract = {The Atlantic meridional overturning circulation has weakened over the past decade. Examination of a global reanalysis that matches independent observations shows that the decline is consistent with recovery from an earlier invigoration.},
author = {Jackson, Laura C and Peterson, K. Andrew and Roberts, Chris D and Wood, Richard A},
doi = {10.1038/ngeo2715},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {7},
pages = {518--522},
title = {{Recent slowing of Atlantic overturning circulation as a recovery from earlier strengthening}},
url = {https://doi.org/10.1038/ngeo2715},
volume = {9},
year = {2016}
}
@article{Jackson2020,
abstract = {Different strategies have been proposed in previous studies for monitoring the Atlantic meridional overturning circulation (AMOC). As well as arrays to directly monitor the AMOC strength, various fingerprints have been suggested to represent an aspect of the AMOC based on properties such as temperature and density. The additional value of fingerprints potentially includes the ability to detect a change earlier than a change in the AMOC itself, the ability to extend a time series back into the past, and the ability to detect crossing a threshold. In this study we select metrics that have been proposed as fingerprints in previous studies and evaluate their ability to detect AMOC changes in a number of scenarios (internal variability, weakening from increased greenhouse gases, weakening from hosing and hysteresis) in the eddy-permitting coupled climate model HadGEM3-GC2. We find that the metrics that perform best are the temperature metrics based on large-scale differences, the large-scale meridional density gradient, and the vertical density difference in the Labrador Sea. The best metric for monitoring the AMOC depends somewhat on the processes driving the change. Hence the best strategy would be to consider multiple fingerprints to provide early detection of all likely AMOC changes.},
author = {Jackson, L C and Wood, R A},
doi = {10.1175/JCLI-D-20-0034.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jul},
number = {16},
pages = {7027--7044},
title = {{Fingerprints for Early Detection of Changes in the AMOC}},
url = {https://doi.org/10.1175/JCLI-D-20-0034.1},
volume = {33},
year = {2020}
}
@article{10.1093/icesjms/fsq181,
author = {Jackson, Thomas and Bouman, Heather A and Sathyendranath, Shubha and Devred, Emmanuel},
doi = {10.1093/icesjms/fsq181},
issn = {1054-3139},
journal = {ICES Journal of Marine Science},
number = {4},
pages = {729--736},
title = {{Regional-scale changes in diatom distribution in the Humboldt upwelling system as revealed by remote sensing: implications for fisheries}},
url = {https://doi.org/10.1093/icesjms/fsq181},
volume = {68},
year = {2011}
}
@article{JACOBEL2017160,
abstract = {High resolution paleoclimate records from low latitudes are critical for understanding the role of the tropics in transmitting and generating feedbacks for high-latitude climate change on glacial–interglacial and millennial timescales. Here we present three new records of 230Thxs,0-normalized 232Th-derived dust fluxes from the central equatorial Pacific spanning the last 150 kyr at millennial-resolution. All three dust flux records share the “sawtooth” pattern characteristic of glacial–interglacial cycles in ice volume, confirming a coherent response to global climate forcing on long timescales. These records permit a detailed examination of millennial variability in tropical dust fluxes related to abrupt perturbations in oceanic and atmospheric circulation. Increases in dust flux in association with at least six of the longest Greenland stadials provide evidence that abrupt, high-latitude climate oscillations influenced the atmospheric aerosol load in the equatorial Pacific, with implications for both direct and indirect effects on the tropical energy balance. Our latitudinal transect of cores captures shifts in the position of the Intertropical Convergence Zone (ITCZ) in response to variations in the interhemispheric thermal gradient associated with cooling in Greenland and bipolar seesaw warming in Antarctica. These observations demonstrate that changes in the energy and hydrologic balance of the tropics were repeated features of the penultimate deglaciation, last glacial inception and last glacial cycle, and highlight the role of the tropical atmosphere as a dynamic and responsive component of Earth's climate system.},
author = {Jacobel, A W and McManus, J F and Anderson, R F and Winckler, G},
doi = {10.1016/j.epsl.2016.09.042},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Intertropical Convergence Zone,abrupt climate change,dust,equatorial Pacific,stadial events},
pages = {160--172},
title = {{Climate-related response of dust flux to the central equatorial Pacific over the past 150 kyr}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X16305222},
volume = {457},
year = {2017}
}
@article{James2013,
abstract = {Changes in permafrost distribution in the southern discontinuous zone were evaluated by repeating a 1964 survey through part of the Alaska Highway corridor (56° N–61° N) in northwest Canada. A total of 55 sites from the original survey in northern British Columbia and southern Yukon were located using archival maps and photographs. Probing for frozen ground, manual excavations, air and ground temperature monitoring, borehole drilling and geophysical techniques were used to gather information on present-day permafrost and climatic conditions. Mean annual air temperatures have increased by 1.5–2.0 ° C since the mid-1970s and significant degradation of permafrost has occurred. Almost half of the permafrost sites along the entire transect which exhibited permafrost in 1964 do so no longer. This change is especially evident in the south where two-thirds of the formerly permafrost sites have thawed and the limit of permafrost appears to have shifted northward. The permafrost that persists is patchy, generally less than 15 m thick, has mean annual surface temperatures {\textgreater}0 ° C, mean ground temperatures between −0.5 and 0 ° C, is in peat or beneath a thick organic mat, and appears to have a thicker active layer than in 1964. Its persistence may relate to the latent heat requirements of thawing permafrost or to the large thermal offset of organic soils. The study demonstrates that degradation of permafrost has occurred in the margins of its distribution in the last few decades, a trend that is expected to continue as the climate warms.},
author = {James, Megan and Lewkowicz, Antoni G. and Smith, Sharon L. and Miceli, Christina M.},
doi = {10.1088/1748-9326/8/4/045013},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {climate warming,permafrost geophysics,permafrost thaw,subarctic},
number = {4},
pages = {045013},
title = {{Multi-decadal degradation and persistence of permafrost in the Alaska Highway corridor, northwest Canada}},
volume = {8},
year = {2013}
}
@article{Jansen2020,
abstract = {Abrupt climate change is a striking feature of many climate records, particularly the warming events in Greenland ice cores. These abrupt and high-amplitude events were tightly coupled to rapid sea-ice retreat in the North Atlantic and Nordic Seas, and observational evidence shows they had global repercussions. In the present-day Arctic, sea-ice loss is also key to ongoing warming. This Perspective uses observations and climate models to place contemporary Arctic change into the context of past abrupt Greenland warmings. We find that warming rates similar to or higher than modern trends have only occurred during past abrupt glacial episodes. We argue that the Arctic is currently experiencing an abrupt climate change event, and that climate models underestimate this ongoing warming.},
author = {Jansen, Eystein and Christensen, Jens Hesselbjerg and Dokken, Trond and Nisancioglu, Kerim H and Vinther, Bo M and Capron, Emilie and Guo, Chuncheng and Jensen, Mari F and Langen, Peter L and Pedersen, Rasmus A and Yang, Shuting and Bentsen, Mats and Kj{\ae}r, Helle A and Sadatzki, Henrik and Sessford, Evangeline and Stendel, Martin},
doi = {10.1038/s41558-020-0860-7},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {8},
pages = {714--721},
title = {{Past perspectives on the present era of abrupt Arctic climate change}},
url = {https://doi.org/10.1038/s41558-020-0860-7},
volume = {10},
year = {2020}
}
@article{Jaramillo2015a,
author = {Jaramillo, Fernando and Destouni, Georgia},
doi = {10.1126/science.aad1010},
journal = {Science},
number = {6265},
pages = {1248--1251},
title = {{Local flow regulation and irrigation raise global human water consumption and footprint}},
volume = {350},
year = {2015}
}
@article{Jeong2017,
abstract = {Snow is an important component of the cryosphere and it has a direct and important influence on water storage and supply in snowmelt-dominated regions. This study evaluates the temporal evolution of snow water equivalent (SWE) for the February–April spring period using the GlobSnow observation dataset for the 1980–2012 period. The analysis is performed for different regions of hemispherical to sub-continental scales for the Northern Hemisphere. The detection–attribution analysis is then performed to demonstrate anthropogenic and natural effects on spring SWE changes for different regions, by comparing observations with six CMIP5 model simulations for three different external forcings: all major anthropogenic and natural (ALL) forcings, greenhouse gas (GHG) forcing only, and natural forcing only. The observed spring SWE generally displays a decreasing trend, due to increasing spring temperatures. However, it exhibits a remarkable increasing trend for the southern parts of East Eurasia. The six CMIP5 models with ALL forcings reproduce well the observed spring SWE decreases at the hemispherical scale and continental scales, whereas important differences are noted for smaller regions such as southern and northern parts of East Eurasia and northern part of North America. The effects of ALL and GHG forcings are clearly detected for the spring SWE decline at the hemispherical scale, based on multi-model ensemble signals. The effects of ALL and GHG forcings, however, are less clear for the smaller regions or with single-model signals, indicating the large uncertainty in regional SWE changes, possibly due to stronger influence of natural climate variability.},
author = {Jeong, Dae Il and Sushama, Laxmi and {Naveed Khaliq}, M.},
doi = {10.1007/s00382-016-3291-4},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Climate change,Detection–attribution,Human effects,Northern Hemisphere,Snow water equivalent},
pages = {3645--3658},
title = {{Attribution of spring snow water equivalent (SWE) changes over the northern hemisphere to anthropogenic effects}},
volume = {48},
year = {2017}
}
@article{Jian2000,
abstract = {Cores 255 and B-3GC from the southern and northern Okinawa Trough, respectively, were studied for determining the variability of the Kuroshio Current on centennial scales during the Holocene based on detailed AMS 14C dates, stable isotope, and planktonic foraminiferal distribution. The main flow of the Kuroshio Current was inferred to re-enter the Okinawa Trough at ∼7.3 calendar (cal.) kyr BP, leading to abrupt changes in sedimentation rate, remarkably increased abundance of the Kuroshio Current indicator Pulleniatina obliquiloculata, increased sea surface temperature (SST) and depth of thermocline (DOT). During ∼4.6–2.7 cal. kyr BP, the abundance of P. obliquiloculata sharply decreased, corresponding to a decreases in SST and DOT, implying that the influence of the Kuroshio Current weakened at that time, possibly as a result of the intensified winter monsoon. Significantly, the Kuroshio Current proxies (e.g. the difference in SST between the southern and northern Okinawa Trough) display periodicities of ∼1500 yr and ∼700–800 yr (ascribed to the second harmonic of the 1500 yr cycle in oceanic thermohaline circulation) during the Holocene. The Holocene events (at ∼0.6, 1.7, 3.3, 4.6, 5.9, 8.1, 9.4 cal. kyr BP) in the Okinawa Trough appear to be the most recent manifestation of the millennial scale climate cycle, recorded in the North Atlantic, Arabian Sea marine sediment cores and Greenland ice cores, suggesting global climatic tele-connections.},
author = {Jian, Zhimin and Wang, Pinxian and Saito, Yoshiki and Wang, Jiliang and Pflaumann, Uwe and Oba, Tadamichi and Cheng, Xinrong},
doi = {10.1016/S0012-821X(00)00321-6},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Foraminifera,Holocene,Kuroshio,Okinawa Trough,sea-surface temperature,stable isotopes},
number = {1},
pages = {305--319},
title = {{Holocene variability of the Kuroshio Current in the Okinawa Trough, northwestern Pacific Ocean}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X00003216},
volume = {184},
year = {2000}
}
@article{Jiang2017,
abstract = {Understanding the long-term performance of global satellite leaf area index (LAI) products is important for global change research. However, few effort has been devoted to evaluating the long-term time-series consistencies of LAI products. This study compared four long-term LAI products (GLASS, GLOBMAP, LAI3g, and TCDR) in terms of trends, interannual variabilities, and uncertainty variations from 1982 through 2011. This study also used four ancillary LAI products (GEOV1, MERIS, MODIS C5, and MODIS C6) from 2003 through 2011 to help clarify the performances of the four long-term LAI products. In general, there were marked discrepancies between the four long-term LAI products. During the pre-MODIS period (1982–1999), both linear trends and interannual variabilities of global mean LAI followed the order GLASS{\textgreater}LAI3g{\textgreater}TCDR{\textgreater}GLOBMAP. The GLASS linear trend and interannual variability were almost 4.5 times those of GLOBMAP. During the overlap period (2003–2011), GLASS and GLOBMAP exhibited a decreasing trend, TCDR no trend, and LAI3g an increasing trend. GEOV1, MERIS, and MODIS C6 also exhibited an increasing trend, but to a much smaller extent than that from LAI3g. During both periods, the R2 of detrended anomalies between the four long-term LAI products was smaller than 0.4 for most regions. Interannual variabilities of the four long-term LAI products were considerably different over the two periods, and the differences followed the order GLASS{\textgreater}LAI3g{\textgreater}TCDR{\textgreater}GLOBMAP. Uncertainty variations quantified by a collocation error model followed the same order. Our results indicate that the four long-term LAI products were neither intraconsistent over time nor interconsistent with each other. These inconsistencies may be due to NOAA satellite orbit changes and MODIS sensor degradation. Caution should be used in the interpretation of global changes derived from the four long-term LAI products.},
archivePrefix = {arXiv},
arxivId = {arXiv:physics/0608246v3},
author = {Jiang, Chongya and Ryu, Youngryel and Fang, Hongliang and Myneni, Ranga and Claverie, Martin and Zhu, Zaichun},
doi = {10.1111/gcb.13787},
eprint = {0608246v3},
isbn = {4955139574},
issn = {13652486},
journal = {Global Change Biology},
keywords = {GLASS,GLOBMAP,LAI3g,TCDR,intercomparison,leaf area index (LAI),time series},
number = {10},
pages = {4133--4146},
pmid = {27935037},
primaryClass = {arXiv:physics},
title = {{Inconsistencies of interannual variability and trends in long-term satellite leaf area index products}},
volume = {23},
year = {2017}
}
@article{Jiang2016,
abstract = {The global monsoon domain has been recently determined utilizing two criteria: difference of local maximum and minimum pentad-mean precipitation rates exceeding 4 mm day−1, and wind reversal of low-level cross-equatorial flow. In this paper, 22 major dry–wet alteration regions under six categories were first derived through the k-means clustering method from the climatological evolution of global precipitation. Considering the seasonal influences of the low-level cross-equatorial flow in these major dry–wet alternation regions, the global monsoon was objectively divided into 16 major regions under five climatological precipitation categories. Nine monsoon regions are distributed between Asia and Australia while four regions are from Africa to the Southwest Indian Ocean and three regions in Americas. Precipitation trends during rainy seasons of 1981–2010 were examined in the 16 monsoon regions. Four regions with decreasing trends of precipitation are located in Africa and the Southwest Indian Ocean while three regions with increasing trends are situated in Americas. Six regions of increasing precipitation trends are concentrated in Asia and the biggest increasing trend is found in south China.},
author = {Jiang, Ning and Qian, Weihong and Leung, Jeremy Cheuk Hin},
doi = {10.1007/s00382-015-2967-5},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Cross-equatorial flow,Division,Dry–wet alteration,Global monsoon,k-Means},
number = {7-8},
pages = {2345--2359},
publisher = {Springer Berlin Heidelberg},
title = {{The global monsoon division combining the k-means clustering method and low-level cross-equatorial flow}},
volume = {47},
year = {2016}
}
@article{Jiang2018,
abstract = {Abstract Instead of the La Ni{\~{n}}a events with no significant change in their surface expressions, the recent increasing frequency of central Pacific El Ni{\~{n}}o events is suggested to be related to global warming. There is yet no consensus on the impacts of the recent global warming on such asymmetric changes of El Ni{\~{n}}o-Southern Oscillation (ENSO) events. Here we show the frequency of the extreme cold/moderate warm events both increases in the central equatorial Pacific over the past decades. We attribute the change of ENSO diversity to the positive cold tongue mode under recent global warming, which gives rise to an intensification, contraction, and westward shift of Walker circulation accompanied by an uplift of the thermocline. Our results propose a unified explanation for the changes of ENSO diversity under the recent global warming, which carries important implications for the relationship between global warming and ENSO.},
author = {Jiang, Ning and Zhu, Congwen},
doi = {10.1029/2018GL079494},
journal = {Geophysical Research Letters},
number = {22},
pages = {12,506--512,513},
title = {{Asymmetric Changes of ENSO Diversity Modulated by the Cold Tongue Mode Under Recent Global Warming}},
volume = {45},
year = {2018}
}
@article{doi:10.1175/JCLI-D-16-0235.1,
abstract = {AbstractThe eastern China precipitation dipole (ECPD) features an out-of-phase relationship between boreal summer precipitation over the middle and lower reaches of the Yangtze River and the Hetao region to its northwest. The precipitation dipole is strongly influenced by ENSO teleconnections over the western tropical Pacific. Here it is shown that a pronounced weakening of both the rainfall variability over eastern China as well as the precipitation dipole structure occurred around the mid-1990s. The changes have been analyzed by considering two epochs: one during 1979–95 and the other during 1996–2009. The characteristic feature of the circulation anomaly during the first epoch is the well-known East Asia–Pacific/Pacific–Japan (EAP/PJ) pattern, a quasi-meridional teleconnection pattern emanating from the western tropical Pacific. On the other hand, during the latter epoch eastern China precipitation variability occurs as an integral part of the circulation anomalies over the western Pacific. In contrast to the more meridionally restricted anomalies during canonical ENSO episodes, the western Pacific circulation has a significantly larger meridional scale. Intriguingly correlation of the precipitation dipole with Pacific sea surface temperature flips in sign during the second epoch, with enhanced precipitation over southeastern China associated with La Ni{\~{n}}a–like variability, in contrast to the co-occurrence of enhanced precipitation over this region with El Ni{\~{n}}o during the first epoch. The results suggest that the dominance of Modoki or central Pacific El Ni{\~{n}}os, and the altered structure of ENSO teleconnections associated with these, may play a role in the weakened ECPD structure during the latter epoch.},
author = {Jin, Dachao and Hameed, Saji N and Huo, Liwei},
doi = {10.1175/JCLI-D-16-0235.1},
journal = {Journal of Climate},
number = {21},
pages = {7587--7598},
title = {{Recent Changes in ENSO Teleconnection over the Western Pacific Impacts the Eastern China Precipitation Dipole}},
url = {https://doi.org/10.1175/JCLI-D-16-0235.1},
volume = {29},
year = {2016}
}
@article{Jin2018a,
abstract = {AbstractDecadal variabilities in Indian Ocean subsurface ocean heat content (OHC; 50?300 m) since the 1950s are examined using ocean reanalyses. This study elaborates on how Pacific variability modulates the Indian Ocean on decadal time scales through both oceanic and atmospheric pathways. High correlations between OHC and thermocline depth variations across the entire Indian Ocean Basin suggest that OHC variability is primarily driven by thermocline fluctuations. The spatial pattern of the leading mode of decadal Indian Ocean OHC variability closely matches the regression pattern of OHC on the interdecadal Pacific oscillation (IPO), emphasizing the role of the Pacific Ocean in determining Indian Ocean OHC decadal variability. Further analyses identify different mechanisms by which the Pacific influences the eastern and western Indian Ocean. IPO-related anomalies from the Pacific propagate mainly through oceanic pathways in the Maritime Continent to impact the eastern Indian Ocean. By contrast, in the western Indian Ocean, the IPO induces wind-driven Ekman pumping in the central Indian Ocean via the atmospheric bridge, which in turn modifies conditions in the southwestern Indian Ocean via westward-propagating Rossby waves. To confirm this, a linear Rossby wave model is forced with wind stresses and eastern boundary conditions based on reanalyses. This linear model skillfully reproduces observed sea surface height anomalies and highlights both the oceanic connection in the eastern Indian Ocean and the role of wind-driven Ekman pumping in the west. These findings are also reproduced by OGCM hindcast experiments forced by interannual atmospheric boundary conditions applied only over the Pacific and Indian Oceans, respectively.},
annote = {doi: 10.1175/JCLI-D-17-0654.1},
author = {Jin, Xiaolin and Kwon, Young-Oh and Ummenhofer, Caroline C and Seo, Hyodae and Schwarzkopf, Franziska U and Biastoch, Arne and B{\"{o}}ning, Claus W and Wright, Jonathon S},
doi = {10.1175/JCLI-D-17-0654.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {mar},
number = {10},
pages = {4157--4174},
publisher = {American Meteorological Society},
title = {{Influences of Pacific Climate Variability on Decadal Subsurface Ocean Heat Content Variations in the Indian Ocean}},
url = {https://doi.org/10.1175/JCLI-D-17-0654.1},
volume = {31},
year = {2018}
}
@article{Jochumsen2017,
abstract = {The major export route of dense water from the Nordic Seas into the North Atlantic is in the deep channel in Denmark Strait. Here currents have been monitored with one or two moored Acoustic Doppler Current Profilers (ADCPs) since 1996. Volume transport estimates of the Denmark Strait Overflow Water (DSOW) so far were based on these data, which were regressed to the total transport of dense water in a numerical model. The resulting transport has been used in many publications. Here we present results from an extended five-mooring array deployed in 2014/2015, which included measurements outside the swift overflow core. This array provided the basis for new calculations to estimate the DSOW transports. Fur- thermore, a correction is proposed for biases detected on some ADCPs, which led to earlier underestimation of the flow in the lower part of the plume. Using the new method, the mean DSOW transport is estimated to be 3.2 Sv in the period 1996–2016, without a significant trend. Uncertainties are typically +/-0.5 Sv. Beyond variations on the eddy scale, an empirical orthogonal functions (EOF) analysis of the velocity field reveals three dominant modes of variability: the first mode is roughly barotropic and corresponds to pulsations of the plume, the second mode represents the laterally shifting component of the plume's core position, and the third mode indicates the impact of the varying overflow thickness. Finally, DSOW transports are com- pared to the Faroe Bank Channel overflow transports, but no clear relationship is found.},
author = {Jochumsen, Kerstin and Moritz, Martin and Nunes, Nuno and Quadfasel, Detlef and Larsen, Karin M. H. and Hansen, Bogi and Valdimarsson, Hedinn and Jonsson, Steingrimur},
doi = {10.1002/2017JC012803},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
month = {apr},
number = {4},
pages = {3434--3450},
title = {{Revised transport estimates of the Denmark Strait overflow}},
url = {http://doi.wiley.com/10.1002/2017JC012803},
volume = {122},
year = {2017}
}
@article{doi:10.1175/JCLI-D-12-00649.1,
abstract = {AbstractIt is now widely recognized that El Ni{\~{n}}o–Southern Oscillation (ENSO) occurs in more than one form, with the canonical eastern Pacific (EP) and more recently recognized central Pacific (CP) ENSO types receiving the most focus. Given that these various ENSO “flavors” may contribute to climate variability and long-term trends in unique ways, and that ENSO variability is not limited to these two types, this study presents a framework that treats ENSO as a continuum but determines a finite maximum number of statistically distinguishable representative ENSO patterns. A neural network–based cluster analysis called self-organizing map (SOM) analysis paired with a statistical distinguishability test determines nine unique patterns that characterize the September–February tropical Pacific SST anomaly fields for the period from 1950 through 2011. These nine patterns represent the flavors of ENSO, which include EP, CP, and mixed ENSO patterns. Over the 1950–2011 period, the most significant trends reflect changes in La Ni{\~{n}}a patterns, with a shift in dominance of La Ni{\~{n}}a–like patterns with weak or negative western Pacific warm pool SST anomalies until the mid-1970s, followed by a dominance of La Ni{\~{n}}a–like patterns with positive western Pacific warm pool SST anomalies, particularly after the mid-1990s. Both an EP and especially a CP El Ni{\~{n}}o pattern experienced positive frequency trends, but these trends are indistinguishable from natural variability. Overall, changes in frequency within the ENSO continuum contributed to the pattern of tropical Pacific warming, particularly in the equatorial eastern Pacific and especially in relation to changes of La Ni{\~{n}}a–like rather than El Ni{\~{n}}o–like patterns.},
author = {Johnson, Nathaniel C},
doi = {10.1175/JCLI-D-12-00649.1},
journal = {Journal of Climate},
number = {13},
pages = {4816--4827},
title = {{How Many ENSO Flavors Can We Distinguish?}},
url = {https://doi.org/10.1175/JCLI-D-12-00649.1},
volume = {26},
year = {2013}
}
@article{Johnson2014,
abstract = {Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet, has been undergoing rapid thinning and retreat for the past two decades. We demonstrate, using glacial-geological and geochronological data, that Pine Island Glacier (PIG) also experienced rapid thinning during the early Holocene, around 8000 years ago. Cosmogenic (10)Be concentrations in glacially transported rocks show that this thinning was sustained for decades to centuries at an average rate of more than 100 centimeters per year, which is comparable with contemporary thinning rates. The most likely mechanism was a reduction in ice shelf buttressing. Our findings reveal that PIG has experienced rapid thinning at least once in the past and that, once set in motion, rapid ice sheet changes in this region can persist for centuries.},
author = {Johnson, J. S. and Bentley, M. J. and Smith, J. A. and Finkel, R. C. and Rood, D. H. and Gohl, K. and Balco, G. and Larter, R. D. and Schaefer, J. M.},
doi = {10.1126/science.1247385},
issn = {0036-8075},
journal = {Science},
month = {feb},
number = {6174},
pages = {999--1001},
title = {{Rapid Thinning of Pine Island Glacier in the Early Holocene}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1247385},
volume = {343},
year = {2014}
}
@article{JOHNSON2019127,
abstract = {The glacial history of the westernmost Weddell Sea sector of Antarctica since the Last Glacial Maximum is virtually unknown, and yet it has been identified as critical for improving reliability of glacio-isostatic adjustment models that are required to correct satellite-derived estimates of ice sheet mass balance. Better knowledge of the glacial history of this region is also important for validating ice sheet models that are used to predict future contribution of the Antarctic ice sheet to sea level rise. Here we present a new Holocene deglacial chronology from a site on the Lassiter Coast of the Antarctic Peninsula, which is situated in the western Weddell Sea sector. Samples from 12 erratic cobbles and 18 bedrock surfaces from a series of presently-exposed ridges were analysed for cosmogenic 10Be exposure dating, and a smaller suite of 7 bedrock samples for in situ 14C dating. The resulting 10Be ages are predominantly in the range 80–690 ka, whereas bedrock yielded much younger in situ 14C ages, in the range 6.0–7.5 ka for samples collected from 138–385 m above the modern ice surface. From these we infer that the ice sheet experienced a period of abrupt thinning over a short time interval (no more than 2700 years) in the mid-Holocene, resulting in lowering of its surface by at least 250 m. Any late Holocene change in ice sheet thickness — such as re-advance, postulated by several modelling studies — must lie below the present ice sheet surface. The substantial difference in exposure ages derived from 10Be and 14C dating for the same samples additionally implies ubiquitous 10Be inheritance acquired during ice-free periods prior to the last deglaciation, an interpretation that is consistent with our glacial-geomorphological field observations for former cold-based ice cover. The results of this study provide evidence for an episode of abrupt ice sheet surface lowering in the mid-Holocene, similar in rate, timing and magnitude to at least two other locations in Antarctica.},
author = {Johnson, Joanne S and Nichols, Keir A and Goehring, Brent M and Balco, Greg and Schaefer, Joerg M},
doi = {10.1016/j.epsl.2019.05.002},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Antarctica,Holocene,Weddell Sea,cosmogenic dating,ice sheet,in situ C},
pages = {127--135},
title = {{Abrupt mid-Holocene ice loss in the western Weddell Sea Embayment of Antarctica}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X19302638},
volume = {518},
year = {2019}
}
@article{Johnson2020a,
abstract = {The ocean takes up about 93{\%} of the global warming heat entering Earth's climate system. In addition, the associated thermal expansion contributes substantially to sea-level rise. Hence, quantifying the oceanic heat uptake rate and its statistical significance has been a research focus. Here we use gridded ocean heat content maps to examine regional trends in ocean warming for 0–700 m depth from 1993–2019 and 1968–2019, periods based on sampling distributions. The maps are from four research groups, three based on ocean temperature alone and one combining ocean temperature with satellite altimeter sea-level anomalies. We show that use of longer periods results in larger percentages of ocean area with statistically significant warming trends and less ocean area covered by statistically significant cooling trends. We discuss relations of these patterns to climate phenomena, including the Pacific Decadal Oscillation, the Atlantic Meridional Overturning Circulation and global warming.},
author = {Johnson, Gregory C and Lyman, John M},
doi = {10.1038/s41558-020-0822-0},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {8},
pages = {757--761},
title = {{Warming trends increasingly dominate global ocean}},
url = {https://doi.org/10.1038/s41558-020-0822-0},
volume = {10},
year = {2020}
}
@article{Johnson2020,
author = {Johnson, G.C. and Lyman, J.M. and Boyer, T. and Cheng, L. and Domingues, C.M. and Gilson, J. and Ishii, M. and Killick, R.E. and Monselesan, D. and Purkey, S.G. and Wijffels, S.E.},
doi = {10.1175/BAMS-D-20-0105.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S140--S144},
title = {{Ocean heat content. In State of the Climate in 2019, Global Oceans}},
volume = {101},
year = {2020}
}
@article{doi:10.1029/2011JD017139,
abstract = {This study is an extensive revision of the Climatic Research Unit (CRU) land station temperature database that has been used to produce a grid-box data set of 5° latitude × 5° longitude temperature anomalies. The new database (CRUTEM4) comprises 5583 station records of which 4842 have enough data for the 1961–1990 period to calculate or estimate the average temperatures for this period. Many station records have had their data replaced by newly homogenized series that have been produced by a number of studies, particularly from National Meteorological Services (NMSs). Hemispheric temperature averages for land areas developed with the new CRUTEM4 data set differ slightly from their CRUTEM3 equivalent. The inclusion of much additional data from the Arctic (particularly the Russian Arctic) has led to estimates for the Northern Hemisphere (NH) being warmer by about 0.1°C for the years since 2001. The NH/Southern Hemisphere (SH) warms by 1.12°C/0.84°C over the period 1901–2010. The robustness of the hemispheric averages is assessed by producing five different analyses, each including a different subset of 20{\%} of the station time series and by omitting some large countries. CRUTEM4 is also compared with hemispheric averages produced by reanalyses undertaken by the European Centre for Medium-Range Weather Forecasts (ECMWF): ERA-40 (1958–2001) and ERA-Interim (1979–2010) data sets. For the NH, agreement is good back to 1958 and excellent from 1979 at monthly, annual, and decadal time scales. For the SH, agreement is poorer, but if the area is restricted to the SH north of 60°S, the agreement is dramatically improved from the mid-1970s.},
author = {Jones, P D and Lister, D H and Osborn, T J and Harpham, C and Salmon, M and Morice, C P},
doi = {10.1029/2011JD017139},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {global temperature,hemispheric temperature,land surface},
number = {D5},
pages = {D05127},
title = {{Hemispheric and large-scale land-surface air temperature variations: An extensive revision and an update to 2010}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011JD017139},
volume = {117},
year = {2012}
}
@article{Jones2015a,
abstract = {Outlet glaciers grounded on a bed that deepens inland and extends below sea level are potentially vulnerable to /`marine ice sheet instability/'. This instability, which may lead to runaway ice loss, has been simulated in models, but its consequences have not been directly observed in geological records. Here we provide new surface-exposure ages from an outlet of the East Antarctic Ice Sheet that reveal rapid glacier thinning occurred approximately 7,000 years ago, in the absence of large environmental changes. Glacier thinning persisted for more than two and a half centuries, resulting in hundreds of metres of ice loss. Numerical simulations indicate that ice surface drawdown accelerated when the otherwise steadily retreating glacier encountered a bedrock trough. Together, the geological reconstruction and numerical simulations suggest that centennial-scale glacier thinning arose from unstable grounding line retreat. Capturing these instability processes in ice sheet models is important for predicting Antarctica/'s future contribution to sea level change.},
author = {Jones, R. S. and Mackintosh, A. N. and Norton, K. P. and Golledge, N. R. and Fogwill, C. J. and Kubik, P. W. and Christl, M. and Greenwood, S. L.},
doi = {10.1038/ncomms9910},
issn = {20411723},
journal = {Nature Communications},
pages = {8910},
title = {{Rapid Holocene thinning of an East Antarctic outlet glacier driven by marine ice sheet instability}},
volume = {6},
year = {2015}
}
@article{Jones2014a,
author = {Jones, P.D. and Harpham, C and Vinther, B. M.},
doi = {10.1002/2014JD021561},
journal = {Journal of Geophysical Research: Atmospheres},
pages = {6497--6505},
title = {{Winter-responding proxy temperature reconstructions and the North Atlantic Oscillation}},
volume = {119},
year = {2014}
}
@article{Jones2017c,
abstract = {The polar oceans are particularly vulnerable to ocean acidification; the lowering of seawater pH and carbonate mineral saturation states due to uptake of atmospheric carbon dioxide (CO2). High spatial variability in surface water pH and saturation states ($\Omega$) for two biologically-important calcium carbonate minerals calcite and aragonite was observed in Ryder Bay, in the coastal sea-ice zone of the West Antarctic Peninsula. Glacial meltwater and melting sea ice stratified the water column and facilitated the development of large phytoplankton blooms and subsequent strong uptake of atmospheric CO2 of up to 55 mmol m-2 day-1 during austral summer. Concurrent high pH (8.48) and calcium carbonate mineral supersaturation ($\Omega$aragonite {\~{}}3.1) occurred in the meltwater-influenced surface ocean. Biologically-induced increases in calcium carbonate mineral saturation states counteracted any effects of carbonate ion dilution. Accumulation of CO2 through remineralisation of additional organic matter from productive coastal waters lowered the pH (7.84) and caused deep-water corrosivity ($\Omega$aragonite {\~{}}0.9) in regions impacted by Circumpolar Deep Water. Episodic mixing events enabled CO2-rich subsurface water to become entrained into the surface and eroded seasonal stratification to lower surface water pH (8.21) and saturation states ($\Omega$aragonite {\~{}}1.8) relative to all surface waters across Ryder Bay. Uptake of atmospheric CO2 of 28 mmol m-2 day-1 in regions of vertical mixing may enhance the susceptibility of the surface layer to future ocean acidification in dynamic coastal environments. Spatially-resolved studies are essential to elucidate the natural variability in carbonate chemistry in order to better understand and predict carbon cycling and the response of marine organisms to future ocean acidification in the Antarctic coastal zone.},
author = {Jones, Elizabeth M and Fenton, Mairi and Meredith, Michael P and Clargo, Nicola M and Ossebaar, Sharyn and Ducklow, Hugh W and Venables, Hugh J and de Baar, Hein J W},
doi = {10.1016/j.dsr2.2017.01.007},
issn = {0967-0645},
journal = {Deep-Sea Research Part II: Topical Studies in Oceanography},
keywords = {Carbonate chemistry,Ocean acidification,Ryder Bay,Sea ice,West Antarctic Peninsula,glacial meltwater},
pages = {181--194},
title = {{Ocean acidification and calcium carbonate saturation states in the coastal zone of the West Antarctic Peninsula}},
url = {http://www.sciencedirect.com/science/article/pii/S0967064517300243},
volume = {139},
year = {2017}
}
@article{Jones2016a,
abstract = {{\textless}p{\textgreater}Abstract. Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0 °C. In this study, we document the presence of residual permafrost plateaus in the western Kenai Peninsula lowlands of south-central Alaska, a region with a MAAT of 1.5 ± 1 °C (1981–2010). Continuous ground temperature measurements between 16 September 2012 and 15 September 2015, using calibrated thermistor strings, documented the presence of warm permafrost (−0.04 to −0.08 °C). Field measurements (probing) on several plateau features during the fall of 2015 showed that the depth to the permafrost table averaged 1.48 m but at some locations was as shallow as 0.53 m. Late winter surveys (augering, coring, and GPR) in 2016 showed that the average seasonally frozen ground thickness was 0.45 m, overlying a talik above the permafrost table. Measured permafrost thickness ranged from 0.33 to  {\textgreater}  6.90 m. Manual interpretation of historic aerial photography acquired in 1950 indicates that residual permafrost plateaus covered 920 ha as mapped across portions of four wetland complexes encompassing 4810 ha. However, between 1950 and ca. 2010, permafrost plateau extent decreased by 60.0 {\%}, with lateral feature degradation accounting for 85.0 {\%} of the reduction in area. Permafrost loss on the Kenai Peninsula is likely associated with a warming climate, wildfires that remove the protective forest and organic layer cover, groundwater flow at depth, and lateral heat transfer from wetland surface waters in the summer. Better understanding the resilience and vulnerability of ecosystem-protected permafrost is critical for mapping and predicting future permafrost extent and degradation across all permafrost regions that are currently warming. Further work should focus on reconstructing permafrost history in south-central Alaska as well as additional contemporary observations of these ecosystem-protected permafrost sites south of the regions with relatively stable permafrost.{\textless}/p{\textgreater}},
author = {Jones, Benjamin M. and Baughman, Carson A. and Romanovsky, Vladimir E. and Parsekian, Andrew D. and Babcock, Esther L. and Stephani, Eva and Jones, Miriam C. and Grosse, Guido and Berg, Edward E.},
doi = {10.5194/tc-10-2673-2016},
issn = {1994-0424},
journal = {The Cryosphere},
month = {nov},
number = {6},
pages = {2673--2692},
title = {{Presence of rapidly degrading permafrost plateaus in south-central Alaska}},
url = {https://tc.copernicus.org/articles/10/2673/2016/},
volume = {10},
year = {2016}
}
@article{doi:10.1002/qj.3871,
abstract = {Abstract Simulated historic near-surface air temperature variations are often compared with observations of land air temperatures blended with sea surface temperatures. This study investigates claims that this is not a “true like-with-like” comparison, which may cause small biases in simulated twentieth century temperature changes, with implications for different climate attribution and projection studies. A more appropriate analysis, it is claimed, should use simulated sea surface temperatures blended with land air temperatures; an apparent discrepancy with observed trends is then reduced. As the temperature of the uppermost level in a model's ocean is used to represent simulated sea surface temperatures, that models have inconsistent ways of representing land, and that simulations have differing sea ice coverages, the claim of an idealised analysis approach is challenged. An examination of Coupled Model Intercomparison Project simulations, compared with an observational dataset of near-surface temperatures, suggests there is a bias in simulated historic trends when upper-ocean temperatures are used instead of marine air temperatures, but this bias is small compared to other model and observational uncertainties and the impact of analysis choices. The results indicate that it is generally appropriate to use global near-surface air temperature diagnostics to compare simulated historic climate change with observed temperature changes. Alternative model diagnostics are not necessarily superior to those used in standard approaches, and the emphasis of model and observational discrepancies may be based on overconfident reasoning.},
author = {Jones, Gareth S},
doi = {10.1002/qj.3871},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {CMIP5,climate change,climate models,observed temperatures},
pages = {3747--3771},
title = {{‘Apples and Oranges': On comparing simulated historic near-surface temperature changes with observations}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.3871},
volume = {146},
year = {2020}
}
@article{Jones2016,
author = {Jones, Julie M and Gille, Sarah T and Goosse, Hugues and Abram, Nerilie J and Canziani, Pablo O and Charman, Dan J and Clem, Kyle R and Crosta, Xavier and de Lavergne, Casimir and Eisenman, Ian and England, Matthew H and Fogt, Ryan L and Frankcombe, Leela M and Marshall, Gareth J and Masson-Delmotte, Val{\'{e}}rie and Morrison, Adele K and Orsi, Ana{\"{i}}s J and Raphael, Marilyn N and Renwick, James A and Schneider, David P and Simpkins, Graham R and Steig, Eric J and Stenni, Barbara and Swingedouw, Didier and Vance, Tessa R},
doi = {10.1038/nclimate3103},
journal = {Nature Climate Change},
month = {sep},
pages = {917},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Assessing recent trends in high-latitude Southern Hemisphere surface climate}},
url = {http://dx.doi.org/10.1038/nclimate3103 http://10.0.4.14/nclimate3103 https://www.nature.com/articles/nclimate3103{\#}supplementary-information},
volume = {6},
year = {2016}
}
@article{Jongeward2016,
author = {Jongeward, Andrew R. and Li, Zhanqing and He, Hao and Xiong, Xiaoxiong},
doi = {10.1175/JAS-D-15-0308.1},
issn = {0022-4928},
journal = {Journal of the Atmospheric Sciences},
month = {nov},
number = {11},
pages = {4469--4485},
title = {{Natural and Anthropogenic Aerosol Trends from Satellite and Surface Observations and Model Simulations over the North Atlantic Ocean from 2002 to 2012}},
url = {http://journals.ametsoc.org/doi/10.1175/JAS-D-15-0308.1},
volume = {73},
year = {2016}
}
@article{Jonkers2019,
abstract = {The ocean—the Earth's largest ecosystem—is increasingly affected by anthropogenic climate change1,2. Large and globally consistent shifts have been detected in species phenology, range extension and community composition in marine ecosystems3–5. However, despite evidence for ongoing change, it remains unknown whether marine ecosystems have entered an Anthropocene6 state beyond the natural decadal to centennial variability. This is because most observational time series lack a long-term baseline, and the few time series that extend back into the pre-industrial era have limited spatial coverage7,8. Here we use the unique potential of the sedimentary record of planktonic foraminifera—ubiquitous marine zooplankton—to provide a global pre-industrial baseline for the composition of modern species communities. We use a global compilation of 3,774 seafloor-derived planktonic foraminifera communities of pre-industrial age9 and compare these with communities from sediment-trap time series that have sampled plankton flux since ad 1978 (33 sites, 87 observation years). We find that the Anthropocene assemblages differ from their pre-industrial counterparts in proportion to the historical change in temperature. We observe community changes towards warmer or cooler compositions that are consistent with historical changes in temperature in 85{\%} of the cases. These observations not only confirm the existing evidence for changes in marine zooplankton communities in historical times, but also demonstrate that Anthropocene communities of a globally distributed zooplankton group systematically differ from their unperturbed pre-industrial state.},
author = {Jonkers, Lukas and Hillebrand, Helmut and Kucera, Michal},
doi = {10.1038/s41586-019-1230-3},
issn = {1476-4687},
journal = {Nature},
number = {7761},
pages = {372--375},
title = {{Global change drives modern plankton communities away from the pre-industrial state}},
url = {https://doi.org/10.1038/s41586-019-1230-3},
volume = {570},
year = {2019}
}
@article{Josey2018,
abstract = {Cold ocean temperature anomalies have been observed in the mid- to high-latitude North Atlantic on interannual to centennial timescales. Most notably, a large region of persistently low surface temperatures accompanied by a sharp reduction in ocean heat content was evident in the subpolar gyre from the winter of 2013–2014 to 2016, and the presence of this feature at a time of pervasive warming elsewhere has stimulated considerable debate. Here, we review the role of air-sea interaction and ocean processes in generating this cold anomaly and place it in a longer-term context. We also discuss the potential impacts of surface temperature anomalies for the atmosphere, including the North Atlantic Oscillation and European heat waves; contrast the behavior of the Atlantic with the extreme warm surface event that occurred in the North Pacific over a similar timescale; and consider the possibility that these events represent a response to a change in atmospheric planetary wave forcing.},
author = {Josey, Simon A. and Hirschi, Joel J.-M. and Sinha, Bablu and Duchez, Aur{\'{e}}lie and Grist, Jeremy P. and Marsh, Robert},
doi = {10.1146/annurev-marine-121916-063102},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
pages = {475--501},
title = {{The Recent Atlantic Cold Anomaly: Causes, Consequences, and Related Phenomena}},
volume = {10},
year = {2018}
}
@article{Joyce2004a,
author = {Joyce, R J and Janowiak, J E and Arkin, Phillip A. and Xie, Pingping},
doi = {10.1175/1525-7541(2004)005<0487:CAMTPG>2.0.CO;2},
journal = {Journal of Hydrometeorology},
number = {3},
pages = {487--503},
title = {{CMORPH: A Method that Produces Global Precipitation Estimates from Passive Microwave and Infrared Data at High Spatial and Temporal Resolution}},
volume = {5},
year = {2004}
}
@article{article,
author = {Jung, Myung-Pyo and Shim, Kyo-Moon and Kim, Yongseok and Choi, In-Tae},
doi = {10.5338/KJEA.2015.34.3.27},
journal = {Korean Journal of Environmental Agriculture},
pages = {192--195},
title = {{Change of Climatic Growing Season in Korea}},
volume = {34},
year = {2015}
}
@article{Jungclaus2017,
abstract = {The pre-industrial millennium is among the periods selected by the Paleoclimate Model Intercomparison Project (PMIP) for experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and the fourth phase of the PMIP (PMIP4). The past1000 transient simulations serve to investigate the response to (mainly) natural forcing under background conditions not too different from today, and to discriminate between forced and internally generated variability on interannual to centennial timescales. This paper describes the motivation and the experimental set-ups for the PMIP4-CMIP6 past1000 simulations, and discusses the forcing agents orbital, solar, volcanic, and land use/land cover changes, and variations in greenhouse gas concentrations. The past1000 simulations covering the pre-industrial millennium from 850 Common Era (CE) to 1849 CE have to be complemented by historical simulations (1850 to 2014 CE) following the CMIP6 protocol. The external forcings for the past1000 experiments have been adapted to provide a seamless transition across these time periods. Protocols for the past1000 simulations have been divided into three tiers. A default forcing data set has been defined for the Tier 1 (the CMIP6 past1000) experiment. However, the PMIP community has maintained the flexibility to conduct coordinated sensitivity experiments to explore uncertainty in forcing reconstructions as well as parameter uncertainty in dedicated Tier 2 simulations. Additional experiments (Tier 3) are defined to foster collaborative model experiments focusing on the early instrumental period and to extend the temporal range and the scope of the simulations. This paper outlines current and future research foci and common analyses for collaborative work between the PMIP and the observational communities (reconstructions, instrumental data).},
author = {Jungclaus, Johann H. and Bard, Edouard and Baroni, M{\'{e}}lanie and Braconnot, Pascale and Cao, Jian and Chini, Louise P. and Egorova, Tania and Evans, Michael and {Fidel Gonz{\'{a}}lez-Rouco}, J. and Goosse, Hugues and Hurtt, George C. and Joos, Fortunat and Kaplan, Jed O. and Khodri, Myriam and {Klein Goldewijk}, Kees and Krivova, Natalie and Legrande, Allegra N. and Lorenz, Stephan J. and Luterbacher, J{\"{u}}rg and Man, Wenmin and Maycock, Amanda C. and Meinshausen, Malte and Moberg, Anders and Muscheler, Raimund and Nehrbass-Ahles, Christoph and Otto-Bliesner, Bette I. and Phipps, Steven J. and Pongratz, Julia and Rozanov, Eugene and Schmidt, Gavin A. and Schmidt, Hauke and Schmutz, Werner and Schurer, Andrew and Shapiro, Alexander I. and Sigl, Michael and Smerdon, Jason E. and Solanki, Sami K. and Timmreck, Claudia and Toohey, Matthew and Usoskin, Ilya G. and Wagner, Sebastian and Wu, Chi Ju and {Leng Yeo}, Kok and Zanchettin, Davide and Zhang, Qiong and Zorita, Eduardo},
doi = {10.5194/gmd-10-4005-2017},
issn = {19919603},
journal = {Geoscientific Model Development},
month = {nov},
number = {11},
pages = {4005--4033},
title = {{The PMIP4 contribution to CMIP6 – Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 past1000 simulations}},
volume = {10},
year = {2017}
}
@article{doi:10.1002/joc.6354,
abstract = {Abstract Near-surface air temperature over the oceans is a relatively unused parameter in understanding the current state of climate, but is useful as an independent temperature metric over the oceans and serves as a geographical and physical complement to near-surface air temperature over land. Although one complete version of this dataset exists (HadNMAT2), it has been strongly recommended that various groups generate climate records independently, which is one motivation here. This University of Alabama in Huntsville (UAH) study began with the construction of monthly night-time marine air temperature (UAHNMATv1) values from the early-twentieth century through to the present era using air temperatures on ships. Data from the International Comprehensive Ocean–Atmosphere Data Set (ICOADS) Release 3.0 (R3.0) were used to compile a complete time series of gridded UAHNMATv1. The observations required detailed homogenization procedures since there are many biases to account for such as increasing ship height and changing observing practices. The UAHNMATv1 dataset, once homogenized, is gridded to 5.0° monthly anomalies from 1900 to 2018. This study will present results which quantify the variability and trends and compare to current trends of other related datasets that include HadNMAT2 and sea-surface temperatures (HadISST {\&} ERSSTv4). This new dataset has broad overall agreement both globally and regionally with HadNMAT2, HadISST, and ERSSTv4 datasets.},
author = {Junod, Robert A and Christy, John R},
doi = {10.1002/joc.6354},
journal = {International Journal of Climatology},
keywords = {ICOADS,NMAT,UAHNMATv1},
number = {5},
pages = {2609--2623},
title = {{A new compilation of globally gridded night-time marine air temperatures: The UAHNMATv1 dataset}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.6354},
volume = {40},
year = {2020}
}
@article{Jurikova2020,
abstract = {The Permian/Triassic boundary approximately 251.9 million years ago marked the most severe environmental crisis identified in the geological record, which dictated the onwards course for the evolution of life. Magmatism from Siberian Traps is thought to have played an important role, but the causational trigger and its feedbacks are yet to be fully understood. Here we present a new boron-isotope-derived seawater pH record from fossil brachiopod shells deposited on the Tethys shelf that demonstrates a substantial decline in seawater pH coeval with the onset of the mass extinction in the latest Permian. Combined with carbon isotope data, our results are integrated in a geochemical model that resolves the carbon cycle dynamics as well as the ocean redox conditions and nitrogen isotope turnover. We find that the initial ocean acidification was intimately linked to a large pulse of carbon degassing from the Siberian sill intrusions. We unravel the consequences of the greenhouse effect on the marine environment, and show how elevated sea surface temperatures, export production and nutrient input driven by increased rates of chemical weathering gave rise to widespread deoxygenation and sporadic sulfide poisoning of the oceans in the earliest Triassic. Our findings enable us to assemble a consistent biogeochemical reconstruction of the mechanisms that resulted in the largest Phanerozoic mass extinction.},
author = {Jurikova, Hana and Gutjahr, Marcus and Wallmann, Klaus and Fl{\"{o}}gel, Sascha and Liebetrau, Volker and Posenato, Renato and Angiolini, Lucia and Garbelli, Claudio and Brand, Uwe and Wiedenbeck, Michael and Eisenhauer, Anton},
doi = {10.1038/s41561-020-00646-4},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {11},
pages = {745--750},
title = {{Permian–Triassic mass extinction pulses driven by major marine carbon cycle perturbations}},
url = {https://doi.org/10.1038/s41561-020-00646-4},
volume = {13},
year = {2020}
}
@article{Kohler2015,
abstract = {Abstract. It is still an open question how equilibrium warming in response to increasing radiative forcing – the specific equilibrium climate sensitivity S – depends on background climate. We here present palaeodata-based evidence on the state dependency of S, by using CO2 proxy data together with a 3-D ice-sheet-model-based reconstruction of land ice albedo over the last 5 million years (Myr). We find that the land ice albedo forcing depends non-linearly on the background climate, while any non-linearity of CO2 radiative forcing depends on the CO2 data set used. This non-linearity has not, so far, been accounted for in similar approaches due to previously more simplistic approximations, in which land ice albedo radiative forcing was a linear function of sea level change. The latitudinal dependency of ice-sheet area changes is important for the non-linearity between land ice albedo and sea level. In our set-up, in which the radiative forcing of CO2 and of the land ice albedo (LI) is combined, we find a state dependence in the calculated specific equilibrium climate sensitivity, S[CO2,LI], for most of the Pleistocene (last 2.1 Myr). During Pleistocene intermediate glaciated climates and interglacial periods, S[CO2,LI] is on average {\~{}} 45 {\%} larger than during Pleistocene full glacial conditions. In the Pliocene part of our analysis (2.6–5 Myr BP) the CO2 data uncertainties prevent a well-supported calculation for S[CO2,LI], but our analysis suggests that during times without a large land ice area in the Northern Hemisphere (e.g. before 2.82 Myr BP), the specific equilibrium climate sensitivity, S[CO2,LI], was smaller than during interglacials of the Pleistocene. We thus find support for a previously proposed state change in the climate system with the widespread appearance of northern hemispheric ice sheets. This study points for the first time to a so far overlooked non-linearity in the land ice albedo radiative forcing, which is important for similar palaeodata-based approaches to calculate climate sensitivity. However, the implications of this study for a suggested warming under CO2 doubling are not yet entirely clear since the details of necessary corrections for other slow feedbacks are not fully known and the uncertainties that exist in the ice-sheet simulations and global temperature reconstructions are large.},
author = {K{\"{o}}hler, P. and de Boer, B. and von der Heydt, A. S. and Stap, L. B. and van de Wal, R. S. W.},
doi = {10.5194/cp-11-1801-2015},
issn = {1814-9332},
journal = {Climate of the Past},
month = {dec},
number = {12},
pages = {1801--1823},
title = {{On the state dependency of the equilibrium climate sensitivity during the last 5 million years}},
url = {https://www.clim-past.net/11/1801/2015/},
volume = {11},
year = {2015}
}
@article{kurschner_oak_1996,
author = {K{\"{u}}rschner, Wolfram M and van der Burgh, Johan and Visscher, Henk and Dilcher, David L},
doi = {10.1016/0377-8398(95)00067-4},
issn = {03778398},
journal = {Marine Micropaleontology},
month = {apr},
number = {1-4},
pages = {299--312},
title = {{Oak leaves as biosensors of late neogene and early pleistocene paleoatmospheric CO2 concentrations}},
url = {https://linkinghub.elsevier.com/retrieve/pii/0377839895000674},
volume = {27},
year = {1996}
}
@article{Kadow2020b,
abstract = {Historical temperature measurements are the basis of global climate datasets like HadCRUT4. This dataset contains many missing values, particularly for periods before the mid-twentieth century, although recent years are also incomplete. Here we demonstrate that artificial intelligence can skilfully fill these observational gaps when combined with numerical climate model data. We show that recently developed image inpainting techniques perform accurate monthly reconstructions via transfer learning using either 20CR (Twentieth-Century Reanalysis) or the CMIP5 (Coupled Model Intercomparison Project Phase 5) experiments. The resulting global annual mean temperature time series exhibit high Pearson correlation coefficients (≥0.9941) and low root mean squared errors (≤0.0547 °C) as compared with the original data. These techniques also provide advantages relative to state-of-the-art kriging interpolation and principal component analysis-based infilling. When applied to HadCRUT4, our method restores a missing spatial pattern of the documented El Ni{\~{n}}o from July 1877. With respect to the global mean temperature time series, a HadCRUT4 reconstruction by our method points to a cooler nineteenth century, a less apparent hiatus in the twenty-first century, an even warmer 2016 being the warmest year on record and a stronger global trend between 1850 and 2018 relative to previous estimates. We propose image inpainting as an approach to reconstruct missing climate information and thereby reduce uncertainties and biases in climate records.},
author = {Kadow, Christopher and Hall, David Matthew and Ulbrich, Uwe},
doi = {10.1038/s41561-020-0582-5},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {6},
pages = {408--413},
title = {{Artificial intelligence reconstructs missing climate information}},
url = {https://doi.org/10.1038/s41561-020-0582-5},
volume = {13},
year = {2020}
}
@article{gmd-10-4035-2017,
author = {Kageyama, M and Albani, S and Braconnot, P and Harrison, S P and Hopcroft, P O and Ivanovic, R F and Lambert, F and Marti, O and Peltier, W R and Peterschmitt, J.-Y. and Roche, D M and Tarasov, L and Zhang, X and Brady, E C and Haywood, A M and LeGrande, A N and Lunt, D J and Mahowald, N M and Mikolajewicz, U and Nisancioglu, K H and Otto-Bliesner, B L and Renssen, H and Tomas, R A and Zhang, Q and Abe-Ouchi, A and Bartlein, P J and Cao, J and Li, Q and Lohmann, G and Ohgaito, R and Shi, X and Volodin, E and Yoshida, K and Zhang, X and Zheng, W},
doi = {10.5194/gmd-10-4035-2017},
journal = {Geoscientific Model Development},
number = {11},
pages = {4035--4055},
title = {{The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experiments}},
url = {https://www.geosci-model-dev.net/10/4035/2017/},
volume = {10},
year = {2017}
}
@article{cp-17-37-2021,
author = {Kageyama, M and Sime, L C and Sicard, M and Guarino, M.-V. and de Vernal, A and Stein, R and Schroeder, D and Malmierca-Vallet, I and Abe-Ouchi, A and Bitz, C and Braconnot, P and Brady, E C and Cao, J and Chamberlain, M A and Feltham, D and Guo, C and LeGrande, A N and Lohmann, G and Meissner, K J and Menviel, L and Morozova, P and Nisancioglu, K H and Otto-Bliesner, B L and O'ishi, R and {Ramos Buarque}, S and y Melia, D and Sherriff-Tadano, S and Stroeve, J and Shi, X and Sun, B and Tomas, R A and Volodin, E and Yeung, N K H and Zhang, Q and Zhang, Z and Zheng, W and Ziehn, T},
doi = {10.5194/cp-17-37-2021},
journal = {Climate of the Past},
number = {1},
pages = {37--62},
title = {{A multi-model CMIP6-PMIP4 study of Arctic sea ice at 127ka: sea ice data compilation and model differences}},
url = {https://cp.copernicus.org/articles/17/37/2021/},
volume = {17},
year = {2021}
}
@article{cp-2019-169,
author = {Kageyama, Masa and Harrison, Sandy P and Kapsch, Marie-L. and Lofverstrom, Marcus and Lora, Juan M and Mikolajewicz, Uwe and Sherriff-Tadano, Sam and Vadsaria, Tristan and Abe-Ouchi, Ayako and Bouttes, Nathaelle and Chandan, Deepak and Gregoire, Lauren J. and Ivanovic, Ruza F. and Izumi, Kenji and LeGrande, Allegra N and Lhardy, Fanny and Lohmann, Gerrit and Morozova, Polina A and Ohgaito, Rumi and Paul, Andr{\'{e}} and Peltier, W Richard and Poulsen, Christopher J. and Quiquet, Aur{\'{e}}lien and Roche, Didier M and Shi, Xiaoxu and Tierney, Jessica E and Valdes, Paul J. and Volodin, Evgeny and Zhu, Jiang},
doi = {10.5194/cp-17-1065-2021},
issn = {1814-9332},
journal = {Climate of the Past},
month = {may},
number = {3},
pages = {1065--1089},
title = {{The PMIP4 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3 simulations}},
url = {https://cp.copernicus.org/articles/17/1065/2021/},
volume = {17},
year = {2021}
}
@article{KalanskyJ.RosenthalY.HerbertT.BovaS.Altabet2015,
author = {Kalansky, Julie and Rosenthal, Yair and Herbert, Timothy and Bova, Samantha and Altabet, Mark},
doi = {10.1016/j.epsl.2015.05.013},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {aug},
pages = {158--167},
title = {{Southern Ocean contributions to the Eastern Equatorial Pacific heat content during the Holocene}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X15003027},
volume = {424},
year = {2015}
}
@article{Kamae2017,
abstract = {Natural climate variability contributes to recent decadal climate trends. Specifically the trends during the satellite era since 1979 include Atlantic and Indian Ocean warming and Pacific cooling associated with phase shifts of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation, and enhanced global monsoon (GM) circulation and rainfall especially in the Northern Hemisphere. Here we evaluate effects of the oceanic changes on the global and regional monsoon trends by partial ocean temperature restoring experiments in a coupled atmosphere--ocean general circulation model. Via trans-basin atmosphere--ocean teleconnections, the Atlantic warming drives a global pattern of sea surface temperature change that resembles observations, giving rise to the enhanced GM. The tropical Atlantic warming and the resultant Indian Ocean warming favor subtropical deep-tropospheric warming in both hemispheres, resulting in the enhanced monsoon circulations and precipitation over North America, South America and North Africa. The extratropical North Atlantic warming makes an additional contribution to the monsoon enhancement via Eurasian continent warming and resultant land--sea thermal gradient over Asia. The results of this study suggest that the Atlantic multidecadal variability can explain a substantial part of global climate variability including the recent decadal trends of GM.},
author = {Kamae, Youichi and Li, Xichen and Xie, Shang Ping and Ueda, Hiroaki},
doi = {10.1007/s00382-017-3522-3},
isbn = {0038201735223},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {AMO,Global monsoon,Meridional thermal gradient,PDO},
number = {9-10},
pages = {3443--3455},
publisher = {Springer Berlin Heidelberg},
title = {{Atlantic effects on recent decadal trends in global monsoon}},
volume = {49},
year = {2017}
}
@article{Kanner2013,
abstract = {Stable oxygen isotope ($\delta$18O) measurements of two speleothems, collected from Huagapo Cave in the central Peruvian Andes and with overlapping age from 1.1 to 1.4ka, characterize tropical South American climate variability over the last 7150 years. In the study region, precipitation $\delta$18O ($\delta$18Op) is inversely correlated to rainfall amount upstream in the Amazon Basin and the intensity of convection associated with the South American summer monsoon (SASM). Speleothem long-axis profiles yield an average age resolution of five years and permit investigation of climate over orbital to decadal timescales. Variations in the isotopic composition of Huagapo Cave calcite ($\delta$18Oc) are in good agreement with several precipitation proxy records from ice cores, speleothems, and lake sediments from the central Peruvian Andes. From the mid-Holocene to today, $\delta$18Oc, a proxy for $\delta$18Op, tracks changes in local insolation and exhibits a {\~{}}2‰ decrease. In the Late Holocene, Huagapo Cave $\delta$18Oc is characterized by two periods of significant decline in SASM intensity (up to 1.5‰ increase in $\delta$18Oc) even when insolation is reaching a local maximum and the SASM would be expected to intensify. These millennial-scale reductions in SASM intensity could in part be influenced by a reduction in the zonal SST gradient of the Pacific Ocean, favoring El Ni{\~{n}}o-like development. {\textcopyright} 2013 Elsevier Ltd.},
author = {Kanner, Lisa C. and Burns, Stephen J. and Cheng, Hai and Edwards, R. Lawrence and Vuille, Mathias},
doi = {10.1016/j.quascirev.2013.05.008},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {El Ni{\~{n}}o-Southern Oscillation,Oxygen isotopes,Peruvian Andes,South American summer monsoon,Speleothem},
pages = {1--10},
publisher = {Elsevier Ltd},
title = {{High-resolution variability of the South American summer monsoon over the last seven millennia: Insights from a speleothem record from the central Peruvian Andes}},
url = {http://dx.doi.org/10.1016/j.quascirev.2013.05.008},
volume = {75},
year = {2013}
}
@article{Kao2017,
author = {Kao, A and Jiang, Xun and Li, Liming and Su, Hui and Yung, Yuk},
doi = {10.1002/2017EA000319},
journal = {Earth and Space Science},
pages = {597--606},
title = {{Precipitation, circulation, and cloud variability over the past two decades}},
volume = {4},
year = {2017}
}
@article{Kaplan2016,
abstract = {We present a comprehensive10Be chronology for Holocene moraines in the Lago Argentino basin, on the east side of the South Patagonian Icefield. We focus on three different areas, where prior studies show ample glacier moraine records exist because they were formed by outlet glaciers sensitive to climate change. The10Be dated records are from the Lago Pearson, Herminita Pen{\'{i}}nsula-Brazo Upsala, and Lago Fr{\'{i}}as areas, which span a distance of almost 100 km adjacent to the modern Icefield. New10Be ages show that expanded glaciers and moraine building events occurred at least at 6120 ± 390 (n = 13), 4450 ± 220 (n = 7), 1450 or 1410 ± 110 (n = 18), 360 ± 30 (n = 5), and 240 ± 20 (n = 8) years ago. Furthermore, other less well-dated glacier expansions of the Upsala Glacier occurred between {\~{}}1400 and {\~{}}1000 and {\~{}}2300 and {\~{}}2000 years ago. The most extensive glaciers occurred over the interval from {\~{}}6100 to {\~{}}4500 years ago, and their margins over the last {\~{}}600 years were well within and lower than those in the middle Holocene. The10Be ages agree with14C-limiting data for the glacier histories in this area.We then link southern South American, adjacent South Atlantic, and other Southern Hemisphere records to elucidate broader regional patterns of climate and their possible causes. In the early Holocene, a far southward position of the westerly winds fostered warmth, small Patagonian glaciers, and reduced sea ice coverage over the South Atlantic. Although we infer a pronounced southward displacement of the westerlies during the early Holocene, these conditions did not occur throughout the southern mid-high latitudes, an important exception being over the southwest Pacific sector. Subsequently, a northward locus and/or expansion of the winds over the Patagonia-South Atlantic sector promoted the largest glaciers between {\~{}}6100 and {\~{}}4500 years ago and greatest sea ice coverage. Over the last few millennia, the South Patagonian Icefield has experienced successive century-scale advances superimposed on a long-term net decrease in size. Our findings indicate that glaciers and sea ice in the Patagonian-South Atlantic sector of the Southern Hemisphere did not achieve their largest Holocene extents over the last millennium. We conclude that a pattern of more extensive Holocene ice prior to the last millennium is characteristic of the Southern Hemisphere middle latitudes, which differs from the glacier history traditionally thought for the Northern Hemisphere.},
author = {Kaplan, M.R. and Schaefer, J.M. and Strelin, J.A. and Denton, G.H. and Anderson, R.F. and Vandergoes, M.J. and Finkel, R.C. and Schwartz, R. and Travis, S.G. and Garcia, J.L. and Martini, M.A. and Nielsen, S.H.H.},
doi = {10.1016/j.quascirev.2016.03.014},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Cosmogenic dating,Holocene,Paleoclimate,Patagonia,South Atlantic Ocean},
month = {jun},
pages = {112--125},
title = {{Patagonian and southern South Atlantic view of Holocene climate}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379116300750},
volume = {141},
year = {2016}
}
@article{Kaplan2017,
abstract = {Anthropogenic land cover change (ALCC) is the most important transformation of the Earth system that occurred in the preindustrial Holocene, with implications for carbon, water and sediment cycles, biodiversity and the provision of ecosystem services and regional and global climate. For example, anthropogenic deforestation in preindustrial Eurasia may have led to feedbacks to the climate system: both biogeophysical, regionally amplifying winter cold and summer warm temperatures, and biogeochemical, stabilizing atmospheric CO 2 concentrations and thus influencing global climate. Quantification of these effects is difficult, however, because scenarios of anthropogenic land cover change over the Holocene vary widely, with increasing disagreement back in time. Because land cover change had such widespread ramifications for the Earth system, it is essential to assess current ALCC scenarios in light of observations and provide guidance on which models are most realistic. Here, we perform a systematic evaluation of two widely-used ALCC scenarios (KK10 and HYDE3.1) in northern and part of central Europe using an independent, pollen-based reconstruction of Holocene land cover (REVEALS). Considering that ALCC in Europe primarily resulted in deforestation, we compare modeled land use with the cover of non-forest vegetation inferred from the pollen data. Though neither land cover change scenario matches the pollen-based reconstructions precisely, KK10 correlates well with REVEALS at the country scale, while HYDE systematically underestimates land use with increasing magnitude with time in the past. Discrepancies between modeled and reconstructed land use are caused by a number of factors, including assumptions of per-capita land use and socio-cultural factors that cannot be predicted on the basis of the characteristics of the physical environment, including dietary preferences, long-distance trade, the location of urban areas and social organization.},
author = {Kaplan, Jed and Krumhardt, Kristen and Gaillard, Marie-Jos{\'{e}} and Sugita, Shinya and Trondman, Anna-Kari and Fyfe, Ralph and Marquer, Laurent and Mazier, Florence and Nielsen, Anne},
doi = {10.3390/land6040091},
issn = {2073-445X},
journal = {Land},
keywords = {environment interactions,environmental history,human,land use,paleoecology},
number = {4},
pages = {91},
title = {{Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions}},
volume = {6},
year = {2017}
}
@article{Karamperidou2015,
abstract = {Abstract The response of El Ni{\~{n}}o–Southern Oscillation (ENSO) to mid-Holocene boundary conditions remains an open question: paleoclimate proxies and climate model simulations do not agree in the magnitude of the reduction of ENSO variability, while recent proxy evidence from fossil corals from the central Pacific show that the reduction in mid-Holocene ENSO variability compared to the end of the twentieth century is not different from the reduction during other Holocene time intervals. This is inconsistent with the interpretation of lake and ocean sediment records from the eastern Pacific, which show a significant reduction compared to all other Holocene periods. In order to reconcile the seemingly conflicting proxy evidence from the eastern and central Pacific, we hypothesize that ENSO remained active during the mid-Holocene; however, there was a change in the spatial pattern of the sea surface temperature anomalies, also known as ENSO flavors. Using National Center for Atmospheric Research's Community Climate System Model version 4 forced with mid-Holocene orbital conditions, we find that the frequency of occurrence of the strongest eastern Pacific (EP) events decreases in the mid-Holocene and their variance is reduced by ∼30{\%}, while the frequency of central Pacific (CP) events slightly increases and their variance does not change. We also find a shift in the seasonality of EP events, but not in that of CP events. Lastly, mid-Holocene EP events develop more slowly and decay faster. The differential response of ENSO flavors to mid-Holocene forcing is remotely forced by the West Pacific, where a weakening of the trade winds in early boreal spring in the mid-Holocene initiates an anomalous downwelling annual Kelvin wave, which reaches the eastern Pacific during the ENSO development season, weakens the upper ocean stratification, and results in reduced ENSO upwelling feedback. The simulated reduction in the EP flavor versus the CP flavor in the mid-Holocene is consistent with proxy evidence: The teleconnection patterns of the two flavors with temperature, precipitation, and salinity are distinct, and proxies from different regions of the Pacific might be recording variability associated with only one of the flavors, or some combination of their relative effects.},
author = {Karamperidou, Christina and {Di Nezio}, Pedro N and Timmermann, Axel and Jin, Fei-Fei and Cobb, Kim M},
doi = {10.1002/2014PA002742},
journal = {Paleoceanography},
number = {5},
pages = {527--547},
title = {{The response of ENSO flavors to mid-Holocene climate: Implications for proxy interpretation}},
volume = {30},
year = {2015}
}
@article{Kassi2018,
abstract = {The coastal regions of the Gulf of Guinea constitute one of the major marine ecosystems, producing essential living marine resources for the populations of Western Africa. In this region, the Ivorian continental shelf is under pressure from various anthropogenic sources, which have put the regional fish stocks, especially Sardinella aurita, the dominant pelagic species in Ivorian industrial fishery landings, under threat from overfishing. Here, we combine in situ observations of Sardinella aurita catch, temperature, and nutrient profiles, with remote-sensing ocean-color observations, and reanalysis data of wind and sea surface temperature, to investigate relationships between Sardinella aurita catch and oceanic primary producers (including biomass and phenology of phytoplankton), and between Sardinella aurita catch and environmental conditions (including upwelling index, and turbulent mixing). We show that variations in Sardinella aurita catch in the following year may be predicted, with a confidence of 78{\%}, based on a bilinear model using only physical variables, and with a confidence of 40{\%} when using only biological variables. However, the physics-based model alone is not sufficient to explain the mechanism driving the year-to-year variations in Sardinella aurita catch. Based on the analysis of the relationships between biological variables, we demonstrate that in the Ivorian continental shelf, during the study period 1998{\&}ndash;2014, population dynamics of Sardinella aurita, and oceanic primary producers, may be controlled, mainly by top-down trophic interactions. Finally, based on the predictive models constructed here, we discuss how they can provide powerful tools to support evaluation and monitoring of fishing activity, which may help towards the development of a Fisheries Information and Management System.},
author = {Kassi, Jean-Baptiste and Racault, Marie-Fanny and Mobio, Brice and Platt, Trevor and Sathyendranath, Shubha and Raitsos, Dionysios and Affian, Kouadio},
doi = {10.3390/rs10050785},
issn = {2072-4292},
journal = {Remote Sensing},
keywords = {Sardinella aurita,chlorophyll,ecology,fish landings,fisheries management,interannual variability,ocean color,phenology,phytoplankton,predictive model,remote sensing,trophic interactions},
month = {may},
number = {5},
pages = {785},
publisher = {Multidisciplinary Digital Publishing Institute},
title = {{Remotely Sensing the Biophysical Drivers of Sardinella aurita Variability in Ivorian Waters}},
url = {http://www.mdpi.com/2072-4292/10/5/785},
volume = {10},
year = {2018}
}
@article{Kaufman2020,
abstract = {An extensive new multi-proxy database of paleo-temperature time series (Temperature 12k) enables a more robust analysis of global mean surface temperature (GMST) and associated uncertainties than was previously available. We applied five different statistical methods to reconstruct the GMST of the past 12,000 years (Holocene). Each method used different approaches to averaging the globally distributed time series and to characterizing various sources of uncertainty, including proxy temperature, chronology and methodological choices. The results were aggregated to generate a multi-method ensemble of plausible GMST and latitudinal-zone temperature reconstructions with a realistic range of uncertainties. The warmest 200-year-long interval took place around 6500 years ago when GMST was 0.7 °C (0.3, 1.8) warmer than the 19th Century (median, 5th, 95th percentiles). Following the Holocene global thermal maximum, GMST cooled at an average rate −0.08 °C per 1000 years (−0.24, −0.05). The multi-method ensembles and the code used to generate them highlight the utility of the Temperature 12k database, and they are now available for future use by studies aimed at understanding Holocene evolution of the Earth system.},
author = {Kaufman, Darrell and McKay, Nicholas and Routson, Cody and Erb, Michael and D{\"{a}}twyler, Christoph and Sommer, Philipp S and Heiri, Oliver and Davis, Basil},
doi = {10.1038/s41597-020-0530-7},
issn = {2052-4463},
journal = {Scientific Data},
number = {1},
pages = {201},
title = {{Holocene global mean surface temperature, a multi-method reconstruction approach (2020a)}},
url = {https://doi.org/10.1038/s41597-020-0530-7},
volume = {7},
year = {2020}
}
@article{Kaufman2020a,
author = {Kaufman, Darrell and McKay, Nicholas and Routson, Cody and Erb, Michael and Davis, Basil and Heiri, Oliver and Jaccard, Samuel and Tierney, Jessica and D{\"{a}}twyler, Christoph and Axford, Yarrow and Brussel, Thomas and Cartapanis, Olivier and Chase, Brian and Dawson, Andria and de Vernal, Anne and Engels, Stefan and Jonkers, Lukas and Marsicek, Jeremiah and Moffa-S{\'{a}}nchez, Paola and Morrill, Carrie and Orsi, Anais and Rehfeld, Kira and Saunders, Krystyna and Sommer, Philipp S and Thomas, Elizabeth and Tonello, Marcela and T{\'{o}}th, M{\'{o}}nika and Vachula, Richard and Andreev, Andrei and Bertrand, Sebastien and Biskaborn, Boris and Bringu{\'{e}}, Manuel and Brooks, Stephen and Caniup{\'{a}}n, Magaly and Chevalier, Manuel and Cwynar, Les and Emile-Geay, Julien and Fegyveresi, John and Feurdean, Angelica and Finsinger, Walter and Fortin, Marie-Claude and Foster, Louise and Fox, Mathew and Gajewski, Konrad and Grosjean, Martin and Hausmann, Sonja and Heinrichs, Markus and Holmes, Naomi and Ilyashuk, Boris and Ilyashuk, Elena and Juggins, Steve and Khider, Deborah and Koinig, Karin and Langdon, Peter and Larocque-Tobler, Isabelle and Li, Jianyong and Lotter, Andr{\'{e}} and Luoto, Tomi and Mackay, Anson and Magyari, Eniko and Malevich, Steven and Mark, Bryan and Massaferro, Julieta and Montade, Vincent and Nazarova, Larisa and Novenko, Elena and Pařil, Petr and Pearson, Emma and Peros, Matthew and Pienitz, Reinhard and P{\l}{\'{o}}ciennik, Mateusz and Porinchu, David and Potito, Aaron and Rees, Andrew and Reinemann, Scott and Roberts, Stephen and Rolland, Nicolas and Salonen, Sakari and Self, Angela and Sepp{\"{a}}, Heikki and Shala, Shyhrete and St-Jacques, Jeannine-Marie and Stenni, Barbara and Syrykh, Liudmila and Tarrats, Pol and Taylor, Karen and van den Bos, Valerie and Velle, Gaute and Wahl, Eugene and Walker, Ian and Wilmshurst, Janet and Zhang, Enlou and Zhilich, Snezhana},
doi = {10.1038/s41597-020-0445-3},
issn = {2052-4463},
journal = {Scientific Data},
number = {1},
pages = {115},
title = {{A global database of Holocene paleotemperature records (2020b)}},
url = {https://doi.org/10.1038/s41597-020-0445-3},
volume = {7},
year = {2020}
}
@article{doi:10.1002/joc.5886,
abstract = {The Pacific Interdecadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) influence in different ways the La Ni{\~{n}}a (LN) related teleconnections in South America. The low-frequency backgrounds in the Atlantic and Pacific Oceans play an important role in modulating the LN-related Walker and Hadley cells and the Rossby wavetrain pattern in the Southern Hemisphere. The illustration shows the LN-related SST anomaly pattern during the austral summer for distinct low-frequency backgrounds. This analysis investigates the concomitant influence of two dominant low-frequency modes, the Pacific Interdecadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), on the La Ni{\~{n}}a (LN) related climate teleconnections over South America (SA). Four possible low-frequency backgrounds are analysed: WAMO/WPDO, WAMO/CPDO, CAMO/WPDO and CAMO/CPDO, with the letters “W” and “C” referring, respectively, to the warm and cold phases of the AMO and PDO. The low-frequency anomalous sea surface cooling (warming) in the tropical Pacific during the CPDO (WPDO) favours (impedes) the settling of the LN-related negative SST anomalies in this oceanic sector. Thus, the LN-related SST anomaly patterns in the tropical Pacific in the CPDO backgrounds are meridionally more extensive and stronger than those in the WPDO backgrounds. The highest and lowest percentages of the years that experienced LN events occurred during the WAMO/CPDO and CAMO/WPDO backgrounds, respectively. The northern node of the LN-related wet–dry dipole between northern SA and southeastern SA (SESA) occurs in most seasons for all backgrounds. However, the southern node occurs in specific seasons: spring and summer for the WAMO/WPDO, winter and spring for the WAMO/CPDO, winter and summer for the CAMO/WPDO and spring for the CAMO/CPDO. Also, the LN effect on the South American monsoon with a wet–dry dipole between northern SA and eastern Brazil during summer is noted in most backgrounds, but with differences among them. We discuss here the differences in the precipitation anomaly patterns, Walker and Hadley cells and Rossby wavetrain patterns among the backgrounds. The low-frequency Atlantic and Pacific backgrounds play an important role in defining the rainfall anomaly pattern associated with the LN. The results shown here have not been discussed before and might be useful mainly for climate monitoring purposes.},
author = {Kayano, Mary Toshie and Andreoli, Rita Val{\'{e}}ria and de Souza, Rodrigo Augusto Ferreira},
doi = {10.1002/joc.5886},
journal = {International Journal of Climatology},
keywords = {Atlantic Multidecadal Oscillation,La Ni{\~{n}}a,Pacific Interdecadal Oscillation,climate variability,climatology},
number = {3},
pages = {1359--1372},
title = {{El Ni{\~{n}}o–Southern Oscillation related teleconnections over South America under distinct Atlantic Multidecadal Oscillation and Pacific Interdecadal Oscillation backgrounds: La Ni{\~{n}}a}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.5886},
volume = {39},
year = {2019}
}
@article{Keenan2018,
abstract = {Global ecosystem function is highly dependent on climate and atmospheric composition, yet ecosystem responses to environmental changes remain uncertain. Cold, high-latitude ecosystems in particular have experienced rapid warming1, with poorly understood consequences2–4. Here, we use a satellite-observed proxy for vegetation cover—the fraction of absorbed photosynthetically active radiation5—to identify a decline in the temperature limitation of vegetation in global ecosystems between 1982 and 2012. We quantify the spatial functional response of maximum annual vegetation cover to temperature and show that the observed temporal decline in temperature limitation is consistent with expectations based on observed recent warming. An ensemble of Earth system models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) mischaracterized the functional response to temperature, leading to a large overestimation of vegetation cover in cold regions. We identify a 16.4{\%} decline in the area of vegetated land that is limited by temperature over the past three decades, and suggest an expected large decline in temperature limitation under future warming scenarios. This rapid observed and expected decline in temperature limitation highlights the need for an improved understanding of other limitations to vegetation growth in cold regions3,4,6, such as soil characteristics, species migration, recruitment, establishment, competition and community dynamics.},
author = {Keenan, T. F. and Riley, W. J.},
doi = {10.1038/s41558-018-0258-y},
issn = {17586798},
journal = {Nature Climate Change},
pages = {825--828},
title = {{Greening of the land surface in the world's cold regions consistent with recent warming}},
volume = {8},
year = {2018}
}
@incollection{KeenlysideN.BaJ.MeckingJ.OmraniNE.LatifM.ZhangR.Msadek2015,
author = {Keenlyside, N. and Ba, J. and Mecking, J. and Omrani, NE. and Latif, M. and Zhang, R. and Msadek, R.},
booktitle = {Climate Change: Multidecadal and Beyond},
doi = {10.1142/9789814579933_0007},
editor = {Chang, Chih-Pei and Ghil, Michael and Latif, Mojib and Wallace, John M},
pages = {141--157},
publisher = {World Scientific},
title = {{North Atlantic Multi-Decadal Variability – Mechanisms and Predictability}},
url = {https://www.worldscientific.com/doi/abs/10.1142/9789814579933{\_}0009},
year = {2015}
}
@article{Keigwin2007a,
abstract = {A simple ocean/atmosphere feedback may reduce the amplitude of climate variability in around the North Atlantic during interglacial compared to glacial states. When climate is warm in the North Atlantic region, the Intertropical Convergence Zone has a relatively northward position, and moisture is exported from the tropical Atlantic to the tropical Pacific. At the same time the east Asian summer monsoon is strong, which helps maintain a positive balance of precipitation over evaporation in the subpolar North Pacific. This is thought to account for lower salinity in the North Pacific relative to the North Atlantic, which, in turn, drives northward flow through the Bering Strait to the northern North Atlantic. Freshening in the North Atlantic by water of Pacific origin suppresses the meridional overturning circulation and reduces the heat flux. The opposite situation exists during cold climate. Thus the combination of atmospheric vapor transport and flow through Bering Strait tends to cool the North Atlantic region when warm and warm the region when cool. Copyright 2007 by the American Geophysical Union.},
author = {Keigwin, Lloyd D. and Cook, Mea S.},
doi = {10.1029/2007PA001420},
issn = {08838305},
journal = {Paleoceanography},
number = {3},
pages = {PA3102},
title = {{A role for North Pacific salinity in stabilizing North Atlantic climate}},
volume = {22},
year = {2007}
}
@article{Keil2020,
author = {Keil, Paul and Mauritsen, Thorsten and Jungclaus, Johann and Hedemann, Christopher and Olonscheck, Dirk and Ghosh, Rohit},
doi = {10.1038/s41558-020-0819-8},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {7},
pages = {667--671},
title = {{Multiple drivers of the North Atlantic warming hole}},
url = {https://doi.org/10.1038/s41558-020-0819-8},
volume = {10},
year = {2020}
}
@article{Kemp2018,
author = {Kemp, Andrew C and Wright, Alexander J and Edwards, Robin J and Barnett, Robert L and Brain, Matthew J and Kopp, Robert E and Cahill, Niamh and Horton, Benjamin P. and Charman, Dan J. and Hawkes, Andrea D. and Hill, Troy D. and van de Plassche, Orson},
doi = {10.1016/j.quascirev.2018.10.012},
journal = {Quaternary Science Reviews},
pages = {89--110},
title = {{Relative sea-level change in Newfoundland, Canada, during the past {\~{}}3000 years}},
volume = {201},
year = {2018}
}
@article{doi:10.1029/2010JD015218,
abstract = {New estimates of measurement and sampling uncertainties of gridded in situ sea surface temperature anomalies are calculated for 1850 to 2006. The measurement uncertainties account for correlations between errors in observations made by the same ship or buoy due, for example, to miscalibration of the thermometer. Correlations between the errors increase the estimated uncertainties on grid box averages. In grid boxes where there are many observations from only a few ships or drifting buoys, this increase can be large. The correlations also increase uncertainties of regional, hemispheric, and global averages above and beyond the increase arising solely from the inflation of the grid box uncertainties. This is due to correlations in the errors between grid boxes visited by the same ship or drifting buoy. At times when reliable estimates can be made, the uncertainties in global average, Southern Hemisphere, and tropical sea surface temperature anomalies are between 2 and 3 times as large as when calculated assuming the errors are uncorrelated. Uncertainties of Northern Hemisphere averages are approximately double. A new estimate is also made of sampling uncertainties. They are largest in regions of high sea surface temperature variability such as the western boundary currents and along the northern boundary of the Southern Ocean. The sampling uncertainties are generally smaller in the tropics and in the ocean gyres.},
author = {Kennedy, J J and Rayner, N A and Smith, R O and Parker, D E and Saunby, M},
doi = {10.1029/2010JD015218},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {SST},
number = {D14},
pages = {D14103},
title = {{Reassessing biases and other uncertainties in sea surface temperature observations measured in situ since 1850: 1. Measurement and sampling uncertainties}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010JD015218},
volume = {116},
year = {2011}
}
@article{doi:10.1002/2013RG000434,
abstract = {Abstract Archives of in situ sea surface temperature (SST) measurements extend back more than 160 years. Quality of the measurements is variable, and the area of the oceans they sample is limited, especially early in the record and during the two world wars. Measurements of SST and the gridded data sets that are based on them are used in many applications so understanding and estimating the uncertainties are vital. The aim of this review is to give an overview of the various components that contribute to the overall uncertainty of SST measurements made in situ and of the data sets that are derived from them. In doing so, it also aims to identify current gaps in understanding. Uncertainties arise at the level of individual measurements with both systematic and random effects and, although these have been extensively studied, refinement of the error models continues. Recent improvements have been made in the understanding of the pervasive systematic errors that affect the assessment of long-term trends and variability. However, the adjustments applied to minimize these systematic errors are uncertain and these uncertainties are higher before the 1970s and particularly large in the period surrounding the Second World War owing to a lack of reliable metadata. The uncertainties associated with the choice of statistical methods used to create globally complete SST data sets have been explored using different analysis techniques, but they do not incorporate the latest understanding of measurement errors, and they want for a fair benchmark against which their skill can be objectively assessed. These problems can be addressed by the creation of new end-to-end SST analyses and by the recovery and digitization of data and metadata from ship log books and other contemporary literature.},
author = {Kennedy, John J},
doi = {10.1002/2013RG000434},
journal = {Reviews of Geophysics},
keywords = {error assessment,in situ SST,measurement,measurement uncertainty,satellite SST,sea surface temperature},
number = {1},
pages = {1--32},
title = {{A review of uncertainty in in situ measurements and data sets of sea surface temperature}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013RG000434},
volume = {52},
year = {2014}
}
@article{Kennedy2019,
author = {Kennedy, J J and Rayner, N. A. and Atkinson, Christopher P and Killick, R. E.},
doi = {10.1029/2018JD029867},
journal = {Journal of Geophysical Research: Atmospheres},
number = {14},
pages = {7719--7763},
title = {{An ensemble data set of sea-surface temperature change from 1850: the Met Office 1 Hadley Centre HadSST.4.0.0.0 data set}},
volume = {124},
year = {2019}
}
@article{Kent2013,
author = {Kent, E C and Fangohr, S and Berry, D I},
doi = {10.1002/joc.3606},
journal = {International Journal of Climatology},
pages = {2520--2541},
title = {{A comparative assessment of monthly mean wind speed products over the global ocean}},
volume = {33},
year = {2013}
}
@article{Kent2021,
abstract = {Surface temperature documents our changing climate, and the marine record represents one of the longest widely distributed, observation-based estimates. Measurements of near-surface marine air temperature and sea-surface temperature have been recorded on platforms ranging from sailing ships to autonomous drifting buoys. The raw observations show an imprint of differing measurement methods and are sparse in certain periods and regions. This review describes how the real signal of global climate change can be determined from these sparse and noisy observations, including the quantification of measurement method–dependent biases and the reduction of spurious signals. Recent progress has come from analysis of the observations at increasing levels of granularity and from accounting for artifacts in the data that depend on platform types, measurement methods, and environmental conditions. Cutting across these effects are others caused by how the data were recorded, transcribed, and archived. These insights will be integrated into the next generation of global products quantified with validated estimates of uncertainty and the dependencies of its correlation structure. Further analysis of these records using improved data, metadata, and methods will certainly uncover more idiosyncrasies and new ways to improve the record.},
author = {Kent, Elizabeth C. and Kennedy, John J.},
doi = {10.1146/annurev-marine-042120-111807},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {283--311},
title = {{Historical Estimates of Surface Marine Temperatures}},
url = {https://www.annualreviews.org/doi/10.1146/annurev-marine-042120-111807},
volume = {13},
year = {2021}
}
@article{doi:10.1175/BAMS-D-15-00251.1,
abstract = { AbstractGlobal surface temperature changes are a fundamental expression of climate change. Recent, much-debated variations in the observed rate of surface temperature change have highlighted the importance of uncertainty in adjustments applied to sea surface temperature (SST) measurements. These adjustments are applied to compensate for systematic biases and changes in observing protocol. Better quantification of the adjustments and their uncertainties would increase confidence in estimated surface temperature change and provide higher-quality gridded SST fields for use in many applications.Bias adjustments have been based on either physical models of the observing processes or the assumption of an unchanging relationship between SST and a reference dataset, such as night marine air temperature. These approaches produce similar estimates of SST bias on the largest space and time scales, but regional differences can exceed the estimated uncertainty. We describe challenges to improving our understanding of SST biases. Overcoming these will require clarification of past observational methods, improved modeling of biases associated with each observing method, and the development of statistical bias estimates that are less sensitive to the absence of metadata regarding the observing method.New approaches are required that embed bias models, specific to each type of observation, within a robust statistical framework. Mobile platforms and rapid changes in observation type require biases to be assessed for individual historic and present-day platforms (i.e., ships or buoys) or groups of platforms. Lack of observational metadata and high-quality observations for validation and bias model development are likely to remain major challenges. },
author = {Kent, Elizabeth C and Kennedy, John J and Smith, Thomas M and Hirahara, Shoji and Huang, Boyin and Kaplan, Alexey and Parker, David E and Atkinson, Christopher P and Berry, David I and Carella, Giulia and Fukuda, Yoshikazu and Ishii, Masayoshi and Jones, Philip D and Lindgren, Finn and Merchant, Christopher J and Morak-Bozzo, Simone and Rayner, Nick A and Venema, Victor and Yasui, Souichiro and Zhang, Huai-Min},
doi = {10.1175/BAMS-D-15-00251.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {1601--1616},
title = {{A Call for New Approaches to Quantifying Biases in Observations of Sea Surface Temperature}},
url = {https://doi.org/10.1175/BAMS-D-15-00251.1},
volume = {98},
year = {2017}
}
@article{doi:10.1175/JTECH1845.1,
abstract = { Abstract A method is developed to quantify systematic errors in two types of sea surface temperature (SST) observations: bucket and engine-intake measurements. A simple linear model is proposed where the SST measured using a bucket is cooled or warmed by a fraction of the air–sea temperature difference and the SST measured using an engine intake has a constant bias. The model is applied to collocated nighttime observations made at moderate wind speeds, allowing the effects of solar radiation and strong vertical gradients in the upper ocean to be neglected. The analysis is complicated by large random errors in all of the variables used. To estimate coefficients in this model, a novel type of linear regression, where errors in two variables are correlated with each other, is introduced. Because of the uncertainty in a priori estimates of the error covariance matrix, a Bayesian analysis of the regression problem is developed, and maximum likelihood approximations to the posterior distributions of the model parameters are obtained. Results show that the temperature change in bucket SST resulting from the air–sea temperature difference can be detected. The analysis suggests that bucket SST may be in error by a fraction from 0.12° ± 0.02° to 0.16° ± 0.02°C of the air–sea temperature difference. When this temperature change of the bucket SST is accounted for, a warm bias in engine-intake SST in the mid- to late 1970s and the 1980s was found to be smaller than that suggested by previous studies, ranging between 0.09° ± 0.06° and 0.18° ± 0.05°C. For the early 1990s the model suggests that the engine-intake SSTs may have a cold bias of −0.13° ± 0.07°C. },
author = {Kent, Elizabeth C and Kaplan, Alexey},
doi = {10.1175/JTECH1845.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {3},
pages = {487--500},
title = {{Toward Estimating Climatic Trends in SST. Part III: Systematic Biases}},
url = {https://doi.org/10.1175/JTECH1845.1},
volume = {23},
year = {2006}
}
@article{Kent2014,
author = {Kent, Elizabeth C and Berry, David I and Roberts, J Brent},
doi = {10.1002/joc.3691},
journal = {International Journal of Climatology},
keywords = {air,atmospheric reanalysis,marine climatology,observations,sea interaction,specific,surface humidity},
number = {April 2013},
pages = {355--376},
title = {{A comparison of global marine surface-specific humidity datasets from in situ observations and atmospheric reanalysis}},
volume = {376},
year = {2014}
}
@article{Kersale2020,
abstract = {The Meridional Overturning Circulation (MOC) is a primary mechanism driving oceanic heat redistribution on Earth, thereby affecting Earth's climate and weather. However, the full-depth structure and variability of the MOC are still poorly understood, particularly in the South Atlantic. This study presents unique multiyear records of the oceanic volume transport of both the upper ({\&}lt;{\~{}}3100 meters) and abyssal ({\&}gt;{\~{}}3100 meters) overturning cells based on daily moored measurements in the South Atlantic at 34.5°S. The vertical structure of the time-mean flows is consistent with the limited historical observations. Both the upper and abyssal cells exhibit a high degree of variability relative to the temporal means at time scales, ranging from a few days to a few weeks. Observed variations in the abyssal flow appear to be largely independent of the flow in the overlying upper cell. No meaningful trends are detected in either cell.},
author = {Kersal{\'{e}}, M and Meinen, C S and Perez, R C and {Le H{\'{e}}naff}, M and Valla, D and Lamont, T and Sato, O T and Dong, S and Terre, T and van Caspel, M and Chidichimo, M P and van den Berg, M and Speich, S and Piola, A R and Campos, E J D and Ansorge, I and Volkov, D L and Lumpkin, R and Garzoli, S L},
doi = {10.1126/sciadv.aba7573},
journal = {Science Advances},
month = {aug},
number = {32},
pages = {eaba7573},
title = {{Highly variable upper and abyssal overturning cells in the South Atlantic}},
url = {http://advances.sciencemag.org/content/6/32/eaba7573.abstract},
volume = {6},
year = {2020}
}
@article{KHAN201713,
abstract = {We present a Holocene relative sea-level (RSL) database for the Caribbean region (5°N to 25°N and 55°W to 90°W) that consists of 499 sea-level index points and 238 limiting dates. The database was compiled from multiple sea-level indicators (mangrove peat, microbial mats, beach rock and acroporid and massive corals). We subdivided the database into 20 regions to investigate the influence of tectonics and glacial isostatic adjustment on RSL. We account for the local-scale processes of sediment compaction and tidal range change using the stratigraphic position (overburden thickness) of index points and paleotidal modeling, respectively. We use a spatio-temporal empirical hierarchical model to estimate RSL position and its rates of change in the Caribbean over 1-ka time slices. Because of meltwater input, the rates of RSL change were highest during the early Holocene, with a maximum of 10.9 ± 0.6 m/ka in Suriname and Guyana and minimum of 7.4 ± 0.7 m/ka in south Florida from 12 to 8 ka. Following complete deglaciation of the Laurentide Ice Sheet (LIS) by ∼7 ka, mid-to late-Holocene rates slowed to {\textless} 2.4 ± 0.4 m/ka. The hierarchical model constrains the spatial extent of the mid-Holocene highstand. RSL did not exceed the present height during the Holocene, except on the northern coast of South America, where in Suriname and Guyana, RSL attained a height higher than present by 6.6 ka (82{\%} probability). The highstand reached a maximum elevation of +1.0 ± 1.1 m between 5.3 and 5.2 ka. Regions with a highstand were located furthest away from the former LIS, where the effects from ocean syphoning and hydro-isostasy outweigh the influence of subsidence from forebulge collapse.},
author = {Khan, Nicole S and Ashe, Erica and Horton, Benjamin P and Dutton, Andrea and Kopp, Robert E and Brocard, Gilles and Engelhart, Simon E and Hill, David F and Peltier, W R and Vane, Christopher H and Scatena, Fred N},
doi = {10.1016/j.quascirev.2016.08.032},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Caribbean,Glacial-isostatic adjustment,Hierarchical statistical modeling,Holocene,Relative sea level,Vertical tectonic motion},
pages = {13--36},
title = {{Drivers of Holocene sea-level change in the Caribbean}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379116303304},
volume = {155},
year = {2017}
}
@article{Khan2020,
abstract = {The Greenland Ice Sheet is the largest land ice contributor to sea level rise. This will continue in the future but at an uncertain rate and observational estimates are limited to the last few decades. Understanding the long-term glacier response to external forcing is key to improving projections. Here we use historical photographs to calculate ice loss from 1880–2012 for Jakobshavn, Helheim, and Kangerlussuaq glacier. We estimate ice loss corresponding to a sea level rise of 8.1 ± 1.1 millimetres from these three glaciers. Projections of mass loss for these glaciers, using the worst-case scenario, Representative Concentration Pathways 8.5, suggest a sea level contribution of 9.1–14.9 mm by 2100. RCP8.5 implies an additional global temperature increase of 3.7 °C by 2100, approximately four times larger than that which has taken place since 1880. We infer that projections forced by RCP8.5 underestimate glacier mass loss which could exceed this worst-case scenario.},
author = {Khan, Shfaqat A. and Bj{\o}rk, Anders A. and Bamber, Jonathan L. and Morlighem, Mathieu and Bevis, Michael and Kj{\ae}r, Kurt H. and Mouginot, J{\'{e}}r{\'{e}}mie and L{\o}kkegaard, Anja and Holland, David M. and Aschwanden, Andy and Zhang, Bao and Helm, Veit and Korsgaard, Niels J. and Colgan, William and Larsen, Nicolaj K. and Liu, Lin and Hansen, Karina and Barletta, Valentina and Dahl-Jensen, Trine S. and S{\o}ndergaard, Anne Sofie and Csatho, Beata M. and Sasgen, Ingo and Box, Jason and Schenk, Toni},
doi = {10.1038/s41467-020-19580-5},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {5718},
title = {{Centennial response of Greenland's three largest outlet glaciers}},
url = {http://www.nature.com/articles/s41467-020-19580-5},
volume = {11},
year = {2020}
}
@article{Khaykin2017,
abstract = {Abstract Temperature changes in the lower and middle stratosphere during 2001–2016 are evaluated using measurements from GPS Radio Occultation (RO) and Advanced Microwave Sounding Unit (AMSU) aboard the Aqua satellite. After downsampling of GPS-RO profiles according to the AMSU weighting functions, the spatially and seasonally resolved trends from the two data sets are in excellent agreement. The observations indicate that the middle stratosphere has cooled in the time period 2002–2016 at an average rate of −0.14 ± 0.12 to −0.36 ± 0.14 K/decade, while no significant change was found in the lower stratosphere. The meridionally and vertically resolved trends from high-resolution GPS-RO data exhibit a marked interhemispheric asymmetry and highlight a distinct boundary between tropospheric and stratospheric temperature change regimes matching the tropical thermal tropopause. The seasonal pattern of trend reveals significant opposite-sign structures at high and low latitudes, providing indication of seasonally varying change in stratospheric circulation.},
author = {Khaykin, S M and Funatsu, B M and Hauchecorne, A and Godin-Beekmann, S and Claud, C and Keckhut, P and Pazmino, A and Gleisner, H and Nielsen, J K and Syndergaard, S and Lauritsen, K B},
doi = {10.1002/2017GL074353},
journal = {Geophysical Research Letters},
number = {14},
pages = {7510--7518},
title = {{Postmillennium changes in stratospheric temperature consistently resolved by GPS radio occultation and AMSU observations}},
volume = {44},
year = {2017}
}
@article{Kilbourne2014a,
abstract = {Traces of environmental conditions found in natural archives can serve as proxies for direct climate measurements to extend our knowledge of past climate variability beyond the relatively short instrumental record. Such paleoclimate proxies have demonstrated significant multidecadal climate variability in the Atlantic sector since at least the mid-1700s. However, Atlantic multidecadal climate variability is primarily defined by fluctuations in sea surface temperature (SST) and the proxy evidence comes from a variety of sources, many of which are terrestrial and are not directly recording sea surface temperature. Further analysis into the causes and consequences of Atlantic multidecadal climate variability requires development of a spatial network of decadal resolution proxy SST records with both low and high latitude contributions. An initial attempt at a low latitude Atlantic SST reconstruction found only 4 sites with ≤5year resolution data, demonstrating the paucity of appropriate data available. The 4-site average correlated significantly with instrumental average SST and the Atlantic Multidecadal Oscillation (AMO). The full record, 1360–2000C.E., and a shortened version 1460–1850C.E., had significant multidecadal variability centered at a 60-year period. Comparing our reconstruction with reconstructions of SST anomalies in the North Atlantic shows that there is no consensus yet on the history of Atlantic multidecadal variability.},
author = {Kilbourne, K Halimeda and Alexander, Michael A and Nye, Janet A},
doi = {10.1016/j.jmarsys.2013.09.004},
issn = {0924-7963},
journal = {Journal of Marine Systems},
keywords = {Atlantic Multidecadal Oscillation,Atlantic multidecadal variability,Caribbean,Paleoclimate,Sea},
pages = {4--13},
title = {{A low latitude paleoclimate perspective on Atlantic multidecadal variability}},
url = {http://www.sciencedirect.com/science/article/pii/S092479631300198X},
volume = {133},
year = {2014}
}
@article{Kim2019b,
author = {Kim, H},
doi = {10.1175/2019BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {9},
pages = {S35--S37},
title = {{Hydrological cycle: river discharge and runoff [in “State of the Climate in 2018”]}},
volume = {100},
year = {2019}
}
@article{Kim2015b,
author = {Kim, JongChun and Paik, Kyungrock},
doi = {10.1007/s00382-015-2546-9},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {sep},
number = {5-6},
pages = {1699--1712},
title = {{Recent recovery of surface wind speed after decadal decrease: a focus on South Korea}},
url = {http://link.springer.com/10.1007/s00382-015-2546-9},
volume = {45},
year = {2015}
}
@article{Kim2015c,
author = {Kim, S-H and Ha, K-J},
doi = {10.1007/s00382-014-2304-4},
journal = {Climate Dynamics},
pages = {2479--2491},
title = {{Two leading modes of Northern Hemisphere blocking variability in the boreal wintertime and their relationship with teleconnection patterns}},
volume = {44},
year = {2015}
}
@article{Kim2014d,
abstract = {Successive cold winters of severely low temperatures in recent years have had critical social and economic impacts on the mid-latitude continents in the Northern Hemisphere. Although these cold winters are thought to be partly driven by dramatic losses of Arctic sea-ice, the mechanism that links sea-ice loss to cold winters remains a subject of debate. Here, by conducting observational analyses and model experiments, we show how Arctic sea-ice loss and cold winters in extra-polar regions are dynamically connected through the polar stratosphere. We find that decreased sea-ice cover during early winter months (November–December), especially over the Barents–Kara seas, enhances the upward propagation of planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric polar vortex in mid-winter (January–February). The weakened polar vortex preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low temperatures in mid-latitudes.},
author = {Kim, Baek-Min and Son, Seok-Woo and Min, Seung-Ki and Jeong, Jee-Hoon and Kim, Seong-Joong and Zhang, Xiangdong and Shim, Taehyoun and Yoon, Jin-Ho},
doi = {10.1038/ncomms5646},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {4646},
title = {{Weakening of the stratospheric polar vortex by Arctic sea-ice loss}},
url = {https://doi.org/10.1038/ncomms5646},
volume = {5},
year = {2014}
}
@article{King2018c,
abstract = {Abstract We present freeboard measurements from airborne laser scanner (ALS), the Airborne Synthetic Aperture and Interferometric Radar Altimeter System (ASIRAS), and CryoSat‐2 SIRAL radar altimeter; ice thickness measurements from both helicopter‐borne and ground‐based electromagnetic‐sounding; and point measurements of ice properties. This case study was carried out in April 2015 during the N‐ICE2015 expedition in the area of the Arctic Ocean north of Svalbard. The region is represented by deep snow up to 1.12 m and a widespread presence of negative freeboards. The main scattering surfaces from both CryoSat‐2 and ASIRAS are shown to be closer to the snow freeboard obtained by ALS than to the ice freeboard measured in situ. This case study documents the complexity of freeboard retrievals from radar altimetry. We show that even under cold (below −15°C) conditions the radar freeboard can be close to the snow freeboard on a regional scale of tens of kilometers. We derived a modal sea‐ice thickness for the study region from CryoSat‐2 of 3.9 m compared to measured total thickness 1.7 m, resulting in an overestimation of sea‐ice thickness on the order of a factor 2. Our results also highlight the importance of year‐to‐year regional scale information about the depth and density of the snowpack, as this influences the sea‐ice freeboard, the radar penetration, and is a key component of the hydrostatic balance equations used to convert radar freeboard to sea‐ice thickness.},
author = {King, Jennifer and Skourup, Henriette and Hvidegaard, Sine M. and R{\"{o}}sel, Anja and Gerland, Sebastian and Spreen, Gunnar and Polashenski, Chris and Helm, Veit and Liston, Glen E.},
doi = {10.1002/2017JC013233},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
number = {2},
pages = {1123--1141},
title = {{Comparison of Freeboard Retrieval and Ice Thickness Calculation From ALS, ASIRAS, and CryoSat-2 in the Norwegian Arctic to Field Measurements Made During the N-ICE2015 Expedition}},
volume = {123},
year = {2018}
}
@article{King2017a,
abstract = {Limiting warming to 1.5 °C is expected to lessen the risk of extreme events, relative to 2 °C. Considering Australia, this work shows a decrease of about 25{\%} in the likelihood of record heat, both air and sea surface, if warming is limited to 1.5 °C.},
author = {King, Andrew D and Karoly, David J and Henley, Benjamin J},
doi = {10.1038/nclimate3296},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {6},
pages = {412--416},
title = {{Australian climate extremes at 1.5 °C and 2 °C of global warming}},
url = {https://doi.org/10.1038/nclimate3296},
volume = {7},
year = {2017}
}
@article{Kingslake2018,
abstract = {To predict the future contributions of the Antarctic ice sheets to sea-level rise, numerical models use reconstructions of past ice-sheet retreat after the Last Glacial Maximum to tune model parameters1. Reconstructions of the West Antarctic Ice Sheet have assumed that it retreated progressively throughout the Holocene epoch (the past 11,500 years or so)2–4. Here we show, however, that over this period the grounding line of the West Antarctic Ice Sheet (which marks the point at which it is no longer in contact with the ground and becomes a floating ice shelf) retreated several hundred kilometres inland of today's grounding line, before isostatic rebound caused it to re-advance to its present position. Our evidence includes, first, radiocarbon dating of sediment cores recovered from beneath the ice streams of the Ross Sea sector, indicating widespread Holocene marine exposure; and second, ice-penetrating radar observations of englacial structure in the Weddell Sea sector, indicating ice-shelf grounding. We explore the implications of these findings with an ice-sheet model. Modelled re-advance of the grounding line in the Holocene requires ice-shelf grounding caused by isostatic rebound. Our findings overturn the assumption of progressive retreat of the grounding line during the Holocene in West Antarctica, and corroborate previous suggestions of ice-sheet re-advance5. Rebound-driven stabilizing processes were apparently able to halt and reverse climate-initiated ice loss. Whether these processes can reverse present-day ice loss6on millennial timescales will depend on bedrock topography and mantle viscosity—parameters that are difficult to measure and to incorporate into ice-sheet models.},
author = {Kingslake, J and Scherer, R P and Albrecht, T and Coenen, J and Powell, R D and Reese, R and Stansell, N D and Tulaczyk, S and Wearing, M G and Whitehouse, P L},
doi = {10.1038/s41586-018-0208-x},
issn = {1476-4687},
journal = {Nature},
number = {7710},
pages = {430--434},
title = {{Extensive retreat and re-advance of the West Antarctic Ice Sheet during the Holocene}},
url = {https://doi.org/10.1038/s41586-018-0208-x},
volume = {558},
year = {2018}
}
@article{Kinne2019,
author = {Kinne, Stefan},
doi = {10.5194/acp-19-10919-2019},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {aug},
number = {16},
pages = {10919--10959},
title = {{Aerosol radiative effects with MACv2}},
url = {https://acp.copernicus.org/articles/19/10919/2019/},
volume = {19},
year = {2019}
}
@article{Kirschke2013a,
abstract = {Methane is an important greenhouse gas, responsible for about 20{\%} of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, their relative contributions to atmospheric methane levels are highly uncertain. As such, the factors responsible for the observed stabilization of atmospheric methane levels in the early 2000s, and the renewed rise after 2006, remain unclear. Here, we construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions. The resultant budgets suggest that data-driven approaches and ecosystem models overestimate total natural emissions. We build three contrasting emission scenarios — which differ in fossil fuel and microbial emissions — to explain the decadal variability in atmospheric methane levels detected, here and in previous studies, since 1985. Although uncertainties in emission trends do not allow definitive conclusions to be drawn, we show that the observed stabilization of methane levels between 1999 and 2006 can potentially be explained by decreasing-to-stable fossil fuel emissions, combined with stable-to-increasing microbial emissions. We show that a rise in natural wetland emissions and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006, although the relative contribution of these two sources remains uncertain.},
archivePrefix = {arXiv},
arxivId = {1302.3283},
author = {Kirschke, Stefanie and Bousquet, Philippe and Ciais, Philippe and Saunois, Marielle and Canadell, Josep G. and Dlugokencky, Edward J. and Bergamaschi, Peter and Bergmann, Daniel and Blake, Donald R. and Bruhwiler, Lori and Cameron-Smith, Philip and Castaldi, Simona and Chevallier, Fr{\'{e}}d{\'{e}}ric and Feng, Liang and Fraser, Annemarie and Heimann, Martin and Hodson, Elke L. and Houweling, Sander and Josse, B{\'{e}}atrice and Fraser, Paul J. and Krummel, Paul B. and Lamarque, Jean Fran{\c{c}}ois and Langenfelds, Ray L. and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Naik, Vaishali and O'doherty, Simon and Palmer, Paul I. and Pison, Isabelle and Plummer, David and Poulter, Benjamin and Prinn, Ronald G. and Rigby, Matt and Ringeval, Bruno and Santini, Monia and Schmidt, Martina and Shindell, Drew T. and Simpson, Isobel J. and Spahni, Renato and Steele, L. Paul and Strode, Sarah A. and Sudo, Kengo and Szopa, Sophie and {Van Der Werf}, Guido R. and Voulgarakis, Apostolos and {Van Weele}, Michiel and Weiss, Ray F. and Williams, Jason E. and Zeng, Guang},
doi = {10.1038/ngeo1955},
eprint = {1302.3283},
isbn = {1752-0894},
issn = {17520894},
journal = {Nature Geoscience},
pages = {813--823},
pmid = {22994201},
title = {{Three decades of global methane sources and sinks}},
volume = {6},
year = {2013}
}
@article{KirtlandTurner2018,
abstract = {The Paleocene–Eocene Thermal Maximum (PETM, approx. 56 Ma) provides a test case for investigating how the Earth system responds to rapid greenhouse gas-driven warming. However, current rates of carbon emissions are approximately 10 Pg C yr −1 , whereas those proposed for the PETM span orders of magnitude—from ≪1 Pg C yr −1 to greater than the anthropogenic rate. Emissions rate estimates for the PETM are hampered by uncertainty over the total mass of PETM carbon released as well as the PETM onset duration. Here, I review constraints on the onset duration of the carbon isotope excursion (CIE) that is characteristic of the event with a focus on carbon cycle model-based attempts that forgo the need for a traditional sedimentary age model. I also review and compare existing PETM carbon input scenarios employing the Earth system model cGENIE and suggest another possibility—that abrupt input of an isotopically depleted carbon source combined with elevated volcanic outgassing over a longer interval can together account for key features of the PETM CIE.},
author = {{Kirtland Turner}, Sandra},
doi = {10.1098/rsta.2017.0082},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {oct},
number = {2130},
pages = {20170082},
title = {{Constraints on the onset duration of the Paleocene–Eocene Thermal Maximum}},
url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2017.0082},
volume = {376},
year = {2018}
}
@article{Kitoh2013a,
author = {Kitoh, Akio and Endo, Hirokazu and {Krishna Kumar}, K. and Cavalcanti, Iracema F A and Goswami, Prashant and Zhou, Tianjun},
doi = {10.1002/jgrd.50258},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {apr},
number = {8},
pages = {3053--3065},
title = {{Monsoons in a changing world: A regional perspective in a global context}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/jgrd.50258},
volume = {118},
year = {2013}
}
@article{Kjeldsen2015,
abstract = {The response of the Greenland Ice Sheet (GIS) to changes in temperature during the twentieth century remains contentious, largely owing to difficulties in estimating the spatial and temporal distribution of ice mass changes before 1992, when Greenland-wide observations first became available. The only previous estimates of change during the twentieth century are based on empirical modelling and energy balance modelling. Consequently, no observation-based estimates of the contribution from the GIS to the global-mean sea level budget before 1990 are included in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Here we calculate spatial ice mass loss around the entire GIS from 1900 to the present using aerial imagery from the 1980s. This allows accurate high-resolution mapping of geomorphic features related to the maximum extent of the GIS during the Little Ice Age at the end of the nineteenth century. We estimate the total ice mass loss and its spatial distribution for three periods: 1900–1983 (75.1 ± 29.4 gigatonnes per year), 1983–2003 (73.8 ± 40.5 gigatonnes per year), and 2003–2010 (186.4 ± 18.9 gigatonnes per year). Furthermore, using two surface mass balance model we partition the mass balance into a term for surface mass balance (that is, total precipitation minus total sublimation minus runoff) and a dynamic term. We find that many areas currently undergoing change are identical to those that experienced considerable thinning throughout the twentieth century. We also reveal that the surface mass balance term shows a considerable decrease since 2003, whereas the dynamic term is constant over the past 110 years. Overall, our observation-based findings show that during the twentieth century the GIS contributed at least 25.0 ± 9.4 millimetres of global-mean sea level rise. Our result will help to close the twentieth-century sea level budget, which remains crucial for evaluating the reliability of models used to predict global sea level rise.},
author = {Kjeldsen, Kristian K. and Korsgaard, Niels J. and Bj{\o}rk, Anders A. and Khan, Shfaqat A. and Box, Jason E. and Funder, Svend and Larsen, Nicolaj K. and Bamber, Jonathan L. and Colgan, William and {Van Den Broeke}, Michiel and Siggaard-Andersen, Marie Louise and Nuth, Christopher and Schomacker, Anders and Andresen, Camilla S. and Willerslev, Eske and Kj{\ae}r, Kurt H.},
doi = {10.1038/nature16183},
isbn = {(print) 0028-0836, (electronic) 1476-4687},
issn = {14764687},
journal = {Nature},
pages = {396--400},
pmid = {26672555},
title = {{Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since AD 1900}},
volume = {528},
year = {2015}
}
@article{knies_emergence_2014,
author = {Knies, Jochen and Cabedo-Sanz, Patricia and Belt, Simon T and Baranwal, Soma and Fietz, Susanne and Rosell-Mel{\'{e}}, Antoni},
doi = {10.1038/ncomms6608},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {5608},
title = {{The emergence of modern sea ice cover in the Arctic Ocean}},
url = {http://www.nature.com/articles/ncomms6608},
volume = {5},
year = {2014}
}
@article{Knutson2018b,
abstract = {Precipitation trends for 1901-2010, 1951-2010, and 1981-2010 over relatively well-observed global land regions are assessed for detectable anthropogenic influences and for consistency with historical simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5). The CMIP5 historical all-forcing runs are broadly consistent with the observed trend pattern (1901-2010), but with an apparent low trend bias tendency in the simulations. Despite this bias, observed and modeled trends are statistically consistent over 59{\%} of the analyzed area. Over 20{\%} (9{\%}) of the analyzed area, increased (decreased) precipitation is partly attributable to anthropogenic forcing. These inferred human-induced changes include increases over regions of the north-central United States, southern Canada, Europe, and southern South America and decreases over parts of the Mediterranean region and northern tropical Africa. Trends for the shorter periods (1951-2010 and 1981-2010) do not indicate a prominent low trend bias in the models, as found for the 1901-2010 trends. An atmosphere-only model, forced with observed sea surface temperatures and other climate forcing agents, also underpredicts the observed precipitation increase in the Northern Hemisphere extratropics since 1901. The CMIP5 all-forcing ensemble's low bias in simulated trends since 1901 is a tentative finding that, if borne out in further studies, suggests that precipitation projections using these regions and models could overestimate future drought risk and underestimate future flooding risk, assuming all other factors equal.},
author = {Knutson, Thomas R. and Zeng, Fanrong},
doi = {10.1175/JCLI-D-17-0672.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Anthropogenic effects,Atmosphere,Climate change,Climate models,Precipitation},
number = {12},
pages = {4617--4637},
title = {{Model assessment of observed precipitation trends over land regions: Detectable human influences and possible low bias in model trends}},
volume = {31},
year = {2018}
}
@article{Knutz2019,
author = {Knutz, Paul C. and Newton, Andrew M. W. and Hopper, John R. and Huuse, Mads and Gregersen, Ulrik and Sheldon, Emma and Dybkj{\ae}r, Karen},
doi = {10.1038/s41561-019-0340-8},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {may},
number = {5},
pages = {361--368},
title = {{Eleven phases of Greenland Ice Sheet shelf-edge advance over the past 2.7 million years}},
volume = {12},
year = {2019}
}
@article{Kobashi2017a,
abstract = {Solar variability has been hypothesized to be a major driver of North Atlantic millennial-scale climate variations through the Holocene along with orbitally induced insolation change. However, another important climate driver, volcanic forcing has generally been underestimated prior to the past 2,500 years partly owing to the lack of proper proxy temperature records. Here, we reconstruct seasonally unbiased and physically constrained Greenland Summit temperatures over the Holocene using argon and nitrogen isotopes within trapped air in a Greenland ice core (GISP2). We show that a series of volcanic eruptions through the Holocene played an important role in driving centennial to millennial-scale temperature changes in Greenland. The reconstructed Greenland temperature exhibits significant millennial correlations with K+ and Na+ ions in the GISP2 ice core (proxies for atmospheric circulation patterns), and $\delta$18O of Oman and Chinese Dongge cave stalagmites (proxies for monsoon activity), indicating that the reconstructed temperature contains hemispheric signals. Climate model simulations forced with the volcanic forcing further suggest that a series of large volcanic eruptions induced hemispheric-wide centennial to millennial-scale variability through ocean/sea-ice feedbacks. Therefore, we conclude that volcanic activity played a critical role in driving centennial to millennial-scale Holocene temperature variability in Greenland and likely beyond.},
author = {Kobashi, Takuro and Menviel, Laurie and Jeltsch-Th{\"{o}}mmes, Aurich and Vinther, Bo M and Box, Jason E and Muscheler, Raimund and Nakaegawa, Toshiyuki and Pfister, Patrik L and D{\"{o}}ring, Michael and Leuenberger, Markus and Wanner, Heinz and Ohmura, Atsumu},
doi = {10.1038/s41598-017-01451-7},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {1441},
title = {{Volcanic influence on centennial to millennial Holocene Greenland temperature change}},
volume = {7},
year = {2017}
}
@article{Kobayashi2015,
author = {Kobayashi, Shinya and Ota, Yukinari and Harada, Yayoi and Ebita, Ayataka and Moriya, Masami and Onoda, Hirokatsu and Onogi, Kazutoshi and Kamahori, Hirotaka and Kobayashi, Chiaki and Endo, Hirokazu and Others},
doi = {10.2151/jmsj.2015-001},
journal = {Journal of the Meteorological Society of Japan. Series II},
number = {1},
pages = {5--48},
publisher = {Meteorological Society of Japan},
title = {{The JRA-55 reanalysis: General specifications and basic characteristics}},
volume = {93},
year = {2015}
}
@article{Koeller2009,
abstract = {The past decade has seen a tremendous increase in our understanding of how climate anomalies affect hydrographic properties in North Atlantic Shelf ecosystems, but less about how these events impact organisms. Koeller et al. (p. 791, see the Perspective by Greene et al.) measured the egg incubation and hatching times of an important fisheries resource, the pink North Atlantic shrimp, at a variety of locations and compared them to the timing of the local spring phytoplankton bloom. Shrimp reproduction was determined locally by bottom-water temperatures and was not directly coupled with the spring bloom. While the local bottom temperatures and bloom timing are well-matched in general, and match egg hatching to food availability, this evolved relationship can be decoupled by interannual variability and climate change.Climate change could lead to mismatches between the reproductive cycles of marine organisms and their planktonic food. We tested this hypothesis by comparing shrimp (Pandalus borealis) egg hatching times and satellite-derived phytoplankton bloom dynamics throughout the North Atlantic. At large spatial and long temporal (10 years or longer) scales, hatching was correlated with the timing of the spring phytoplankton bloom. Annual egg development and hatching times were determined locally by bottom water temperature. We conclude that different populations of P. borealis have adapted to local temperatures and bloom timing, matching egg hatching to food availability under average conditions. This strategy is vulnerable to interannual oceanographic variability and long-term climatic changes.},
author = {Koeller, P and Fuentes-Yaco, C and Platt, T and Sathyendranath, S and Richards, A and Ouellet, P and Orr, D and Sk{\'{u}}lad{\'{o}}ttir, U and Wieland, K and Savard, L and Aschan, M},
doi = {10.1126/science.1170987},
journal = {Science},
month = {may},
number = {5928},
pages = {791},
title = {{Basin-Scale Coherence in Phenology of Shrimps and Phytoplankton in the North Atlantic Ocean}},
url = {http://science.sciencemag.org/content/324/5928/791.abstract},
volume = {324},
year = {2009}
}
@article{Koenig2015a,
abstract = {{\textless}p{\textgreater}Abstract. The understanding of the nature and behavior of ice sheets in past warm periods is important for constraining the potential impacts of future climate change. The Pliocene warm period (between 3.264 and 3.025 Ma) saw global temperatures similar to those projected for future climates; nevertheless, Pliocene ice locations and extents are still poorly constrained. We present results from the efforts to simulate mid-Pliocene Greenland Ice Sheets by means of the international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP). We compare the performance of existing numerical ice sheet models in simulating modern control and mid-Pliocene ice sheets with a suite of sensitivity experiments guided by available proxy records. We quantify equilibrated ice sheet volume on Greenland, identifying a potential range in sea level contributions from warm Pliocene scenarios. A series of statistical measures are performed to quantify the confidence of simulations with focus on inter-model and inter-scenario differences. We find that Pliocene Greenland Ice Sheets are less sensitive to differences in ice sheet model configurations and internal physical quantities than to changes in imposed climate forcing. We conclude that Pliocene ice was most likely to be limited to the highest elevations in eastern and southern Greenland as simulated with the highest confidence and by synthesizing available regional proxies; however, the extent of those ice caps needs to be further constrained by using a range of general circulation model (GCM) climate forcings.{\textless}/p{\textgreater}},
author = {Koenig, S. J. and Dolan, A. M. and de Boer, B. and Stone, E. J. and Hill, D. J. and DeConto, R. M. and Abe-Ouchi, A. and Lunt, D. J. and Pollard, D. and Quiquet, A. and Saito, F. and Savage, J. and van de Wal, R.},
doi = {10.5194/cp-11-369-2015},
issn = {1814-9332},
journal = {Climate of the Past},
month = {mar},
number = {3},
title = {{Ice sheet model dependency of the simulated Greenland Ice Sheet in the mid-Pliocene}},
volume = {11},
year = {2015}
}
@article{Koffman2014a,
author = {Koffman, B. G. and Kreutz, K. J. and Breton, D. J. and Kane, E. J. and Winski, D. A. and Birkel, S. D. and Handley, M. J.},
doi = {10.5194/cp-10-1125-2014},
journal = {Climate of the Past},
number = {3},
pages = {112--125},
title = {{Centennial-scale variability of the Southern Hemisphere westerly wind belt in the eastern Pacific over the past two millennia}},
volume = {10},
year = {2014}
}
@article{Kokelj2017,
abstract = {Ice-marginal glaciated landscapes demarcate former boundaries of the continental ice sheets. Throughout circumpolar regions, permafrost has preserved relict ground ice and glacigenic sediments, delaying the sequence of postglacial landscape change that transformed temperate environments millennia earlier. Here we show that within 7 {\{}$\backslash$texttimes{\}} 106 km2 of glaciated permafrost terrain, extensive landscapes remain poised for major climate-driven change. Across northwestern Canada, 60–100-km-wide concentric swaths of thaw slump–affected terrain delineate the maximum and recessional positions of the Laurentide Ice Sheet. These landscapes comprise ∼17{\%} of continuous permafrost terrain in a 1.27 {\{}$\backslash$texttimes{\}} 106 km2 study area, indicating widespread preservation of late Pleistocene ground ice. These thaw slump, relict ground ice, and glacigenic terrain associations are also evident at the circumpolar scale. Recent intensification of thaw slumping across northwestern Canada has mobilized primary glacial sediments, triggering a cascade of fluvial, lacustrine, and coastal effects. These geologically significant processes, highlighted by the spatial distribution of thaw slumps and patterns of fluvial sediment mobilization, signal the climate-driven renewal of deglaciation and postglacial permafrost landscape evolution.},
author = {Kokelj, Steven V. and Lantz, Trevor C. and Tunnicliffe, Jon and Segal, Rebecca and Lacelle, Denis},
doi = {10.1130/G38626.1},
isbn = {0091-7613 1943-2682},
issn = {19432682},
journal = {Geology},
number = {4},
pages = {371--374},
title = {{Climate-driven thaw of permafrost preserved glacial landscapes, northwestern Canada}},
volume = {45},
year = {2017}
}
@article{Kong2017,
abstract = {This study investigated vegetation response to climate change exhibited by temperature, soil moisture, and solar radiation at Northern Hemisphere (NH) scale during the growing season and seasonal periods by analyzing satellite observations of vegetation activity and climatic data for a period of 1982–2013. Generally, About 75.8{\%} of NH was dominated by increasing NDVI3g during growing season in 1982–2013, and 50.7{\%} significantly increase. Autumn NDVI3g is the main cause, with 77.7{\%} increase (45.0{\%} significantly increase). The increasing tendency of greenness was stalled and even shifted to vegetation browning after 1994–1997 specifically in Central Europe, Northern North America, and Central Siberia. NDVI3g increase during the growing season shifts from 0.017 year− 1 to 0.006 year− 1, which mainly due to decreased spring NDVI3g and slowdown of summer NDVI3g increase. Specifically, three time intervals were identified with relatively peak NDVI3g, i.e., 1990, 1997 and 2010, and three time intervals with trough NDVI3g, i.e., 1983, 1992–1994, 2002–2005. The factors potentially influencing vegetation growth in different parts of NH are complex and varied. Temperature is recognized as the critical factor behind vegetation greenness in high latitudes especially for spring and autumn temperature, in North America and Siberia. Soil moisture is the key factor influencing vegetation growth in central Canada, eastern USA and western Africa. And solar radiation is corresponding to vegetation trend in North part of North America, eastern China. This study helps identify key factors for vegetation changes and understand vegetation response to climate change at NH scale.},
author = {Kong, Dongdong and Zhang, Qiang and Singh, Vijay P. and Shi, Peijun},
doi = {10.1016/j.gloplacha.2016.10.020},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Climate change,Normalized difference vegetation index (NDVI),Northern Hemisphere,Vegetation response},
pages = {1--8},
title = {{Seasonal vegetation response to climate change in the Northern Hemisphere (1982–2013)}},
volume = {148},
year = {2017}
}
@article{Kononova2020,
author = {Kononova, N K and Lupo, A R},
doi = {doi:10.3390/atmos11030255},
journal = {Atmosphere},
number = {3},
pages = {255},
title = {{Changes in the dynamics of the Northern Hemisphere atmospheric circulation and the relationship to surface temperature in the 20th and 21st centuries}},
volume = {11},
year = {2020}
}
@article{Konopka2016,
abstract = {Abstract Based on simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the period 1979?2013, with model transport driven by the ECMWF ERA-Interim reanalysis, we discuss the impact of the El Ni{\~{n}}o Southern Oscillation (ENSO) on the variability of the dynamics, water vapor, ozone, and mean age of air (AoA) in the tropical lower stratosphere during boreal winter. Our zonally resolved analysis at the 390 K potential temperature level reveals that not only (deseasonalized) ENSO-related temperature anomalies are confined to the tropical Pacific (180?300°E) but also anomalous wave propagation and breaking, as quantified in terms of the Eliassen-Palm (EP) flux divergence, with strongest local contribution during the La Ni{\~{n}}a phase. This anomaly is coherent with respective anomalies of water vapor (±0.5 ppmv) and ozone (±100 ppbv) derived from CLaMS being in excellent agreement with the Aura Microwave Limb Sounder observations. Thus, during El Ni{\~{n}}o a more zonally symmetric wave forcing drives a deep branch of the Brewer-Dobson (BD) circulation. During La Ni{\~{n}}a this forcing increases at lower levels (≈390 K) over the tropical Pacific, likely influencing the shallow branch of the BD circulation. In agreement with previous studies, wet (dry) and young (old) tape recorder anomalies propagate upward in the subsequent months following El Ni{\~{n}}o (La Ni{\~{n}}a). Using CLaMS, these anomalies are found to be around +0.3 (?0.2) ppmv and ?4 (+4) months for water vapor and AoA, respectively. The AoA ENSO anomaly is more strongly affected by the residual circulation (≈2/3) than by eddy mixing (≈1/3).},
author = {Konopka, Paul and Ploeger, Felix and Tao, Mengchu and Riese, Martin},
doi = {10.1002/2015JD024698},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {sep},
number = {19},
pages = {11486--11501},
publisher = {Wiley-Blackwell},
title = {{Zonally resolved impact of ENSO on the stratospheric circulation and water vapor entry values}},
volume = {121},
year = {2016}
}
@article{Kopp2016a,
abstract = {We assess the relationship between temperature and global sea-level (GSL) variability over the Common Era through a statistical metaanalysis of proxy relative sea-level reconstructions and tide-gauge data. GSL rose at 0.1 ± 0.1 mm/y (2$\sigma$) over 0–700 CE. A GSL fall of 0.2 ± 0.2 mm/y over 1000–1400 CE is associated with ∼0.2 °C global mean cooling. A significant GSL acceleration began in the 19th century and yielded a 20th century rise that is extremely likely (probability P ≥ 0.95) faster than during any of the previous 27 centuries. A semiempirical model calibrated against the GSL reconstruction indicates that, in the absence of anthropogenic cli-mate change, it is extremely likely (P = 0.95) that 20th century GSL would have risen by less than 51{\%} of the observed 13.8 ± 1.5 cm. The new semiempirical model largely reconciles previous differ-ences between semiempirical 21st century GSL projections and the process model-based projections summarized in the Inter-governmental Panel on Climate Change's Fifth Assessment Report. sea level | Common Era | late Holocene | climate | ocean},
author = {Kopp, Robert E and Kemp, Andrew C and Bittermann, Klaus and Horton, Benjamin P and Donnelly, Jeffrey P and Gehrels, W Roland and Hay, Carling C and Mitrovica, Jerry X and Morrow, Eric D and Rahmstorf, Stefan},
doi = {10.1073/pnas.1517056113},
isbn = {0027-8424$\backslash$r1091-6490},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {11},
pages = {E1434--E1441},
pmid = {26903659},
publisher = {National Academy of Sciences},
title = {{Temperature-driven global sea-level variability in the Common Era}},
volume = {113},
year = {2016}
}
@article{Kosaka2013a,
abstract = {Global warming has stalled since the late 1990s, puzzling researchers; here a climate model that includes observed sea surface temperatures in the eastern equatorial Pacific reproduces the hiatus as part of natural variation, suggesting that long-term global warming is likely to continue.},
author = {Kosaka, Yu and Xie, Shang-Ping},
doi = {10.1038/nature12534},
issn = {1476-4687},
journal = {Nature},
number = {7467},
pages = {403--407},
title = {{Recent global-warming hiatus tied to equatorial Pacific surface cooling}},
url = {https://doi.org/10.1038/nature12534},
volume = {501},
year = {2013}
}
@article{Kousari2013,
author = {Kousari, M R and Ahani, H and Hakimelahi, H},
doi = {10.1007/s00704-012-0811-y},
journal = {Theoretical and Applied Climatology},
pages = {153--168},
title = {{An investigation of near-surface wind speed trends in arid and semiarid regions of Iran}},
volume = {114},
year = {2013}
}
@article{doi:10.1029/2012PA002378,
abstract = {The El Ni{\~{n}}o–Southern Oscillation (ENSO) is the largest engine of interannual climate variability on the planet, yet its past behavior and potential for future change are poorly understood and vigorously contested. Reconstructions of past ENSO are indispensable for testing climate models tasked with predicting future ENSO activity in a warming world, but suitable geologic archives are scarce, especially for the last glacial period. Here we reconstruct mean climate and ENSO variability in the Holocene and Last Glacial Maximum (LGM) from oxygen isotopic ratios ($\delta$18O) of individual foraminifera retrieved from deep-sea sediments. Our results document coordinated adjustments of the tropical Pacific/ENSO system between two diametrically opposite states: an “amplified ENSO” state in the LGM associated with a reduced zonal temperature gradient, and a “damped ENSO” state in the Mid-Holocene with enhanced gradient. Orbital precession provided the switch between these states and acted as the dominant external driver of the tropical Pacific/ENSO system in the past 25,000 years. The linked response of the mean state and variability to orbital forcing provides an integrated framework for testing ENSO theory and models.},
author = {Koutavas, Athanasios and Joanides, Stephan},
doi = {10.1029/2012PA002378},
journal = {Paleoceanography},
keywords = {ENSO,G. ruber,Holocene,Last Glacial Maximum,sea surface temperature,tropical Pacific},
number = {4},
pages = {PA4208},
title = {{El Ni{\~{n}}o–Southern Oscillation extrema in the Holocene and Last Glacial Maximum}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012PA002378},
volume = {27},
year = {2012}
}
@article{Kovacs2017,
author = {Kov{\'{a}}cs, T and Feng, W and Totterdill, A and Plane, J M C and Dhomse, S and G{\'{o}}mez-Martin, J C and Stiller, G P and Haenel, F J and Smith, C and Forster, P M and Garcia, R R and Marsh, D R and Chipperfield, M P},
doi = {10.5194/acp-17-883-2017},
journal = {Atmospheric Chemistry and Physics},
number = {2},
pages = {883--898},
title = {{Determination of the atmospheric lifetime and global warming potential of sulfur hexafluoride using a three-dimensional model}},
volume = {17},
year = {2017}
}
@article{KREMER201893,
abstract = {The Yermak Plateau is located north of Svalbard at the entrance to the Arctic Ocean, i.e. in an area highly sensitive to climate change. A multi proxy approach was carried out on Core PS92/039-2 to study glacial-interglacial environmental changes at the northern Barents Sea margin during the last 160 ka. The main emphasis was on the reconstruction of sea ice cover, based on the sea ice proxy IP25 and the related phytoplankton - sea ice index PIP25. Sea ice was present most of the time but showed significant temporal variability decisively affected by movements of the Svalbard Barents Sea Ice Sheet. For the first time, we prove the occurrence of seasonal sea ice at the eastern Yermak Plateau during glacial intervals, probably steered by a major northward advance of the ice sheet and the formation of a coastal polynya in front of it. Maximum accumulation of terrigenous organic carbon, IP25 and the phytoplankton biomarkers (brassicasterol, dinosterol, HBI III) can be correlated to distinct deglaciation events. More severe, but variable sea ice cover prevailed at the Yermak Plateau during interglacials. The general proximity to the sea ice margin is further indicated by biomarker (GDGT) - based sea surface temperatures below 2.5 °C.},
author = {Kremer, A and Stein, R and Fahl, K and Ji, Z and Yang, Z and Wiers, S and Matthiessen, J and Forwick, M and L{\"{o}}wemark, L and O'Regan, M and Chen, J and Snowball, I},
doi = {10.1016/j.quascirev.2017.12.016},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {93--108},
title = {{Changes in sea ice cover and ice sheet extent at the Yermak Plateau during the last 160 ka – Reconstructions from biomarker records}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379117309666},
volume = {182},
year = {2018}
}
@article{Kremser2016,
author = {Kremser, Stefanie and Thomason, Larry W. and von Hobe, Marc and Hermann, Markus and Deshler, Terry and Timmreck, Claudia and Toohey, Matthew and Stenke, Andrea and Schwarz, Joshua P. and Weigel, Ralf and Fueglistaler, Stephan and Prata, Fred J. and Vernier, Jean-Paul and Schlager, Hans and Barnes, John E. and Antu{\~{n}}a-Marrero, Juan-Carlos and Fairlie, Duncan and Palm, Mathias and Mahieu, Emmanuel and Notholt, Justus and Rex, Markus and Bingen, Christine and Vanhellemont, Filip and Bourassa, Adam and Plane, John M. C. and Klocke, Daniel and Carn, Simon A. and Clarisse, Lieven and Trickl, Thomas and Neely, Ryan and James, Alexander D. and Rieger, Landon and Wilson, James C. and Meland, Brian},
doi = {10.1002/2015RG000511},
issn = {87551209},
journal = {Reviews of Geophysics},
number = {2},
pages = {278--335},
title = {{Stratospheric aerosol – Observations, processes, and impact on climate}},
volume = {54},
year = {2016}
}
@article{Kretschmer2018a,
abstract = {Over the last decades, the stratospheric polar vortex has shifted towards more frequent weak states which can explain Eurasian cooling trends in boreal winter in the era of Arctic amplification.},
author = {Kretschmer, M and Coumou, D and Agel, L and Barlow, M and Tziperman, E and Cohen, J},
doi = {10.1175/BAMS-D-16-0259.1},
isbn = {0003-0007},
issn = {00030007},
journal = {Bulletin of the American Meteorological Society},
number = {1},
pages = {49--60},
title = {{More-persistent weak stratospheric polar vortex States linked to cold extremes}},
volume = {99},
year = {2018}
}
@article{Krishnamurthy2016a,
abstract = {The variability of the Indian Ocean on interannual and decadal timescales is investigated in observations, coupled model simulation and model experiment. The Indian Ocean Dipole (IOD) mode was specifically analyzed using a data-adaptive method. This study reveals one decadal mode and two interannual modes in the sea surface temperature (SST) of the IOD. The decadal mode in the IOD is associated with the Pacific Decadal Oscillation (PDO) of the North Pacific SST. The two interannual modes are related to the biennial and canonical components of El Ni{\~{n}}o-Southern Oscillation (ENSO), consistent with previous studies. This study hypothesizes that the relation between the Indian Ocean and the North Pacific on decadal scale may be through the northerly winds from the western North Pacific. The long simulation of Community Climate System Model version 4 also indicates the presence of IOD modes associated with the decadal PDO and canonical ENSO modes. However, the model fails to simulate the biennial ENSO mode in the Indian Ocean. The relation between the Indian Ocean and North Pacific Ocean is further supported by the regionally de-coupled model experiment.},
author = {Krishnamurthy, Lakshmi and Krishnamurthy, V},
doi = {10.1007/s00382-015-2568-3},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {1},
pages = {57--70},
title = {{Decadal and interannual variability of the Indian Ocean SST}},
url = {https://doi.org/10.1007/s00382-015-2568-3},
volume = {46},
year = {2016}
}
@article{refId0,
author = {Krivova, N. A. and Solanki, S. K. and Floyd, L.},
doi = {10.1051/0004-6361:20064809},
issn = {0004-6361},
journal = {Astronomy {\&} Astrophysics},
month = {jun},
number = {2},
pages = {631--639},
title = {{Reconstruction of solar UV irradiance in cycle 23}},
url = {https://doi.org/10.1051/0004-6361:20064809 http://www.aanda.org/10.1051/0004-6361:20064809},
volume = {452},
year = {2006}
}
@article{Krumpen2019,
abstract = {Sea ice is an important transport vehicle for gaseous, dissolved and particulate matter in the Arctic Ocean. Due to the recently observed acceleration in sea ice drift, it has been assumed that more matter is advected by the Transpolar Drift from shallow shelf waters to the central Arctic Ocean and beyond. However, this study provides first evidence that intensified melt in the marginal zones of the Arctic Ocean interrupts the transarctic conveyor belt and has led to a reduction of the survival rates of sea ice exported from the shallow Siberian shelves (−15{\%} per decade). As a consequence, less and less ice formed in shallow water areas ({\textless}30 m) has reached Fram Strait (−17{\%} per decade), and more ice and ice-rafted material is released in the northern Laptev Sea and central Arctic Ocean. Decreasing survival rates of first-year ice are visible all along the Russian shelves, but significant only in the Kara Sea, East Siberian Sea and western Laptev Sea. Identified changes affect biogeochemical fluxes and ecological processes in the central Arctic: A reduced long-range transport of sea ice alters transport and redistribution of climate relevant gases, and increases accumulation of sediments and contaminates in the central Arctic Ocean, with consequences for primary production, and the biodiversity of the Arctic Ocean.},
author = {Krumpen, Thomas and Belter, H Jakob and Boetius, Antje and Damm, Ellen and Haas, Christian and Hendricks, Stefan and Nicolaus, Marcel and N{\"{o}}thig, Eva-Maria and Paul, Stephan and Peeken, Ilka and Ricker, Robert and Stein, R{\"{u}}diger},
doi = {10.1038/s41598-019-41456-y},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {5459},
title = {{Arctic warming interrupts the Transpolar Drift and affects long-range transport of sea ice and ice-rafted matter}},
url = {https://doi.org/10.1038/s41598-019-41456-y},
volume = {9},
year = {2019}
}
@article{Kukal2018,
abstract = {{\textcopyright} 2018 The Author(s). Significant air temperature changes have occurred globally during the 20 th century, which are spatially variable to a considerable degree and these changes can have substantial implications in agroecosystem productivity. The agroclimate indicators that are responsible in these contexts are first fall frost (FFF), last spring frost (LSF), climatological growing season (CGS) length, and heat accumulation (growing degree days, GDD). We explore spatial and temporal trends associated with these indices across the continental U.S. (CONUS) during 1900-2014 using datasets collected at 1218 sites. On average, FFF has been occurring later (by 5.4 days century -1 ), and LSF has been occurring earlier (by 6.9 days century -1 ), resulting in the average lengthening of the CGS (by 12.7 days century -1 ). Annual GDD has been increasing by 50 °C century -1 . We also report trends for agricultural belts and climate regions. We developed relationships between county-level crop yields vs. agroclimate changes and found that all crops (maize, soybean, sorghum, spring wheat, winter wheat, and cotton) responded positively to a lengthened CGS, while responding negatively to increase in GDD, except cotton. Overall, we find that the observed changes in agroclimate, were beneficial for crop yields in the CONUS, albeit some crop and region specific exceptions.},
author = {Kukal, Meetpal S. and Irmak, Suat},
doi = {10.1038/s41598-018-25212-2},
isbn = {2045-2322 (Electronic) 2045-2322 (Linking)},
issn = {20452322},
journal = {Scientific Reports},
pages = {6977},
pmid = {29725053},
title = {{U.S. Agro-Climate in 20th Century: Growing Degree Days, First and Last Frost, Growing Season Length, and Impacts on Crop Yields}},
volume = {8},
year = {2018}
}
@article{Kunkel2016,
abstract = {Recent studies of snow climatology show a mix of trends but a preponderance of evidence suggest an overall tendency toward decreases in several metrics of snow extremes. The analysis performed herein on maximum seasonal snow depth points to a robust negative trend in this variable for the period of winter 1960/1961--winter 2014/2015. This conclusion is applicable to North America. Maximum snow depth is also mostly decreasing for those European stations analyzed. Research studies show generally negative trends in snow cover extent and snow water equivalent across both North America and Eurasia. These results are mostly, but not fully, consistent with simple hypotheses for the effects of global warming on snow characteristics.},
author = {Kunkel, Kenneth E. and Robinson, David A. and Champion, Sarah and Yin, Xungang and Estilow, Thomas and Frankson, Rebekah M.},
doi = {10.1007/s40641-016-0036-8},
issn = {21986061},
journal = {Current Climate Change Reports},
keywords = {Extremes,Snow,Snow cover,Snowdepth,Snowfall},
pages = {65--73},
title = {{Trends and Extremes in Northern Hemisphere Snow Characteristics}},
volume = {2},
year = {2016}
}
@article{Kurtz2013,
abstract = {Abstract. The study of sea ice using airborne remote sensing platforms provides unique capabilities to measure a wide variety of sea ice properties. These measurements are useful for a variety of topics including model evaluation and improvement, assessment of satellite retrievals, and incorporation into climate data records for analysis of interannual variability and long-term trends in sea ice properties. In this paper we describe methods for the retrieval of sea ice thickness, freeboard, and snow depth using data from a multi-sensor suite of instruments on NASA's Operation IceBridge airborne campaign. We assess the consistency of the results through comparison with independent data sets that demonstrate that the IceBridge products are capable of providing a reliable record of snow depth and sea ice thickness. We explore the impact of inter-campaign instrument changes and associated algorithm adaptations as well as the applicability of the adapted algorithms to the ongoing IceBridge mission. The uncertainties associated with the retrieval methods are determined and placed in the context of their impact on the retrieved sea ice thickness. Lastly, we present results for the 2009 and 2010 IceBridge campaigns, which are currently available in product form via the National Snow and Ice Data Center.},
author = {Kurtz, N. T. and Farrell, S. L. and Studinger, M. and Galin, N. and Harbeck, J. P. and Lindsay, R. and Onana, V. D. and Panzer, B. and Sonntag, J. G.},
doi = {10.5194/tc-7-1035-2013},
isbn = {1994-0416},
issn = {1994-0424},
journal = {The Cryosphere},
month = {jul},
number = {4},
pages = {1035--1056},
title = {{Sea ice thickness, freeboard, and snow depth products from Operation IceBridge airborne data}},
url = {https://tc.copernicus.org/articles/7/1035/2013/},
volume = {7},
year = {2013}
}
@article{doi:10.1098/rspa.2018.0400,
abstract = { Argo floats measure seawater temperature and salinity in the upper 2000 m of the global ocean. Statistical analysis of the resulting spatio-temporal dataset is challenging owing to its non-stationary structure and large size. We propose mapping these data using locally stationary Gaussian process regression where covariance parameter estimation and spatio-temporal prediction are carried out in a moving-window fashion. This yields computationally tractable non-stationary anomaly fields without the need to explicitly model the non-stationary covariance structure. We also investigate Student t-distributed fine-scale variation as a means to account for non-Gaussian heavy tails in ocean temperature data. Cross-validation studies comparing the proposed approach with the existing state of the art demonstrate clear improvements in point predictions and show that accounting for the non-stationarity and non-Gaussianity is crucial for obtaining well-calibrated uncertainties. This approach also provides data-driven local estimates of the spatial and temporal dependence scales for the global ocean, which are of scientific interest in their own right. },
author = {Kuusela, Mikael and Stein, Michael L},
doi = {10.1098/rspa.2018.0400},
journal = {Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences},
number = {2220},
pages = {20180400},
title = {{Locally stationary spatio-temporal interpolation of Argo profiling float data}},
url = {https://royalsocietypublishing.org/doi/abs/10.1098/rspa.2018.0400},
volume = {474},
year = {2018}
}
@article{Kwok2015,
abstract = {We present our estimates of the thickness and volume of the Arctic Ocean ice cover from CryoSat-2 data acquired between October 2010 and May 2014. Average ice thickness and draft differences are within 0.16 m of measurements from other sources (moorings, submarine, electromagnetic sensors, IceBridge). The choice of parameters that affect the conversion of ice freeboard to thickness is discussed. Estimates between 2011 and 2013 suggest moderate decreases in volume followed by a notable increase of more than 2500 km3 (or 0.34 m of thickness over the basin) in 2014, which could be attributed to not only a cooler summer in 2013 but also to large-scale ice convergence just west of the Canadian Arctic Archipelago due to wind-driven onshore drift. Variability of volume and thickness in the multiyear ice zone underscores the importance of dynamics in maintaining the thickness of the Arctic ice cover. Volume estimates are compared with those from ICESat as well as the trends in ice thickness derived from submarine ice draft between 1980 and 2004. The combined ICESat and CryoSat-2 record yields reduced trends in volume loss compared with the 5 year ICESat record, which was weighted by the record-setting ice extent after the summer of 2007.},
author = {Kwok, R. and Cunningham, G. F.},
doi = {10.1098/rsta.2014.0157},
isbn = {1471-2962},
issn = {1364503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Arctic ocean,Ice deformation,Ice drift,Ice thickness,Ice volume},
pages = {2045},
pmid = {26032317},
title = {{Variability of arctic sea ice thickness and volume from CryoSat-2}},
volume = {373},
year = {2015}
}
@article{Kwok2013,
abstract = {We examine the basinwide trends in sea ice circulation and drift speed and highlight the changes between 1982 and 2009 in connection to regional winds, multiyear sea ice coverage, ice export, and the thinning of the ice cover. The polarity of the Arctic Oscillation (AO) is used as a backdrop for summarizing the variance and shifts in decadal drift patterns. The 28-year circulation fields show a net strengthening of the Beaufort Gyre and the Transpolar Drift, especially during the last decade. The imprint of the arctic dipole anomaly on the mean summer circulation is evident (2001–2009) and enhances summer ice area export at the Fram Strait. Between 2001 and 2009, the large spatially averaged trends in drift speeds (winter: +23.6{\%}/decade, summer: +17.7{\%}/decade) are not explained by the much smaller trends in wind speeds (winter: 1.46{\%}/decade, summer: −3.42{\%}/decade). Notably, positive trends in drift speed are found in regions with reduced multiyear sea ice coverage. Over 90{\%} of the Arctic Ocean has positive trends in drift speed and negative trends in multiyear sea ice coverage. The increased responsiveness of ice drift to geostrophic wind is consistent with a thinner and weaker seasonal ice cover and suggests large-scale changes in the air-ice-ocean momentum balance. The retrieved mean ocean current field from decadal-scale average ice motion captures a steady drift from Siberia to the Fram Strait, an inflow north of the Bering Strait, and a westward drift along coastal Alaska. This mean current is comparable to geostrophic currents from satellite-derived dynamic topography.},
author = {Kwok, R. and Spreen, G. and Pang, S.},
doi = {10.1002/jgrc.20191},
isbn = {2169-9291},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Arctic Ocean,circulation,current,ice drift,sea ice,trends},
month = {may},
number = {5},
pages = {2408--2425},
title = {{Arctic sea ice circulation and drift speed: Decadal trends and ocean currents}},
url = {http://doi.wiley.com/10.1002/jgrc.20191},
volume = {118},
year = {2013}
}
@article{Kwok2018,
abstract = {Large-scale changes in Arctic sea ice thickness, volume and multiyear sea ice (MYI) coverage with available measurements from submarine sonars, satellite altimeters (ICESat and CryoSat-2), and satellite scatterometers are summarized. The submarine record spans the period between 1958 and 2000, the satellite altimeter records between 2003 and 2018, and the scatterometer records between 1999 and 2017. Regional changes in ice thickness (since 1958) and within the data release area of the Arctic Ocean, previously reported by Kwok and Rothrock (2009 Geophys. Res. Lett. 36 L15501), have been updated to include the 8 years of CryoSat-2 (CS-2) retrievals. Between the pre-1990 submarine period (1958-1976) and the CS-2 period (2011-2018) the average thickness near the end of the melt season, in six regions, decreased by 2.0 m or some 66{\%} over six decades. Within the data release area (∼38{\%} of the Arctic Ocean) of submarine ice draft, the thinning of ∼1.75 m in winter since 1980 (maximum thickness of 3.64 m in the regression analysis) has not changed significantly; the mean thickness over the CS-2 period is ∼2 m. The 15 year satellite record depicts losses in sea ice volume at 2870 km 3 /decade and 5130 km 3 /decade in winter (February-March) and fall (October-November), respectively: more moderate trends compared to the sharp decreases over the ICESat period, where the losses were weighted by record-setting melt in 2007. Over the scatterometer record (1999-2017), the Arctic has lost more than 2×10 6 km 2 of MYI-a decrease of more than 50{\%}; MYI now covers less than one-third of the Arctic Ocean. Independent MYI coverage and volume records co-vary in time, the MYI area anomalies explain ∼85{\%} of the variance in the anomalies in Arctic sea ice volume. If losses of MYI continue, Arctic thickness/volume will be controlled by seasonal ice, suggesting that the thickness/volume trends will be more moderate (as seen here) but more sensitive to climate forcing.},
author = {Kwok, R.},
doi = {10.1088/1748-9326/aae3ec},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {Arctic multiyear sea ice coverage,Arctic sea ice thickness,Arctic sea ice volume},
number = {10},
pages = {105005},
title = {{Arctic sea ice thickness, volume, and multiyear ice coverage: Losses and coupled variability (1958–2018)}},
volume = {13},
year = {2018}
}
@article{Kwok2018c,
author = {Kwok, Ron and Kacimi, Sahra},
doi = {10.5194/tc-12-2789-2018},
issn = {1994-0424},
journal = {The Cryosphere},
month = {aug},
number = {8},
pages = {2789--2801},
title = {{Three years of sea ice freeboard, snow depth, and ice thickness of the Weddell Sea from Operation IceBridge and CryoSat-2}},
url = {https://tc.copernicus.org/articles/12/2789/2018/},
volume = {12},
year = {2018}
}
@article{doi:10.1002/joc.3497,
abstract = {Abstract We examine changes in El Ni{\~{n}}o and Southern Oscillation (ENSO)/Pacific Decadal Oscillation (PDO) relationship under the global warming using coupled climate models participated in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). The temporal structure for the ENSO–PDO relationship is changed remarkably. The relationship between ENSO and PDO during the boreal winter (December, January and February) becomes stronger so that there would be more frequent in phase occurrence of ENSO and PDO (i.e. El Ni{\~{n}}o—a positive phase of PDO or La Ni{\~{n}}a—a negative phase of PDO). As PDO could constructively interfere with the ENSO-related climate when ENSO and PDO are in phase, in the future one may expect stronger climate signal because of ENSO in the midlatitude. The IPCC AR4 model also shows that the Pacific North America-like pattern is slightly shifted eastward and much stronger. We also discuss the possible reason for these changes. Copyright {\textcopyright} 2012 Royal Meteorological Society},
author = {Kwon, MinHo and Yeh, Sang-Wook and Park, Young-Gyu and Lee, Yoon-Kyoung},
doi = {10.1002/joc.3497},
journal = {International Journal of Climatology},
keywords = {ENSO,PDO,relationship},
number = {5},
pages = {1121--1128},
title = {{Changes in the linear relationship of ENSO–PDO under the global warming}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.3497},
volume = {33},
year = {2013}
}
@article{KylanderM.E.Martinez-CortizasA.BindlerR.GreenwoodS.L.MorthC.-M.andRauch2016,
author = {Kylander, M. E. and Martínez-Cortizas, A and Bindler, R. and Greenwood, S. L. and Mörth, C.-M. and Rauch, S},
doi = {10.1016/j.gca.2016.06.028},
journal = {Geochimica et Cosmochimica Acta},
pages = {156--174},
title = {{Potentials and problems of building detailed dust records using peat archives: An example from Store Mosse (the “Great Bog”), Sweden}},
volume = {190},
year = {2016}
}
@article{LHeureux2013,
abstract = {The Pacific Walker circulation is a large overturning cell that spans the tropical Pacific Ocean, characterized by rising motion (lower sea-level pressure) over Indonesia and sinking motion (higher sea level-pressure) over the eastern Pacific1,2. Fluctuations in the Walker circulation reflect changes in the location and strength of tropical heating, so related circulation anomalies have global impacts3,4. On interannual timescales, the El Ni{\~{n}}o/Southern Oscillation accounts for much of the variability in the Walker circulation, but there is considerable interest in longer-term trends and their drivers, including anthropogenic climate change5–12. Here, we examine sea-level pressure trends in ten different data sets drawn from reanalysis, reconstructions and in situ measurements for 1900–2011. We show that periods with fewer in situ measurements result in lower signal-to-noise ratios, making assessments of sea-level pressure trends largely unsuitable before about the 1950s. Multidecadal trends evaluated since 1950 reveal statistically significant, negative values over the Indonesian region, with weaker, positive trends over the eastern Pacific. The overall trend towards a stronger, La Ni{\~{n}}alike Walker circulation is nearly concurrent with the observed increase in global average temperatures, thereby justifying closer scrutiny of how the Pacific climate system has changed in the historical record},
author = {L'Heureux, Michelle L. and Lee, Sukyoung and Lyon, Bradfield},
doi = {10.1038/nclimate1840},
isbn = {1758-6798},
issn = {1758678X},
journal = {Nature Climate Change},
number = {6},
pages = {571--576},
publisher = {Nature Publishing Group},
title = {{Recent multidecadal strengthening of the Walker circulation across the tropical Pacific}},
url = {http://dx.doi.org/10.1038/nclimate1840},
volume = {3},
year = {2013}
}
@article{Lubbecke2018,
abstract = {Sea surface temperature (SST) variability in the tropical Atlantic Ocean strongly impacts the climate on the surrounding continents. On interannual time scales, highest SST variability occurs in the eastern equatorial region and off the coast of southwestern Africa. The pattern of SST variability resembles the Pacific El Ni{\~{n}}o, but features notable differences, and has been discussed in the context of various climate modes, that is, reoccurring patterns resulting from particular interactions in the climate system. Here, we attempt to reconcile those different definitions, concluding that almost all of them are essentially describing the same mode that we refer to as the ?Atlantic Ni{\~{n}}o.? We give an overview of the mechanisms that have been proposed to underlie this mode, and we discuss its interaction with other climate modes within and outside the tropical Atlantic. The impact of Atlantic Ni{\~{n}}o-related SST variability on rainfall, in particular over the Gulf of Guinea and north eastern South America is also described. An important aspect we highlight is that the Atlantic Ni{\~{n}}o and its teleconnections are not stationary, but subject to multidecadal modulations. Simulating the Atlantic Ni{\~{n}}o proves a challenge for state-of-the-art climate models, and this may be partly due to the large mean state biases in the region. Potential reasons for these model biases and implications for seasonal prediction are discussed. This article is categorized under: Climate Models and Modeling {\textgreater} Knowledge Generation with Models},
annote = {doi: 10.1002/wcc.527},
author = {L{\"{u}}bbecke, Joke F and Rodr{\'{i}}guez-Fonseca, Belen and Richter, Ingo and Mart{\'{i}}n-Rey, Marta and Losada, Teresa and Polo, Irene and Keenlyside, Noel S},
doi = {10.1002/wcc.527},
issn = {1757-7780},
journal = {WIREs Climate Change},
keywords = {Atlantic Ni{\~{n}}o,climate models,climate variability,tropical Atlantic},
month = {jul},
number = {4},
pages = {e527},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Equatorial Atlantic variability – Modes, mechanisms, and global teleconnections}},
url = {https://doi.org/10.1002/wcc.527},
volume = {9},
year = {2018}
}
@article{doi:10.1175/JCLI-D-13-00438.1,
abstract = {AbstractA decadal change in the character of ENSO was observed around year 2000 toward weaker-amplitude, higher-frequency events with an increased occurrence of central Pacific El Ni{\~{n}}os. Here these changes are assessed in terms of the Bjerknes stability index (BJ index), which is a measure of the growth rate of ENSO-related SST anomalies. The individual terms of the index are calculated from ocean reanalysis products separately for the time periods 1980–99 and 2000–10. The spread between the products is large, but they show a robust weakening of the thermocline feedback due to a reduced thermocline slope response to anomalous zonal wind stress as well as a weakened wind stress response to eastern equatorial Pacific SST anomalies. These changes are consistent with changes in the background state of the tropical Pacific: cooler mean SST in the eastern and central equatorial Pacific results in reduced convection there together with a westward shift in the ascending branch of the Walker circulation. This shift leads to a weakening in the relationship between eastern Pacific SST and longitudinally averaged equatorial zonal wind stress. Also, despite a steeper mean thermocline slope in the more recent period, the thermocline slope response to wind stress anomalies weakened due to a smaller zonal wind fetch that results from ENSO-related wind anomalies being more confined to the western basin. As a result, the total BJ index is more negative, corresponding to a more strongly damped system in the past decade compared to the 1980s and 1990s.},
author = {L{\"{u}}bbecke, Joke F and McPhaden, Michael J},
doi = {10.1175/JCLI-D-13-00438.1},
journal = {Journal of Climate},
number = {7},
pages = {2577--2587},
title = {{Assessing the Twenty-First-Century Shift in ENSO Variability in Terms of the Bjerknes Stability Index}},
url = {https://doi.org/10.1175/JCLI-D-13-00438.1},
volume = {27},
year = {2014}
}
@article{LUNING201970,
abstract = {The Medieval Climate Anomaly (MCA) is a climatic perturbation with a core period of 1000-1200 AD that is well-recognized in the Northern Hemisphere (NH). Its existence in the Southern Hemisphere (SH) and the level of synchronicity with the NH is still a matter of debate. Here we present a palaeotemperature synthesis for South America encompassing the past 1500 years based on multiproxy data from 76 published land and marine sites. The data sets have been thoroughly graphically correlated and the MCA trends palaeoclimatologically mapped. The vast majority of all South American land sites suggest a warm MCA. Andean vegetation zones moved upslope, glaciers retreated, biological productivity in high altitude lakes increased, the duration of cold season ice cover on Andean lakes shortened, and trees produced thicker annual rings. Similar MCA warming occurred in coastal seas, except in the year-round upwelling zones of Peru, northern Chile and Cabo Frio (Brazil) where upwelling processes intensified during the MCA due to changes in winds and ocean currents. MCA warming in South America and the NH appears to have occurred largely synchronous, probably reaching comparable intensities. Future studies will have to address major MCA data gaps that still exist outside the Andes in the central and eastern parts of the continent. The most likely key drivers for the medieval climate change are multi-centennial Pacific and Atlantic ocean cycles, probably linked to solar forcing.},
author = {L{\"{u}}ning, Sebastian and Ga{\l}ka, Mariusz and Bamonte, Florencia Paula and Rodr{\'{i}}guez, Felipe Garc{\'{i}}a and Vahrenholt, Fritz},
doi = {10.1016/j.quaint.2018.10.041},
issn = {1040-6182},
journal = {Quaternary International},
keywords = {Climate change,El Ni{\~{n}}o-Southern Oscillation,Late Holocene,Little Ice Age,Medieval Warm Period,Palaeoclimatology,Southern Hemisphere,Temperature reconstructions},
pages = {70--87},
title = {{The Medieval Climate Anomaly in South America}},
url = {http://www.sciencedirect.com/science/article/pii/S1040618218308322},
volume = {508},
year = {2019}
}
@article{Luning2018,
author = {L{\"{u}}ning, Sebastian and Ga, Mariusz and Danladi, Iliya Bauchi and Adagunodo, Theophilus Aanuoluwa and Vahrenholt, Fritz},
doi = {10.1016/j.palaeo.2018.01.025},
journal = {Palaeogeography, Palaeoclimatology, Palaeoecology},
pages = {309--322},
title = {{Hydroclimate in Africa during the Medieval Climate Anomaly}},
volume = {495},
year = {2018}
}
@article{doi:10.1029/2019PA003734,
abstract = {Abstract The Medieval Climate Anomaly (MCA) is a preindustrial phase of pronounced natural climate variability with a core period from 1000 to 1200 CE. The paper presents a synthesis that integrates palaeotemperature records from the Greater Mediterranean Region encompassing the past 1,500 years based on multiproxy data from 79 published land and marine sites. MCA warming dominated the Western Mediterranean (Iberia, NW Africa) as well as the northern land areas of the Central and Eastern Mediterranean region. MCA cooling prevailed in the Canary Current Upwelling System, southern Levant, and some sea areas of the Central and Eastern Mediterranean. Previous palaeoreconstructions suggest persistent positive Atlantic Multidecadal Oscillation (AMO+) and North Atlantic Oscillation (NAO+) conditions during the MCA, while the Little Ice Age was dominated by an AMO− and NAO− regime. During the past 150 years, AMO+ conditions are typically associated with warming episodes in the Mediterranean area. A similar relationship appears to have also been established during the MCA as the majority of all Mediterranean land sites experienced warm climate conditions. In contrast, the NAO typically leads to a characteristic west-east temperature dipole pattern in the basin, as documented for the last decades. During NAO+ conditions the Western Mediterranean is generally warm (and dry), while large parts of the Central and Eastern Mediterranean are cold. Similar trends seem to have been developed during the MCA when the NAO+ regime led to consistent warming in the Western Mediterranean, while a significant number of sites with MCA cooling existed in the Central and Eastern Mediterranean.},
author = {L{\"{u}}ning, S and Schulte, L and Garc{\'{e}}s-Pastor, S and Danladi, I B and Ga{\l}ka, M},
doi = {10.1029/2019PA003734},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Late Holocene,Little Ice Age,North Atlantic Oscillation,climate change,palaeoclimatology,temperature reconstructions},
number = {10},
pages = {1625--1649},
title = {{The Medieval Climate Anomaly in the Mediterranean Region}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019PA003734},
volume = {34},
year = {2019}
}
@article{Lopez2017a,
author = {L{\'{o}}pez, Oliver and Houborg, Rasmus and McCabe, Matthew Francis},
doi = {10.5194/hess-21-323-2017},
journal = {Hydrology and Earth System Sciences},
pages = {323--343},
title = {{Evaluating the hydrological consistency of evaporation products using satellite-based gravity and rainfall data}},
volume = {21},
year = {2017}
}
@article{Lachkar2019,
abstract = {Abstract The highly saline, oxygen-saturated waters of the Arabian Gulf (hereafter the Gulf) sink to intermediate depths (200?300 m) when they enter the Arabian Sea, ventilating the World's thickest oxygen minimum zone (OMZ). Here, we investigate the impacts of a warming of the Gulf consistent with climate change projections on the intensity of this OMZ. Using a series of eddy-resolving model simulations, we show that the warming of the Gulf waters increases their buoyancy and hence limits their contribution to the ventilation of intermediate depths. This leads to an intensification of the OMZ and an increase in denitrification that depletes subsurface nitrate and limits deoxygenation at depth. The projected future concomitant increase of Gulf salinity only partially reduces the OMZ intensification. Our findings highlight the importance of the Arabian marginal seas for the biogeochemistry of the North Indian Ocean and stress the need for improving their representation in global climate models.},
annote = {doi: 10.1029/2018GL081631},
author = {Lachkar, Z and L{\'{e}}vy, M and Smith, K S},
doi = {10.1029/2018GL081631},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Arabian Gulf,Arabian Sea,Persian Gulf,climate change,marginal seas,oxygen minimum zones},
month = {may},
number = {10},
pages = {5420--5429},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Strong Intensification of the Arabian Sea Oxygen Minimum Zone in Response to Arabian Gulf Warming}},
url = {https://doi.org/10.1029/2018GL081631},
volume = {46},
year = {2019}
}
@article{amt-8-1819-2015,
author = {Ladst{\"{a}}dter, F and Steiner, A K and Schw{\"{a}}rz, M and Kirchengast, G},
doi = {10.5194/amt-8-1819-2015},
journal = {Atmospheric Measurement Techniques},
number = {4},
pages = {1819--1834},
title = {{Climate intercomparison of GPS radio occultation, RS90/92 radiosondes and GRUAN from 2002 to 2013}},
url = {https://www.atmos-meas-tech.net/8/1819/2015/},
volume = {8},
year = {2015}
}
@article{Lambeck15296,
author = {Lambeck, Kurt and Rouby, H{\'{e}}l{\`{e}}ne and Purcell, Anthony and Sun, Yiying and Sambridge, Malcolm},
doi = {10.1073/pnas.1411762111},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {43},
pages = {15296--15303},
publisher = {National Academy of Sciences},
title = {{Sea level and global ice volumes from the Last Glacial Maximum to the Holocene}},
url = {https://www.pnas.org/content/111/43/15296},
volume = {111},
year = {2014}
}
@article{doi:10.1002/2015GL064250,
abstract = {Abstract Mineral dust aerosols play a major role in present and past climates. To date, we rely on climate models for estimates of dust fluxes to calculate the impact of airborne micronutrients on biogeochemical cycles. Here we provide a new global dust flux data set for Holocene and Last Glacial Maximum (LGM) conditions based on observational data. A comparison with dust flux simulations highlights regional differences between observations and models. By forcing a biogeochemical model with our new data set and using this model's results to guide a millennial-scale Earth System Model simulation, we calculate the impact of enhanced glacial oceanic iron deposition on the LGM-Holocene carbon cycle. On centennial timescales, the higher LGM dust deposition results in a weak reduction of {\textless}10 ppm in atmospheric CO2 due to enhanced efficiency of the biological pump. This is followed by a further {\~{}}10 ppm reduction over millennial timescales due to greater carbon burial and carbonate compensation.},
author = {Lambert, Fabrice and Tagliabue, Alessandro and Shaffer, Gary and Lamy, Frank and Winckler, Gisela and Farias, Laura and Gallardo, Laura and {De Pol-Holz}, Ricardo},
doi = {10.1002/2015GL064250},
journal = {Geophysical Research Letters},
keywords = {LGM,atmospheric CO2,carbon cycle,dust,iron fertilization,paleoclimate},
number = {14},
pages = {6014--6023},
title = {{Dust fluxes and iron fertilization in Holocene and Last Glacial Maximum climates}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015GL064250},
volume = {42},
year = {2015}
}
@article{LAMPING2020106103,
abstract = {The Amundsen Sea drainage sector of the West Antarctic Ice Sheet (WAIS) is widely regarded as a candidate for triggering potential WAIS collapse. The grounded ice sheet drains into the Amundsen Sea Embayment and is thereby buttressed by its fringing ice shelves, which have thinned at an alarming rate. Satellite-based observations additionally reveal a considerable long-term decrease in sea-ice cover in the Amundsen Sea over the last two decades although the long-term significance of this trend is unclear due to the short instrumental record since the 1970s. In this context, investigations of past sea-ice conditions are crucial for improving our understanding of the influence that sea-ice variability has on the adjacent marine environment as well as any role it plays in modulating ice shelf and ice sheet dynamics. In this study, we apply novel organic geochemical biomarker techniques to a marine sediment core from the western Amundsen Sea shelf in order to provide a valuable long-term perspective on sea-ice conditions and the retreat of the Getz Ice Shelf during the last deglaciation. We analysed a specific biomarker lipid called IPSO25 alongside a phytoplankton biomarker and sedimentological parameters and additionally applied diatom transfer functions for reconstructing palaeo sea-ice coverage. This multi-proxy data set reveals a dynamic behaviour of the Getz Ice Shelf and sea-ice cover during the deglaciation following the last ice age, with potential linkages to inter-hemispheric seesaw climate patterns. We further apply and evaluate the recently proposed PIPSO25 approach for semi-quantitative sea-ice reconstructions and discuss potential limitations.},
author = {Lamping, Nele and M{\"{u}}ller, Juliane and Esper, Oliver and Hillenbrand, Claus-Dieter and Smith, James A and Kuhn, Gerhard},
doi = {10.1016/j.quascirev.2019.106103},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Antarctica,HBIs,IPSO,Marine biomarkers,Palaeoclimatology,Quaternary,Sea ice,West Antarctic Ice Sheet},
pages = {106103},
title = {{Highly branched isoprenoids reveal onset of deglaciation followed by dynamic sea-ice conditions in the western Amundsen Sea, Antarctica}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379119306535},
volume = {228},
year = {2020}
}
@article{Lamy403,
abstract = {Dust deposition in the Southern Ocean constitutes a critical modulator of past global climate variability, but how it has varied temporally and geographically is underdetermined. Here, we present data sets of glacial-interglacial dust-supply cycles from the largest Southern Ocean sector, the polar South Pacific, indicating three times higher dust deposition during glacial periods than during interglacials for the past million years. Although the most likely dust source for the South Pacific is Australia and New Zealand, the glacial-interglacial pattern and timing of lithogenic sediment deposition is similar to dust records from Antarctica and the South Atlantic dominated by Patagonian sources. These similarities imply large-scale common climate forcings, such as latitudinal shifts of the southern westerlies and regionally enhanced glaciogenic dust mobilization in New Zealand and Patagonia.The effect of windblown dust on marine productivity in the Southern Ocean is thought to be a key determinant of atmospheric CO2 concentrations. Lamy et al. (p. 403) present a record of dust supply to the Pacific sector of the Southern Ocean for the past one million years, derived from a suite of deep-sea sediment cores. Dust deposition during glacial periods was 3 times greater than during interglacials, and its major source region was probably Australia or New Zealand.},
author = {Lamy, F and Gersonde, R and Winckler, G and Esper, O and Jaeschke, A and Kuhn, G and Ullermann, J and Martinez-Garcia, A and Lambert, F and Kilian, R},
doi = {10.1126/science.1245424},
issn = {0036-8075},
journal = {Science},
month = {jan},
number = {6169},
pages = {403--407},
publisher = {American Association for the Advancement of Science},
title = {{Increased Dust Deposition in the Pacific Southern Ocean During Glacial Periods}},
url = {http://science.sciencemag.org/content/343/6169/403 https://www.sciencemag.org/lookup/doi/10.1126/science.1245424},
volume = {343},
year = {2014}
}
@article{Lamy2015,
abstract = {The Drake Passage (DP) represents the most important oceanic gateway along the pathway of the world's largest current: the Antarctic Circumpolar Current (ACC). Resolving changes in the flow of circumpolar water masses through the DP is crucial for advancing our understanding of the Southern Ocean's role in affecting ocean and climate change on a global scale. We reconstruct current intensity from marine sediment records around the southern tip of South America with unprecedented millennial-scale resolution covering the past ∼65,000 y. For the last glacial period, we infer intervals of strong weakening of the ACC entering the DP, implying an enhanced export of northern ACC surface and intermediate waters into the South Pacific Gyre and reduced Pacific–Atlantic exchange through the cold water route.The Drake Passage (DP) is the major geographic constriction for the Antarctic Circumpolar Current (ACC) and exerts a strong control on the exchange of physical, chemical, and biological properties between the Atlantic, Pacific, and Indian Ocean basins. Resolving changes in the flow of circumpolar water masses through this gateway is, therefore, crucial for advancing our understanding of the Southern Ocean's role in global ocean and climate variability. Here, we reconstruct changes in DP throughflow dynamics over the past 65,000 y based on grain size and geochemical properties of sediment records from the southernmost continental margin of South America. Combined with published sediment records from the Scotia Sea, we argue for a considerable total reduction of DP transport and reveal an up to ∼40{\%} decrease in flow speed along the northernmost ACC pathway entering the DP during glacial times. Superimposed on this long-term decrease are high-amplitude, millennial-scale variations, which parallel Southern Ocean and Antarctic temperature patterns. The glacial intervals of strong weakening of the ACC entering the DP imply an enhanced export of northern ACC surface and intermediate waters into the South Pacific Gyre and reduced Pacific–Atlantic exchange through the DP (“cold water route”). We conclude that changes in DP throughflow play a critical role for the global meridional overturning circulation and interbasin exchange in the Southern Ocean, most likely regulated by variations in the westerly wind field and changes in Antarctic sea ice extent.},
author = {Lamy, Frank and Arz, Helge W and Kilian, Rolf and Lange, Carina B and Lembke-Jene, Lester and Wengler, Marc and Kaiser, J{\'{e}}r{\^{o}}me and Baeza-Urrea, Oscar and Hall, Ian R and Harada, Naomi and Tiedemann, Ralf},
doi = {10.1073/pnas.1509203112},
journal = {Proceedings of the National Academy of Sciences},
month = {nov},
number = {44},
pages = {13496},
title = {{Glacial reduction and millennial-scale variations in Drake Passage throughflow}},
url = {http://www.pnas.org/content/112/44/13496.abstract},
volume = {112},
year = {2015}
}
@article{Lamy2010,
author = {Lamy, F. and Kilian, R. and Arz, H. W. and Francois, J. P. and Kaiser, J. and Prange, M. and Steinke, T.},
doi = {10.1038/ngeo959},
journal = {Nature Geoscience},
number = {10},
pages = {695--699},
title = {{Holocene changes in the position and intensity of the southern westerly wind belt}},
volume = {3},
year = {2010}
}
@incollection{Langematz2018,
address = {Geneva, Switzerland},
author = {Langematz, U. and Tully, M. and Calvo, N. and Dameris, M. and de Laat, J. and Klekociuk, A. and M{\"{u}}ller, R. and Young, P.},
booktitle = {Scientific Assessment of Ozone Depletion: 2018},
pages = {4.1--4.63},
series = {Global Ozone Research and Monitoring Project – Report No. 58},
title = {{Polar Stratospheric Ozone: Past, Present and Future}},
url = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
year = {2018}
}
@article{Lapointe2017a,
abstract = {Abstract. Understanding how internal climate variability influences arctic regions is required to better forecast future global climate variations. This paper investigates an annually-laminated (varved) record from the western Canadian Arctic and finds that the varves are negatively correlated with both the instrumental Pacific Decadal Oscillation (PDO) during the past century and also with reconstructed PDO over the past 700 years, suggesting drier Arctic conditions during high-PDO phases, and vice versa. These results are in agreement with known regional teleconnections, whereby the PDO is negatively and positively correlated with summer precipitation and mean sea level pressure respectively. This pattern is also evident during the positive phase of the North Pacific Index (NPI) in autumn. Reduced sea-ice cover during summer–autumn is observed in the region during PDO− (NPI+) and is associated with low-level southerly winds that originate from the northernmost Pacific across the Bering Strait and can reach as far as the western Canadian Arctic. These climate anomalies are associated with the PDO− (NPI+) phase and are key factors in enhancing evaporation and subsequent precipitation in this region of the Arctic. Collectively, the sedimentary evidence suggests that North Pacific climate variability has been a persistent regulator of the regional climate in the western Canadian Arctic. Since projected sea-ice loss will contribute to enhanced future warming in the Arctic, future negative phases of the PDO (or NPI+) will likely act to amplify this positive feedback.},
author = {Lapointe, Fran{\c{c}}ois and Francus, Pierre and Lamoureux, Scott F. and Vuille, Mathias and Jenny, Jean-Philippe and Bradley, Raymond S. and Massa, Charly},
doi = {10.5194/cp-13-411-2017},
isbn = {1843761300},
issn = {1814-9332},
journal = {Climate of the Past},
month = {apr},
number = {4},
pages = {411--420},
title = {{Influence of North Pacific decadal variability on the western Canadian Arctic over the past 700 years}},
url = {https://cp.copernicus.org/articles/13/411/2017/},
volume = {13},
year = {2017}
}
@article{LARSEN2014310,
abstract = {The possible demise of the Greenland ice sheet and its effect on global sea level rank among the most serious climate threats to society. To improve our knowledge about the future behaviour of the ice margin, we studied the ice sheet's response to early Holocene warming in West Greenland using 47 cosmogenic 10Be exposure ages, 26 optically-stimulated luminescence ages as well as 15 new and 28 previously published radiocarbon ages. Paired bedrock and boulder ages show that the entire area was covered by warm-based ice during the Last Glacial Maximum (LGM), although glacial erosion was insufficient to completely remove the upper rock surface containing 10Be inherited from a previous period of exposure in bedrock samples above an elevation of 800 m. Our compilation of 10Be and 14C ages demonstrates that the ice sheet retreated from the outer-coast to the present ice margin between c. 11.4 and 10.4 cal. ka BP in the Godth{\aa}bsfjord system and between 10.7 ± 0.6 and 10.1 ± 0.4 ka ago in Buksefjord, whereas the coast at Sermilik became ice free at c. 10.5 cal. ka BP. We find no significant changes in the retreat rates between the deep Godth{\aa}bsfjord system and the Buksefjord-Sermilik region, which is characterized by only a few narrow and shallow fjords. However, deglaciation was initiated c. 700–900 years earlier in the Godth{\aa}bsfjord system indicating that the deep fjords probably triggered land-based deglaciation by dynamic ice loss leading to an overall rapid early Holocene ice retreat and drawdown of the ice sheet in West Greenland. These results demonstrate that even if there was a topographic control on the onset of deglaciation, fast ice retreat is not restricted to deep fjord systems but may occur independently of the topographic setting.},
annote = {APEX II: Arctic Palaeoclimate and its Extremes},
author = {Larsen, Nicolaj K and Funder, Svend and Kj{\ae}r, Kurt H and Kjeldsen, Kristian K and Knudsen, Mads F and Linge, Henriette},
doi = {10.1016/j.quascirev.2013.05.027},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Cosmogenic surface exposure dating,Early Holocene,Greenland ice sheet,Ice retreat},
pages = {310--323},
title = {{Rapid early Holocene ice retreat in West Greenland}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379113002163},
volume = {92},
year = {2014}
}
@article{10.1130/G36476.1,
abstract = {To determine the long-term sensitivity of the Greenland ice sheet to a warmer climate, we explored how it responded to the Holocene thermal maximum (8–5 cal. kyr B.P.; calibrated to calendar years before present, i.e., A.D. 1950), when lake records show that local atmospheric temperatures in Greenland were 2–4 °C warmer than the present. Records from five new threshold lakes complemented with existing geological data from south of 70°N show that the ice margin was retracted behind its present-day extent in all sectors for a limited period between ca. 7 and 4 cal. kyr B.P. and in most sectors from ca. 1.5 to 1 cal. kyr B.P., in response to higher atmospheric and ocean temperatures. Ice sheet simulations constrained by observations show good correlation with the timing of minimum ice volume indicated by the threshold lake observations; the simulated volume reduction suggests a minimum contribution of 0.16 m sea-level equivalent from the entire Greenland ice sheet, with a centennial ice loss rate of as much as 100 Gt/yr for several millennia during the Holocene thermal maximum. Our results provide an estimate of the long-term rates of volume loss that can be expected in the future as regional air and ocean temperatures approach those reconstructed for the Holocene thermal maximum.},
author = {Larsen, Nicolaj K and Kj{\ae}r, Kurt H and Lecavalier, Benoit and Bj{\o}rk, Anders A and Colding, Sune and Huybrechts, Philippe and Jakobsen, Karina E and Kjeldsen, Kristian K and Knudsen, Karen-Luise and Odgaard, Bent V and Olsen, Jesper},
doi = {10.1130/G36476.1},
issn = {0091-7613},
journal = {Geology},
number = {4},
pages = {291--294},
title = {{The response of the southern Greenland ice sheet to the Holocene thermal maximum}},
url = {https://doi.org/10.1130/G36476.1},
volume = {43},
year = {2015}
}
@article{Lasher2019,
abstract = {Recent work has documented glacier advances in West Greenland coincident with the Medieval Climate Anomaly (MCA) and warmth across much of northern Europe. The North Atlantic Oscillation (NAO) has been invoked to explain antiphasing of temperatures between these North Atlantic regions. Historical and model observations suggest negative correlation between the mode of NAO and both temperature and $\delta$18O values of precipitation over much of Greenland. We test for a hypothesized positive NAO mode and associated cool conditions during the MCA in South Greenland within the Norse Eastern Settlement by reconstructing $\delta$18O values of precipitation at subcentennial resolution over the past 3000 yr using aquatic insect subfossils preserved in lake sediments. More positive $\delta$18O values are found between 900 and 1400 CE, indicating a period of warmth in South Greenland superimposed on late Holocene insolation-forced Neoglacial cooling, and thus not supporting a positive NAO anomaly during the MCA. Highly variable $\delta$18O values record an unstable climate at the end of the MCA, preceding Norse abandonment of Greenland. The spatial pattern of paleoclimate in this region supports proposals that North Atlantic subpolar ocean currents modulated South Greenland's climate over the past 3000 yr, particularly during the MCA. Terrestrial climate in the Labrador Sea and Baffin Bay regions may be spatially heterogeneous on centennial time scales due in part to the influence of the subpolar gyre.},
author = {Lasher, G. Everett and Axford, Yarrow},
doi = {10.1130/G45833.1},
issn = {19432682},
journal = {Geology},
number = {3},
pages = {267--270},
title = {{Medieval warmth confirmed at the Norse Eastern Settlement in Greenland}},
volume = {47},
year = {2019}
}
@article{Laskar2011,
author = {Laskar, J. and Fienga, A. and Gastineau, M. and Manche, H.},
doi = {10.1051/0004-6361/201116836},
issn = {0004-6361},
journal = {Astronomy {\&} Astrophysics},
month = {aug},
pages = {A89},
title = {{La2010: a new orbital solution for the long-term motion of the Earth}},
url = {http://www.aanda.org/10.1051/0004-6361/201116836},
volume = {532},
year = {2011}
}
@article{Laube2014,
abstract = {Ozone-depleting substances emitted through human activities cause large-scale damage to the stratospheric ozone layer, and influence global climate. Consequently, the production of many of these substances has been phased out; prominent examples are the chlorofluorocarbons (CFCs), and their intermediate replacements, the hydrochlorofluorocarbons (HCFCs). So far, seven types of CFC and six types of HCFC have been shown to contribute to stratospheric ozone destruction. Here, we report the detection and quantification of a further three CFCs and one HCFC. We analysed the composition of unpolluted air samples collected in Tasmania between 1978 and 2012, and extracted from deep firn snow in Greenland in 2008, using gas chromatography with mass spectrometric detection. Using the firn data, we show that all four compounds started to emerge in the atmosphere in the 1960s. Two of the compounds continue to accumulate in the atmosphere. We estimate that, before 2012, emissions of all four compounds combined amounted to more than 74,000 tonnes. This is small compared with peak emissions of other CFCs in the 1980s of more than one million tonnes each year. However, the reported emissions are clearly contrary to the intentions behind the Montreal Protocol, and raise questions about the sources of these gases. {\textcopyright} 2014 Macmillan Publishers Limited. All rights reserved.},
author = {Laube, Johannes C. and Newland, Mike J. and Hogan, Christopher and Brenninkmeijer, Carl A.M. and Fraser, Paul J. and Martinerie, Patricia and Oram, David E. and Reeves, Claire E. and R{\"{o}}ckmann, Thomas and Schwander, Jakob and Witrant, Emmanuel and Sturges, William T.},
doi = {10.1038/ngeo2109},
issn = {17520908},
journal = {Nature Geoscience},
pages = {266--269},
title = {{Newly detected ozone-depleting substances in the atmosphere}},
volume = {7},
year = {2014}
}
@article{Lauvset2015,
author = {Lauvset, S K and Gruber, N and Landsch{\"{u}}tzer, P and Olsen, A and Tjiputra, J},
doi = {10.5194/bg-12-1285-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {5},
pages = {1285--1298},
publisher = {Copernicus Publications},
title = {{Trends and drivers in global surface ocean pH over the past 3 decades}},
url = {https://www.biogeosciences.net/12/1285/2015/ https://www.biogeosciences.net/12/1285/2015/bg-12-1285-2015.pdf},
volume = {12},
year = {2015}
}
@article{Lauvset2020,
abstract = {Abstract Ocean acidification evolves on the background of a natural ocean pH gradient that is the result of the interplay between ocean mixing, biological production and remineralization, calcium carbonate cycling, and temperature and pressure changes across the water column. While previous studies have analyzed these processes and their impacts on ocean carbonate chemistry, none have attempted to quantify their impacts on interior ocean pH globally. Here we evaluate how anthropogenic changes and natural processes collectively act on ocean pH, and how these processes set the vulnerability of regions to future changes in ocean acidification. We use the mapped data product from the Global Ocean Data Analysis Project version 2, a novel method to estimate preformed total alkalinity based on a combination of a total matrix intercomparison and locally interpolated regressions, and a comprehensive uncertainty analysis. We find that the largest contribution to the interior ocean pH gradient comes from organic matter remineralization, with CaCO3 cycling being the second most important process. The estimates of the impact of anthropogenic CO2 changes on pH reaffirm the large and well-understood anthropogenic impact on pH in the surface ocean, and put it in the context of the natural pH gradient in the interior ocean. We also show that in the depth layer 500?1,500 m natural processes enhance ocean acidification by on average 28 ± 15{\%}, but with large regional gradients.},
annote = {doi: 10.1029/2019GB006229},
author = {Lauvset, S K and Carter, B R and P{\`{e}}rez, F F and Jiang, L.-Q. and Feely, R A and Velo, A and Olsen, A},
doi = {10.1029/2019GB006229},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {CaCO3,anthropogenic,global ocean,pH,remineralization},
month = {jan},
number = {1},
pages = {e2019GB006229},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Processes Driving Global Interior Ocean pH Distribution}},
url = {https://doi.org/10.1029/2019GB006229},
volume = {34},
year = {2020}
}
@article{Lawrence2016,
abstract = {Human land-use activities have resulted in large changes to the Earth's surface, with resulting implications for climate. In the future, land-use activities are likely to expand and intensify further to meet growing demands for food, fiber, and energy. The Land Use Model Intercomparison Project (LUMIP) aims to further advance understanding of the impacts of land-use and land-cover change (LULCC) on climate, specifically addressing the following questions. (1) What are the effects of LULCC on climate and biogeochemical cycling (past-future)? (2) What are the impacts of land management on surface fluxes of carbon, water, and energy, and are there regional land-management strategies with the promise to help mitigate climate change? In addressing these questions, LUMIP will also address a range of more detailed science questions to get at process-level attribution, uncertainty, data requirements, and other related issues in more depth and sophistication than possible in a multi-model context to date. There will be particular focus on the separation and quantification of the effects on climate from LULCC relative to all forcings, separation of biogeochemical from biogeophysical effects of land use, the unique impacts of land-cover change vs. land-management change, modulation of land-use impact on climate by land-atmosphere coupling strength, and the extent to which impacts of enhanced CO2 concentrations on plant photosynthesis are modulated by past and future land use.LUMIP involves three major sets of science activities: (1) development of an updated and expanded historical and future land-use data set, (2) an experimental protocol for specific LUMIP experiments for CMIP6, and (3) definition of metrics and diagnostic protocols that quantify model performance, and related sensitivities, with respect to LULCC. In this paper, we describe LUMIP activity (2), i.e., the LUMIP simulations that will formally be part of CMIP6. These experiments are explicitly designed to be complementary to simulations requested in the CMIP6 DECK and historical simulations and other CMIP6 MIPs including ScenarioMIP, C4MIP, LS3MIP, and DAMIP. LUMIP includes a two-phase experimental design. Phase one features idealized coupled and land-only model simulations designed to advance process-level understanding of LULCC impacts on climate, as well as to quantify model sensitivity to potential land-cover and land-use change. Phase two experiments focus on quantification of the historic impact of land use and the potential for future land management decisions to aid in mitigation of climate change. This paper documents these simulations in detail, explains their rationale, outlines plans for analysis, and describes a new subgrid land-use tile data request for selected variables (reporting model output data separately for primary and secondary land, crops, pasture, and urban land-use types). It is essential that modeling groups participating in LUMIP adhere to the experimental design as closely as possible and clearly report how the model experiments were executed.},
author = {Lawrence, David M. and Hurtt, George C. and Arneth, Almut and Brovkin, Victor and Calvin, Kate V. and Jones, Andrew D. and Jones, Chris D. and Lawrence, Peter J. and Noblet-Ducoudr{\'{e}}, Nathalie De and Pongratz, Julia and Seneviratne, Sonia I. and Shevliakova, Elena},
doi = {10.5194/gmd-9-2973-2016},
issn = {19919603},
journal = {Geoscientific Model Development},
number = {9},
pages = {2973--2998},
title = {{The Land Use Model Intercomparison Project (LUMIP) contribution to CMIP6: Rationale and experimental design}},
volume = {9},
year = {2016}
}
@article{Laxon2013,
abstract = {Satellite records show a decline in ice extent over more than three decades, with a record minimum in September 2012. Results from the Pan-Arctic Ice-Ocean Modelling and Assimilation system (PIOMAS) suggest that the decline in extent has been accompanied by a decline in volume, but this has not been confirmed by data. Using new data from the European Space Agency CryoSat-2 (CS-2) mission, validated with in situ data, we generate estimates of ice volume for the winters of 2010/11 and 2011/12. We compare these data with current estimates from PIOMAS and earlier (2003-8) estimates from the National Aeronautics and Space Administration ICESat mission. Between the ICESat and CryoSat-2 periods, the autumn volume declined by 4291 km3 and the winter volume by 1479 km3. This exceeds the decline in ice volume in the central Arctic from the PIOMAS model of 2644 km3 in the autumn, but is less than the 2091 km3 in winter, between the two time periods. Key Points CryoSat-2 can provide accurate pan-Arctic measurements of sea ice thickness The data show a decrease in sea ice volume over the last decade This is the first observational evidence to confirm the decline from models {\textcopyright}2013. American Geophysical Union. All Rights Reserved.},
author = {Laxon, Seymour W. and Giles, Katharine A. and Ridout, Andy L. and Wingham, Duncan J. and Willatt, Rosemary and Cullen, Robert and Kwok, Ron and Schweiger, Axel and Zhang, Jinlun and Haas, Christian and Hendricks, Stefan and Krishfield, Richard and Kurtz, Nathan and Farrell, Sinead and Davidson, Malcolm},
doi = {10.1002/grl.50193},
isbn = {0094-8276},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Altimetry,CryoSat,Sea Ice,Volume},
month = {feb},
number = {4},
pages = {732--737},
title = {{CryoSat-2 estimates of Arctic sea ice thickness and volume}},
url = {http://doi.wiley.com/10.1002/grl.50193},
volume = {40},
year = {2013}
}
@article{LeahyT.P.F.P.LlopisM.D.Palmer2018,
abstract = {Biases in expendable bathythermograph (XBT) instruments have emerged as a leading uncertainty in reconstructions of historical ocean heat content change and therefore climate change. Corrections for these biases depend on the type of XBT used; however, this is unspecified for 52{\%} of the historical XBT profiles in the World Ocean Database. Here, we use profiles of known XBT type to train a neural network that can classify probe type based on three covariates: profile date, maximum recorded depth, and country of origin. Whereas previous studies have shown an average classification skill of 77{\%}, falling below 50{\%} for some periods, our new algorithm maintains an average skill of 90{\%}, with a minimum of 70{\%}. Our study illustrates the potential for successfully applying machine learning approaches in a wide variety of instrument classification problems in order to promote more homogeneous climate data records.},
author = {Leahy, Thomas P. and Llopis, Francesc Pons and Palmer, Matthew D. and Robinson, Niall H.},
doi = {10.1175/JTECH-D-18-0012.1},
issn = {0739-0572},
journal = {Journal of Atmospheric and Oceanic Technology},
month = {oct},
number = {10},
pages = {2053--2059},
title = {{Using Neural Networks to Correct Historical Climate Observations}},
url = {https://journals.ametsoc.org/view/journals/atot/35/10/jtech-d-18-0012.1.xml},
volume = {35},
year = {2018}
}
@article{doi:10.1002/2017EA000357,
abstract = {Abstract Solar total and spectral irradiance are estimated from 850 to 1610 by regressing cosmogenic irradiance indices against the National Oceanic and Atmospheric Administration Solar Irradiance Climate Data Record after 1610. The new estimates differ from those recommended for use in the Paleoclimate Model Intercomparison Project (PMIP4) in the magnitude of multidecadal irradiance changes, spectral distribution of the changes, and amplitude and phasing of the 11-year activity cycle. The new estimates suggest that total solar irradiance increased 0.036 ± 0.009{\%} from the Maunder Minimum (1645–1715) to the Medieval Maximum (1100 to 1250), compared with 0.068{\%} from the Maunder Minimum to the Modern Maximum (1950–2009). PMIP4's corresponding increases are 0.026{\%} and 0.055{\%}, respectively. Multidecadal irradiance changes in the new estimates are comparable in magnitude to the PMIP4 recommendations in the ultraviolet spectrum (100–400 nm) but somewhat larger at visible (400–700 nm) and near-infrared (700–1,000 nm) wavelengths; the new estimates suggest increases from the Maunder Minimum to the Medieval Maximum of 0.17 ± 0.04{\%}, 0.030 ± 0.008{\%}, and 0.036 ± 0.009{\%} in the ultraviolet, visible, and near-infrared spectral regions, respectively, compared with PMIP4 increases of 0.17{\%}, 0.021{\%}, and 0.016{\%}. The uncertainties are 1$\sigma$ estimates accruing from the statistical procedures that reconstruct irradiance in the Medieval Maximum relative to the Modern Maximum, not from the specification of Modern Maximum irradiances per se. In the new estimates, solar irradiance cycle amplitudes in the Medieval Maximum are comparable to those in the Modern Maximum, whereas in the PMIP4 reconstruction they are at times almost a factor of 2 larger at some wavelengths and differ also in phase.},
author = {Lean, J L},
doi = {10.1002/2017EA000357},
journal = {Earth and Space Science},
keywords = {natural climate forcing,preindustrial millennium,solar irradiance},
number = {4},
pages = {133--149},
title = {{Estimating Solar Irradiance Since 850 CE}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017EA000357},
volume = {5},
year = {2018}
}
@article{LECAVALIER201454,
abstract = {An ice sheet model was constrained to reconstruct the evolution of the Greenland Ice Sheet (GrIS) from the Last Glacial Maximum (LGM) to present to improve our understanding of its response to climate change. The study involved applying a glaciological model in series with a glacial isostatic adjustment and relative sea-level (RSL) model. The model reconstruction builds upon the work of Simpson et al. (2009) through four main extensions: (1) a larger constraint database consisting of RSL and ice extent data; model improvements to the (2) climate and (3) sea-level forcing components; (4) accounting for uncertainties in non-Greenland ice. The research was conducted primarily to address data-model misfits and to quantify inherent model uncertainties with the Earth structure and non-Greenland ice. Our new model (termed Huy3) fits the majority of observations and is characterised by a number of defining features. During the LGM, the ice sheet had an excess of 4.7 m ice-equivalent sea-level (IESL), which reached a maximum volume of 5.1 m IESL at 16.5 cal ka BP. Modelled retreat of ice from the continental shelf progressed at different rates and timings in different sectors. Southwest and Southeast Greenland began to retreat from the continental shelf by ∼16 to 14 cal ka BP, thus responding in part to the B{\o}lling-Aller{\o}d warm event (c. 14.5 cal ka BP); subsequently ice at the southern tip of Greenland readvanced during the Younger Dryas cold event. In northern Greenland the ice retreated rapidly from the continental shelf upon the climatic recovery out of the Younger Dryas to present-day conditions. Upon entering the Holocene (11.7 cal ka BP), the ice sheet soon became land-based. During the Holocene Thermal Maximum (HTM; 9-5 cal ka BP), air temperatures across Greenland were marginally higher than those at present and the GrIS margin retreated inland of its present-day southwest position by 40–60 km at 4 cal ka BP which produced a deficit volume of 0.16 m IESL relative to present. In response to the HTM warmth, our optimal model reconstruction lost mass at a maximum centennial rate of c. 103.4 Gt/yr. Our results suggest that remaining data-model discrepancies are affiliated with missing physics and sub-grid processes of the glaciological model, uncertainties in the climate forcing, lateral Earth structure, and non-Greenland ice (particularly the North American component). Finally, applying the Huy3 Greenland reconstruction with our optimal Earth model we generate present-day uplift rates across Greenland due to past changes in the ocean and ice loads with explicit error bars due to uncertainties in the Earth structure. Present-day uplift rates due to past changes are spatially variable and range from 3.5 to −7 mm/a (including Earth model uncertainty).},
author = {Lecavalier, Benoit S and Milne, Glenn A and Simpson, Matthew J R and Wake, Leanne and Huybrechts, Philippe and Tarasov, Lev and Kjeldsen, Kristian K and Funder, Svend and Long, Antony J and Woodroffe, Sarah and Dyke, Arthur S and Larsen, Nicolaj K},
doi = {10.1016/j.quascirev.2014.07.018},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Deglaciation,Geological data,Glacial isostatic adjustment,Glacialogical model,Greenland ice sheet,Ice sheet reconstruction,Relative sea level},
pages = {54--84},
title = {{A model of Greenland ice sheet deglaciation constrained by observations of relative sea level and ice extent}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379114003011},
volume = {102},
year = {2014}
}
@article{Lechleitner2017,
abstract = {The presence of a low-to mid-latitude interhemispheric hydrologic seesaw is apparent over orbital and glacial-interglacial timescales, but its existence over the most recent past remains unclear. Here we investigate, based on climate proxy reconstructions from both hemispheres, the inter-hemispherical phasing of the Intertropical Convergence Zone (ITCZ) and the low-to mid-latitude teleconnections in the Northern Hemisphere over the past 2000 years. A clear feature is a persistent southward shift of the ITCZ during the Little Ice Age until the beginning of the 19th Century. Strong covariation between our new composite ITCZ-stack and North Atlantic Oscillation (NAO) records reveals a tight coupling between these two synoptic weather and climate phenomena over decadal-to-centennial timescales. This relationship becomes most apparent when comparing two precisely dated, high-resolution paleorainfall records from Belize and Scotland, indicating that the low-to mid-latitude teleconnection was also active over annual-decadal timescales. It is likely a combination of external forcing, i.e., solar and volcanic, and internal feedbacks, that drives the synchronous ITCZ and NAO shifts via energy flux perturbations in the tropics.},
author = {Lechleitner, Franziska A. and Breitenbach, Sebastian F.M. and Rehfeld, Kira and Ridley, Harriet E. and Asmerom, Yemane and Prufer, Keith M. and Marwan, Norbert and Goswami, Bedartha and Kennett, Douglas J. and Aquino, Valorie V. and Polyak, Victor and Haug, Gerald H. and Eglinton, Timothy I. and Baldini, James U.L.},
doi = {10.1038/srep45809},
issn = {20452322},
journal = {Scientific Reports},
number = {March},
pages = {1--9},
pmid = {28378755},
publisher = {Nature Publishing Group},
title = {{Tropical rainfall over the last two millennia: Evidence for a low-latitude hydrologic seesaw}},
volume = {7},
year = {2017}
}
@article{cp-9-307-2013,
author = {Ledru, M.-P. and Jomelli, V and Samaniego, P and Vuille, M and Hidalgo, S and Herrera, M and Ceron, C},
doi = {10.5194/cp-9-307-2013},
journal = {Climate of the Past},
number = {1},
pages = {307--321},
title = {{The Medieval Climate Anomaly and the Little Ice Age in the eastern Ecuadorian Andes}},
url = {https://www.clim-past.net/9/307/2013/},
volume = {9},
year = {2013}
}
@article{doi:10.1029/2008PA001701,
abstract = {Changes in El Ni{\~{n}}o–Southern Oscillation (ENSO) variability are difficult to extract from paleoceanographic reconstructions because they are superimposed on changes in seasonal variability that modulate the first-order climate signal. Here we address this problem by reconstructing thermocline structure from a marine sediment core retrieved from the eastern equatorial Pacific. At the core location, changes in hydrologic parameters within the thermocline are linked to ENSO activity, with a reduced influence of seasonal variability compared to surface waters. We performed repeated isotopic analyses ($\delta$18O) on single specimens of the thermocline-dwelling planktonic foraminifera Neogloboquadrina dutertrei at several targeted time periods over the last 50 ka to extract the total thermocline variance, a parameter supposed to reveal changes in ENSO. No fundamental changes in amplitude and frequency of the events were detected despite differences in climatic background. However, our data suggest that long-term variations in the thermocline variability occurred over the last 50 ka, with the highest and lowest ENSO activities occurring during the last glacial period and the Last Glacial Maximum, respectively.},
author = {Leduc, Guillaume and Vidal, Laurence and Cartapanis, Olivier and Bard, Edouard},
doi = {10.1029/2008PA001701},
journal = {Paleoceanography},
keywords = {El Ni{\~{n}}o–Southern Oscillation,last glacial period,thermocline variability},
number = {3},
pages = {PA3202},
title = {{Modes of eastern equatorial Pacific thermocline variability: Implications for ENSO dynamics over the last glacial period}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2008PA001701},
volume = {24},
year = {2009}
}
@article{Lee2018,
abstract = {Using historical simulations of the Coupled Model Intercomparison Project-5 (CMIP5) and multiple observationally-based datasets, we employ skill metrics to analyze the fidelity of the simulated Northern Annular Mode, the North Atlantic Oscillation, the Pacific North America pattern, the Southern Annular Mode, the Pacific Decadal Oscillation, the North Pacific Oscillation, and the North Pacific Gyre Oscillation. We assess the benefits of a unified approach to evaluate these modes of variability, which we call the common basis function (CBF) approach, based on projecting model anomalies onto observed empirical orthogonal functions (EOFs). The CBF approach circumvents issues with conventional EOF analysis, eliminating, for example, corrections of arbitrarily assigned, but inconsistent, signs of the EOF's/PC's being compared. It also avoids the problem that sometimes the first observed EOF is more similar to a higher order model EOF, particularly if the simulated EOFs are not well separated. Compared to conventional EOF analysis of models, the CBF approach indicates that models compare significantly better with observations in terms of pattern correlation and root-mean-squared-error (RMSE) than heretofore suggested. In many cases, models are doing a credible job at capturing the observationally-based estimates of patterns; however, errors in simulated amplitudes can be large and more egregious than pattern errors. In the context of the broad distribution of errors in the CMIP5 ensemble, sensitivity tests demonstrate that our results are relatively insensitive to methodological considerations (CBF vs. conventional approach), observational uncertainties in pattern (as determined by using multiple datasets), and internal variability (when multiple realizations from the same model are compared). The skill metrics proposed in this study can provide a useful summary of the ability of models to reproduce the observed EOF patterns and amplitudes. Additionally, the skill metrics can be used as a tool to objectively highlight where potential model improvements might be made. We advocate more systematic and objective testing of simulated extratropical variability, especially during the non-dominant seasons of each mode, when many models are performing relatively poorly.},
author = {Lee, Jiwoo and Sperber, Kenneth R. and Gleckler, Peter J. and Bonfils, C{\'{e}}line J.W. and Taylor, Karl E.},
doi = {10.1007/s00382-018-4355-4},
isbn = {0123456789},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {CMIP5 model evaluation,Common basis function,EOF,Metrics,Modes of variability},
pages = {4057--4089},
publisher = {Springer Berlin Heidelberg},
title = {{Quantifying the agreement between observed and simulated extratropical modes of interannual variability}},
url = {http://dx.doi.org/10.1007/s00382-018-4355-4},
volume = {52},
year = {2019}
}
@article{doi:10.1175/JCLI-D-15-0154.1,
abstract = {AbstractTwo dominant global-scale teleconnections—namely, western North Pacific–North American (WPNA) and circumglobal teleconnection (CGT)—in the Northern Hemisphere (NH) extratropics during boreal summer (June–August) have been identified as important sources for NH summer climate variability and predictability. An interdecadal shift in interannual variability and predictability of the WPNA and CGT that occurred around the late 1970s was investigated using reanalysis data and six coupled models' retrospective forecast with a 1 May initial condition for the period 1960–79 (P1) and 1980–2005 (P2). The WPNA had a tight relationship with the decaying phase of El Ni{\~{n}}o–Southern Oscillation (ENSO) in P1, whereas it had a remarkably enhanced linkage with western North Pacific (WNP) summer monsoon rainfall in P2. The correlation coefficient between the WPNA and preceding ENSO (WNP monsoon rainfall) was reduced (increased) from −0.69 (0.1) in P1 to −0.60 (0.5) in P2. The CGT had a considerable connection with Indian summer monsoon rainfall (ISMR) in P1, whereas it had a strengthened relationship with the developing ENSO in P2. The correlation coefficient between the CGT and simultaneous ENSO (ISMR) was increased (decreased) from −0.41 (0.47) in P1 to −0.59 (0.24) in P2. Although dynamical models have difficulties in capturing the observed interdecadal changes, they are able to predict the interannual variation of the WPNA and CGT one month ahead, to some extent. The prediction skill of six models' multimodel ensemble (MME) decreased (increased) from 0.78 (0.23) to 0.67 (0.67) for the WPNA (CGT) interannual variation. It is also noted that the spatial distribution of predictability and MME skill for 200-hPa geopotential height has been changed in relation to the changes in the WPNA and CGT.},
author = {Lee, June-Yi and Ha, Kyung-Ja},
doi = {10.1175/JCLI-D-15-0154.1},
journal = {Journal of Climate},
number = {21},
pages = {8634--8647},
title = {{Understanding of Interdecadal Changes in Variability and Predictability of the Northern Hemisphere Summer Tropical–Extratropical Teleconnection}},
url = {https://doi.org/10.1175/JCLI-D-15-0154.1},
volume = {28},
year = {2015}
}
@article{Lee2019,
author = {Lee, S H and William, P D and Frame, T A},
doi = {10.1038/s41586-019-1465-z},
journal = {Nature},
pages = {639--643},
title = {{Increased shear in the North Atlantic upper-level jet stream over the past four decades}},
volume = {572},
year = {2019}
}
@article{Lee2015b,
abstract = {The slow surface warming since 1998 has been linked to high ocean heat uptake. An analysis of observations and ocean model simulations suggests that the increase in Pacific heat uptake has been compensated by heat transport to the Indian Ocean.},
author = {Lee, Sang-Ki and Park, Wonsun and Baringer, Molly O and Gordon, Arnold L and Huber, Bruce and Liu, Yanyun},
doi = {10.1038/ngeo2438},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {6},
pages = {445--449},
title = {{Pacific origin of the abrupt increase in Indian Ocean heat content during the warming hiatus}},
url = {https://doi.org/10.1038/ngeo2438},
volume = {8},
year = {2015}
}
@article{LegeaisJ.-F.W.Llovel2020,
author = {Legeais, J.-F. and Llovel, W. and Melet, A. and Meyssignac, B.},
doi = {10.1080/1755876X.2020.1785097},
journal = {Journal of Operational Oceanography},
number = {sup1},
pages = {S77--S81},
title = {{Evidence of the TOPEX-A Altimeter Instrumental Anomaly and Acceleration of the Global Mean Sea Level [In “Copernicus Marine Service Ocean State Report, Issue 4”]}},
volume = {13},
year = {2020}
}
@article{LeGrande2011,
abstract = {Paleosalinity reconstructions are a goal of paleoceanographic study because of their potential to provide insight into past ocean circulation. While temperature reconstructions have been assessed by using multiple independent proxies, the skill of existing salinity reconstructions remains poorly quantified. We examine the applicability of two different approaches using a set of coupled water isotope-enabled general circulation model experiments as a numerical analog for the real climate system. These simulations for the Holocene, at roughly 1000 year time steps, explicitly track variability in both the water isotopologues and salinity. Our simulations suggest that quantitative reconstructions of past salinity variability based solely on inferred {\$}\delta{\$}18Osw variability have very large errors and uncertainties. However, we find that paired {\$}\delta{\$}18Osw and {\$}\delta{\$}D variability (from combining biomarker and calcite proxies) holds promise for providing better quantitative estimates of salinity variability. Copyright 2011 by the American Geophysical Union.},
author = {LeGrande, Allegra N and Schmidt, Gavin A},
doi = {10.1029/2010PA002043},
issn = {08838305},
journal = {Paleoceanography},
month = {sep},
number = {3},
pages = {PA3225},
title = {{Water isotopologues as a quantitative paleosalinity proxy}},
volume = {26},
year = {2011}
}
@article{Lejeune2020,
author = {Lejeune, Quentin and Davin, Edouard and Duveiller, Gr{\'{e}}gory and Crezee, Bas and Meier, Ronny and Cescatti, Alessandro and Seneviratne, Sonia},
doi = {10.5194/esd-2019-94},
issn = {2190-4979},
journal = {Earth System Dynamics},
number = {4},
pages = {1209--1232},
title = {{Biases in the albedo sensitivity to deforestation in CMIP5 models and their impacts on the associated historical Radiative Forcing}},
volume = {11},
year = {2020}
}
@article{Lenoir2015,
abstract = {Poleward and upward shifts are the most frequent types of range shifts that have been reported in response to contemporary climate change. However, the number of reports documenting other types of range shifts – such as in east-west directions across longitudes or, even more unexpectedly, towards tropical latitudes and lower elevations – is increasing rapidly. Recent studies show that these range shifts may not be so unexpected once the local climate changes are accounted for. We here provide an updated synthesis of the fast-moving research on climate-related range shifts. By describing the current state of the art on geographical patterns of species range shifts under contemporary climate change for plants and animals across both terrestrial and marine ecosystems, we identified a number of research shortfalls. In addition to the recognised geographic shortfall in the tropics, we found taxonomic and methodological shortfalls with knowledge gaps regarding range shifts of prokaryotes, lowland range shifts of terrestrial plants, and bathymetric range shifts of marine plants. Based on this review, we provide a research agenda for filling these gaps. We outline a comprehensive framework for assessing multidimensional changes in species distributions, which should then be contrasted with expectations based on climate change indices, such as velocity measures accounting for complex local climate changes. Finally, we propose a unified classification of geographical patterns of species range shifts, arranged in a bi-dimensional space defined by species' persistence and movement rates. Placing the observed and expected shifts into this bi-dimensional space should lead to more informed assessments of extinction risks.},
author = {Lenoir, J. and Svenning, J. C.},
doi = {10.1111/ecog.00967},
isbn = {1600-0587},
issn = {16000587},
journal = {Ecography},
number = {1},
pages = {15--28},
pmid = {24998392},
title = {{Climate-related range shifts – a global multidimensional synthesis and new research directions}},
volume = {38},
year = {2015}
}
@article{Lenoir2008a,
abstract = {Spatial fingerprints of climate change on biotic communities are usually associated with changes in the distribution of species at their latitudinal or altitudinal extremes. By comparing the altitudinal distribution of 171 forest plant species between 1905 and 1985 and 1986 and 2005 along the entire elevation range (0 to 2600 meters above sea level) in west Europe, we show that climate warming has resulted in a significant upward shift in species optimum elevation averaging 29 meters per decade. The shift is larger for species restricted to mountain habitats and for grassy species, which are characterized by faster population turnover. Our study shows that climate change affects the spatial core of the distributional range of plant species, in addition to their distributional margins, as previously reported.},
author = {Lenoir, J. and G{\'{e}}gout, J. C. and Marquet, P. A. and {De Ruffray}, P. and Brisse, H.},
doi = {10.1126/science.1156831},
issn = {00368075},
journal = {Science},
pmid = {18583610},
title = {{A significant upward shift in plant species optimum elevation during the 20th century}},
year = {2008}
}
@article{Lenoir2020,
abstract = {There is mounting evidence of species redistribution as climate warms. Yet, our knowledge of the coupling between species range shifts and isotherm shifts remains limited. Here, we introduce BioShifts—a global geo-database of 30,534 range shifts. Despite a spatial imbalance towards the most developed regions of the Northern Hemisphere and a taxonomic bias towards the most charismatic animals and plants of the planet, data show that marine species are better at tracking isotherm shifts, and move towards the pole six times faster than terrestrial species. More specifically, we find that marine species closely track shifting isotherms in warm and relatively undisturbed waters (for example, the Central Pacific Basin) or in cold waters subject to high human pressures (for example, the North Sea). On land, human activities impede the capacity of terrestrial species to track isotherm shifts in latitude, with some species shifting in the opposite direction to isotherms. Along elevational gradients, species follow the direction of isotherm shifts but at a pace that is much slower than expected, especially in areas with warm climates. Our results suggest that terrestrial species are lagging behind shifting isotherms more than marine species, which is probably related to the interplay between the wider thermal safety margin of terrestrial versus marine species and the more constrained physical environment for dispersal in terrestrial versus marine habitats.},
author = {Lenoir, Jonathan and Bertrand, Romain and Comte, Lise and Bourgeaud, Luana and Hattab, Tarek and Murienne, J{\'{e}}r{\^{o}}me and Grenouillet, Ga{\"{e}}l},
doi = {10.1038/s41559-020-1198-2},
issn = {2397334X},
journal = {Nature Ecology and Evolution},
number = {8},
pages = {1044--1059},
title = {{Species better track climate warming in the oceans than on land}},
volume = {4},
year = {2020}
}
@article{doi:10.1029/2018JD029522,
abstract = {Abstract We outline a new and improved uncertainty analysis for the Goddard Institute for Space Studies Surface Temperature product version 4 (GISTEMP v4). Historical spatial variations in surface temperature anomalies are derived from historical weather station data and ocean data from ships, buoys, and other sensors. Uncertainties arise from measurement uncertainty, changes in spatial coverage of the station record, and systematic biases due to technology shifts and land cover changes. Previously published uncertainty estimates for GISTEMP included only the effect of incomplete station coverage. Here, we update this term using currently available spatial distributions of source data, state-of-the-art reanalyses, and incorporate independently derived estimates for ocean data processing, station homogenization, and other structural biases. The resulting 95{\%} uncertainties are near 0.05 °C in the global annual mean for the last 50 years and increase going back further in time reaching 0.15 °C in 1880. In addition, we quantify the benefits and inherent uncertainty due to the GISTEMP interpolation and averaging method. We use the total uncertainties to estimate the probability for each record year in the GISTEMP to actually be the true record year (to that date) and conclude with 86{\%} likelihood that 2016 was indeed the hottest year of the instrumental period (so far).},
author = {Lenssen, Nathan J L and Schmidt, Gavin A and Hansen, James E and Menne, Matthew J and Persin, Avraham and Ruedy, Reto and Zyss, Daniel},
doi = {10.1029/2018JD029522},
journal = {Journal of Geophysical Research: Atmospheres},
number = {12},
pages = {6307--6326},
title = {{Improvements in the GISTEMP Uncertainty Model}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD029522},
volume = {124},
year = {2019}
}
@article{Leroy2018,
abstract = {Abstract Trends in monthly average, zonal average temperature in the stratosphere as retrieved from highly accurate modern satellite data are intercompared and compared with climate reanalyses from 2003 through 2014. The data sets used are those of Atmospheric Infrared Sounder and Global Positioning System (GPS) radio occultation, and the reanalyses are those of MERRA and ERA-Interim. Trends produced by all data sets agree to within 0.02 K/year in the lower stratosphere and 0.05 K/year in the middle stratosphere. A number of retrieval errors are found that introduce incorrect trends and seasonal anomalies. Adding microwave data to the infrared retrieval changes trends by approximately 0.01 K/year, thus improving agreement with the other data sets. The signature of the quasi-biennial oscillation in temperature and the annual cycle of temperature over Antarctica as retrieved from infrared data contain null-space errors of more than 3 K due to erroneous priors used in retrieval. Nonuniformity in GPS radio occultation gives rise to errors because changes in received GPS signal strength alter the upper boundary initialization in radio occultation retrieval. Finally, an incorrect specification of atmospheric water vapor introduces an erroneous seasonal cycle of temperature as retrieved from GPS radio occultation data in the upper troposphere. All of these time-dependent retrieval errors can be corrected with future research and improvements to spectral infrared and GPS radio occultation retrieval systems.},
author = {Leroy, S S and Ao, C O and Verkhoglyadova, O P},
doi = {10.1029/2018JD028990},
journal = {Journal of Geophysical Research: Atmospheres},
number = {20},
pages = {11431--11444},
title = {{Temperature Trends and Anomalies in Modern Satellite Data: Infrared Sounding and GPS Radio Occultation}},
volume = {123},
year = {2018}
}
@article{doi:10.1029/2012GL051106,
abstract = {We provide updated estimates of the change of ocean heat content and the thermosteric component of sea level change of the 0–700 and 0–2000 m layers of the World Ocean for 1955–2010. Our estimates are based on historical data not previously available, additional modern data, and bathythermograph data corrected for instrumental biases. We have also used Argo data corrected by the Argo DAC if available and used uncorrected Argo data if no corrections were available at the time we downloaded the Argo data. The heat content of the World Ocean for the 0–2000 m layer increased by 24.0 ± 1.9 × 1022 J (±2S.E.) corresponding to a rate of 0.39 W m−2 (per unit area of the World Ocean) and a volume mean warming of 0.09°C. This warming corresponds to a rate of 0.27 W m−2 per unit area of earth's surface. The heat content of the World Ocean for the 0–700 m layer increased by 16.7 ± 1.6 × 1022 J corresponding to a rate of 0.27 W m−2(per unit area of the World Ocean) and a volume mean warming of 0.18°C. The World Ocean accounts for approximately 93{\%} of the warming of the earth system that has occurred since 1955. The 700–2000 m ocean layer accounted for approximately one-third of the warming of the 0–2000 m layer of the World Ocean. The thermosteric component of sea level trend was 0.54 ± .05 mm yr−1 for the 0–2000 m layer and 0.41 ± .04 mm yr−1 for the 0–700 m layer of the World Ocean for 1955–2010.},
author = {Levitus, S and Antonov, J I and Boyer, T P and Baranova, O K and Garcia, H E and Locarnini, R A and Mishonov, A V and Reagan, J R and Seidov, D and Yarosh, E S and Zweng, M M},
doi = {10.1029/2012GL051106},
journal = {Geophysical Research Letters},
keywords = {climate variability,ocean heat content},
number = {10},
title = {{World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012GL051106},
volume = {39},
year = {2012}
}
@article{Levy2016a,
abstract = {Geological records from the Antarctic margin offer direct evidence of environmental variability at high southern latitudes and provide insight regarding ice sheet sensitivity to past climate change. The early to mid-Miocene (23-14 Mya) is a compelling interval to study as global temperatures and atmospheric CO2 concentrations were similar to those projected for coming centuries. Importantly, this time interval includes the Miocene Climatic Optimum, a period of global warmth during which average surface temperatures were 3-4 °C higher than today. Miocene sediments in the ANDRILL-2A drill core from the Western Ross Sea, Antarctica, indicate that the Antarctic ice sheet (AIS) was highly variable through this key time interval. A multiproxy dataset derived from the core identifies four distinct environmental motifs based on changes in sedimentary facies, fossil assemblages, geochemistry, and paleotemperature. Four major disconformities in the drill core coincide with regional seismic discontinuities and reflect transient expansion of grounded ice across the Ross Sea. They correlate with major positive shifts in benthic oxygen isotope records and generally coincide with intervals when atmospheric CO2 concentrations were at or below preindustrial levels (∼280 ppm). Five intervals reflect ice sheet minima and air temperatures warm enough for substantial ice mass loss during episodes of high (∼500 ppm) atmospheric CO2 These new drill core data and associated ice sheet modeling experiments indicate that polar climate and the AIS were highly sensitive to relatively small changes in atmospheric CO2 during the early to mid-Miocene.},
author = {Levy, Richard and Harwood, David and Florindo, Fabio and Sangiorgi, Francesca and Tripati, Robert and von Eynatten, Hilmar and Gasson, Edward and Kuhn, Gerhard and Tripati, Aradhna and DeConto, Robert and Fielding, Christopher and Field, Brad and Golledge, Nicholas and McKay, Robert and Naish, Timothy and Olney, Matthew and Pollard, David and Schouten, Stefan and Talarico, Franco and Warny, Sophie and Willmott, Veronica and Acton, Gary and Panter, Kurt and Paulsen, Timothy and Taviani, Marco and {SMS Science Team}, SMS Science},
doi = {10.1073/pnas.1516030113},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {13},
pages = {3453--3458},
pmid = {26903644},
publisher = {National Academy of Sciences},
title = {{Antarctic ice sheet sensitivity to atmospheric CO2 variations in the early to mid-Miocene}},
volume = {113},
year = {2016}
}
@article{article,
author = {Lewis, K and Dijken, G and Arrigo, K},
doi = {10.1126/science.aay8380},
journal = {Science},
pages = {198--202},
title = {{Changes in phytoplankton concentration now drive increased Arctic Ocean primary production}},
volume = {369},
year = {2020}
}
@article{Lewkowicz2019,
abstract = {Retrogressive thaw slumps (RTS) – landslides caused by the melt of ground ice in permafrost – have become more common in the Arctic, but the timing of this recent increase and its links to climate have not been fully established. Here we annually resolve RTS formation and longevity for Banks Island, Canada (70,000 km2) using the Google Earth Engine Timelapse dataset. We describe a 60-fold increase in numbers between 1984 and 2015 as more than 4000 RTS were initiated, primarily following four particularly warm summers. Colour change due to increased turbidity occurred in 288 lakes affected by RTS outflows and sediment accumulated in many valley floors. Modelled RTS initiation rates increased by an order of magnitude between 1906–1985 and 2006–2015, and are projected under RCP4.5 to rise to {\textgreater}10,000 decade−1 after 2075. These results provide additional evidence that ice-rich continuous permafrost terrain can be highly vulnerable to changing summer climate.},
author = {Lewkowicz, Antoni G and Way, Robert G},
doi = {10.1038/s41467-019-09314-7},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {1329},
title = {{Extremes of summer climate trigger thousands of thermokarst landslides in a High Arctic environment}},
url = {https://doi.org/10.1038/s41467-019-09314-7},
volume = {10},
year = {2019}
}
@article{Li2014a,
abstract = {Abstract. The Aerosol Robotic Network (AERONET) has been providing high-quality retrievals of aerosol optical properties from the surface at worldwide locations for more than a decade. Many sites have continuous and consistent records for more than 10 years, which enables the investigation of long-term trends in aerosol properties at these locations. In this study, we present the results of a trend analysis at selected stations with long data records. In addition to commonly studied parameters such as aerosol optical depth (AOD) and {\AA}ngstr{\"{o}}m exponent (AE), we also focus on inversion products including absorption aerosol optical depth (ABS), single-scattering albedo (SSA) and the absorption {\AA}ngstr{\"{o}}m exponent (AAE). Level 2.0 quality assured data are the primary source. However, due to the scarcity of level 2.0 inversion products resulting from the strict AOD quality control threshold, we have also analyzed level 1.5 data, with some quality control screening to provide a reference for global results. Two statistical methods are used to detect and estimate the trend: the Mann–Kendall test associated with Sen's slope and linear least-squares fitting. The results of these statistical tests agree well in terms of the significance of the trend for the majority of the cases. The results indicate that Europe and North America experienced a uniform decrease in AOD, while significant ({\textgreater}90{\%}) increases in these two parameters are found for North India and the Arabian Peninsula. The AE trends turn out to be different for North America and Europe, with increases for the former and decreases for the latter, suggesting opposite changes in fine/coarse-mode fraction. For level 2.0 inversion parameters, Beijing and Kanpur both experienced an increase in SSA. Beijing also shows a reduction in ABS, while the SSA increase for Kanpur is mainly due the increase in scattering aerosols. Increased absorption and reduced SSA are found at Solar{\_}Village. At level 1.5, most European and North American sites also show positive SSA and negative ABS trends, although the data are more uncertain. The AAE trends are less spatially coherent due to large uncertainties, except for a robust increase at three sites in West Africa, which suggests a possible reduction in black carbon. Overall, the trends do not exhibit obvious seasonality for the majority of parameters and stations.},
author = {Li, J. and Carlson, B. E. and Dubovik, O. and Lacis, A. A.},
doi = {10.5194/acp-14-12271-2014},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {nov},
number = {22},
pages = {12271--12289},
title = {{Recent trends in aerosol optical properties derived from AERONET measurements}},
url = {https://www.atmos-chem-phys.net/14/12271/2014/},
volume = {14},
year = {2014}
}
@article{Li2013,
author = {Li, Jinbao and Xie, Shang-Ping and Cook, Edward R and Morales, Mariano S and Christie, Duncan A and Johnson, Nathaniel C and Chen, Fahu and D'Arrigo, Rosanne and Fowler, Anthony M and Gou, Xiaohua and Fang, Keyan},
doi = {10.1038/nclimate1936},
journal = {Nature Climate Change},
keywords = {bctrewin},
month = {jul},
pages = {822},
publisher = {Nature Publishing Group},
title = {{El Ni{\~{n}}o modulations over the past seven centuries}},
url = {http://dx.doi.org/10.1038/nclimate1936 http://10.0.4.14/nclimate1936 https://www.nature.com/articles/nclimate1936{\#}supplementary-information},
volume = {3},
year = {2013}
}
@article{doi:10.1175/JCLI-D-12-00698.1,
abstract = {AbstractThe impact of urbanization on temperature trends in China was investigated with emphasis on two aspects of urbanization, land cover change, and human activity. A new station classification scheme was developed to incorporate these two aspects by utilizing land cover and energy consumption data. Observation temperature data of 274 stations and National Centers for Environmental Prediction (NCEP)–National Center for Atmospheric Research (NCAR) reanalysis temperature from 1979 to 2010 were used in conducting the observation minus reanalysis (OMR) method to detect urban influence. Results indicated that nearly half of the stations in the study area have been converted from nonurban to urban stations as a result of land cover change associated with urban expansion. It was determined that both land cover change and human activity play important roles in temperature change and contribute to the observed warming, particularly in urbanized stations, where the highest amount of warming was detected. Urbanized stations showed higher OMR temperature trends than those of unchanged stations. In addition, a statistically significant positive relationship was detected between human activity and temperature trends, which suggests that the observed warming is closely related to the intensity and spatial extent of human activity. In fact, the urbanization effect is strongly affected by specific characteristics of urbanization in local and regional scales.},
author = {Li, Yan and Zhu, Lijuan and Zhao, Xinyi and Li, Shuangcheng and Yan, Yan},
doi = {10.1175/JCLI-D-12-00698.1},
journal = {Journal of Climate},
number = {22},
pages = {8765--8780},
title = {{Urbanization Impact on Temperature Change in China with Emphasis on Land Cover Change and Human Activity}},
url = {https://doi.org/10.1175/JCLI-D-12-00698.1},
volume = {26},
year = {2013}
}
@article{li_mid-pliocene_2015,
author = {Li, Xiangyu and Jiang, Dabang and Zhang, Zhongshi and Zhang, Ran and Tian, Zhiping and Yan, Qing},
doi = {10.1007/s00376-014-4171-7},
issn = {0256-1530, 1861-9533},
journal = {Advances in Atmospheric Sciences},
month = {jul},
number = {7},
pages = {909--923},
title = {{Mid-Pliocene westerlies from PlioMIP simulations}},
url = {http://link.springer.com/10.1007/s00376-014-4171-7},
volume = {32},
year = {2015}
}
@article{Li2018h,
abstract = {NCEP reanalysis wind data from 1948 to 2016 and Makassar Strait transport from 2004 to 2011 are used to construct a multi-decadal timeseries of 0–300 m Makassar Throughflow using a back-propagation (BP) neural network. Based on the 2004–2015 Makassar timeseries, 0–300 m transport accounts for 75{\%} (±8{\%}) of the total Makassar throughflow. Results from the INSTANT program 2004–2006 indicate that the Makassar throughflow provides 78{\%} of the Indonesian Throughflow (ITF) within the upper 1000 m (77{\%} of the full depth ITF). As the ITF is driven largely by North Pacific winds, we use the North Pacific zonal wind to construct a 68-year timeseries of 0–300 m Makassar Throughflow to trace interannual to decadal variability. The constructed timeseries has a mean transport of 9.2 ± 1 Sv within the 0–300 m layer. Using the 2004–2015 statistics this converts to a total Makassar Strait throughflow of 12.2 Sv and using the 2004–2006 INSTANT data, to a total ITF within the upper kilometer of 14.7 Sv. The Makassar throughflow decreases from 1948 to 1995, increases after 1995, then rapidly decreases after 2013, which agrees with the Pacific to Indian inter-ocean pressure difference across the Indonesian seas based on SODA reanalysis with a correlation coefficients of 0.6. The Pacific Decadal Oscillation (PDO) and El Nino-Southern Oscillation (ENSO), have correlation coefficients with the constructed Makassar throughflow of −0.6 and −0.4 respectively.},
author = {Li, Mingting and Gordon, Arnold L and Wei, Jun and Gruenburg, Laura K and Jiang, Guoqing},
doi = {10.1016/j.dynatmoce.2018.02.001},
issn = {0377-0265},
journal = {Dynamics of Atmospheres and Oceans},
keywords = {Indonesian throughflow (ITF) makassar strait multi},
pages = {84--95},
title = {{Multi-decadal timeseries of the Indonesian throughflow}},
url = {http://www.sciencedirect.com/science/article/pii/S0377026517301021},
volume = {81},
year = {2018}
}
@article{Li2016,
author = {Li, Xiaofan and Hu, Zeng-zhen and Jiang, Xingwen and Li, Yueqing and Gao, Zongting and Yang, Song and Zhu, Jieshun and Jha, Bhaskar},
doi = {10.1002/joc.4592},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {accepted 6 november 2015,climatology and trend,land precipitation,mean and seasonality,observations and cmip5,received 22 july 2015,revised 2 november 2015},
month = {sep},
number = {11},
pages = {3781--3793},
title = {{Trend and seasonality of land precipitation in observations and CMIP5 model simulations}},
url = {http://doi.wiley.com/10.1002/joc.4592},
volume = {36},
year = {2016}
}
@article{Li2020a,
abstract = {In an attempt to quantify Holocene anthropogenic land-cover change in temperate China, we 1) applied the REVEALS model to estimate plant-cover change using 94 pollen records and relative pollen productivity for 27 plant taxa, 2) reviewed earlier interpretation of pollen studies in terms of climate- and human-induced vegetation change, and 3) reviewed information on past land use from archaeological studies. REVEALS achieved a more realistic reconstruction of plant-cover change than pollen percentages in terms of openland versus woodland. The study suggests successive human-induced changes in vegetation cover. The first signs of human- induced land-cover change (crop cultivation, otherwise specified) are found c. 7 ka BP in the temperate deciduous forest, and S and NE Tibetan Plateau (mainly grazing, possibly crop cultivation), 6.5–6 ka BP in the temperate steppe and temperate desert (grazing, uncertain), and 5.5–5 ka BP in the coniferous-deciduous mixed forest, NE subtropical region, and NW Tibetan Plateau (grazing). Further intensification of anthropogenic land-cover change is indicated 5–4.5 ka BP in the E temperate steppe, and S and NE Tibetan Plateau (grazing, cultivation uncertain), 3.5–3 ka BP in S and NE Tibetan Plateau, W temperate steppe, temperate desert (grazing), and NW Tibetan Plateau (probably grazing), and 2.5–2 ka BP in the temperate deciduous forest, N subtropical region, and temperate desert (grazing). These changes generally agree with increased human activity as documented by archaeological studies. REVEALS reconstructions have a stronger potential than biomization to evaluate scenarios of anthropogenic land-cover change such as HYDE, given they are combined with information from archaeological studies.},
author = {Li, Furong and Gaillard, Marie-Jos{\'{e}} and Cao, Xianyong and Herzschuh, Ulrike and Sugita, Shinya and Tarasov, Pavel E. and Wagner, Mayke and Xu, Qinghai and Ni, Jian and Wang, Weiming and Zhao, Yan and An, Chengbang and Beusen, A.H.W. and Chen, Fahu and Feng, Zhaodong and Goldewijk, C.G.M. Klein and Huang, Xiaozhong and Li, Yuecong and Li, Yu and Liu, Hongyan and Sun, Aizhi and Yao, Yifeng and Zheng, Zhuo and Jia, Xin},
doi = {10.1016/j.earscirev.2020.103119},
issn = {00128252},
journal = {Earth-Science Reviews},
month = {apr},
pages = {103119},
title = {{Towards quantification of Holocene anthropogenic land-cover change in temperate China: A review in the light of pollen-based REVEALS reconstructions of regional plant cover}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012825219304441},
volume = {203},
year = {2020}
}
@article{LI201856,
annote = {Cenozoic Climate Change in Eastern Asia - PART II},
author = {Li, Xiangyu and Jiang, Dabang and Tian, Zhiping and Yang, Yibo},
doi = {10.1016/j.palaeo.2018.06.027},
issn = {0031-0182},
journal = {Palaeogeography, Palaeoclimatology, Palaeoecology},
keywords = {Carbon cycle,Climate feedback,Major Northern Hemisphere glaciation,Mid-Piacenzian,Pliocene,Reconstruction},
pages = {56--70},
title = {{Mid-Pliocene global land monsoon from PlioMIP1 simulations}},
url = {http://www.sciencedirect.com/science/article/pii/S0031018218302256},
volume = {512},
year = {2018}
}
@article{Li2020e,
abstract = {Changes in the tropical atmospheric overturning circulation can strongly influence the global weather pattern via affecting the location, extent, and strength of tropical convective heating. However, due to limitations in obtaining reliable global data before the satellite era, there are still uncertainties on long-term changes in the tropical overturning features, such as the Walker Circulation. By analysing the 20th century reanalysis products, ship-based observations and gauge-based land precipitation data, robust intensification of convection is found over the western equatorial Pacific and Maritime Continent (WEP-MC; 90°E–150°E/15°S–15°N), where rainfall and total cloud cover increased by 15–20{\%} in boreal spring during 1901–2010. The signal is noticeably seasonally dependent, and both rainfall and cloud cover show consistent and significant increasing trends only in the boreal spring season. General circulation model (GCM) experiments were conducted using two different reconstructed SST data sets as forcing; results from both runs indicate springtime intensification of WEP-MC convection, even with relatively uniform SST warming. Further, numerical experiments using a simplified model show that the Pacific trade wind can be accelerated by intensifying cumulus heating; however, this can be sensitive to the location of convection, and only occurs if the latter is within ±5° in latitude along the equator. Our findings suggest that the secular change in the Walker Circulation is potentially discovered from the current reanalysis and observational data sets if “regional-up” approaches are applied.},
author = {Li, Zhenning and Yang, Song and Tam, Chi‐Yung and Hu, Chundi},
doi = {10.1002/joc.6856},
issn = {0899-8418},
journal = {International Journal of Climatology},
keywords = {20th century,Pacific trade wind,Walker Circulation,observational uncertainty,tropical convective feedback},
month = {oct},
number = {2},
pages = {1455--1464},
title = {{Strengthening western equatorial Pacific and Maritime Continent atmospheric convection and its modulation on the trade wind during spring of 1901–2010}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.6856},
volume = {41},
year = {2020}
}
@article{Liang2016,
author = {Liang, Yu Chiao and Chou, Chin Chieh and Yu, Jin Yi and Lo, Min Hui},
doi = {10.1088/1748-9326/11/4/044012},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {Central Pacific El Ni{\~{n}}o,Eastern Pacific El Ni{\~{n}}o,mapping responses of global rivers,two types of El Ni{\~{n}}o},
number = {4},
pages = {044012},
publisher = {IOP Publishing},
title = {{Mapping the locations of asymmetric and symmetric discharge responses in global rivers to the two types of El Ni{\~{n}}o}},
volume = {11},
year = {2016}
}
@article{doi:10.1002/joc.4908,
abstract = {ABSTRACT We examine the urban effect on surface warming in Eastern China, where a substantial portion of the land area has undergone rapid urbanization in the last few decades. Daily surface air temperature records during the period 1971–2010 at 277 meteorological stations are used to investigate temperature changes. Owing to urban expansion, some of the stations formerly located in rural areas are becoming increasingly influenced by urban environments. To estimate the effect of this urbanization on observed surface warming, the stations are dynamically classified into urban and rural types based on the land use data for four periods, i.e. 1980, 1990, 2000 and 2010. After eliminating the temperature trend bias induced by time-varying latitudinal distributions of urban and rural stations, the estimated urban-induced trends in the daily minimum and mean temperature are 0.167 and 0.085 °C decade−1, accounting for 33.6 and 22.4{\%} of total surface warming, respectively. The temperature difference between urban and rural stations indicates that urban heat island intensity has dramatically increased owing to rapid urbanization, and is highly correlated with the difference in fractional coverage of artificial surfaces between these two types of stations. This study highlights the importance of dynamic station classification in estimating the contribution of urbanization to long-term surface warming over large areas.},
author = {Liao, Weilin and Wang, Dagang and Liu, Xiaoping and Wang, Guiling and Zhang, Jinbao},
doi = {10.1002/joc.4908},
journal = {International Journal of Climatology},
keywords = {Eastern China,UHI,land use,surface warming,temperature,urbanization},
number = {7},
pages = {3197--3208},
title = {{Estimated influence of urbanization on surface warming in Eastern China using time-varying land use data}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.4908},
volume = {37},
year = {2017}
}
@article{Liefert2020,
author = {Liefert, David T and Shuman, Bryan N},
doi = {10.1029/2019GL086412},
journal = {Geophysical Research Letters},
pages = {e2019GL086412},
title = {{Pervasive Desiccation of North American Lakes During the Late Quaternary}},
volume = {47},
year = {2020}
}
@article{Liljedahl2016,
abstract = {Ice wedges are common features of the subsurface in permafrost regions. They develop by repeated frost cracking and ice vein growth over hundreds to thousands of years. Ice-wedge formation causes the archetypal polygonal patterns seen in tundra across the Arctic landscape. Here we use field and remote sensing observations to document polygon succession due to ice-wedge degradation and trough development in ten Arctic localities over sub-decadal timescales. Initial thaw drains polygon centres and forms disconnected troughs that hold isolated ponds. Continued ice-wedge melting leads to increased trough connectivity and an overall draining of the landscape. We find that melting at the tops of ice wedges over recent decades and subsequent decimetre-scale ground subsidence is a widespread Arctic phenomenon. Although permafrost temperatures have been increasing gradually, we find that ice-wedge degradation is occurring on sub-decadal timescales. Our hydrological model simulations show that advanced ice-wedge degradation can significantly alter the water balance of lowland tundra by reducing inundation and increasing runoff, in particular due to changes in snow distribution as troughs form. We predict that ice-wedge degradation and the hydrological changes associated with the resulting differential ground subsidence will expand and amplify in rapidly warming permafrost regions.},
author = {Liljedahl, Anna K. and Boike, Julia and Daanen, Ronald P. and Fedorov, Alexander N. and Frost, Gerald V. and Grosse, Guido and Hinzman, Larry D. and Iijma, Yoshihiro and Jorgenson, Janet C. and Matveyeva, Nadya and Necsoiu, Marius and Raynolds, Martha K. and Romanovsky, Vladimir E. and Schulla, J{\"{o}}rg and Tape, Ken D. and Walker, Donald A. and Wilson, Cathy J. and Yabuki, Hironori and Zona, Donatella},
doi = {10.1038/ngeo2674},
isbn = {1752-0894},
issn = {17520908},
journal = {Nature Geoscience},
pages = {312--318},
title = {{Pan-Arctic ice-wedge degradation in warming permafrost and its influence on tundra hydrology}},
volume = {9},
year = {2016}
}
@article{Liman2018,
abstract = {Latent heat flux (LHF) is one of the main contributors to the global energy budget. As the density of in situ LHF measurements over the global oceans is generally poor, the potential of remotely sensed LHF for meteorological applications is enormous. However, to date none of the available satellite products have included estimates of systematic, random, and sampling uncertainties, all of which are essential for assessing their quality. Here, the challenge is taken on by matching LHF-related pixel-level data of the Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite (HOAPS) climatology (version 3.3) to in situ measurements originating from a high-quality data archive of buoys and selected ships. Assuming the ground reference to be bias-free, this allows for deriving instantaneous systematic uncertainties as a function of four atmospheric predictor variables. The approach is regionally independent and therefore overcomes the issue of sparse in situ data densities over large oceanic areas. Likewise, random uncertainties are derived, which include not only a retrieval component but also contributions from in situ measurement noise and the collocation procedure. A recently published random uncertainty decomposition approach is applied to isolate the random retrieval uncertainty of all LHF-related HOAPS parameters. It makes use of two combinations of independent data triplets of both satellite and in situ data, which are analysed in terms of their pairwise variances of differences. Instantaneous uncertainties are finally aggregated, allowing for uncertainty characterizations on monthly to multi-annual timescales. Results show that systematic LHF uncertainties range between 15 and 50g2 with a global mean of 25g2. Local maxima are mainly found over the subtropical ocean basins as well as along the western boundary currents. Investigations indicate that contributions from a to the overall LHF uncertainty are on the order of 60g{\%} (25g{\%}). From an instantaneous point of view, random retrieval uncertainties are specifically large over the subtropics with a global average of 37gWgmg2. In a climatological sense, their magnitudes become negligible, as do respective sampling uncertainties. Regional and seasonal analyses suggest that largest total LHF uncertainties are seen over the Gulf Stream and the Indian monsoon region during boreal winter. In light of the uncertainty measures, the observed continuous global mean LHF increase up to 2009 needs to be treated with caution. The demonstrated approach can easily be transferred to other satellite retrievals, which increases the significance of the present work.},
author = {Liman, Julian and Schr{\"{o}}der, Marc and Fennig, Karsten and Andersson, Axel and Hollmann, Rainer},
doi = {10.5194/amt-11-1793-2018},
issn = {18678548},
journal = {Atmospheric Measurement Techniques},
number = {3},
pages = {1793--1815},
title = {{Uncertainty characterization of HOAPS 3.3 latent heat-flux-related parameters}},
volume = {11},
year = {2018}
}
@article{Lin2014,
abstract = {With the motivation to identify whether a reasonably simulated atmospheric circulation would necessarily lead to a successful reproduction of monsoon precipitation, the performances of five sets of reanalysis data {\{}[{\}}NCEP-U.S. Department of Energy (DOE) Atmospheric Model Intercomparison Project II (AMIP-II) reanalysis (NCEP-2), 40-yr ECMWF Re-Analysis (ERA-40), Japanese 25-yr Reanalysis Project (JRA-25), Interim ECMWF Re-Analysis (ERA-Interim), and Modern-Era Retrospective Analysis for Research and Applications (MERRA)] in reproducing the climatology, interannual variation, and long-term trend of global monsoon (GM) precipitation are comprehensively evaluated. To better understand the variability and long-term trend of GM precipitation, the authors also examined the major components of water budget, including evaporation, water vapor convergence, and the change in local column water vapor, based on the five reanalysis datasets. Results show that all five reanalysis datasets reasonably reproduce the climatology of GM precipitation. ERA-Interim (NCEP-2) shows the highest (lowest) skill among the five datasets. The observed GM precipitation shows an increasing tendency during 1979-2011 along with a strong interannual variability, which is reasonably reproduced by five reanalysis datasets. The observed increasing trend of GM precipitation is dominated by contributions from the Asian, North American, Southern African, and Australian monsoons. All five datasets fail in reproducing the increasing tendency of the North African monsoon precipitation. The wind convergence term in the water budget equation dominates the GM precipitation variation, indicating a consistency between the GM precipitation and the seasonal change of prevailing wind.},
author = {Lin, Renping and Zhou, Tianjun and Qian, Yun},
doi = {10.1175/JCLI-D-13-00215.1},
isbn = {0894-8755; 1520-0442},
issn = {08948755},
journal = {Journal of Climate},
number = {3},
pages = {1271--1289},
title = {{Evaluation of global monsoon precipitation changes based on five reanalysis datasets}},
volume = {27},
year = {2014}
}
@article{Lindsay2015,
abstract = {Sea ice thickness is a fundamental climate state variable that provides an integrated measure of changes in the high-latitude energy balance. However, observations of ice thickness have been sparse in time and space making the construction of observation-based time series difficult. Moreover, different groups use a variety of methods and processing procedures to measure ice thickness and each observational source likely has different and poorly characterized measurement and sampling biases. Observational sources include upward looking sonars mounted on submarines or moorings, electromagnetic sensors on helicopters or aircraft, and lidar or radar altimeters on airplanes or satellites. Here we use a curve-fitting approach to evaluate the systematic differences between eight different observation systems in the Arctic Basin. The approach determines the large-scale spatial and temporal variability of the ice thickness as well as the mean differences between the observation systems using over 3000 estimates of the ice thickness. The thickness estimates are measured over spatial scales of approximately 50 km or time scales of 1 month and the primary time period analyzed is 2000–2013 when the modern mix of observations is available. Good agreement is found between five of the systems, within 0.15 m, while systematic differences of up to 0.5 m are found for three others compared to the five. The trend in annual mean ice thickness over the Arctic Basin is −0.58 ± 0.07 m decade−1 over the period 2000–2013, while the annual mean ice thickness for the central Arctic Basin alone (the SCICEX Box) has decreased from 3.45 m in 1975 to 1.11 m in 2013, a 68{\%} reduction. This is nearly double the 36{\%} decline reported by an earlier study. These results provide additional direct observational confirmation of substantial sea ice losses found in model analyses.},
author = {Lindsay, R. and Schweiger, A.},
doi = {10.5194/tc-9-269-2015},
issn = {19940424},
journal = {Cryosphere},
number = {1},
pages = {269--283},
title = {{Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations}},
volume = {9},
year = {2015}
}
@article{Linsley2015a,
author = {Linsley, Braddock K and Wu, Henry C and Dassi{\'{e}}, Emilie P and Schrag, Daniel P},
doi = {10.1002/2015GL063045},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {apr},
number = {7},
pages = {2358--2366},
title = {{Decadal changes in South Pacific sea surface temperatures and the relationship to the Pacific decadal oscillation and upper ocean heat content}},
url = {http://doi.wiley.com/10.1002/2015GL063045},
volume = {42},
year = {2015}
}
@article{Lippold2019,
abstract = {Abstract There is a converging body of evidence supporting a measurable slowdown of the Atlantic Meridional Overturning Circulation (AMOC) as climate warms and Northern Hemisphere ice sheets inexorably shrink. Within this context, we assess the variability of the AMOC during the Holocene based on a marine sediment core retrieved from the deep northwest Atlantic, which sensitively recorded large-scale deglacial transitions in deep water circulation. While there is a diffuse notion of Holocene variability in Labrador and Nordic Seas overturning, we report a largely invariable deep water circulation for the last {\~{}}11,000 years, even during the meltwater pulse associated with the 8.2-ka event. Sensitivity tests along with high-resolution 231Pa/230Th data constrain the duration and the magnitude of possible Holocene AMOC variations. The generally constant baseline during the Holocene suggests attenuated natural variability of the large-scale AMOC on submillennial timescales and calls for compensating effects involving the upstream components of North Atlantic Deep Water.},
annote = {doi: 10.1029/2019GL084988},
author = {Lippold, J{\"{o}}rg and P{\"{o}}ppelmeier, Frerk and S{\"{u}}fke, Finn and Gutjahr, Marcus and Goepfert, Tyler J and Blaser, Patrick and Friedrich, Oliver and Link, Jasmin M and Wacker, Lukas and Rheinberger, Stefan and Jaccard, Samuel L},
doi = {10.1029/2019GL084988},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {AMOC,Bermuda Rise,Holocene,high resolution 231Pa/230Th,sensitivity tests},
month = {oct},
number = {20},
pages = {11338--11346},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Constraining the Variability of the Atlantic Meridional Overturning Circulation During the Holocene}},
url = {https://doi.org/10.1029/2019GL084988},
volume = {46},
year = {2019}
}
@article{https://doi.org/10.1029/2019JC015152,
author = {Little, Christopher M and Hu, Aixue and Hughes, Chris W and McCarthy, Gerard D and Piecuch, Christopher G and Ponte, Rui M and Thomas, Matthew D},
doi = {10.1029/2019JC015152},
journal = {Journal of Geophysical Research: Oceans},
keywords = {AMOC,United States,climate model,coastal,review,sea level},
number = {9},
pages = {6435--6458},
title = {{The Relationship Between U.S. East Coast Sea Level and the Atlantic Meridional Overturning Circulation: A Review}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015152},
volume = {124},
year = {2019}
}
@article{Liu2017b,
author = {Liu, Yu and Cobb, Kim M and Song, Huiming and Li, Qiang and Li, Ching-Yao and Nakatsuka, Takeshi and An, Zhisheng and Zhou, Weijian and Cai, Qiufang and Li, Jinbao and Leavitt, Steven W and Sun, Changfeng and Mei, Ruochen and Shen, Chuan-Chou and Chan, Ming-Hsun and Sun, Junyan and Yan, Libin and Lei, Ying and Ma, Yongyong and Li, Xuxiang and Chen, Deliang and Linderholm, Hans W},
doi = {10.1038/ncomms15386},
journal = {Nature Communications},
month = {may},
pages = {15386},
publisher = {The Author(s)},
title = {{Recent enhancement of central Pacific El Ni{\~{n}}o variability relative to last eight centuries}},
url = {https://doi.org/10.1038/ncomms15386 http://10.0.4.14/ncomms15386 https://www.nature.com/articles/ncomms15386{\#}supplementary-information},
volume = {8},
year = {2017}
}
@article{LiuE3501,
abstract = {Marine and terrestrial proxy records suggest global cooling during the Late Holocene, following the peak warming of the Holocene Thermal Maximum ({\~{}}10 to 6 ka) until the rapid warming induced by increasing anthropogenic greenhouses gases. However, the physical mechanism responsible for this global cooling has remained elusive. Here, we show that climate models simulate a robust global annual mean warming in the Holocene, mainly in response to rising CO2 and the retreat of ice sheets. This model-data inconsistency demands a critical reexamination of both proxy data and models.A recent temperature reconstruction of global annual temperature shows Early Holocene warmth followed by a cooling trend through the Middle to Late Holocene [Marcott SA, et al., 2013, Science 339(6124):1198{\{}$\backslash$textendash{\}}1201]. This global cooling is puzzling because it is opposite from the expected and simulated global warming trend due to the retreating ice sheets and rising atmospheric greenhouse gases. Our critical reexamination of this contradiction between the reconstructed cooling and the simulated warming points to potentially significant biases in both the seasonality of the proxy reconstruction and the climate sensitivity of current climate models.},
author = {Liu, Zhengyu and Zhu, Jiang and Rosenthal, Yair and Zhang, Xu and Otto-Bliesner, Bette L and Timmermann, Axel and Smith, Robin S and Lohmann, Gerrit and Zheng, Weipeng and {Elison Timm}, Oliver},
doi = {10.1073/pnas.1407229111},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {34},
pages = {E3501--E3505},
publisher = {National Academy of Sciences},
title = {{The Holocene temperature conundrum}},
url = {https://www.pnas.org/content/111/34/E3501},
volume = {111},
year = {2014}
}
@article{Liu2012,
author = {Liu, J. and Song, M. and Hu, Y. and Ren, X.},
doi = {10.5194/cp-8-1169-2012},
issn = {18149324},
journal = {Climate of the Past},
number = {4},
pages = {1169--1175},
title = {{Changes in the strength and width of the Hadley Circulation since 1871}},
volume = {8},
year = {2012}
}
@article{doi:10.1175/JCLI-D-14-00007.1,
abstract = { AbstractDescribed herein is the parametric and structural uncertainty quantification for the monthly Extended Reconstructed Sea Surface Temperature (ERSST) version 4 (v4). A Monte Carlo ensemble approach was adopted to characterize parametric uncertainty, because initial experiments indicate the existence of significant nonlinear interactions. Globally, the resulting ensemble exhibits a wider uncertainty range before 1900, as well as an uncertainty maximum around World War II. Changes at smaller spatial scales in many regions, or for important features such as Ni{\~{n}}o-3.4 variability, are found to be dominated by particular parameter choices.Substantial differences in parametric uncertainty estimates are found between ERSST.v4 and the independently derived Hadley Centre SST version 3 (HadSST3) product. The largest uncertainties are over the mid and high latitudes in ERSST.v4 but in the tropics in HadSST3. Overall, in comparison with HadSST3, ERSST.v4 has larger parametric uncertainties at smaller spatial and shorter time scales and smaller parametric uncertainties at longer time scales, which likely reflects the different sources of uncertainty quantified in the respective parametric analyses. ERSST.v4 exhibits a stronger globally averaged warming trend than HadSST3 during the period of 1910–2012, but with a smaller parametric uncertainty. These global-mean trend estimates and their uncertainties marginally overlap.Several additional SST datasets are used to infer the structural uncertainty inherent in SST estimates. For the global mean, the structural uncertainty, estimated as the spread between available SST products, is more often than not larger than the parametric uncertainty in ERSST.v4. Neither parametric nor structural uncertainties call into question that on the global-mean level and centennial time scale, SSTs have warmed notably. },
author = {Liu, Wei and Huang, Boyin and Thorne, Peter W and Banzon, Viva F and Zhang, Huai-Min and Freeman, Eric and Lawrimore, Jay and Peterson, Thomas C and Smith, Thomas M and Woodruff, Scott D},
doi = {10.1175/JCLI-D-14-00007.1},
journal = {Journal of Climate},
number = {3},
pages = {931--951},
title = {{Extended Reconstructed Sea Surface Temperature Version 4 (ERSST.v4): Part II. Parametric and Structural Uncertainty Estimations}},
url = {https://doi.org/10.1175/JCLI-D-14-00007.1},
volume = {28},
year = {2015}
}
@article{Liu2016,
abstract = {The timing of the end of the vegetation growing season (EOS) plays a key role in terrestrial ecosystem carbon and nutrient cycles. Autumn phenology is, however, still poorly understood and previous studies generally focused on few species or were very limited in scale. In this study, we applied four methods to extract EOS dates from NDVI records between 1982 and 2011 for the northern hemisphere, and determined the temporal correlations between EOS and environmental factors (i.e. temperature, precipitation and insolation), as well as the correlation between spring and autumn phenology, using partial correlation analyses. Overall, we observed trend towards later EOS in {\~{}} 70{\%} of the pixels in Northern Hemisphere, with a mean rate of 0.18 ± 0.38 days per year. Warming preseason temperature was positively associated with the rate of EOS in most of our study area, except for arid/semi-arid regions, where the precipitation sum played a dominant positive role. Interestingly, increased preseason insolation sum might also lead to a later date of EOS. In addition to the climatic effects on EOS, we found an influence of spring vegetation green-up dates (SOS) on EOS, albeit biome dependent. Our study, therefore, suggests that both environmental factors and spring phenology should be included in the modeling of EOS to improve the predictions of autumn phenology as well as our understanding of the global carbon and nutrient balances. This article is protected by copyright. All rights reserved.},
author = {Liu, Qiang and Fu, Yongshuo H. and Zhu, Zaichun and Liu, Yongwen and Liu, Zhuo and Huang, Mengtian and Janssens, Ivan A. and Piao, Shilong},
doi = {10.1111/gcb.13311},
issn = {13652486},
journal = {Global Change Biology},
keywords = {Normalize Differenced Vegetation Index,autumn phenology,climate change,end of growing season,spring phenology},
number = {11},
pages = {3702--3711},
title = {{Delayed autumn phenology in the Northern Hemisphere is related to change in both climate and spring phenology}},
volume = {22},
year = {2016}
}
@article{Liu2015b,
abstract = {Changes in vegetation activity are driven by multiple natural and anthropogenic factors, which can be reflected by Normalized Difference Vegetation Index (NDVI) derived from satellites. In this paper, NDVI trends from 1982 to 2012 are first estimated by the Theil–Sen median slope method to explore their spatial and temporal patterns. Then, the impact of climate variables and human activity on the observed NDVI trends is analyzed. Our results show that on average, NDVI increased by 0.46 × 10−3 per year from 1982 to 2012 globally with decadal variations. For most regions of the world, a greening (increasing)–browning (decreasing)–greening (G-B-G) trend is observed over the periods 1982–2004, 1995–2004, and 2005–2012, respectively. A positive partial correlation of NDVI and temperature is observed in the first period but it decreases and occasionally becomes negative in the following periods, especially in the Humid Temperate and Dry Domain Regions. This suggests a weakened effect of temperature on vegetation growth. Precipitation, on the other hand, is found to have a positive impact on the NDVI trend. This effect becomes stronger in the third period of 1995–2004, especially in the Dry Domain Region. Anthropogenic effects and human activities, derived here from the Human Footprint Dataset and the associated Human Influence Index (HII), have varied impacts on the magnitude (absolute value) of the NDVI trends across continents. Significant positive effects are found in Asia, Africa, and Europe, suggesting that intensive human activity could accelerate the change in NDVI and vegetation. A more accurate attribution of vegetation change to specific climatic and anthropogenic factors is instrumental to understand vegetation dynamics and requires further research.},
author = {Liu, Ya and Li, Yan and Li, Shuangcheng and Motesharrei, Safa},
doi = {10.3390/rs71013233},
issn = {20724292},
journal = {Remote Sensing},
keywords = {Human footprint,NDVI,Spatio-temporal pattern,Temperature and precipitation,Vegetation},
number = {10},
pages = {13233--13250},
title = {{Spatial and temporal patterns of global NDVI trends: Correlations with climate and human factors}},
volume = {7},
year = {2015}
}
@article{Liu2015d,
author = {Liu, Yi and Lo, Li and Shi, Zhengguo and Wei, Kuo-yen and Chou, Chien-ju and Chen, Yi-chi and Chuang, Chih-kai and Wu, Chung-che and Mii, Horng-sheng and Peng, Zicheng and Amakawa, Hiroshi and Burr, George S and Lee, Shih-yu and Delong, Kristine L and Elderfield, Henry and Shen, Chuan-chou},
doi = {10.1038/ncomms10018},
journal = {Nature Communications},
number = {10018},
pages = {1--7},
title = {{Obliquity pacing of the western Pacific Intertropical Convergence Zone over the past 282,000 years}},
volume = {6},
year = {2015}
}
@article{Liu2013a,
author = {Liu, C and Allan, Richard P},
doi = {10.1088/1748-9326/8/3/034002},
journal = {Environmental Research Letters},
keywords = {034002,8,available from stacks,cmip5 simulations,erl,iop,mmedia,observations,org,precipitation trends,s online supplementary data,wet and dry regions},
number = {3},
pages = {034002},
title = {{Observed and simulated precipitation responses in wet and dry regions 1850–2100}},
volume = {8},
year = {2013}
}
@article{Liu2017f,
abstract = {Land and sea surface temperatures, precipitation, and storm tracks in North America and the North Pacific are controlled to a large degree by atmospheric variability associated with the Pacific North American (PNA) pattern. The modern instrumental record indicates a trend toward a positive PNA phase in recent decades, which has led to accelerated warming and snowpack decline in northwestern North America. The brevity of the instrumental record, however, limits our understanding of long-term PNA variability and its directional or cyclic patterns. Here we develop a 937-y-long reconstruction of the winter PNA based on a network of annually resolved tree-ring proxy records across North America. The reconstruction is consistent with previous regional records in suggesting that the recent persistent positive PNA pattern is unprecedented over the past millennium, but documents patterns of decadal-scale variability that contrast with previous reconstructions. Our reconstruction shows that PNA has been strongly and consistently correlated with sea surface temperature variation, solar irradiance, and volcanic forcing over the period of record, and played a significant role in translating these forcings into decadal-to-multidecadal hydroclimate variability over North America. Climate model ensembles show limited power to predict multidecadal variation in PNA over the period of our record, raising questions about their potential to project future hydroclimatic change modulated by this circulation pattern.},
author = {Liu, Zhongfang and Tang, Yanlin and Jian, Zhimin and Poulsen, Christopher J. and Welker, Jeffrey M. and Bowen, Gabriel J.},
doi = {10.1073/pnas.1618201114},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Atmospheric circulation,Climate change,Holocene,North America,Paleoclimate},
number = {13},
pages = {3340--3345},
pmid = {28289226},
title = {{Pacific North American circulation pattern links external forcing and North American hydroclimatic change over the past millennium}},
volume = {114},
year = {2017}
}
@article{Liu2015e,
abstract = {Abstract Based on 30 year repeated expendable bathythermograph (XBT) deployments between Fremantle, Western Australia, and the Sunda Strait, Indonesia, from 1984 to 2013, interannual variability of geostrophic transport of the Indonesian Throughflow (ITF) and its relationships with El Ni{\~{n}}o Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are investigated. The IOD induced coastal Kelvin waves propagate along the Sumatra-Java coast of Indonesia, and ENSO induced coastal Kelvin waves propagate along the northwest coast of Australia, both influencing interannual variations of the ITF transport. The ITF geostrophic transport is stronger during La Ni{\~{n}}a phase and weaker during El Ni{\~{n}}o phase, with the Ni{\~{n}}o3.4 index leading the ITF variability by 7 months. The Indian Ocean wind variability associated with the IOD to a certain extent offset the Pacific ENSO influences on the ITF geostrophic transport during the developing and mature phases of El Ni{\~{n}}o and La Ni{\~{n}}a, due to the covarying IOD variability with ENSO. The ITF geostrophic transport experiences a strengthening trend of about 1 Sv every 10 years over the study period, which is mostly due to a response to the strengthening of the trade winds in the Pacific during the climate change hiatus period. Decadal variations of the temperature-salinity relationships need to be considered when estimating the geostrophic transport of the ITF using XBT data.},
annote = {doi: 10.1002/2015JC011351},
author = {Liu, Qin-Yan and Feng, Ming and Wang, Dongxiao and Wijffels, Susan},
doi = {10.1002/2015JC011351},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {ENSO,IOD,ITF,geostrophic transport,planetary wave dynamics},
month = {dec},
number = {12},
pages = {8270--8282},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Interannual variability of the Indonesian Throughflow transport: A revisit based on 30 year expendable bathythermograph data}},
url = {https://doi.org/10.1002/2015JC011351},
volume = {120},
year = {2015}
}
@article{Liu2017a,
author = {Liu, Guangyue and Zhao, Lin and Li, Ren and Wu, Tonghua and Jiao, Keqin and Ping, Chienlu},
doi = {10.1002/ppp.1885},
issn = {10456740},
journal = {Permafrost and Periglacial Processes},
month = {jan},
number = {1},
pages = {130--139},
title = {{Permafrost Warming in the Context of Step-wise Climate Change in the Tien Shan Mountains, China}},
url = {http://doi.wiley.com/10.1002/ppp.1885},
volume = {28},
year = {2017}
}
@article{Liu2016f,
abstract = {Sea level rose rapidly during Meltwater Pulse 1A, about 14,500 years ago. A reassessment of sea-level rise and isostatic adjustment suggests sea level rose roughly 8 to 15 m in total, with 0 to 10 m derived from the Antarctic ice sheets.},
author = {Liu, Jean and Milne, Glenn A and Kopp, Robert E and Clark, Peter U and Shennan, Ian},
doi = {10.1038/ngeo2616},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {2},
pages = {130--134},
title = {{Sea-level constraints on the amplitude and source distribution of Meltwater Pulse 1A}},
url = {https://doi.org/10.1038/ngeo2616},
volume = {9},
year = {2016}
}
@article{Liu2019c,
abstract = {The strength of the Pacific Walker circulation (WC) over the historical period is uncertain and strongly debated, largely due to the limited length of reliable instrumental records. Tropical Pacific corals provide continuous, highly-resolved records that can be used to overcome the limitations of the instrumental records. Here we combine coral $\delta$18O records from the western Pacific Warm Pool (WPWP) and tropical central-eastern Pacific (CEP) to develop a coral WC index back to 1886. Our coral WC index is in good agreement with post-1950 instrumental records, justifying both a direct comparison with earlier instrumental records and an evaluation of twentieth century WC trends. Our results show that pre-1950 instrumental records appear to underestimate WC variability. The coral WC index reveals a significant weakening of the WC over the twentieth century in response to development of El Ni{\~{n}}o like SST pattern in the tropical Pacific and enhanced hydrological cycle over the CEP under greenhouse warming. Our results provide new evidence for twentieth century WC variability and offer an observational constraint for improving models and their prediction of future WC behavior.},
author = {Liu, Zhongfang and Jian, Zhimin and Poulsen, Christopher J. and Zhao, Liang},
doi = {10.1016/j.epsl.2018.12.002},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {ENSO,Walker circulation,coral $\delta$18O,global warming},
pages = {85--93},
publisher = {Elsevier B.V.},
title = {{Isotopic evidence for twentieth-century weakening of the Pacific Walker circulation}},
url = {https://doi.org/10.1016/j.epsl.2018.12.002},
volume = {507},
year = {2019}
}
@article{GlobalPatternsofSpatialandTemporalVariabilityinSalinityfromMultipleGriddedArgoProducts,
address = {Boston MA, USA},
author = {Liu, Chao and Liang, Xinfeng and Chambers, Don P and Ponte, Rui M},
doi = {10.1175/JCLI-D-20-0053.1},
journal = {Journal of Climate},
number = {20},
pages = {8751--8766},
publisher = {American Meteorological Society},
title = {{Global Patterns of Spatial and Temporal Variability in Salinity from Multiple Gridded Argo Products}},
url = {https://journals.ametsoc.org/view/journals/clim/33/20/jcliD200053.xml},
volume = {33},
year = {2020}
}
@article{Lockwood2020,
abstract = {Recent reconstructions of total solar irradiance (TSI) postulate that quiet-Sun variations could give significant changes to the solar power input to Earth's climate (radiative climate forcings of 0.7–1.1 W m −2 over 1700–2019) arising from changes in quiet-Sun magnetic fields that have not, as yet, been observed. Reconstructions without such changes yield solar forcings that are smaller by a factor of more than 10. We study the quiet-Sun TSI since 1995 for three reasons: (i) this interval shows rapid decay in average solar activity following the grand solar maximum in 1985 (such that activity in 2019 was broadly equivalent to that in 1900); (ii) there is improved consensus between TSI observations; and (iii) it contains the first modelling of TSI that is independent of the observations. Our analysis shows that the most likely upward drift in quiet-Sun radiative forcing since 1700 is between +0.07 and −0.13 W m −2 . Hence, we cannot yet discriminate between the quiet-Sun TSI being enhanced or reduced during the Maunder and Dalton sunspot minima, although there is a growing consensus from the combinations of models and observations that it was slightly enhanced. We present reconstructions that add quiet-Sun TSI and its uncertainty to models that reconstruct the effects of sunspots and faculae.},
author = {Lockwood, Mike and Ball, William T.},
doi = {10.1098/rspa.2020.0077},
issn = {1364-5021},
journal = {Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences},
number = {2238},
pages = {20200077},
title = {{Placing limits on long-term variations in quiet-Sun irradiance and their contribution to total solar irradiance and solar radiative forcing of climate}},
volume = {476},
year = {2020}
}
@article{Loeb2018,
abstract = {This study examines changes in Earth's energy budget during and after the global warming "pause" (or "hiatus") using observations from the Clouds and the Earth's Radiant Energy System. We find a marked 0.83 ± 0.41 Wm-2 reduction in global mean reflected shortwave (SW) top-of-atmosphere (TOA) flux during the three years following the hiatus that results in an increase in net energy into the climate system. A partial radiative perturbation analysis reveals that decreases in low cloud cover are the primary driver of the decrease in SW TOA flux. The regional distribution of the SW TOA flux changes associated with the decreases in low cloud cover closely matches that of sea-surface temperature warming, which shows a pattern typical of the positive phase of the Pacific Decadal Oscillation. Large reductions in clear-sky SW TOA flux are also found over much of the Pacific and Atlantic Oceans in the northern hemisphere. These are associated with a reduction in aerosol optical depth consistent with stricter pollution controls in China and North America. A simple energy budget framework is used to show that TOA radiation (particularly in the SW) likely played a dominant role in driving the marked increase in temperature tendency during the post-hiatus period.},
author = {Loeb, Norman G. and Thorsen, Tyler J. and Norris, Joel R. and Wang, Hailan and Su, Wenying},
doi = {10.3390/cli6030062},
issn = {22251154},
journal = {Climate},
number = {3},
pages = {62},
title = {{Changes in Earth's energy budget during and after the “Pause” in global warming: An observational perspective}},
volume = {6},
year = {2018}
}
@article{acp-17-14593-2017,
author = {Long, C S and Fujiwara, M and Davis, S and Mitchell, D M and Wright, C J},
doi = {10.5194/acp-17-14593-2017},
journal = {Atmospheric Chemistry and Physics},
number = {23},
pages = {14593--14629},
title = {{Climatology and interannual variability of dynamic variables in multiple reanalyses evaluated by the SPARC Reanalysis Intercomparison Project (S-RIP)}},
url = {https://www.atmos-chem-phys.net/17/14593/2017/},
volume = {17},
year = {2017}
}
@book{Longhurst2007,
abstract = {This book presents an in-depth discussion of the biological and ecological geography of the oceans. It synthesizes locally restricted studies of the ocean to generate a global geography of the vast marine world. Based on patterns of algal ecology, the book divides the ocean into four primary compartments, which are then subdivided into secondary compartments},
author = {Longhurst, A.R.},
doi = {10.1016/B978-0-12-455521-1.X5000-1},
isbn = {978-0-12-455521-1},
pages = {560},
publisher = {Academic Press},
title = {{Ecological Geography of the Sea}},
url = {https://www.sciencedirect.com/book/9780124555211/ecological-geography-of-the-sea{\#}book-info},
year = {2007}
}
@article{https://doi.org/10.1029/2010JD013949,
abstract = {The change in evaporation over the oceans in climate models is analyzed from the perspective of air-sea turbulent fluxes of water and energy. The results challenge the view that the change in evaporation is predominantly constrained by the change in the net radiation at the surface. For fixed net radiation change, it is found that (1) robust increases in near-surface relative humidity and (2) robust decreases in turbulent exchange coefficient lead to a substantial reduction in evaporation below the rate of increase implied by the net radiation alone. This reduction of evaporation is associated with corresponding changes in the sensible heat flux. In addition, a net imbalance in the surface energy budget under transient greenhouse gas forcing provides a further reduction in the evaporation change in climate models. Further results also suggest that it might be more physical to view the evaporation change as a function of relative humidity change rather than net radiation. In this view, the relative humidity controls the net surface shortwave radiation through changes in low-level cloudiness and the temperature controls the net surface radiation through the changes in longwave radiation. In addition, the results demonstrate the dominant role of both the air-sea temperature difference and relative humidity over, for example, wind speed in reducing the evaporation change in climate models below the Clausius-Clapeyron rate.},
author = {Lorenz, David J and DeWeaver, Eric T and Vimont, Daniel J},
doi = {10.1029/2010JD013949},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {global warming,hydrological cycle},
number = {D20},
pages = {D20118},
title = {{Evaporation Change and Global Warming: The Role of Net Radiation and Relative Humidity}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010JD013949},
volume = {115},
year = {2010}
}
@article{Lossow2018,
author = {Lossow, S and Hurst, D F and Rosenlof, K H and Stiller, G P and von Clarmann, T and Brinkop, S and Dameris, M and J{\"{o}}ckel, P and Kinnison, D E and Plieninger, J and Plummer, D A and Ploeger, F and Read, W G and Remsberg, E E and Russell, J M and Tao, M},
doi = {10.5194/acp-18-8331-2018},
journal = {Atmospheric Chemistry and Physics},
number = {11},
pages = {8331--8351},
title = {{Trend differences in lower stratospheric water vapour between Boulder and the zonal mean and their role in understanding fundamental observational discrepancies}},
volume = {18},
year = {2018}
}
@article{Loulergue2008a,
author = {Loulergue, Laetitia and Schilt, Adrian and Spahni, Renato and Masson-Delmotte, Val{\'{e}}rie and Blunier, Thomas and Lemieux, B{\'{e}}n{\'{e}}dicte and Barnola, Jean-Marc and Raynaud, Dominique and Stocker, Thomas F and Chappellaz, J{\'{e}}r{\^{o}}me},
doi = {10.1038/nature06950},
journal = {Nature},
month = {may},
pages = {383},
publisher = {Nature Publishing Group},
title = {{Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years}},
volume = {453},
year = {2008}
}
@article{LOWELL2013128,
abstract = {The Greenland Ice Sheet is undergoing dynamic changes that will have global implications if they continue into the future. In this regard, an understanding of how the ice sheet responded to past climate changes affords a baseline for anticipating future behavior. Small, independent ice caps adjacent to the Greenland Ice Sheet (hereinafter called “local ice caps”) are sensitive indicators of the response of Greenland ice-marginal zones to climate change. Therefore, we reconstructed late Holocene ice-marginal fluctuations of the local Istorvet ice cap in east Greenland, using radiocarbon dates of subfossil plants, 10Be dates of surface boulders, and analyses of sediment cores from both threshold and control lakes. During the last termination, the Istorvet ice cap had retreated close to its maximum Holocene position by ∼11,730 cal yr BP. Radiocarbon dates of subfossil plants exposed by recent recession of the ice margin indicate that the Istorvet cap was smaller than at present from AD 200 to AD 1025. Sediments from a threshold lake show no glacial input until the ice cap advanced to within 365 m of its Holocene maximum position by ∼AD 1150. Thereafter the ice cap remained at or close to this position until at least AD 1660. The timing of this, the most extensive of the Holocene, expansion is similar to that recorded at some glaciers in the Alps and in southern Alaska. However, in contrast to these other regions, the expansion in east Greenland at AD 1150 appears to have been very close to, if not at, a maximum Holocene value. Comparison of the Istorvet ice-cap fluctuations with Holocene glacier extents in Southern Hemisphere middle-to-high latitude locations on the Antarctic Peninsula and in the Andes and the Southern Alps suggests an out-of-phase relationship. If correct, this pattern supports the hypothesis that a bipolar see-saw of oceanic and/or atmospheric circulation during the Holocene produced asynchronous glacier response at some localities in the two polar hemispheres.},
author = {Lowell, Thomas V and Hall, Brenda L and Kelly, Meredith A and Bennike, Ole and Lusas, Amanda R and Honsaker, William and Smith, Colby A and Levy, Laura B and Travis, Scott and Denton, George H},
doi = {10.1016/j.quascirev.2012.11.012},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {East Greenland,Istorvet ice cap,Late Holocene,Little Ice Age},
pages = {128--140},
title = {{Late Holocene expansion of Istorvet ice cap, Liverpool Land, east Greenland}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379112004830},
volume = {63},
year = {2013}
}
@article{Lowry2018a,
author = {Lowry, Daniel P and Morrill, Carrie},
doi = {10.1007/s00382-018-4385-y},
isbn = {0123456789},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {8},
pages = {4407--4427},
publisher = {Springer Berlin Heidelberg},
title = {{Is the Last Glacial Maximum a reverse analog for future hydroclimate changes in the Americas?}},
volume = {52},
year = {2018}
}
@article{Lozier516,
abstract = {The Atlantic meridional overturning circulation (AMOC) has a strong influence on climate, so it is important to understand how global warming may affect it. Lozier et al. report initial results from the Overturning in the Subpolar North Atlantic Program (OSNAP) (see the Perspective by Rhein). OSNAP has been measuring the flux of water transported by overturning in the high latitudes in the North Atlantic. The measurements reveal the strong variability of transport in the region and show that deep water formation in the Labrador Sea may not, as previously believed, be the major determinant of AMOC variability.Science, this issue p. 516; see also p. 456To provide an observational basis for the Intergovernmental Panel on Climate Change projections of a slowing Atlantic meridional overturning circulation (MOC) in the 21st century, the Overturning in the Subpolar North Atlantic Program (OSNAP) observing system was launched in the summer of 2014. The first 21-month record reveals a highly variable overturning circulation responsible for the majority of the heat and freshwater transport across the OSNAP line. In a departure from the prevailing view that changes in deep water formation in the Labrador Sea dominate MOC variability, these results suggest that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward in the Irminger and Iceland basins is largely responsible for overturning and its variability in the subpolar basin.},
author = {Lozier, M S and Li, F and Bacon, S and Bahr, F and Bower, A S and Cunningham, S A and de Jong, M F and de Steur, L and DeYoung, B and Fischer, J and Gary, S F and Greenan, B J W and Holliday, N P and Houk, A and Houpert, L and Inall, M E and Johns, W E and Johnson, H L and Johnson, C and Karstensen, J and Koman, G and {Le Bras}, I A and Lin, X and Mackay, N and Marshall, D P and Mercier, H and Oltmanns, M and Pickart, R S and Ramsey, A L and Rayner, D and Straneo, F and Thierry, V and Torres, D J and Williams, R G and Wilson, C and Yang, J and Yashayaev, I and Zhao, J},
doi = {10.1126/science.aau6592},
issn = {0036-8075},
journal = {Science},
number = {6426},
pages = {516--521},
publisher = {American Association for the Advancement of Science},
title = {{A sea change in our view of overturning in the subpolar North Atlantic}},
url = {https://science.sciencemag.org/content/363/6426/516},
volume = {363},
year = {2019}
}
@article{Lucas2014,
abstract = {This review provides comprehensive coverage of the tropical expansion literature to date. The primary focus is on the annual- and zonal-mean behavior of the phenomenon. An idealized model that identifies the mean meridional circulation as a hemisphere-wide structure with significant tropical–extratropical interaction is introduced as background for the understanding of the expansion and the methodologies used for detection. A variety of metrics from different data sources have been used to identify an expansion of the global tropics since 1979 by 1◦–3◦ latitude in each hemisphere, an average trend of approximately 0.5◦–1.0◦ decade−1. The symmetry of this expansion—whether Northern and Southern hemispheres are expanding at the same rate—is unclear. Limitations of observational datasets, including reanalyses, prevent a more precise determination at this time. General circulationmodels are able to qualitatively reproduce this expansion, but generally underestimate its magnitude. Multiple factors have been identified as potential drivers of the expansion, including increasing greenhouses gases, stratospheric ozone depletion, and anthropogenic aerosols. No single factor by itself appears to explain the full expansion, perhaps a shortcoming of the models or experiment design. Itmay be that some combination of these forcings is producing the change, but the relative contribution of each forcing to the expansion is currently unknown. The key issues remaining to be resolved are briefly summarized at the end.},
author = {Lucas, Christopher and Timbal, Bertrand and Nguyen, Hanh},
doi = {10.1002/wcc.251},
isbn = {1757-7799},
issn = {17577799},
journal = {WIREs Climate Change},
number = {1},
pages = {89--112},
title = {{The expanding tropics: A critical assessment of the observational and modeling studies}},
volume = {5},
year = {2014}
}
@article{Lucas2015,
author = {Lucas, Christopher and Nguyen, Hanh},
doi = {10.1002/2015JD023130},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jul},
number = {14},
pages = {6809--6824},
title = {{Regional characteristics of tropical expansion and the role of climate variability}},
url = {http://doi.wiley.com/10.1002/2015JD023130},
volume = {120},
year = {2015}
}
@article{Lunt2017a,
author = {Lunt, D J and Huber, M and Anagnostou, E and Baatsen, M L J and Caballero, R and DeConto, R and Dijkstra, H A and Donnadieu, Y and Evans, D and Feng, R and Foster, G L and Gasson, E and von der Heydt, A S and Hollis, C J and Inglis, G N and Jones, S M and Kiehl, J and {Kirtland Turner}, S and Korty, R L and Kozdon, R and Krishnan, S and Ladant, J.-B. and Langebroek, P and Lear, C H and LeGrande, A N and Littler, K and Markwick, P and Otto-Bliesner, B and Pearson, P and Poulsen, C J and Salzmann, U and Shields, C and Snell, K and St{\"{a}}rz, M and Super, J and Tabor, C and Tierney, J E and Tourte, G J L and Tripati, A and Upchurch, G R and Wade, B S and Wing, S L and Winguth, A M E and Wright, N M and Zachos, J C and Zeebe, R E},
doi = {10.5194/gmd-10-889-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {feb},
number = {2},
pages = {889--901},
publisher = {Copernicus Publications},
title = {{The DeepMIP contribution to PMIP4: experimental design for model simulations of the EECO, PETM, and pre-PETM (version 1.0)}},
url = {https://www.geosci-model-dev.net/10/889/2017/ https://www.geosci-model-dev.net/10/889/2017/gmd-10-889-2017.pdf},
volume = {10},
year = {2017}
}
@article{cp-2019-149,
author = {Lunt, D J and Bragg, F and Chan, W.-L. and Hutchinson, D K and Ladant, J.-B. and Morozova, P and Niezgodzki, I and Steinig, S and Zhang, Z and Zhu, J and Abe-Ouchi, A and de Boer, A M and Coxall, H K and Donnadieu, Y and Knorr, G and Langebroek, P M and Lohmann, G and Poulsen, C J and Sepulchre, P and Tierney, J and Valdes, P J and {Dunkley Jones}, T and Hollis, C J and Huber, M and Otto-Bliesner, B L},
doi = {10.5194/cp-17-203-2021},
journal = {Climate of the Past},
number = {1},
pages = {203--227},
title = {{DeepMIP: Model intercomparison of early Eocene climatic optimum (EECO) large-scale climate features and comparison with proxy data}},
url = {https://cp.copernicus.org/articles/17/203/2021/},
volume = {17},
year = {2021}
}
@misc{Luo,
author = {Luo, B.},
language = {Refcheck: Is this citation written somewhere online? Need more reference details. 'et al' here but only have one author in Mendeley},
title = {{Aerosol Radiative Forcing and SAD version v4.0.0 1850–2016}},
url = {ftp://iacftp.ethz.ch/pub{\_}read/luo/CMIP6{\_}SAD{\_}radForcing{\_}v4.0.0/},
year = {2018}
}
@article{Luo2016,
author = {Luo, D and Xiao, Y and Yao, Y and Dai, A and Simmonds, I and Franzke, C L E},
doi = {10.1175/JCLI-D-15-0611.1},
journal = {Journal of Climate},
pages = {3925--3947},
title = {{Impact of Ural blocking on winter warm Arctic–cold Eurasian anomalies. Part I: Blocking-induced amplification}},
volume = {29},
year = {2016}
}
@article{Lynch-Stieglitz2017,
abstract = {Abrupt changes in climate have occurred in many locations around the globe over the last glacial cycle, with pronounced temperature swings on timescales of decades or less in the North Atlantic. The global pattern of these changes suggests that they reflect variability in the Atlantic meridional overturning circulation (AMOC). This review examines the evidence from ocean sediments for ocean circulation change over these abrupt events. The evidence for changes in the strength and structure of the AMOC associated with the Younger Dryas and many of the Heinrich events is strong. Although it has been difficult to directly document changes in the AMOC over the relatively short Dansgaard-Oeschger events, there is recent evidence supporting AMOC changes over most of these oscillations as well. The lack of direct evidence for circulation changes over the shortest events leaves open the possibility of other driving mechanisms for millennial-scale climate variability.},
author = {Lynch-Stieglitz, Jean},
doi = {10.1146/annurev-marine-010816-060415},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
pages = {83--104},
pmid = {27814029},
title = {{The Atlantic Meridional Overturning Circulation and Abrupt Climate Change}},
volume = {9},
year = {2017}
}
@article{Lynch-Stieglitz2016a,
abstract = {Abstract The interaction between ocean circulation and biological processes in the Southern Ocean is thought to be a major control on atmospheric carbon dioxide content over glacial cycles. A better understanding of stratification and circulation in the Southern Ocean during the Last Glacial Maximum (LGM) provides information that will help us to assess these scenarios. First, we evaluate the link between Southern Ocean stratification and circulation states in a suite of climate model simulations. While simulated Antarctic Circumpolar Current (ACC) transport varies widely (80?350?Sverdrup (Sv)), it co-varies with horizontal and vertical stratification and the formation of the southern deep water. We then test the LGM simulations against available data from paleoceanographic proxies, which can be used to assess the density stratification and ACC transport south of Australia. The paleoceanographic data suggest a moderate increase in the Southern Ocean stratification and the ACC strength during the LGM. Even with the relatively large uncertainty in the proxy-based estimates, extreme scenarios exhibited by some climate models with ACC transports of greater than 250?Sv and highly saline Antarctic Bottom Water are highly unlikely.},
annote = {doi: 10.1002/2015PA002915},
author = {Lynch-Stieglitz, Jean and Ito, Takamitsu and Michel, Elisabeth},
doi = {10.1002/2015PA002915},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {Antarctic Circumpolar Current,Last Glacial Maximum,benthic foraminifera,oxygen isotopes},
month = {may},
number = {5},
pages = {539--552},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Antarctic density stratification and the strength of the circumpolar current during the Last Glacial Maximum}},
url = {https://doi.org/10.1002/2015PA002915},
volume = {31},
year = {2016}
}
@article{Lynch-Stieglitz2007,
abstract = {The circulation of the deep Atlantic Ocean during the height of the last ice age appears to have been quite different from today. We review observations implying that Atlantic meridional overturning circulation during the Last Glacial Maximum was neither extremely sluggish nor an enhanced version of present-day circulation. The distribution of the decay products of uranium in sediments is consistent with a residence time for deep waters in the Atlantic only slightly greater than today. However, evidence from multiple water-mass tracers supports a different distribution of deep-water properties, including density, which is dynamically linked to circulation.},
author = {Lynch-Stieglitz, Jean and Adkins, Jess F and Curry, William B and Dokken, Trond and Hall, Ian R and Herguera, Juan Carlos and Hirschi, Jo{\"{e}}l J.-M. and Ivanova, Elena V and Kissel, Catherine and Marchal, Olivier and Marchitto, Thomas M and McCave, I Nicholas and McManus, Jerry F and Mulitza, Stefan and Ninnemann, Ulysses and Peeters, Frank and Yu, Ein-Fen and Zahn, Rainer},
doi = {10.1126/science.1137127},
journal = {Science},
month = {apr},
number = {5821},
pages = {66},
title = {{Atlantic Meridional Overturning Circulation During the Last Glacial Maximum}},
url = {http://science.sciencemag.org/content/316/5821/66.abstract},
volume = {316},
year = {2007}
}
@article{acp-19-10335-2019,
author = {M{\"{u}}hle, Jens and Trudinger, Cathy M and Western, Luke M and Rigby, Matthew and Vollmer, Martin K and Park, Sunyoung and Manning, Alistair J and Say, Daniel and Ganesan, Anita and Steele, L Paul and Ivy, Diane J and Arnold, Tim and Li, Shanlan and Stohl, Andreas and Harth, Christina M and Salameh, Peter K and McCulloch, Archie and O'Doherty, Simon and Park, Mi-Kyung and Jo, Chun Ok and Young, Dickon and Stanley, Kieran M and Krummel, Paul B and Mitrevski, Blagoj and Hermansen, Ove and Lunder, Chris and Evangeliou, Nikolaos and Yao, Bo and Kim, Jooil and Hmiel, Benjamin and Buizert, Christo and Petrenko, Vasilii V and Arduini, Jgor and Maione, Michela and Etheridge, David M and Michalopoulou, Eleni and Czerniak, Mike and Severinghaus, Jeffrey P and Reimann, Stefan and Simmonds, Peter G and Fraser, Paul J and Prinn, Ronald G and Weiss, Ray F},
doi = {10.5194/acp-19-10335-2019},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {aug},
number = {15},
pages = {10335--10359},
title = {{Perfluorocyclobutane (PFC-318, c-C4F8) in the global atmosphere}},
url = {https://acp.copernicus.org/articles/19/10335/2019/},
volume = {19},
year = {2019}
}
@article{Muller2020,
abstract = {The loss of carbonate production during the Toarcian Oceanic Anoxic Event (T-OAE, ca. 183 Ma) is hypothesized to have been at least partly triggered by ocean acidification linked to magmatism from the Karoo-Ferrar large igneous province (southern Africa and Antarctica). However, the dynamics of acidification have never been directly quantified across the T-OAE. Here, we present the first record of temporal evolution of seawater pH spanning the late Pliensbachian and early Toarcian from the Lusitanian Basin (Portugal) reconstructed on the basis of boron isotopic composition ($\delta$11B) of brachiopod shells. $\delta$11B declines by {\~{}}1‰ across the Pliensbachian-Toarcian boundary (Pl-To) and attains the lowest values ({\~{}}12.5‰) just prior to and within the T-OAE, followed by fluctuations and a moderately increasing trend afterwards. The decline in $\delta$11B coincides with decreasing bulk CaCO3 content, in parallel with the two-phase decline in carbonate production observed at global scales and with changes in pCO2 derived from stomatal indices. Seawater pH had declined significantly already prior to the T-OAE, probably due to the repeated emissions of volcanogenic CO2. During the earliest phase of the T-OAE, pH increased for a short period, likely due to intensified continental weathering and organic carbon burial, resulting in atmospheric CO2 drawdown. Subsequently, pH dropped again, reaching the minimum in the middle of the T-OAE. The early Toarcian marine extinction and carbonate collapse were thus driven, in part, by ocean acidification, similar to other Phanerozoic events caused by major CO2 emissions and warming.},
author = {M{\"{u}}ller, Tam{\'{a}}s and Jurikova, Hana and Gutjahr, Marcus and Toma{\v{s}}ov{\'{y}}ch, Adam and Schl{\"{o}}gl, Jan and Liebetrau, Volker and Duarte, Lu{\'{i}}s v. and Milovsk{\'{y}}, Rastislav and Suan, Guillaume and Mattioli, Emanuela and Pittet, Bernard and Eisenhauer, Anton},
doi = {10.1130/G47781.1},
issn = {0091-7613},
journal = {Geology},
month = {aug},
number = {12},
pages = {1184--1188},
title = {{Ocean acidification during the early Toarcian extinction event: Evidence from boron isotopes in brachiopods}},
url = {https://doi.org/10.1130/G47781.1},
volume = {48},
year = {2020}
}
@article{Ma2016,
abstract = {AbstractIn this study, the zonal mass streamfunction ?, which depicts intuitively the tropical Pacific Walker circulation (PWC) structure, characterized by an enclosed and anticlockwise rotation cell in the zonal-vertical section over the equatorial Pacific, was used to study the changes of PWC spatial structure during 1979-2012. To examine the robustness of changes in PWC characteristics, the linear trends of PWC were evaluated and compared among the current seven sets of reanalysis data, along with a comparison to the trends of surface climate variables. The spatial pattern of ? trend exhibited a strengthening and westward shifting trend of PWC in all reanalysis data sets, with the significantly positive ? dominating the western Pacific and negative ? controlling the eastern Pacific. This kind of change is physically in agreement with the changes of the sea level pressure (SLP), surface winds and precipitation derived from both the reanalyses and independent observations. Quantitative analyses of the changes in the PWC intensity and western edge, defined based on the zonal mass streamfunction ?, also revealed a robust strengthening and westward shifting trend among all reanalysis data sets, with a trend of 15.08{\%} (10yr)-1 and 3.70 longitudes (10yr)-1 in the ensemble mean of 7 sets of reanalysis data, with the strongest (weakest) intensification of 17.53{\%} (7.96{\%}) (10yr)-1 in 20CR (NCEP2) and largest (smallest) westward shift of -4.68 (-2.55) longitudes (10yr)-1 in JRA55 (JRA25). In response to the recent observed La Ni{\~{n}}a-like anomalous SST forcing, the Atmospheric Model Inter-Comparison Project, phase 5 (AMIP5) ensemble simulations with 26 models reasonably reproduced the observed strengthening and westward shifting trend of PWC, implying the dominant forcing of the La Ni{\~{n}}a-like SST anomalies to the recent PWC change.},
author = {Ma, Shuangmei and Zhou, Tianjun},
doi = {10.1175/JCLI-D-15-0398.1},
isbn = {8610829952},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Atmospheric circulation,Circulation/dynamics,Climate models,Climate variability,Models and modeling,Physical meteorology and climatology,Trends,Variability},
number = {9},
pages = {3097--3118},
title = {{Robust Strengthening and westward shift of the tropical Pacific Walker circulation during 1979-2012: A comparison of 7 sets of reanalysis data and 26 CMIP5 models}},
volume = {29},
year = {2016}
}
@article{Ma2018b,
author = {Ma, X and Zhang, Y},
doi = {10.1007/s00382-018-4104-8},
journal = {Climate Dynamics},
pages = {3685--3698},
title = {{Interannual variability of the North Pacific winter storm track and its relationship with extratropical atmospheric circulation}},
volume = {51},
year = {2018}
}
@article{acp-19-6861-2019,
author = {Ma, Z and Liu, R and Liu, Y and Bi, J},
doi = {10.5194/acp-19-6861-2019},
journal = {Atmospheric Chemistry and Physics},
number = {10},
pages = {6861--6877},
title = {{Effects of air pollution control policies on PM2.5 pollution improvement in China from 2005 to 2017: a satellite-based perspective}},
url = {https://acp.copernicus.org/articles/19/6861/2019/},
volume = {19},
year = {2019}
}
@article{MacDonald2008a,
abstract = {The Russian treeline is a dynamic ecotone typified by steep gradients in summer temperature and regionally variable gradients in albedo and heat flux. The location of the treeline is largely controlled by summer temperatures and growing season length. Temperatures have responded strongly to twentieth-century global warming and will display a magnified response to future warming. Dendroecological studies indicate enhanced conifer recruitment during the twentieth century. However, conifers have not yet recolonized many areas where trees were present during the Medieval Warm period (ca AD 800-1,300) or the Holocene Thermal Maximum (HTM; ca 10,000-3,000 years ago). Reconstruction of tree distributions during the HTM suggests that the future position of the treeline due to global warming may approximate its former Holocene maximum position. An increased dominance of evergreen tree species in the northern Siberian forests may be an important difference between past and future conditions. Based on the slow rates of treeline expansion observed during the twentieth century, the presence of steep climatic gradients associated with the current Arctic coastline and the prevalence of organic soils, it is possible that rates of treeline expansion will be regionally variable and transient forest communities with species abundances different from today's may develop.},
author = {MacDonald, G. M. and Kremenetski, K. V. and Beilman, D. W.},
doi = {10.1098/rstb.2007.2200},
issn = {09628436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
keywords = {Arctic,Boreal forest,Climate change,Eurasia,Holocene,Treeline},
pages = {2283--2299},
title = {{Climate change and the northern Russian treeline zone}},
volume = {363},
year = {2008}
}
@article{MacDonald2000a,
abstract = {Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern Russia. Treeline advance on the Kola Peninsula, however, appears to have occurred later than in other regions. During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5°to 7.0°C warmer than modern. The development of forest and expansion of treeline likely reflects a number of complimentary environmental conditions, including heightened summer insolation, the demise of Eurasian ice sheets, reduced sea-ice cover, greater continentality with eustatically lower sea level, and extreme Arctic penetration of warm North Atlantic waters. The late Holocene retreat of Eurasian treeline coincides with declining summer insolation, cooling arctic waters, and neoglaciation. (C) 2000 University of Washington.},
author = {MacDonald, Glen M. and Velichko, Andrei A. and Kremenetski, Constantine V. and Borisova, Olga K. and Goleva, Aleksandra A. and Andreev, Andrei A. and Cwynar, Les C. and Riding, Richard T. and Forman, Steven L. and Edwards, Tom W.D. and Aravena, Ramon and Hammarlund, Dan and Szeicz, Julian M. and Gattaulin, Valery N.},
doi = {10.1006/qres.1999.2123},
isbn = {0033-5894},
issn = {00335894},
journal = {Quaternary Research},
number = {3},
pages = {302 -- 311},
pmid = {75},
title = {{Holocene treeline history and climate change across northern Eurasia}},
volume = {53},
year = {2000}
}
@article{MacFarlingMeure2006b,
abstract = {New measurements of atmospheric greenhouse gas concentrations in ice from Law Dome, Antarctica reproduce published Law Dome CO2 and CH4 records, extend them back to 2000 years BP, and include N2O. They have very high air age resolution, data density and measurement precision. Firn air measurements span the past 65 years and overlap with the ice core and direct atmospheric observations. Major increases in CO2, CH4 and N2O concentrations during the past 200 years followed a period of relative stability beforehand. Decadal variations during the industrial period include the stabilization of CO2 and slowing of CH4 and N2O growth in the 1940s and 1950s. Variations of up to 10 ppm CO2, 40 ppb CH4 and 10 ppb N2O occurred throughout the preindustrial period. Methane concentrations grew by 100 ppb from AD 0 to 1800, possibly due to early anthropogenic emissions.},
author = {{MacFarling Meure}, C. and Etheridge, D. and Trudinger, C. and Steele, P. and Langenfelds, R. and {Van Ommen}, T. and Smith, A. and Elkins, J.},
doi = {10.1029/2006GL026152},
isbn = {1944-8007},
issn = {00948276},
journal = {Geophysical Research Letters},
number = {14},
pages = {L14810},
title = {{Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP}},
volume = {33},
year = {2006}
}
@article{Machida1995,
abstract = {In order to estimate the concentrations of atmospheric nitrous oxide (N2O) during the last 250 years, air samples were extracted from an Antarctic ice core, H15, using a dry extraction system and were then analyzed with a precision of ±2 ppbv. The results obtained were clearly less scattered and much tighter than those of the previous studies. Our data showed that the concentrations of atmospheric N2O in the 18th century were about 276 ppbv on average. It was also obvious that the N2O concentration began to increase in the mid-19th century and reached approximately 293 ppbv around 1965, the trend of the concentration increase correlating quite well with the direct atmospheric measurements at the South Pole. Such an increase in the atmospheric N2O concentration is thought to be of anthropogenic origin.},
author = {Machida, T and Nakazawa, T and Fujii, Y and Aoki, S and Watanabe, O},
doi = {10.1029/95GL02822},
journal = {Geophysical Research Letters},
number = {21},
pages = {2921--2924},
title = {{Increase in the atmospheric nitrous oxide concentration during the last 250 years}},
volume = {22},
year = {1995}
}
@article{doi:10.1146/annurev-marine-010816-060610,
abstract = { Arctic sea ice has declined precipitously in both extent and thickness over the past four decades; by contrast, Antarctic sea ice has shown little overall change, but this masks large regional variability. Climate models have not captured these changes. But these differences do not represent a paradox. The processes governing, and impacts of, natural variability and human-induced changes differ markedly at the poles largely because of the ways in which differences in geography control the properties of and interactions among the atmosphere, ice, and ocean. The impact of natural variability on the ice cover is large at both poles, so modeled ice trends are not entirely inconsistent with contributions from both natural variability and anthropogenic forcing. Despite this concurrence, the coupling of natural climate variability, climate feedbacks, and sea ice is not well understood, and significant biases remain in model representations of the ice cover and the processes that drive it. },
annote = {PMID: 30216739},
author = {Maksym, Ted},
doi = {10.1146/annurev-marine-010816-060610},
journal = {Annual Review of Marine Science},
number = {1},
pages = {187--213},
title = {{Arctic and Antarctic Sea Ice Change: Contrasts, Commonalities, and Causes}},
url = {https://doi.org/10.1146/annurev-marine-010816-060610},
volume = {11},
year = {2019}
}
@article{Mann2009,
abstract = {The global climate record of the past 1500 years shows two long intervals of anomalous temperatures before the obvious anthropogenic warming of the 20th century: the warm Medieval Climate Anomaly between roughly 950 and 1250 A.D. and the Little Ice Age between around 1400 and 1700 A.D. It has become increasingly clear in recent years, however, that climate changes inevitably involve a complex pattern of regional changes, whose inhomogeneities contain valuable insights into the mechanisms that cause them. Mann et al. (p. 1256) analyzed proxy records of climate since 500 A.D. and compared their global patterns with model reconstructions. The results identify the large-scale processes—like El Ni{\~{n}}o and the North Atlantic Oscillation—that can account for the observations and suggest that dynamic responses to variable radiative forcing were their primary causes.Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Ni{\~{n}}a–like conditions in the tropical Pacific. The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extratropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Ni{\~{n}}o and the North Atlantic Oscillation–Arctic Oscillation.},
author = {Mann, Michael E and Zhang, Zhihua and Rutherford, Scott and Bradley, Raymond S and Hughes, Malcolm K and Shindell, Drew and Ammann, Caspar and Faluvegi, Greg and Ni, Fenbiao},
doi = {10.1126/science.1177303},
journal = {Science},
month = {nov},
number = {5957},
pages = {1256},
title = {{Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly}},
url = {http://science.sciencemag.org/content/326/5957/1256.abstract},
volume = {326},
year = {2009}
}
@article{Manney2018,
abstract = {{\textcopyright} 2018 American Meteorological Society. Long-term changes in upper-tropospheric jet latitude, altitude, and strength are assessed for 1980-2014 using five modern reanalyses: MERRA, MERRA-2, ERA-Interim, JRA-55, and NCEP CFSR. Changes are computed from jet locations evaluated daily at each longitude to analyze regional and seasonal variations. The changes in subtropical and polar (eddy driven) jets are evaluated separately. Good agreement among the reanalyses in many regions and seasons provides confidence in the robustness of the diagnosed trends. Jet shifts show strong regional and seasonal variations, resulting in changes that are not robust in zonal or annual means. Robust changes in the subtropical jet indicate tropical widening over Africa except during Northern Hemisphere (NH) spring, and tropical narrowing over the eastern Pacific in NH winter. The Southern Hemisphere (SH) polar jet shows a robust poleward shift, while the NH polar jet shifts equatorward in most regions/seasons. Both subtropical and polar jet altitudes typically increase; these changes are more robust in the NH than in the SH. Subtropical jet wind speeds have generally increased in winter and decreased in summer, whereas polar jet wind speeds have weakened (strengthened) over Africa and eastern Asia (elsewhere) during winter in both hemispheres. The Asian monsoon has increased in area and appears to have shifted slightly westward toward Africa. The results herein highlight the importance of understanding regional and seasonal variations when quantifying long-term changes in jet locations, the mechanisms for those changes, and their potential human impacts. Comparison of multiple reanalyses is a valuable tool for assessing the robustness of jet changes.},
author = {Manney, Gloria L. and Hegglin, Michaela I.},
doi = {10.1175/JCLI-D-17-0303.1},
isbn = {0037601400069},
issn = {08948755},
journal = {Journal of Climate},
number = {1},
pages = {423--448},
title = {{Seasonal and regional variations of long-term changes in upper-tropospheric jets from reanalyses}},
volume = {31},
year = {2018}
}
@article{Manney2011a,
abstract = {Chemical ozone destruction occurs over both polar regions in local winter–spring. In the Antarctic, essentially complete removal of lower-stratospheric ozone currently results in an ozone hole every year, whereas in the Arctic, ozone loss is highly variable and has until now been much more limited. Here we demonstrate that chemical ozone destruction over the Arctic in early 2011 was—for the first time in the observational record—comparable to that in the Antarctic ozone hole. Unusually long-lasting cold conditions in the Arctic lower stratosphere led to persistent enhancement in ozone-destroying forms of chlorine and to unprecedented ozone loss, which exceeded 80 per cent over 18–20 kilometres altitude. Our results show that Arctic ozone holes are possible even with temperatures much milder than those in the Antarctic. We cannot at present predict when such severe Arctic ozone depletion may be matched or exceeded.},
author = {Manney, Gloria L and Santee, Michelle L and Rex, Markus and Livesey, Nathaniel J and Pitts, Michael C and Veefkind, Pepijn and Nash, Eric R and Wohltmann, Ingo and Lehmann, Ralph and Froidevaux, Lucien and Poole, Lamont R and Schoeberl, Mark R and Haffner, David P and Davies, Jonathan and Dorokhov, Valery and Gernandt, Hartwig and Johnson, Bryan and Kivi, Rigel and Kyr{\"{o}}, Esko and Larsen, Niels and Levelt, Pieternel F and Makshtas, Alexander and McElroy, C Thomas and Nakajima, Hideaki and Parrondo, Maria Concepci{\'{o}}n and Tarasick, David W and von der Gathen, Peter and Walker, Kaley A and Zinoviev, Nikita S},
doi = {10.1038/nature10556},
issn = {1476-4687},
journal = {Nature},
number = {7370},
pages = {469--475},
title = {{Unprecedented Arctic ozone loss in 2011}},
url = {https://doi.org/10.1038/nature10556},
volume = {478},
year = {2011}
}
@article{doi:10.1029/2020GL089063,
abstract = {Abstract Aura Microwave Limb Sounder (MLS) measurements show that chemical processing was critical to the observed record-low Arctic stratospheric ozone in spring 2020. The 16-year MLS record indicates more polar denitrification and dehydration in 2019/2020 than in any Arctic winter except 2015/2016. Chlorine activation and ozone depletion began earlier than in any previously observed winter, with evidence of chemical ozone loss starting in November. Active chlorine then persisted as late into spring as it did in 2011. Empirical estimates suggest maximum chemical ozone losses near 2.8 ppmv by late March in both 2011 and 2020. However, peak chlorine activation, and thus peak ozone loss, occurred at lower altitudes in 2020 than in 2011, leading to the lowest Arctic ozone values ever observed at potential temperature levels from {\~{}}400—480 K, with similar ozone values to those in 2011 at higher levels.},
annote = {e2020GL089063 2020GL089063},
author = {Manney, Gloria L and Livesey, Nathaniel J and Santee, Michelle L and Froidevaux, Lucien and Lambert, Alyn and Lawrence, Zachary D and Mill{\'{a}}n, Luis F and Neu, Jessica L and Read, William G and Schwartz, Michael J and Fuller, Ryan A},
doi = {10.1029/2020GL089063},
journal = {Geophysical Research Letters},
keywords = {Arctic ozone,chemical ozone loss,satellite measurements,stratosphere},
number = {16},
pages = {e2020GL089063},
title = {{Record-low Arctic stratospheric ozone in 2020: MLS observations of chemical processes and comparisons with previous extreme winters}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL089063},
volume = {47},
year = {2020}
}
@article{doi:10.1175/JCLI-D-13-00759.1,
abstract = {AbstractEl Ni{\~{n}}o–Southern Oscillation (ENSO) is a pronounced mode of climate variability that originates in the tropical Pacific and affects weather patterns worldwide. Growing evidence suggests that despite extensive changes in tropical climate, ENSO was active over vast geological epochs stretching millions of years from the late Cretaceous to the Holocene. In particular, ENSO persisted during the Pliocene, when a dramatic reduction occurred in the mean east–west temperature gradient in the equatorial Pacific. The mechanisms for sustained ENSO in such climates are poorly understood. Here a comprehensive climate model is used to simulate ENSO for a broad range of tropical Pacific mean climates characterized by different climatological SST gradients. It is found that the simulated ENSO remains surprisingly robust: when the east–west gradient is reduced from 6° to 1°C, the amplitude of ENSO decreases only by 30{\%}–40{\%}, its dominant period remains close to 3–4 yr, and the spectral peak stays above red noise. To explain these results, the magnitude of ocean–atmosphere feedbacks that control the stability of the natural mode of ENSO (the Bjerknes stability index) is evaluated. It is found that as a result of reorganization of the atmospheric Walker circulation in response to changes in the mean surface temperature gradient, the growth/decay rates of the ENSO mode stay nearly constant throughout different climates. These results explain the persistence of ENSO in the past and, in particular, reconcile the seemingly contradictory findings of ENSO occurrence and the small mean east–west temperature gradient during the Pliocene.},
author = {Manucharyan, Georgy E and Fedorov, Alexey V},
doi = {10.1175/JCLI-D-13-00759.1},
journal = {Journal of Climate},
number = {15},
pages = {5836--5850},
title = {{Robust ENSO across a Wide Range of Climates}},
url = {https://doi.org/10.1175/JCLI-D-13-00759.1},
volume = {27},
year = {2014}
}
@article{Manzanedo2020,
abstract = {Changes in the temporal coherence between populations, which can influence their stability, resilience and persistence, remain a critical uncertainty of climate change. Recent studies have documented increasing spatial synchrony between populations at continental scales and linked it to anthropogenic climate change. However, the lack of long-term and global baseline perspectives on spatial synchrony presents a challenge to understanding the importance of these trends. Here, we show a steady rise in the spatial synchrony of annual tree growth from a global tree ring database over the past 50 years that is consistent across continents, species and environmental conditions and is unprecedented for the past millennium. Increasing growth synchrony coincided with warming trends and potentially rising synchrony in the temperature records. We discuss the potential driving mechanisms and the limitations in the interpretation of this trend, and we propose that increasing mutual dependency on external factors (also known as Moran's effect) linked to rising global temperatures is the most likely driver of more homogeneous global growth dynamics.},
author = {Manzanedo, Rub{\'{e}}n Delgado and HilleRisLambers, Janneke and Rademacher, Tim Tito and Pederson, Neil},
doi = {10.1038/s41559-020-01306-x},
issn = {2397334X},
journal = {Nature Ecology and Evolution},
pages = {1622--1629},
title = {{Evidence of unprecedented rise in growth synchrony from global tree ring records}},
volume = {4},
year = {2020}
}
@article{Marcer2018,
author = {Marcer, Marco and Serrano, Charlie and Brenning, Alexander and Bodin, Xavier and Goetz, Jason and Schoeneich, Philippe},
doi = {10.5194/tc-13-141-2019},
issn = {1994-0424},
journal = {The Cryosphere},
month = {jan},
number = {1},
pages = {141--155},
publisher = {Copernicus Publications},
title = {{Evaluating the destabilization susceptibility of active rock glaciers in the French Alps}},
url = {https://www.the-cryosphere.net/13/141/2019/ https://www.the-cryosphere.net/13/141/2019/tc-13-141-2019.pdf},
volume = {13},
year = {2019}
}
@article{Marcott2013,
abstract = {The climate has been warming since the industrial revolution, but how warm is climate now compared with the rest of the Holocene? Marcott et al. (p. 1198) constructed a record of global mean surface temperature for more than the last 11,000 years, using a variety of land- and marine-based proxy data from all around the world. The pattern of temperatures shows a rise as the world emerged from the last deglaciation, warm conditions until the middle of the Holocene, and a cooling trend over the next 5000 years that culminated around 200 years ago in the Little Ice Age. Temperatures have risen steadily since then, leaving us now with a global temperature higher than those during 90{\%} of the entire Holocene.Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by {\~{}}0.7°C cooling through the middle to late Holocene ({\&}lt;5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with {\~{}}2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during {\~{}}75{\%} of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.},
author = {Marcott, Shaun A and Shakun, Jeremy D and Clark, Peter U and Mix, Alan C},
doi = {10.1126/science.1228026},
journal = {Science},
month = {mar},
number = {6124},
pages = {1198--1201},
title = {{A Reconstruction of Regional and Global Temperature for the Past 11,300 Years}},
url = {http://science.sciencemag.org/content/339/6124/1198.abstract},
volume = {339},
year = {2013}
}
@article{Marcott2014,
abstract = {Global climate and the concentration of atmospheric carbon dioxide (CO2) are correlated over recent glacial cycles. The combination of processes responsible for a rise in atmospheric CO2 at the last glacial termination (23,000 to 9,000 years ago), however, remains uncertain. Establishing the timing and rate of CO2 changes in the past provides critical insight into the mechanisms that influence the carbon cycle and helps put present and future anthropogenic emissions in context. Here we present CO2 and methane (CH4) records of the last deglaciation from a new high-accumulation West Antarctic ice core with unprecedented temporal resolution and precise chronology. We show that although low-frequency CO2 variations parallel changes in Antarctic temperature, abrupt CO2 changes occur that have a clear relationship with abrupt climate changes in the Northern Hemisphere. A significant proportion of the direct radiative forcing associated with the rise in atmospheric CO2 occurred in three sudden steps, each of 10 to 15 parts per million. Every step took place in less than two centuries and was followed by no notable change in atmospheric CO2 for about 1,000 to 1,500 years. Slow, millennial-scale ventilation of Southern Ocean CO2-rich, deep-ocean water masses is thought to have been fundamental to the rise in atmospheric CO2 associated with the glacial termination, given the strong covariance of CO2 levels and Antarctic temperatures. Our data establish a contribution from an abrupt, centennial-scale mode of CO2 variability that is not directly related to Antarctic temperature. We suggest that processes operating on centennial timescales, probably involving the Atlantic meridional overturning circulation, seem to be influencing global carbon-cycle dynamics and are at present not widely considered in Earth system models.},
author = {Marcott, Shaun A. and Bauska, Thomas K. and Buizert, Christo and Steig, Eric J. and Rosen, Julia L. and Cuffey, Kurt M. and Fudge, T. J. and Severinghaus, Jeffery P. and Ahn, Jinho and Kalk, Michael L. and McConnell, Joseph R. and Sowers, Todd and Taylor, Kendrick C. and White, James W.C. and Brook, Edward J.},
doi = {10.1038/nature13799},
isbn = {0028-0836},
issn = {14764687},
journal = {Nature},
month = {oct},
number = {7524},
pages = {616--619},
pmid = {25355363},
publisher = {Nature Publishing Group},
title = {{Centennial-scale changes in the global carbon cycle during the last deglaciation}},
volume = {514},
year = {2014}
}
@article{Margari2020,
abstract = {The abrupt nature of warming events recorded in Greenland ice-cores during the last glacial has generated much debate over their underlying mechanisms. Here, we present joint marine and terrestrial analyses from the Portuguese Margin, showing a succession of cold stadials and warm interstadials over the interval 35–57 ka. Heinrich stadials 4 and 5 contain considerable structure, with a short transitional phase leading to an interval of maximum cooling and aridity, followed by slowly increasing sea-surface temperatures and moisture availability. A climate model experiment reproduces the changes in western Iberia during the final part of Heinrich stadial 4 as a result of the gradual recovery of the Atlantic meridional overturning circulation. What emerges is that Greenland ice-core records do not provide a unique template for warming events, which involved the operation of both fast and slow components of the coupled atmosphere–ocean–sea-ice system, producing adjustments over a range of timescales.},
author = {Margari, Vasiliki and Skinner, Luke C. and Menviel, Laurie and Capron, Emilie and Rhodes, Rachael H. and Mleneck-Vautravers, Maryline J. and Ezat, Mohamed M. and Martrat, Belen and Grimalt, Joan O. and Hodell, David A. and Tzedakis, Polychronis C.},
doi = {10.1038/s43247-020-0006-x},
issn = {2662-4435},
journal = {Communications Earth {\&} Environment},
number = {1},
pages = {1--9},
publisher = {Springer US},
title = {{Fast and slow components of interstadial warming in the North Atlantic during the last glacial}},
url = {http://dx.doi.org/10.1038/s43247-020-0006-x},
volume = {1},
year = {2020}
}
@article{Marino2013a,
abstract = {An ensemble of new, high-resolution records of surface ocean hydrography from the Indian-Atlantic oceanic gateway, south of Africa, demonstrates recurrent and high-amplitude salinity oscillations in the Agulhas Leakage area during the penultimate glacial-interglacial cycle. A series of millennial-scale salinification events, indicating strengthened salt leakage into the South Atlantic, appear to correlate with abrupt changes in the North Atlantic climate and Atlantic Meridional Overturning Circulation (AMOC). This interhemispheric coupling, which plausibly involved changes in the Hadley Cell and midlatitude westerlies that impacted the interocean transport at the tip of Africa, suggests that the Agulhas Leakage acted as a source of negative buoyancy for the perturbed AMOC, possibly aiding its return to full strength. Our finding points to the Indian-to-Atlantic salt transport as a potentially important modulator of the AMOC during the abrupt climate changes of the Late Pleistocene.},
annote = {doi: 10.1002/palo.20038},
author = {Marino, Gianluca and Zahn, Rainer and Ziegler, Martin and Purcell, Conor and Knorr, Gregor and Hall, Ian R and Ziveri, Patrizia and Elderfield, Henry},
doi = {10.1002/palo.20038},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {AMOC,Agulhas Leakage,Southern Hemisphere atmospheric circulation,abrupt climate change,bipolar seesaw,millennial-scale variability},
month = {sep},
number = {3},
pages = {599--606},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Agulhas salt-leakage oscillations during abrupt climate changes of the Late Pleistocene}},
url = {https://doi.org/10.1002/palo.20038},
volume = {28},
year = {2013}
}
@article{Marquer2017,
abstract = {Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen-based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming practices and forestry in response to population growth and industrialization. This is a unique signature of anthropogenic impact within the Holocene but European vegetation remains climatically sensitive and thus may continue to respond to ongoing climate change.},
author = {Marquer, Laurent and Gaillard, Marie Jos{\'{e}} and Sugita, Shinya and Poska, Anneli and Trondman, Anna Kari and Mazier, Florence and Nielsen, Anne Birgitte and Fyfe, Ralph M. and J{\"{o}}nsson, Anna Maria and Smith, Benjamin and Kaplan, Jed O. and Alenius, Teija and Birks, H. John B. and Bjune, Anne E. and Christiansen, J{\"{o}}rg and Dodson, John and Edwards, Kevin J. and Giesecke, Thomas and Herzschuh, Ulrike and Kangur, Mihkel and Koff, Tiiu and Lata{\l}owa, Ma{\l}gorzata and Lechterbeck, Jutta and Olofsson, J{\"{o}}rgen and Sepp{\"{a}}, Heikki},
doi = {10.1016/j.quascirev.2017.07.001},
isbn = {02773791},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Climate,Europe,Holocene,Human impact,LPJ-GUESS,Land use,Pollen,REVEALS,Vegetation composition},
pages = {20--37},
title = {{Quantifying the effects of land use and climate on Holocene vegetation in Europe}},
volume = {171},
year = {2017}
}
@article{Martin-Rey2014a,
abstract = {Atlantic and Pacific El Ni{\~{n}}o are the leading tropical oceanic variability phenomena at interannual timescales. Recent studies have demonstrated how the Atlantic Ni{\~{n}}o is able to influence on the dynamical processes triggering the development of the Pacific La Ni{\~{n}}a and vice versa. However, the stationarity of this interbasin connection is still controversial. Here we show for the first time that the Atlantic–Pacific Ni{\~{n}}os connection takes place at particular decades, coinciding with negative phases of the Atlantic Multidecadal Oscillation (AMO). During these decades, the Atlantic–Pacific connection appears as the leading coupled covariability mode between Tropical Atlantic and Pacific interannual variability. The mode is defined by a predictor field, the summer Atlantic Sea Surface Temperature (SST), and a set of predictand fields which represent a chain of atmospheric and oceanic mechanisms to generate the Pacific El Ni{\~{n}}o phenomenon: alteration of the Walker circulation, surface winds in western Pacific, oceanic Kelvin wave propagating eastward and impacting on the eastern thermocline and changes in the Pacific SST by internal Bjerknes feedback. We suggest that the multidecadal component of the Atlantic acts as a switch for El Ni{\~{n}}o prediction during certain decades, putting forward the AMO as the modulator, acting through changes in the equatorial Atlantic convection and the equatorial Pacific SST variability. These results could have a major relevance for the decadal prediction systems.},
author = {Mart{\'{i}}n-Rey, Marta and Rodr{\'{i}}guez-Fonseca, Bel{\'{e}}n and Polo, Irene and Kucharski, Fred},
doi = {10.1007/s00382-014-2305-3},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {11},
pages = {3163--3178},
title = {{On the Atlantic–Pacific Ni{\~{n}}os connection: a multidecadal modulated mode}},
url = {https://doi.org/10.1007/s00382-014-2305-3},
volume = {43},
year = {2014}
}
@article{Martin-Rey2018,
abstract = {The Atlantic multidecadal oscillation (AMO) is the leading mode of Atlantic sea surface temperature (SST) variability at multidecadal time scales. Previous studies have shown that the AMO could modulate El Ni{\~{n}}o–Southern Oscillation (ENSO) variance. However, the role played by the AMO in the tropical Atlantic variability (TAV) is still uncertain. Here, it is demonstrated that during negative AMO phases, associated with a shallower thermocline, the eastern equatorial Atlantic SST variability is enhanced by more than 150{\%} in boreal summer. Consequently, the interannual TAV modes are modified. During negative AMO, the Atlantic Ni{\~{n}}o displays larger amplitude and a westward extension and it is preceded by a simultaneous weakening of both subtropical highs in winter and spring. In contrast, a meridional seesaw SLP pattern evolving into a zonal gradient leads the Atlantic Ni{\~{n}}o during positive AMO. The north tropical Atlantic (NTA) mode is related to a Scandinavian blocking pattern during winter and spring in negative AMO, while under positive AMO it is part of the SST tripole associated with the North Atlantic Oscillation. Interestingly, the emergence of an overlooked variability mode, here called the horseshoe (HS) pattern on account of its shape, is favored during negative AMO. This anomalous warm (cool) HS surrounding an eastern equatorial cooling (warming) is remotely forced by an ENSO phenomenon. During negative AMO, the tropical–extratropical teleconnections are enhanced and the Walker circulation is altered. This, together with the increased equatorial SST variability, could promote the ENSO impacts on TAV. The results herein give a step forward in the better understanding of TAV, which is essential to improving its modeling, impacts, and predictability.},
author = {Mart{\'{i}}n-Rey, Marta and Polo, Irene and Rodr{\'{i}}guez-Fonseca, Bel{\'{e}}n and Losada, Teresa and Lazar, Alban},
doi = {10.1175/JCLI-D-16-0459.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jan},
number = {2},
pages = {515--536},
title = {{Is There Evidence of Changes in Tropical Atlantic Variability Modes under AMO Phases in the Observational Record?}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0459.1},
volume = {31},
year = {2018}
}
@article{Martinez-Boti2015a,
abstract = {Atmospheric CO2 fluctuations over glacial–interglacial cycles remain a major challenge to our understanding of the carbon cycle and the climate system. Leading hypotheses put forward to explain glacial– interglacial atmospheric CO2 variations invoke changes in deep-ocean carbon storage, probably modulated by processes in the Southern Ocean, where much of the deep ocean is ventilated. A central aspect of such models is that, during deglaciations, an isolated glacial deep ocean carbon reservoir is reconnected with the atmosphere, driving the atmospheric CO2 rise observed in ice-core records. However, direct documentation of changes in surface ocean carbon contentand the associated transfer of carbon to the atmosphere during deglaciations has been hindered by the lack of proxy reconstructions that unambiguously reflect the oceanic carbonate system. Radiocarbon activity tracks changes in ocean ventilation, but not in ocean carbon content, whereas proxies that record increased deglacial upwelling do not constrain the proportion of upwelled carbon that is degassed relative to that which is taken up by the biological pump. Here we apply the boron isotope pH proxy in planktic foraminifera to two sediment cores from the sub-Antarctic, Atlantic and the eastern equatorial Pacific as a more direct tracer of oceanic CO2 outgassing. We show that surface waters at both locations, which partly derive from deep water upwelled in the Southern Ocean, became a significant source of carbon to the atmosphere during the last deglaciation, when the concentration of atmospheric CO2 was increasing. This oceanic CO2 outgassing supports the view that the ventilation of a deep-ocean carbon reservoir in the Southern Ocean had a key role in the deglacial CO2 rise, although our results allow for the possibility that processes operating in other regions may also have been important for the glacial–interglacial ocean–atmosphere exchange of carbon.},
author = {Mart{\'{i}}nez-Bot{\'{i}}, M. A. and Marino, G. and Foster, G. L. and Ziveri, P. and Henehan, M. J. and Rae, J. W. B. and Mortyn, P. G. and Vance, D.},
doi = {10.1038/nature14155},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7538},
pages = {219--222},
publisher = {Nature Publishing Group},
title = {{Boron isotope evidence for oceanic carbon dioxide leakage during the last deglaciation}},
url = {http://www.nature.com/articles/nature14155},
volume = {518},
year = {2015}
}
@article{Martinez-Boti2015,
author = {Mart{\'{i}}nez-Bot{\'{i}}, M A and Foster, G L and Chalk, T B and Rohling, E J and Sexton, P F and Lunt, D J and Pancost, R D and Badger, M P S and Schmidt, D N},
doi = {10.1038/nature14145},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7537},
pages = {49--54},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records}},
url = {http://dx.doi.org/10.1038/nature14145 http://www.nature.com/articles/nature14145},
volume = {518},
year = {2015}
}
@article{Martinez-Mendez2010,
abstract = {Planktonic $\delta$18O and Mg/Ca-derived sea surface temperature (SST) records from the Agulhas Corridor off South Africa display a progressive increase of SST during glacial periods of the last three climatic cycles. The SST increases of up to 4°C coincide with increased abundance of subtropical planktonic foraminiferal marker species which indicates a progressive warming due to an increased influence of subtropical waters at the core sites. Mg/Ca-derived SST maximizes during glacial maxima and glacial Terminations to values about 2.5°C above full-interglacial SST. The paired planktonic $\delta$18O and Mg/Ca-derived SST records yield glacial seawater $\delta$18O anomalies of up to 0.8?, indicating measurably higher surface salinities during these periods. The SST pattern along our record is markedly different from a U37K?-derived SST record at a nearby core location in the Agulhas Corridor that displays SST maxima only during glacial Terminations. Possible explanations are lateral alkenone advection by the vigorous regional ocean currents or the development of SST contrasts during glacials in association with seasonal changes of Agulhas water transports and lateral shifts of the Agulhas retroflection. The different SST reconstructions derived from U37K? and Mg/Ca pose a significant challenge to the interpretation of the proxy records and demonstrate that the reconstruction of the Agulhas Current and interocean salt leakage is not as straightforward as previously suggested.},
annote = {doi: 10.1029/2009PA001879},
author = {Mart{\'{i}}nez-M{\'{e}}ndez, Gema and Zahn, Rainer and Hall, Ian R and Peeters, Frank J C and Pena, Leopoldo D and Cacho, Isabel and Negre, C{\'{e}}sar},
doi = {10.1029/2009PA001879},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {Agulhas Corridor,Indian-Atlantic transport,paleocirculation},
month = {dec},
number = {4},
pages = {PA4227},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Contrasting multiproxy reconstructions of surface ocean hydrography in the Agulhas Corridor and implications for the Agulhas Leakage during the last 345,000 years}},
url = {https://doi.org/10.1029/2009PA001879},
volume = {25},
year = {2010}
}
@article{Martinez-Garcia2014c,
author = {Martinez-Garcia, A. and Sigman, D. M. and Ren, H. and Anderson, R. F. and Straub, M. and Hodell, D. A. and Jaccard, S. L. and Eglinton, T. I. and Haug, G. H.},
doi = {10.1126/science.1246848},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {6177},
pages = {1347--1350},
title = {{Iron Fertilization of the Subantarctic Ocean During the Last Ice Age}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1246848},
volume = {343},
year = {2014}
}
@article{Marty2017,
abstract = {{\textless}p{\textgreater}Snow plays a critical role in the water cycle of many mountain regions and heavily populated areas downstream. In this study, changes of snow water equivalent (SWE) time series from long-term stations in five Alpine countries are analyzed. The sites are located between 500 and 3000 m above mean sea level, and the analysis is mainly based on measurement series from 1 February (winter) and 1 April (spring). The investigation was performed over different time periods, including the last six decades. The large majority of the SWE time series demonstrate a reduction in snow mass, which is more pronounced for spring than for winter. The observed SWE decrease is independent of latitude or longitude, despite the different climate regions in the Alpine domain. In contrast to measurement series from other mountain ranges, even the highest sites revealed a decline in spring SWE. A comparison with a 100-yr mass balance series from a glacier in the central Alps demonstrates that the peak SWEs have been on a record-low level since around the beginning of the twenty-first century at high Alpine sites. In the long term, clearly increasing temperatures and a coincident weak reduction in precipitation are the main drivers for the pronounced snow mass loss in the past.{\textless}/p{\textgreater}},
author = {Marty, Christoph and Tilg, Anna-Maria and Jonas, Tobias},
doi = {10.1175/JHM-D-16-0188.1},
issn = {1525-755X},
journal = {Journal of Hydrometeorology},
month = {apr},
number = {4},
pages = {1021--1031},
title = {{Recent Evidence of Large-Scale Receding Snow Water Equivalents in the European Alps}},
url = {https://journals.ametsoc.org/jhm/article/18/4/1021/342807/Recent-Evidence-of-LargeScale-Receding-Snow-Water},
volume = {18},
year = {2017}
}
@article{tc-9-2399-2015,
author = {Marzeion, B and Leclercq, P W and Cogley, J G and Jarosch, A H},
doi = {10.5194/tc-9-2399-2015},
journal = {The Cryosphere},
number = {6},
pages = {2399--2404},
title = {{Brief Communication: Global reconstructions of glacier mass change during the 20th century are consistent}},
url = {https://tc.copernicus.org/articles/9/2399/2015/},
volume = {9},
year = {2015}
}
@article{Marzeion2018a,
abstract = {Glacier mass loss is a key contributor to sea-level change1,2, slope instability in high-mountain regions3,4 and the changing seasonality and volume of river flow5–7. Understanding the causes, mechanisms and time scales of glacier change is therefore paramount to identifying successful strategies for mitigation and adaptation. Here, we use temperature and precipitation fields from the Coupled Model Intercomparison Project Phase 5 output to force a glacier evolution model, quantifying mass responses to future climatic change. We find that contemporary glacier mass is in disequilibrium with the current climate, and 36 ± 8{\%} mass loss is already committed in response to past greenhouse gas emissions. Consequently, mitigating future emissions will have only very limited influence on glacier mass change in the twenty-first century. No significant differences between 1.5 and 2 K warming scenarios are detectable in the sea-level contribution of glaciers accumulated within the twenty-first century. In the long-term, however, mitigation will exert strong control, suggesting that ambitious measures are necessary for the long-term preservation of glaciers.},
author = {Marzeion, Ben and Kaser, Georg and Maussion, Fabien and Champollion, Nicolas},
doi = {10.1038/s41558-018-0093-1},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {4},
pages = {305--308},
title = {{Limited influence of climate change mitigation on short-term glacier mass loss}},
url = {https://doi.org/10.1038/s41558-018-0093-1},
volume = {8},
year = {2018}
}
@article{Massonnet2015,
abstract = {The record maximum of Antarctic sea ice resulted chiefly from anomalous winds that transported cold air masses away from the Antarctic continent, enhancing thermodynamic sea ice production far offshore.},
author = {Massonnet, F. and Guemas, V. and Fu{\`{e}}kar, N. S. and Doblas-Reyes, F. J.},
doi = {10.1175/BAMS-D-15-00093.1},
issn = {00030007},
journal = {Bulletin of the American Meteorological Society},
number = {12},
pages = {S163--S167},
title = {{The 2014 high record of antarctic sea ice extent}},
volume = {96},
year = {2015}
}
@article{Mathew2016,
abstract = {? 2016 Springer-Verlag Berlin HeidelbergHadley circulation (HC) is a planetary scale circulation spanning one-third of the globe from tropics to the sub-tropics. Recent changes in HC width and its temporal variability is a topic of paramount interest because of the climate implications it carry alongside. The present study attempts to bring out the subtropical climate change indications in the comparatively new Japanese Re-analysis (JRA55) dataset by means of the mean meridional stream function (MSF). The observed features of HC in JRA55 are found to be reproduced in NCEP, MERRA and ECMWF datasets, with notable differences in the magnitudes of MSF. The calculated annual cycle of HC edges, center and total width from this dataset closely resembles the annual cycle of the respective parameters derived from the rest of the datasets, with very less inter-annual variability. For the first time, MSF estimated using four reanalysis datasets (JRA55, NCEP, MERRA and ECMWF datasets) are verified with observations from integrated global radiosonde archive datasets, using the process of subsampling. The features so estimated show a high degree of similarity amongst each other as well as with observations. The monthly trend in the total width of the HC is quantified to show a maximum of expansion during the month of July, which is significant at the 95 {\%} confidence interval for all datasets. The present paper also discusses the presence of a ?minor circulation? feature in the northern hemisphere which is centered on 34?N during the June and July months, but not in all years. The significance of the present study lies in evaluating the relatively new JRA55 datasets with widely used reanalysis data sets and radiosonde observations and revelation of a minor circulation not discussed hitherto in the context of HC dynamics.},
author = {Mathew, Sneha Susan and Kumar, Karanam Kishore and Subrahmanyam, Kandula Venkata},
doi = {10.1007/s00382-016-3051-5},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {HC expansion,Hadley cell,Meridional stream function,Minor circulation,Radiosonde,Reanalysis,Subsampling},
number = {12},
pages = {3917--3930},
publisher = {Springer Berlin Heidelberg},
title = {{Hadley cell dynamics in Japanese Reanalysis-55 dataset: evaluation using other reanalysis datasets and global radiosonde network observations}},
volume = {47},
year = {2016}
}
@article{Mathew2019a,
author = {Mathew, Sneha Susan and Kumar, Karanam Kishore},
doi = {10.1007/s00704-018-2515-4},
journal = {Theoretical and Applied Climatology},
pages = {661--673},
publisher = {Theoretical and Applied Climatology},
title = {{On the role of precipitation latent heating in modulating the strength and width of the Hadley circulation}},
volume = {136},
year = {2019}
}
@article{Matley2020,
abstract = {Fossil pollen from two stalagmites is examined to reconstruct a c. 2400-year history of vegetation change on the Nullarbor Plain. Environmental changes are reflected by variation in chenopod species abundance, and by a peak in woody taxa between 1000 and 800 years ago which is interpreted as evidence of increased moisture conditions associated with a positive phase of the Southern Annular Mode. While no strong palynological signal is observed at the time of European colonization of Australia, a significant change occurs in the past 40 years, which is interpreted as a vegetation response to a recorded fire event. As speleothems (secondary cave carbonates including stalagmites, stalactites and flowstones) rarely contain enough fossil pollen for analysis, the taphonomic biases of speleothem archives remain poorly understood. This study, as well as being a high-resolution record of environmental change, presents an opportunity to examine these taphonomic filters. The record is shown to be sensitive to episodic deposition of presumably insect-borne pollen, but overall appears to provide a faithful representation of local and regional vegetation change. There is a need for greater research into taphonomic processes, if speleothem palynology is to be developed as a viable alternative to lacustrine sediments in the investigation of past environmental change.},
author = {Matley, Kia A. and Sniderman, JM Kale and Drinnan, Andrew N. and Hellstrom, John C.},
doi = {10.1177/0959683619895589},
issn = {14770911},
journal = {Holocene},
keywords = {arid ecology,palaeoecology,palynology,speleothem},
number = {5},
pages = {672--681},
title = {{Late-Holocene environmental change on the Nullarbor Plain, southwest Australia, based on speleothem pollen records}},
volume = {30},
year = {2020}
}
@article{Matthes2017,
abstract = {Abstract. This paper describes the recommended solar forcing dataset for CMIP6 and highlights changes with respect to CMIP5. The solar forcing is provided for radiative properties, namely total solar irradiance (TSI), solar spectral irradiance (SSI), and the F10.7 index as well as particle forcing, including geomagnetic indices Ap and Kp, and ionization rates to account for effects of solar protons, electrons, and galactic cosmic rays. This is the first time that a recommendation for solar-driven particle forcing has been provided for a CMIP exercise. The solar forcing datasets are provided at daily and monthly resolution separately for the CMIP6 preindustrial control, historical (1850–2014), and future (2015–2300) simulations. For the preindustrial control simulation, both constant and time-varying solar forcing components are provided, with the latter including variability on 11-year and shorter timescales but no long-term changes. For the future, we provide a realistic scenario of what solar behavior could be, as well as an additional extreme Maunder-minimum-like sensitivity scenario. This paper describes the forcing datasets and also provides detailed recommendations as to their implementation in current climate models. For the historical simulations, the TSI and SSI time series are defined as the average of two solar irradiance models that are adapted to CMIP6 needs: an empirical one (NRLTSI2–NRLSSI2) and a semi-empirical one (SATIRE). A new and lower TSI value is recommended: the contemporary solar-cycle average is now 1361.0Wm−2. The slight negative trend in TSI over the three most recent solar cycles in the CMIP6 dataset leads to only a small global radiative forcing of −0.04Wm−2. In the 200–400nm wavelength range, which is important for ozone photochemistry, the CMIP6 solar forcing dataset shows a larger solar-cycle variability contribution to TSI than in CMIP5 (50{\%} compared to 35{\%}). We compare the climatic effects of the CMIP6 solar forcing dataset to its CMIP5 predecessor by using time-slice experiments of two chemistry–climate models and a reference radiative transfer model. The differences in the long-term mean SSI in the CMIP6 dataset, compared to CMIP5, impact on climatological stratospheric conditions (lower shortwave heating rates of −0.35Kday−1 at the stratopause), cooler stratospheric temperatures (−1.5K in the upper stratosphere), lower ozone abundances in the lower stratosphere (−3{\%}), and higher ozone abundances (+1.5{\%} in the upper stratosphere and lower mesosphere). Between the maximum and minimum phases of the 11-year solar cycle, there is an increase in shortwave heating rates (+0.2Kday−1 at the stratopause), temperatures ( ∼ 1K at the stratopause), and ozone (+2.5{\%} in the upper stratosphere) in the tropical upper stratosphere using the CMIP6 forcing dataset. This solar-cycle response is slightly larger, but not statistically significantly different from that for the CMIP5 forcing dataset. CMIP6 models with a well-resolved shortwave radiation scheme are encouraged to prescribe SSI changes and include solar-induced stratospheric ozone variations, in order to better represent solar climate variability compared to models that only prescribe TSI and/or exclude the solar-ozone response. We show that monthly-mean solar-induced ozone variations are implicitly included in the SPARC/CCMI CMIP6 Ozone Database for historical simulations, which is derived from transient chemistry–climate model simulations and has been developed for climate models that do not calculate ozone interactively. CMIP6 models without chemistry that perform a preindustrial control simulation with time-varying solar forcing will need to use a modified version of the SPARC/CCMI Ozone Database that includes solar variability. CMIP6 models with interactive chemistry are also encouraged to use the particle forcing datasets, which will allow the potential long-term effects of particles to be addressed for the first time. The consideration of particle forcing has been shown to significantly improve the representation of reactive nitrogen and ozone variability in the polar middle atmosphere, eventually resulting in further improvements in the representation of solar climate variability in global models.},
author = {Matthes, Katja and Funke, Bernd and Andersson, Monika E. and Barnard, Luke and Beer, J{\"{u}}rg and Charbonneau, Paul and Clilverd, Mark A. and {Dudok de Wit}, Thierry and Haberreiter, Margit and Hendry, Aaron and Jackman, Charles H. and Kretzschmar, Matthieu and Kruschke, Tim and Kunze, Markus and Langematz, Ulrike and Marsh, Daniel R. and Maycock, Amanda C. and Misios, Stergios and Rodger, Craig J. and Scaife, Adam A. and Sepp{\"{a}}l{\"{a}}, Annika and Shangguan, Ming and Sinnhuber, Miriam and Tourpali, Kleareti and Usoskin, Ilya and van de Kamp, Max and Verronen, Pekka T. and Versick, Stefan},
doi = {10.5194/gmd-10-2247-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {jun},
number = {6},
pages = {2247--2302},
title = {{Solar forcing for CMIP6 (v3.2)}},
url = {https://www.geosci-model-dev.net/10/2247/2017/},
volume = {10},
year = {2017}
}
@article{doi:10.1029/2018GL078035,
abstract = {Abstract Simulated stratospheric temperatures over the period 1979-2016 in models from the Chemistry-Climate Model Initiative (CCMI) are compared with recently updated and extended satellite observations. The multi-model mean global temperature trends over 1979-2005 are -0.88 ± 0.23, -0.70 ± 0.16, and -0.50 ± 0.12 K decade-1 for the Stratospheric Sounding Unit (SSU) channels 3 ({\~{}}40-50 km), 2 ({\~{}}35-45 km), and 1 ({\~{}}25-35 km), respectively. These are within the uncertainty bounds of the observed temperature trends from two reprocessed satellite datasets. In the lower stratosphere, the multi-model mean trend in global temperature for the Microwave Sounding Unit channel 4 ({\~{}}13-22 km) is -0.25 ± 0.12 K decade-1 over 1979-2005, consistent with estimates from three versions of this satellite record. The simulated stratospheric temperature trends in CCMI models over 1979-2005 agree with the previous generation of chemistry-climate models. The models and an extended satellite dataset of SSU with the Advanced Microwave Sounding Unit-A show weaker global stratospheric cooling over 1998-2016 compared to the period of intensive ozone depletion (1979-1997). This is due to the reduction in ozone-induced cooling from the slow-down of ozone trends and the onset of ozone recovery since the late 1990s. In summary, the results show much better consistency between simulated and satellite observed stratospheric temperature trends than was reported by Thompson et al. (2012) for the previous versions of the SSU record and chemistry-climate models. The improved agreement mainly comes from updates to the satellite records; the range of simulated trends is comparable to the previous generation of models.},
author = {Maycock, Amanda C and Randel, William J and Steiner, Andrea K and Karpechko, Alexey Yu and Christy, John and Saunders, Roger and Thompson, David W J and Zou, Cheng-Zhi and Chrysanthou, Andreas and {Luke Abraham}, N. and Akiyoshi, Hideharu and Archibald, Alex T and Butchart, Neal and Chipperfield, Martyn and Dameris, Martin and Deushi, Makoto and Dhomse, Sandip and {Di Genova}, Glauco and J{\"{o}}ckel, Patrick and Kinnison, Douglas E and Kirner, Oliver and Ladst{\"{a}}dter, Florian and Michou, Martine and Morgenstern, Olaf and O'Connor, Fiona and Oman, Luke and Pitari, Giovanni and Plummer, David A and Revell, Laura E and Rozanov, Eugene and Stenke, Andrea and Visioni, Daniele and Yamashita, Yousuke and Zeng, Guang},
doi = {10.1029/2018GL078035},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Chemistry-climate model,Greenhouse gases,Ozone depletion,Satellites,Stratosphere,Temperature trends},
month = {sep},
number = {18},
pages = {9919--9933},
title = {{Revisiting the Mystery of Recent Stratospheric Temperature Trends}},
url = {http://doi.wiley.com/10.1029/2018GL078035},
volume = {45},
year = {2018}
}
@article{McAfee2017,
abstract = {The Pacific decadal oscillation (PDO) has been used extensively to understand low-frequency climate variability and its impact on ecological and hydrological systems. In the last few years, however, numerous studies have identified various weaknesses in the PDO paradigm. These range from disagreement between proxy-based reconstructions to instability in teleconnections to discrepancy between the publicly available indices. The potential impact of differences between indices on teleconnection stability is evaluated using the 20th Century Reanalysis and Climatic Research Unit Time-Series (CRU TS) 3.22 data. While disagreements between the indices may influence the interpretation of climate drivers in particular years, they do not appear to contribute to teleconnection instability in any significant way. Ruling out this simple explanation for teleconnection instability provides further evidence that the PDO is too simplistic a framework for understanding Pacific atmosphere–ocean impacts on remote climate and suggests that variable relationships between the PDO and climate are likely related to the complex origins of this variability. {\textcopyright} 2016 Royal Meteorological Society},
author = {McAfee, Stephanie A.},
doi = {10.1002/joc.4918},
isbn = {08998418},
issn = {10970088},
journal = {International Journal of Climatology},
keywords = {North America,PDO,climate,decadal variability,teleconnection},
number = {8},
pages = {3509--3516},
title = {{Uncertainty in Pacific decadal oscillation indices does not contribute to teleconnection instability}},
volume = {37},
year = {2017}
}
@article{McCabe2015,
abstract = {The timing of last spring frost dates (LSFDs), first fall frost dates (FFFDs), and frost-free period lengths (FFPLs) constrains freeze–thawprocesses in hydrology, paces the annual life cycles of plants and animals, affects human food production, and influences land–atmosphere interactions, including the water and carbon cycles. Daily minimum temperature data for the conterminous United States (CONUS) from theGlobalHistorical Climatology Network for the 1920–2012 period are used to determine LSFDs, FFFDs, and FFPLs. Analyses of trends and variability in these growing season components indicate a trend towards earlier LSFDs, later FFFDs, and longer FFPLs for most locations in the CONUS. A general change to earlier LSFDs appears to have occurred after about 1983, whereas a change to later FFFDs is most noticeable after about 1993. Comparisons of time series of LSFDs and FFFDs with well-known climate indices indicate only weak correlations for most sites.},
author = {McCabe, Gregory J. and Betancourt, Julio L. and Feng, Song},
doi = {10.1002/joc.4315},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {Climate change,Climate variability,Daily minimum temperatures,First fall frost,Growing season,Last spring frost},
month = {dec},
number = {15},
pages = {4673--4680},
title = {{Variability in the start, end, and length of frost-free periods across the conterminous United States during the past century}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.4315},
volume = {35},
year = {2015}
}
@article{McCabe-Glynn2013a,
author = {McCabe-Glynn, S. and Johnson, K. R. and Strong, C. and Berkelhammer, M. and Sinha, A. and Cheng, H. and Edwards, R. L.},
doi = {10.1038/ngeo1862},
journal = {Nature Geoscience},
number = {8},
pages = {617--621},
title = {{Variable North Pacific influence on drought in southwestern North America since AD 854}},
volume = {6},
year = {2013}
}
@article{McCarthy2015a,
abstract = {Decadal variability is a notable feature of the Atlantic Ocean and the climate of the regions it influences. Prominently, this is manifested in the Atlantic Multidecadal Oscillation (AMO) in sea surface temperatures. Positive (negative) phases of the AMO coincide with warmer (colder) North Atlantic sea surface temperatures. The AMO is linked with decadal climate fluctuations, such as Indian and Sahel rainfall1, European summer precipitation2, Atlantic hurricanes3 and variations in global temperatures4. It is widely believed that ocean circulation drives the phase changes of the AMO by controlling ocean heat content5. However, there are no direct observations of ocean circulation of sufficient length to support this, leading to questions about whether the AMO is controlled from another source6. Here we provide observational evidence of the widely hypothesized link between ocean circulation and the AMO. We take a new approach, using sea level along the east coast of the United States to estimate ocean circulation on decadal timescales. We show that ocean circulation responds to the first mode of Atlantic atmospheric forcing, the North Atlantic Oscillation, through circulation changes between the subtropical and subpolar gyres—the intergyre region7. These circulation changes affect the decadal evolution of North Atlantic heat content and, consequently, the phases of the AMO. The Atlantic overturning circulation is declining8 and the AMO is moving to a negative phase. This may offer a brief respite from the persistent rise of global temperatures4, but in the coupled system we describe, there are compensating effects. In this case, the negative AMO is associated with a continued acceleration of sea-level rise along the northeast coast of the United States.},
author = {McCarthy, Gerard D. and Haigh, Ivan D. and Hirschi, Jo{\"{e}}l J.M. and Grist, Jeremy P. and Smeed, David A.},
doi = {10.1038/nature14491},
isbn = {1203582900},
issn = {14764687},
journal = {Nature},
number = {7553},
pages = {508--510},
pmid = {26017453},
title = {{Ocean impact on decadal Atlantic climate variability revealed by sea-level observations}},
volume = {521},
year = {2015}
}
@article{McCarthy2018,
author = {McCarthy, G D and Joyce, T M and Josey, S A},
doi = {10.1029/2018GL079336},
journal = {Geophysical Research Letters},
number = {20},
pages = {11257--11264},
publisher = {Wiley Online Library},
title = {{Gulf Stream variability in the context of quasi-decadal and multi-decadal Atlantic climate variability}},
volume = {45},
year = {2018}
}
@article{McCave2013,
author = {McCave, I N and Crowhurst, S J and Kuhn, G and Hillenbrand, C-D. and Meredith, M P},
doi = {10.1038/ngeo2037},
journal = {Nature Geoscience},
month = {dec},
pages = {113},
publisher = {Nature Publishing Group},
title = {{Minimal change in Antarctic Circumpolar Current flow speed between the last glacial and Holocene}},
url = {https://doi.org/10.1038/ngeo2037 10.1038/ngeo2037 https://www.nature.com/articles/ngeo2037{\#}supplementary-information},
volume = {7},
year = {2013}
}
@article{McClymont2020a,
author = {McClymont, Erin L and Ford, Heather L and Ho, Sze Ling and Tindall, Julia C and Haywood, Alan M and Alonso-Garcia, Montserrat and Bailey, Ian and Berke, Melissa A and Littler, Kate and Patterson, Molly O. and Petrick, Benjamin and Peterse, Francien and Ravelo, A Christina and Risebrobakken, Bj{\o}rg and {De Schepper}, Stijn and Swann, George E A and Thirumalai, Kaustubh and Tierney, Jessica E and van der Weijst, Carolien and White, Sarah and Abe-Ouchi, Ayako and Baatsen, Michiel L. J. and Brady, Esther C. and Chan, Wing-Le and Chandan, Deepak and Feng, Ran and Guo, Chuncheng and von der Heydt, Anna S. and Hunter, Stephen and Li, Xiangyi and Lohmann, Gerrit and Nisancioglu, Kerim H. and Otto-Bliesner, Bette L. and Peltier, W. Richard and Stepanek, Christian and Zhang, Zhongshi},
doi = {10.5194/cp-16-1599-2020},
issn = {1814-9332},
journal = {Climate of the Past},
month = {aug},
number = {4},
pages = {1599--1615},
publisher = {Copernicus Publications},
title = {{Lessons from a high-CO2 world: an ocean view from ∼3 million years ago}},
volume = {16},
year = {2020}
}
@article{McGee2014,
abstract = {Tropical paleoclimate records provide important insights into the response of precipitation patterns and the Hadley circulation to past climate changes. Paleo-records are commonly interpreted as indicating north–south shifts of the Intertropical Convergence Zone (ITCZ), with the ITCZ's mean position moving toward the warmer hemisphere in response to changes in cross-equatorial temperature gradients. Though a number of records in tropical Central and South America, North Africa, Asia and the Indo-Australian region are consistent with this interpretation, the magnitudes and regional variability of past ITCZ shifts are poorly constrained. Combining estimates of past tropical sea surface temperature (SST) gradients with the strong linear relationship observed between zonally averaged ITCZ position and tropical SST gradients in the modern seasonal cycle and in models of past climates, we quantify past shifts in zonally averaged ITCZ position. We find that mean ITCZ shifts are likely less than 1° latitude during the Last Glacial Maximum (LGM), Heinrich Stadial 1 (HS1) and mid-Holocene (6 ka) climates, with the largest shift during HS1. The ITCZ's position is closely tied to heat transport between the hemispheres by the atmosphere and ocean; accordingly, these small mean ITCZ shifts are associated with relatively large (∼0.1–0.4 PW) changes in cross-equatorial atmospheric heat transport (AHTEQ). These AHTEQ changes point to changes in cross-equatorial ocean heat transport or net radiative fluxes of the opposite sign. During HS1, the increase in northward AHTEQ is large enough to compensate for a partial or total shutdown in northward heat transport by the Atlantic Ocean's meridional overturning circulation. The large AHTEQ response for small changes in mean ITCZ position places limits on the magnitude of past shifts in the globally averaged ITCZ. Large (⩾5°) meridional displacements of the ITCZ inferred from regional compilations of proxy records must be limited in their zonal extent, and ITCZ shifts at other longitudes must be near zero, for the global mean shift to remain ⩽1° as suggested by our results. Our examination of model results and modern observations supports variable regional and seasonal changes in ITCZ precipitation. This work thus highlights the importance of a dense network of tropical precipitation reconstructions to document the regional and seasonal heterogeneity of ITCZ responses to past climate changes.},
author = {McGee, David and Donohoe, Aaron and Marshall, John and Ferreira, David},
doi = {10.1016/j.epsl.2013.12.043},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Heinrich events,ITCZ,Last Glacial Maximum,heat transport,mid-Holocene},
pages = {69--79},
title = {{Changes in ITCZ location and cross-equatorial heat transport at the Last Glacial Maximum, Heinrich Stadial 1, and the mid-Holocene}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X13007589},
volume = {390},
year = {2014}
}
@article{MCGEE2013163,
abstract = {Reconstructions of eolian dust accumulation in northwest African margin sediments provide important continuous records of past changes in atmospheric circulation and aridity in the region. Existing records indicate dramatic changes in North African dust emissions over the last 20ka, but the limited spatial extent of these records and the lack of high-resolution flux data do not allow us to determine whether changes in dust deposition occurred with similar timing, magnitude and abruptness throughout northwest Africa. Here we present new records from a meridional transect of cores stretching from 31°N to 19°N along the northwest African margin. By combining grain size endmember modeling with 230Th-normalized fluxes for the first time, we are able to document spatial and temporal changes in dust deposition under the North African dust plume throughout the last 20ka. Our results provide quantitative estimates of the magnitude of dust flux changes associated with Heinrich Stadial 1, the Younger Dryas, and the African Humid Period (AHP; ∼11.7–5ka), offering robust targets for model-based estimates of the climatic and biogeochemical impacts of past changes in North African dust emissions. Our data suggest that dust fluxes between 8 and 6ka were a factor of ∼5 lower than average fluxes during the last 2ka. Using a simple model to estimate the effects of bioturbation on dust input signals, we find that our data are consistent with abrupt, synchronous changes in dust fluxes in all cores at the beginning and end of the AHP. The mean ages of these transitions are 11.8±0.2ka (1$\sigma$) and 4.9±0.2ka, respectively.},
author = {McGee, D and DeMenocal, P B and Winckler, G and Stuut, J B W and Bradtmiller, L I},
doi = {10.1016/j.epsl.2013.03.054},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {African Humid Period,North Africa,Th normalization,abrupt change,deglaciation,eolian dust},
pages = {163--176},
title = {{The magnitude, timing and abruptness of changes in North African dust deposition over the last 20,000 yr}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X13001817},
volume = {371-372},
year = {2013}
}
@article{McGee2018a,
author = {McGee, David and Moreno-Chamarro, Eduardo and Green, Brian and Marshall, John and Galbraith, Eric and Bradtmiller, Louisa},
doi = {10.1016/j.quascirev.2017.11.020},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {214--228},
publisher = {Elsevier Ltd},
title = {{Hemispherically asymmetric trade wind changes as signatures of past ITCZ shifts}},
url = {https://doi.org/10.1016/j.quascirev.2017.11.020},
volume = {180},
year = {2018}
}
@article{McGregor2013,
author = {McGregor, H V and Fischer, M J and Gagan, M K and Fink, D and Phipps, S J and Wong, H and Woodroffe, C D},
doi = {10.1038/ngeo1936},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {nov},
number = {11},
pages = {949--953},
publisher = {Nature Publishing Group},
title = {{A weak El Ni{\~{n}}o/Southern Oscillation with delayed seasonal growth around 4,300 years ago}},
url = {http://www.nature.com/articles/ngeo1936},
volume = {6},
year = {2013}
}
@article{cp-6-1-2010,
author = {McGregor, S and Timmermann, A and Timm, O},
doi = {10.5194/cp-6-1-2010},
journal = {Climate of the Past},
number = {1},
pages = {1--17},
title = {{A unified proxy for ENSO and PDO variability since 1650}},
url = {https://www.clim-past.net/6/1/2010/},
volume = {6},
year = {2010}
}
@article{cp-9-2269-2013,
author = {McGregor, S and Timmermann, A and England, M H and {Elison Timm}, O and Wittenberg, A T},
doi = {10.5194/cp-9-2269-2013},
journal = {Climate of the Past},
number = {5},
pages = {2269--2284},
title = {{Inferred changes in El Ni{\~{n}}o–Southern Oscillation variance over the past six centuries}},
url = {https://www.clim-past.net/9/2269/2013/},
volume = {9},
year = {2013}
}
@article{McGregor2015a,
abstract = {Sea surface temperatures have varied over the past 2,000 years. A synthesis of surface-temperature reconstructions shows ocean surface cooling from ad 1 to 1800, with much of the trend from 800 to 1800 driven by volcanic eruptions.},
author = {McGregor, Helen V and Evans, Michael N and Goosse, Hugues and Leduc, Guillaume and Martrat, Belen and Addison, Jason A and Mortyn, P Graham and Oppo, Delia W and Seidenkrantz, Marit-Solveig and Sicre, Marie-Alexandrine and Phipps, Steven J and Selvaraj, Kandasamy and Thirumalai, Kaustubh and Filipsson, Helena L and Ersek, Vasile},
doi = {10.1038/ngeo2510},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {9},
pages = {671--677},
title = {{Robust global ocean cooling trend for the pre-industrial Common Era}},
url = {https://doi.org/10.1038/ngeo2510},
volume = {8},
year = {2015}
}
@article{McGregor2014,
author = {McGregor, Shayne and Timmermann, Axel and Stuecker, Malte F. and England, Matthew H. and Merrifield, Mark and Jin, Fei-Fei and Chikamoto, Yoshimitsu},
doi = {10.1038/nclimate2330},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {888--892},
title = {{Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming}},
url = {http://www.nature.com/articles/nclimate2330},
volume = {4},
year = {2014}
}
@article{McKay2012,
abstract = {Cores acquired by the ANDRILL McMurdo Ice Shelf Project (AND-1B) provide the basis for a new sedimentation model for glacimarine depositional sequences that reflect cyclic glacial-interglacial fluctuations of a marine-based ice sheet in the western Ross Embayment over the past 2.0Ma. Notwithstanding periodic erosion during advances of the ice sheet, uncertainties inherent to the sedimentological interpretation, and a limited number of chronological datums, it is clear that subglacial to grounding-zone sedimentation was dominant at the AND-1B site during the Late Pleistocene with interglacials being represented only by thin intervals of ice-shelf sediment. Each sequence is characterised by subglacial, massive diamictite that pass upwards into glacimarine diamictites and mudstones. This provides the first direct evidence that the marine-based Antarctic Ice Sheet has oscillated between a grounded and floating state at least 7times in the Ross Embayment over the last 780ka, implying a Milankovitch orbital influence. An unconformity in AND-1B, that spans most ({\~{}}200kyr) of the Mid-Pleistocene Transition is inferred to represent widespread expansion of a marine-based ice sheet in the Ross Embayment at 0.8Ma. Prior to 1.0Ma, interglacial periods are characterised by open-water conditions at the drill site with high abundances of volcanoclastic deposits and occasional diatomaceous sediments. These may have responded to precession ({\~{}}20-kyr) or obliquity ({\~{}}40-kyr) orbital control. The occurrence of 6.7m of phonolitic glass reworked from Mt Erebus in interglacial deposits beneath Last Glacial Maximum till requires open ocean or ice shelf conditions in the western Ross Sea around the drill site within the past 250ka and implies a Ross Ice Shelf similar to or less extensive than today during Marine Isotope Stage 7 or 5. {\textcopyright} 2011 Elsevier Ltd.},
author = {McKay, Robert and Naish, Tim and Powell, Ross and Barrett, Peter and Scherer, Reed and Talarico, Franco and Kyle, Philip and Monien, Donata and Kuhn, Gerhard and Jackolski, Chris and Williams, Trevor},
doi = {10.1016/j.quascirev.2011.12.012},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
pages = {93--112},
title = {{Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment}},
volume = {34},
year = {2012}
}
@article{10.1130/G37315.1,
abstract = {Geological constraints on the timing of retreat of the Last Glacial Maximum (LGM) Antarctic Ice Sheets provide critical insights into the processes controlling marine-based ice-sheet retreat. The overdeepened, landward-sloping bathymetry of Antarctica's continental shelves is an ideal configuration for marine ice-sheet instability, with the potential for past and future ice-sheet collapse and accelerated sea-level rise. However, the chronology of retreat of the LGM ice sheet in the Ross Sea is largely constrained by imprecise radiocarbon chronology of bulk marine sediments or by coastal records that offer more reliable dating techniques but which may be influenced by local piedmont glaciers derived from East Antarctic outlet glaciers. Consequently, these coastal records may be ambiguous in the broader context of retreat in the central regions of the Ross Sea. Here, we present a sedimentary facies succession and foraminifera-based radiocarbon chronology from within the Ross Sea embayment that indicates glacial retreat and open-marine conditions to the east of Ross Island before 8.6 cal. (calibrated) kyr B.P., at least 1 k.y. earlier than indicated by terrestrial records in McMurdo Sound. Comparing these data to new modeling experiments, we hypothesize that marine-based ice-sheet retreat was triggered by oceanic forcings along most of the Pacific Ocean coastline of Antarctica, but continued Holocene retreat into the inner shelf region of the Ross Sea occurred primarily as a consequence of bathymetric controls on marine ice-sheet instability.},
author = {McKay, R and Golledge, N R and Maas, S and Naish, T and Levy, R and Dunbar, G and Kuhn, G},
doi = {10.1130/G37315.1},
issn = {0091-7613},
journal = {Geology},
number = {1},
pages = {7--10},
title = {{Antarctic marine ice-sheet retreat in the Ross Sea during the early Holocene}},
url = {https://doi.org/10.1130/G37315.1},
volume = {44},
year = {2016}
}
@article{McKenney2014a,
abstract = {We present 50-year updates for two plant hardiness models (maps), developed originally by Agriculture Canada and the US Department of Agriculture (USDA), that are widely used for plant selection decisions in Canada. The updated maps show clear northward shifts in hardiness zones across western Canada. Shifts are less dramatic in southeastern Canada, with modest increases in zone values associated with the Canadian map but modest declines associated with the USDA approach. Species-specific climate envelope models are an alternative to generalized hardiness zones. We generated climate envelopes for 62 northern tree species over the same 50-year interval and found an average northward shift of 57 kilometers. These changes signal an increase in the productivity and diversity of plants that can be grown in Canada. However, late spring frosts and other factors discussed herein may limit the extent to which this potential is realized.},
author = {McKenney, Daniel W. and Pedlar, John H. and Lawrence, Kevin and Papadopol, Pia and Campbell, Kathy and Hutchinson, Michael F.},
doi = {10.1093/biosci/biu016},
issn = {15253244},
journal = {BioScience},
keywords = {climate change,climate envelopes,plant hardiness zones,spring frost damage},
number = {4},
pages = {341--350},
title = {{Change and evolution in the plant hardiness zones of Canada}},
volume = {64},
year = {2014}
}
@article{acp-15-9271-2015,
author = {McLandress, C and Shepherd, T G and Jonsson, A I and von Clarmann, T and Funke, B},
doi = {10.5194/acp-15-9271-2015},
journal = {Atmospheric Chemistry and Physics},
number = {16},
pages = {9271--9284},
title = {{A method for merging nadir-sounding climate records, with an application to the global-mean stratospheric temperature data sets from SSU and AMSU}},
url = {https://www.atmos-chem-phys.net/15/9271/2015/},
volume = {15},
year = {2015}
}
@article{McManus2004a,
abstract = {The Atlantic meridional overturning circulation is widely believed to affect climate. Changes in ocean circulation have been inferred from records of the deep water chemical composition derived from sedimentary nutrient proxies1, but their impact on climate is difficult to assess because such reconstructions provide insufficient constraints on the rate of overturning2. Here we report measurements of 231Pa/230Th, a kinematic proxy for the meridional overturning circulation, in a sediment core from the subtropical North Atlantic Ocean. We find that the meridional overturning was nearly, or completely, eliminated during the coldest deglacial interval in the North Atlantic region, beginning with the catastrophic iceberg discharge Heinrich event H1, 17,500 yr ago, and declined sharply but briefly into the Younger Dryas cold event, about 12,700 yr ago. Following these cold events, the 231Pa/230Th record indicates that rapid accelerations of the meridional overturning circulation were concurrent with the two strongest regional warming events during deglaciation. These results confirm the significance of variations in the rate of the Atlantic meridional overturning circulation for abrupt climate changes.},
author = {McManus, J F and Francois, R and Gherardi, J.-M. and Keigwin, L D and Brown-Leger, S},
doi = {10.1038/nature02494},
issn = {1476-4687},
journal = {Nature},
number = {6985},
pages = {834--837},
title = {{Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes}},
url = {https://doi.org/10.1038/nature02494},
volume = {428},
year = {2004}
}
@article{McManus971,
abstract = {Long, continuous, marine sediment records from the subpolar North Atlantic document the glacial modulation of regional climate instability throughout the past 0.5 million years. Whenever ice sheet size surpasses a critical threshold indicated by the benthic oxygen isotope ($\delta$18O) value of 3.5 per mil during each of the past five glaciation cycles, indicators of iceberg discharge and sea-surface temperature display dramatically larger amplitudes of millennial-scale variability than when ice sheets are small. Sea-surface temperature oscillations of 1{\{}$\backslash$textdegree{\}} to 2{\{}$\backslash$textdegree{\}}C increase in size to approximately 4{\{}$\backslash$textdegree{\}} to 6{\{}$\backslash$textdegree{\}}C, and catastrophic iceberg discharges begin alternating repeatedly with brief quiescent intervals. The glacial growth associated with this amplification threshold represents a relatively small departure from the modern ice sheet configuration and sea level. Instability characterizes nearly all observed climate states, with the exception of a limited range of baseline conditions that includes the current Holocene interglacial.},
author = {McManus, Jerry F and Oppo, Delia W and Cullen, James L},
doi = {10.1126/science.283.5404.971},
issn = {0036-8075},
journal = {Science},
number = {5404},
pages = {971--975},
publisher = {American Association for the Advancement of Science},
title = {{A 0.5-Million-Year Record of Millennial-Scale Climate Variability in the North Atlantic}},
url = {https://science.sciencemag.org/content/283/5404/971},
volume = {283},
year = {1999}
}
@article{McVicar2012,
abstract = {In a globally warming climate, observed rates of atmospheric evaporative demand have declined over recent decades. Several recent studies have shown that declining rates of evaporative demand are primarily governed by trends in the aerodynamic component (primarily being the combination of the effects of wind speed (u) and atmospheric humidity) and secondarily by changes in the radiative component. A number of these studies also show that declining rates of observed near-surface u (termed 'stilling') is the primary factor contributing to declining rates of evaporative demand. One objective of this paper was to review and synthesise the literature to assess whether stilling is a globally widespread phenomenon. We analysed 148 studies reporting terrestrial u trends from across the globe (with uneven and incomplete spatial distribution and differing periods of measurement) and found that the average trend was -0.014ms-1a-1for studies with more than 30 sites observing data for more than 30years, which confirmed that stilling was widespread. Assuming a linear trend this constitutes a -0.7ms-1change in u over 50years. A second objective was to confirm the declining rates of evaporative demand by reviewing papers reporting trends in measured pan evaporation (Epan) and estimated crop reference evapotranspiration (ETo); average trends were -3.19mma-2(n=55) and -1.31mma-2(n=26), respectively. A third objective was to assess the contribution to evaporative demand trends that the four primary meteorological variables (being u; atmospheric humidity; radiation; and air temperature) made. The results from 36 studies highlighted the importance of u trends. We also quantified the sensitivity of rates of evaporative demand to changes in u and how the relative contributions of the aerodynamic and radiative components change seasonally over the globe. Our review: (i) shows that terrestrial stilling is widespread across the globe; (ii) confirms declining rates of evaporative demand; and (iii) highlights the contribution u has made to these declining evaporative rates. Hence we advocate that assessing evaporative demand trends requires consideration of all four primary meteorological variables (being u, atmospheric humidity, radiation and air temperature). This is particularly relevant for long-term water resource assessment because changes in u exert greater influence on energy-limited water-yielding catchments than water-limited ones. {\textcopyright} 2011.},
author = {McVicar, Tim R. and Roderick, Michael L. and Donohue, Randall J. and Li, Ling Tao and {Van Niel}, Thomas G. and Thomas, Axel and Grieser, J{\"{u}}rgen and Jhajharia, Deepak and Himri, Youcef and Mahowald, Natalie M. and Mescherskaya, Anna V. and Kruger, Andries C. and Rehman, Shafiqur and Dinpashoh, Yagob},
doi = {10.1016/j.jhydrol.2011.10.024},
isbn = {0022-1694},
issn = {00221694},
journal = {Journal of Hydrology},
month = {jan},
pages = {182--205},
publisher = {Elsevier B.V.},
title = {{Global review and synthesis of trends in observed terrestrial near-surface wind speeds: Implications for evaporation}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169411007487},
volume = {416-417},
year = {2012}
}
@article{doi:10.1175/JCLI-D-16-0768.1,
abstract = {AbstractTemperature sounding microwave radiometers flown on polar-orbiting weather satellites provide a long-term, global-scale record of upper-atmosphere temperatures, beginning in late 1978 and continuing to the present. The focus of this paper is a lower-tropospheric temperature product constructed using measurements made by the Microwave Sounding Unit channel 2 and the Advanced Microwave Sounding Unit channel 5. The temperature weighting functions for these channels peak in the middle to upper troposphere. By using a weighted average of measurements made at different Earth incidence angles, the effective weighting function can be lowered so that it peaks in the lower troposphere. Previous versions of this dataset used general circulation model output to remove the effects of drifting local measurement time on the measured temperatures. This paper presents a method to optimize these adjustments using information from the satellite measurements themselves. The new method finds a global-mean land diurnal cycle that peaks later in the afternoon, leading to improved agreement between measurements made by co-orbiting satellites. The changes result in global-scale warming [global trend (70°S–80°N, 1979–2016) = 0.174°C decade−1], {\~{}}30{\%} larger than our previous version of the dataset [global trend (70°S–80°N, 1979–2016) = 0.134°C decade−1]. This change is primarily due to the changes in the adjustment for drifting local measurement time. The new dataset shows more warming than most similar datasets constructed from satellites or radiosonde data. However, comparisons with total column water vapor over the oceans suggest that the new dataset may not show enough warming in the tropics.},
author = {Mears, Carl A and Wentz, Frank J},
doi = {10.1175/JCLI-D-16-0768.1},
journal = {Journal of Climate},
number = {19},
pages = {7695--7718},
title = {{A Satellite-Derived Lower-Tropospheric Atmospheric Temperature Dataset Using an Optimized Adjustment for Diurnal Effects}},
url = {https://doi.org/10.1175/JCLI-D-16-0768.1},
volume = {30},
year = {2017}
}
@article{Mears2018,
abstract = {Measurements of total precipitable water (TPW) from 11 satellite-borne microwave imaging radiometers are intercalibrated and merged into a single gridded monthly data set starting in January 1988 and continuing to the present. The resulting data set shows a global mean, ocean-only trend in TPW of 0.436 kg/m2 per decade (1.49{\%} per decade), and a trend in the deep tropics (20°S–20°N) of 0.629 kg/m2 per decade (1.503{\%} per decade). The uncertainty in the merged TPW results is analyzed on multiple time and distance scales using a Monte Carlo approach. This analysis results in an uncertainty ensemble that can be used to evaluate the effects of construction uncertainty on any subsequent application of the data set. We compare the merged data set with measurements of TPW from ground-based Global Navigation Satellite System sensors on small islands. These comparisons show no systematic long-term drifts in the differences, and the observed differences were largely explained by our uncertainty analysis. As an example of the use of the uncertainty ensemble, we evaluate the increase in TPW over the Gulf of Mexico during summer months over 1988–2017.},
author = {Mears, Carl A. and Smith, Deborah K. and Ricciardulli, Lucrezia and Wang, Junhong and Huelsing, Hannah and Wentz, Frank J.},
doi = {10.1002/2018EA000363},
issn = {23335084},
journal = {Earth and Space Science},
keywords = {climate,microwave,satellite,water vapor},
number = {5},
pages = {197--210},
title = {{Construction and Uncertainty Estimation of a Satellite-Derived Total Precipitable Water Data Record Over the World's Oceans}},
volume = {5},
year = {2018}
}
@article{Medley2019,
abstract = {Changes in accumulated snowfall over the Antarctic Ice Sheet have an immediate and time-delayed impact on global mean sea level. The immediate impact is due to the instantaneous change in freshwater storage over the ice sheet, whereas the time-delayed impact acts in opposition through enhanced ice-dynamic flux into the ocean1. Here, we reconstruct 200 years of Antarctic-wide snow accumulation by synthesizing a newly compiled database of ice core records2 using reanalysis-derived spatial coherence patterns. The results reveal that increased snow accumulation mitigated twentieth-century sea-level rise by {\~{}}10 mm since 1901, with rates increasing from 1.1 mm decade−1 between 1901 and 2000 to 2.5 mm decade−1 after 1979. Reconstructed accumulation trends are highly variable in both sign and magnitude at the regional scale, and linked to the trend towards a positive Southern Annular Mode since 19573. Because the observed Southern Annular Mode trend is accompanied by a decrease in Antarctic Ice Sheet accumulation, changes in the strength and location of the circumpolar westerlies cannot explain the reconstructed increase, which may instead be related to stratospheric ozone depletion4. However, our results indicate that a warming atmosphere cannot be excluded as a dominant force in the underlying increase.},
author = {Medley, B and Thomas, E R},
doi = {10.1038/s41558-018-0356-x},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {1},
pages = {34--39},
title = {{Increased snowfall over the Antarctic Ice Sheet mitigated twentieth-century sea-level rise}},
url = {https://doi.org/10.1038/s41558-018-0356-x},
volume = {9},
year = {2019}
}
@article{Meier2013,
abstract = {Abstract. Visible satellite imagery from the 1964 Nimbus I satellite has been recovered, digitized, and processed to estimate Arctic and Antarctic sea ice extent for September 1964. September is the month when the Arctic sea ice reaches its minimum annual extent and the Antarctic sea ice reaches its maximum. Images from a three-week period were manually analyzed to estimate the location of the ice edge and then composited to obtain a hemispheric estimate. Uncertainties were based on limitations in the image analysis and the variation of the ice cover over the three-week period. The 1964 Antarctic extent is higher than estimates from the 1979–present passive microwave record, but is in accord with previous indications of higher extents during the 1960s. The Arctic 1964 extent is near the 1979–2000 average from the passive microwave record, suggesting relatively stable summer extents during the 1960s and 1970s preceding the downward trend since 1979 and particularly the large decrease in the last decade. These early satellite data put the recently observed record into a longer-term context.},
author = {Meier, W. N. and Gallaher, D. and Campbell, G. G.},
doi = {10.5194/tc-7-699-2013},
issn = {1994-0424},
journal = {The Cryosphere},
month = {apr},
number = {2},
pages = {699--705},
title = {{New estimates of Arctic and Antarctic sea ice extent during September 1964 from recovered Nimbus I satellite imagery}},
url = {https://tc.copernicus.org/articles/7/699/2013/},
volume = {7},
year = {2013}
}
@article{Meier_2019,
abstract = {The uncertainties in sea ice extent (total area covered by sea ice with concentration {\textgreater}15{\%}) derived from passive microwave sensors are assessed in two ways. Absolute uncertainty (accuracy) is evaluated based on the comparison of the extent between several products. There are clear biases between the extent from the different products that are of the order of 500 000 to 1 × 106 km2 depending on the season and hemisphere. These biases are due to differences in the algorithm sensitivity to ice edge conditions and the spatial resolution of different sensors. Relative uncertainty is assessed by examining extents from the National Snow and Ice Data Center Sea Ice Index product. The largest source of uncertainty, ∼100 000 km2, is between near-real-time and final products due to different input source data and different processing and quality control. For consistent processing, the uncertainty is assessed using different input source data and by varying concentration algorithm parameters. This yields a relative uncertainty of 30 000–70 000 km2. The Arctic minimum extent uncertainty is ∼40 000 km2. Uncertainties in comparing with earlier parts of the record may be higher due to sensor transitions. For the first time, this study provides a quantitative estimate of sea ice extent uncertainty.},
author = {Meier, Walter N and Stewart, J Scott},
doi = {10.1088/1748-9326/aaf52c},
journal = {Environmental Research Letters},
month = {mar},
number = {3},
pages = {35005},
publisher = {{\{}IOP{\}} Publishing},
title = {{Assessing uncertainties in sea ice extent climate indicators}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2Faaf52c},
volume = {14},
year = {2019}
}
@article{Meinen2018,
abstract = {Six years of simultaneous moored observations near the western and eastern boundaries of the South Atlantic are combined with satellite winds to produce a daily time series of the basin-wide meridional overturning circulation (MOC) volume transport at 34.5°S. The results demonstrate that barotropic and baroclinic signals at both boundaries cause significant transport variations, and as such must be concurrently observed. The data, spanning {\~{}}20 months during 2009–2010 and {\~{}}4 years during 2013–2017, reveal a highly energetic MOC record with a temporal standard deviation of 8.3 Sv, and strong variations at time scales ranging from a few days to years (peak-to-peak range = 54.6 Sv). Seasonal transport variations are found to have both semiannual (baroclinic) and annual (Ekman and barotropic) timescales. Interannual MOC variations result from both barotropic and baroclinic changes, with density profile changes at the eastern boundary having the largest impact on the year-to-year variations.},
author = {Meinen, Christopher S. and Speich, Sabrina and Piola, Alberto R. and Ansorge, Isabelle and Campos, Edmo and Kersal{\'{e}}, Marion and Terre, Thierry and Chidichimo, Maria Paz and Lamont, Tarron and Sato, Olga T. and Perez, Renellys C. and Valla, Daniel and van den Berg, Marcel and {Le H{\'{e}}naff}, Matthieu and Dong, Shenfu and Garzoli, Silvia L.},
doi = {10.1029/2018GL077408},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {9},
pages = {4180--4188},
title = {{Meridional Overturning Circulation Transport Variability at 34.5°S During 2009–2017: Baroclinic and Barotropic Flows and the Dueling Influence of the Boundaries}},
volume = {45},
year = {2018}
}
@article{Meinshausen2017,
author = {Meinshausen, M and Vogel, E and Nauels, A and Lorbacher, K and Meinshausen, N and Etheridge, D M and Fraser, P J and Montzka, S A and Rayner, P J and Trudinger, C M and Krummel, P B and Beyerle, U and Canadell, J G and Daniel, J S and Enting, I G and Law, R M and Lunder, C R and O'Doherty, S and Prinn, R G and Reimann, S and Rubino, M and Velders, G J M and Vollmer, M K and Wang, R H J and Weiss, R},
doi = {10.5194/gmd-10-2057-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {may},
number = {5},
pages = {2057--2116},
publisher = {Copernicus Publications},
title = {{Historical greenhouse gas concentrations for climate modelling (CMIP6)}},
url = {https://www.geosci-model-dev.net/10/2057/2017/ https://www.geosci-model-dev.net/10/2057/2017/gmd-10-2057-2017.pdf},
volume = {10},
year = {2017}
}
@article{Melamed-Turkish2018,
author = {Melamed-Turkish, Kai and Taylor, Peter A. and Liu, John},
doi = {10.1002/joc.5693},
issn = {08998418},
journal = {International Journal of Climatology},
number = {13},
pages = {4740--4757},
title = {{Upper-level winds over eastern North America: A regional jet stream climatology}},
volume = {38},
year = {2018}
}
@article{Mellado-Cano2019,
author = {Mellado-Cano, J. and Barriopedro, D and Garc{\'{i}}a-Herrera, R. and Trigo, R.M. and Hern{\'{a}}ndez, A.},
doi = {10.1175/JCLI-D-18-0135.1.},
journal = {Journal of Climate},
pages = {6285--6298},
title = {{Examining the North Atlantic Oscillation, East Atlantic pattern and jet variability since 1685}},
volume = {32},
year = {2019}
}
@article{https://doi.org/10.1029/2020GL088166,
annote = {e2020GL088166 2020GL088166},
author = {Menary, Matthew B and Robson, Jon and Allan, Richard P and Booth, Ben B B and Cassou, Christophe and Gastineau, Guillaume and Gregory, Jonathan and Hodson, Dan and Jones, Colin and Mignot, Juliette and Ringer, Mark and Sutton, Rowan and Wilcox, Laura and Zhang, Rong},
doi = {10.1029/2020GL088166},
journal = {Geophysical Research Letters},
keywords = {AMOC,CMIP6,aerosols,climate change,historical simulations,strengthening},
number = {14},
pages = {e2020GL088166},
title = {{Aerosol-Forced AMOC Changes in CMIP6 Historical Simulations}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL088166},
volume = {47},
year = {2020}
}
@article{doi:10.1175/JCLI-D-18-0094.1,
abstract = {AbstractWe describe a fourth version of the Global Historical Climatological Network monthly (GHCNm) temperature dataset. Version 4 (v4) fulfills the goal of aligning GHCNm temperature values with the GHCN-daily dataset and makes use of data from previous versions of GHCNm as well as data collated under the auspices of the International Surface Temperature Initiative. GHCNm v4 has many thousands of additional stations compared to version 3 (v3) both historically and with short-time delay updates. The greater number of stations as well as the use of records with incomplete data during the base period provides for greater global coverage throughout the record compared to earlier versions. Like v3, the monthly averages are screened for random errors and homogenized to address systematic errors. New to v4, uncertainties are calculated for each station series, and regional uncertainties scale directly from the station uncertainties. Correlated errors in the station series are quantified by running the homogenization algorithm as an ensemble. Additional uncertainties associated with incomplete homogenization and use of anomalies are then incorporated into the station ensemble. Further uncertainties are quantified at the regional level, the most important of which is for incomplete spatial coverage. Overall, homogenization has a smaller impact on the v4 global trend compared to v3, though adjustments lead to much greater consistency than between the unadjusted versions. The adjusted v3 global mean therefore falls within the range of uncertainty for v4 adjusted data. Likewise, annual anomaly uncertainties for the other major independent land surface air temperature datasets overlap with GHCNm v4 uncertainties.},
author = {Menne, Matthew J and Williams, Claude N and Gleason, Byron E and Rennie, J Jared and Lawrimore, Jay H},
doi = {10.1175/JCLI-D-18-0094.1},
journal = {Journal of Climate},
number = {24},
pages = {9835--9854},
title = {{The Global Historical Climatology Network Monthly Temperature Dataset, Version 4}},
url = {https://doi.org/10.1175/JCLI-D-18-0094.1},
volume = {31},
year = {2018}
}
@article{Menviel2017,
abstract = {Abstract Atmospheric CO2 was ?90 ppmv lower at the Last Glacial Maximum (LGM) compared to the late Holocene, but the mechanisms responsible for this change remain elusive. Here we employ a carbon isotope-enabled Earth System Model to investigate the role of ocean circulation in setting the LGM oceanic $\delta$13C distribution, thereby improving our understanding of glacial/interglacial atmospheric CO2 variations. We find that the mean ocean $\delta$13C change can be explained by a 378 ± 88 Gt C(2$\sigma$) smaller LGM terrestrial carbon reservoir compared to the Holocene. Critically, in this model, differences in the oceanic $\delta$13C spatial pattern can only be reconciled with a LGM ocean circulation state characterized by a weak (10?15 Sv) and relatively shallow (2000?2500 m) North Atlantic Deep Water cell, reduced Antarctic Bottom Water transport (≤10 Sv globally integrated), and relatively weak (6?8 Sv) and shallow (1000?1500 m) North Pacific Intermediate Water formation. This oceanic circulation state is corroborated by results from the isotope-enabled Bern3D ocean model and further confirmed by high LGM ventilation ages in the deep ocean, particularly in the deep South Atlantic and South Pacific. This suggests a poorly ventilated glacial deep ocean which would have facilitated the sequestration of carbon lost from the terrestrial biosphere and atmosphere.},
annote = {doi: 10.1002/2016PA003024},
author = {Menviel, L and Yu, J and Joos, F and Mouchet, A and Meissner, K J and England, M H},
doi = {10.1002/2016PA003024},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {AABW,Last Glacial Maximum,NADW,carbon cycle,ventilation ages,$\delta$13C},
month = {jan},
number = {1},
pages = {2--17},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Poorly ventilated deep ocean at the Last Glacial Maximum inferred from carbon isotopes: A data-model comparison study}},
url = {https://doi.org/10.1002/2016PA003024},
volume = {32},
year = {2017}
}
@article{article,
abstract = {Abstract. Surface temperature is a key aspect of weather and climate, but the term may refer to different quantities that play interconnected roles and are observed by different means. In a community-based activity in June 2012, the EarthTemp Network brought together 55 researchers from five continents to improve the interaction between scientific communities who focus on surface temperature in particular domains, to exploit the strengths of different observing systems and to better meet the needs of different communities. The workshop identified key needs for progress towards meeting scientific and societal requirements for surface temperature understanding and information, which are presented in this community paper. A "whole-Earth" perspective is required with more integrated, collaborative approaches to observing and understanding Earth's various surface temperatures. It is necessary to build understanding of the relationships between different surface temperatures, where presently inadequate, and undertake large-scale systematic intercomparisons. Datasets need to be easier to obtain and exploit for a wide constituency of users, with the differences and complementarities communicated in readily understood terms, and realistic and consistent uncertainty information provided. Steps were also recommended to curate and make available data that are presently inaccessible, develop new observing systems and build capacities to accelerate progress in the accuracy and usability of surface temperature datasets.},
author = {Merchant, C. J. and Matthiesen, Stephan and Rayner, N. A. and Remedios, J. J. and Jones, P. D. and Olesen, Folke and Trewin, Blair and Thorne, P. W. and Auchmann, Renate and Corlett, G. K. and Guillevic, P. C. and Hulley, G. C.},
doi = {10.5194/gi-2-305-2013},
issn = {2193-0864},
journal = {Geoscientific Instrumentation, Methods and Data Systems},
month = {dec},
number = {2},
pages = {305--321},
title = {{The surface temperatures of Earth: steps towards integrated understanding of variability and change}},
url = {https://gi.copernicus.org/articles/2/305/2013/},
volume = {2},
year = {2013}
}
@article{doi:10.1029/2012JC008400,
abstract = {A new record of sea surface temperature (SST) for climate applications is described. This record provides independent corroboration of global variations estimated from SST measurements made in situ. Infrared imagery from Along-Track Scanning Radiometers (ATSRs) is used to create a 20 year time series of SST at 0.1° latitude-longitude resolution, in the ATSR Reprocessing for Climate (ARC) project. A very high degree of independence of in situ measurements is achieved via physics-based techniques. Skin SST and SST estimated for 20 cm depth are provided, with grid cell uncertainty estimates. Comparison with in situ data sets establishes that ARC SSTs generally have bias of order 0.1 K or smaller. The precision of the ARC SSTs is 0.14 K during 2003 to 2009, from three-way error analysis. Over the period 1994 to 2010, ARC SSTs are stable, with better than 95{\%} confidence, to within 0.005 K yr−1(demonstrated for tropical regions). The data set appears useful for cleanly quantifying interannual variability in SST and major SST anomalies. The ARC SST global anomaly time series is compared to the in situ-based Hadley Centre SST data set version 3 (HadSST3). Within known uncertainties in bias adjustments applied to in situ measurements, the independent ARC record and HadSST3 present the same variations in global marine temperature since 1996. Since the in situ observing system evolved significantly in its mix of measurement platforms and techniques over this period, ARC SSTs provide an important corroboration that HadSST3 accurately represents recent variability and change in this essential climate variable.},
author = {Merchant, Christopher J and Embury, Owen and Rayner, Nick A and Berry, David I and Corlett, Gary K and Lean, Katie and Veal, Karen L and Kent, Elizabeth C and Llewellyn-Jones, David T and Remedios, John J and Saunders, Roger},
doi = {10.1029/2012JC008400},
journal = {Journal of Geophysical Research: Oceans},
keywords = {climate,remote sensing,sea surface temperature},
number = {C12},
pages = {C12013},
title = {{A 20 year independent record of sea surface temperature for climate from Along-Track Scanning Radiometers}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012JC008400},
volume = {117},
year = {2012}
}
@article{Mercier2015,
author = {Mercier, Herl{\'{e}} and Lherminier, Pascale and Sarafanov, Artem and Gaillard, Fabienne and Daniault, Nathalie and Desbruy{\`{e}}res, Damien and Falina, Anastasia and Ferron, Bruno and Gourcuff, Claire and Huck, Thierry and Thierry, Virginie},
doi = {10.1016/j.pocean.2013.11.001},
issn = {00796611},
journal = {Progress in Oceanography},
month = {mar},
pages = {250--261},
publisher = {Elsevier},
title = {{Variability of the meridional overturning circulation at the Greenland–Portugal OVIDE section from 1993 to 2010}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0079661113002206},
volume = {132},
year = {2015}
}
@incollection{Al,
author = {Meredith, M. and Sommerkorn, M. and Cassotta, S. and Derksen, C. and Ekaykin, A. and Hollowed, A. and Kofinas, G. and Mackintosh, A. and Melbourne-Thomas, J. and Muelbert, M.M.C. and Ottersen, G. and Pritchard, H. and Schuur, E.A.G.},
booktitle = {IPCC Special Report on the Ocean and Cryosphere in a Changing Climate},
doi = {https://www.ipcc.ch/srocc/chapter/chapter-3-2},
editor = {P{\"{o}}rtner, H.-O. and Roberts, D.C. and Masson-Delmotte, V. and Zhai, P. and Tignor, M. and Poloczanska, E. and Mintenbeck, K. and Alegr{\'{i}}a, A. and Nicolai, M. and Okem, A. and Petzold, J. and Rama, B. and Weyer, N.M.},
pages = {203--320},
publisher = {In Press},
title = {{Polar Regions}},
url = {https://www.ipcc.ch/srocc/chapter/chapter-3-2},
year = {2019}
}
@article{tc-7-1565-2013,
author = {Mernild, S H and Lipscomb, W H and Bahr, D B and Radi{\'{c}}, V and Zemp, M},
doi = {10.5194/tc-7-1565-2013},
journal = {The Cryosphere},
number = {5},
pages = {1565--1577},
title = {{Global glacier changes: a revised assessment of committed mass losses and sampling uncertainties}},
url = {https://tc.copernicus.org/articles/7/1565/2013/},
volume = {7},
year = {2013}
}
@article{10.3389/fmars.2019.00432,
abstract = {The energy radiated by the Earth toward space does not compensate the incoming radiation from the Sun leading to a small positive energy imbalance at the top of the atmosphere (0.4–1 Wm–2). This imbalance is coined Earth's Energy Imbalance (EEI). It is mostly caused by anthropogenic greenhouse gas emissions and is driving the current warming of the planet. Precise monitoring of EEI is critical to assess the current status of climate change and the future evolution of climate. But the monitoring of EEI is challenging as EEI is two orders of magnitude smaller than the radiation fluxes in and out of the Earth system. Over 93{\%} of the excess energy that is gained by the Earth in response to the positive EEI accumulates into the ocean in the form of heat. This accumulation of heat can be tracked with the ocean observing system such that today, the monitoring of Ocean Heat Content (OHC) and its long-term change provide the most efficient approach to estimate EEI. In this community paper we review the current four state-of-the-art methods to estimate global OHC changes and evaluate their relevance to derive EEI estimates on different time scales. These four methods make use of: (1) direct observations of in situ temperature; (2) satellite-based measurements of the ocean surface net heat fluxes; (3) satellite-based estimates of the thermal expansion of the ocean and (4) ocean reanalyses that assimilate observations from both satellite and in situ instruments. For each method we review the potential and the uncertainty of the method to estimate global OHC changes. We also analyze gaps in the current capability of each method and identify ways of progress for the future to fulfill the requirements of EEI monitoring. Achieving the observation of EEI with sufficient accuracy will depend on merging the remote sensing techniques with in situ measurements of key variables as an integral part of the Ocean Observing System.},
author = {Meyssignac, Benoit and Boyer, Tim and Zhao, Zhongxiang and Hakuba, Maria Z and Landerer, Felix W and Stammer, Detlef and K{\"{o}}hl, Armin and Kato, Seiji and L'Ecuyer, Tristan and Ablain, Michael and Abraham, John Patrick and Blazquez, Alejandro and Cazenave, Anny and Church, John A and Cowley, Rebecca and Cheng, Lijing and Domingues, Catia M and Giglio, Donata and Gouretski, Viktor and Ishii, Masayoshi and Johnson, Gregory C and Killick, Rachel E and Legler, David and Llovel, William and Lyman, John and Palmer, Matthew Dudley and Piotrowicz, Steve and Purkey, Sarah G and Roemmich, Dean and Roca, R{\'{e}}my and Savita, Abhishek and von Schuckmann, Karina and Speich, Sabrina and Stephens, Graeme and Wang, Gongjie and Wijffels, Susan Elisabeth and Zilberman, Nathalie},
doi = {10.3389/fmars.2019.00432},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {aug},
pages = {432},
title = {{Measuring Global Ocean Heat Content to Estimate the Earth Energy Imbalance}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00432/full},
volume = {6},
year = {2019}
}
@article{MIDDLETON201812,
abstract = {Sedimentary records of dust deposition in the subtropical Atlantic provide important constraints on millennial- and orbital-scale variability in atmospheric circulation and North African aridity. Constant flux proxies, such as extraterrestrial helium-3, yield dust flux records that are independent of the biases caused by lateral sediment transport and limited resolution that may be associated with age-model-derived mass accumulation rates. However, Atlantic dust records constrained using constant flux proxies are sparsely distributed and generally limited to the past 20 ka. Here we extend the Atlantic record of North African dust deposition to 70 ka using extraterrestrial helium-3 and measurements of titanium, thorium, and terrigenous helium-4 in two sediment cores collected at 26°N and 29°N on the Mid-Atlantic Ridge and compare results to model estimates for dust deposition in the subtropical North Atlantic. Dust proxy fluxes between 26°N and 29°N are well correlated, despite variability in lateral sediment transport, and underscore the utility of extraterrestrial helium-3 for constraining millennial-scale variability in dust deposition. Similarities between Mid-Atlantic dust flux trends and those observed along the Northwest African margin corroborate previous interpretations of dust flux variability over the past 20 ka and suggest that long distance transport and depositional processes do not overly obscure the signal of North African dust emissions. The 70 ka Mid-Atlantic record reveals a slight increase in North African dustiness from Marine Isotope Stage 4 through the Last Glacial Maximum and a dramatic decrease in dustiness associated with the African Humid Period. On the millennial-scale, the new records exhibit brief dust maxima coincident with North Atlantic cold periods such as the Younger Dryas, and multiple Heinrich Stadials. The correlation between Mid-Atlantic dust fluxes and previous constraints on North African aridity is high. However, precipitation exerts less control on dust flux variability prior to the African Humid Period, when wind variability governs dust emissions from consistently dry dust source regions. Thus, the Mid-Atlantic dust record supports the hypothesis that both aridity and wind strength drive dust flux variability across changing climatic conditions.},
author = {Middleton, Jennifer L and Mukhopadhyay, Sujoy and Langmuir, Charles H and McManus, Jerry F and Huybers, Peter J},
doi = {10.1016/j.epsl.2017.10.034},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {North Africa,Subtropical North Atlantic,helium-3,mass accumulation rate,mineral dust,thorium-232},
pages = {12--22},
title = {{Millennial-scale variations in dustiness recorded in Mid-Atlantic sediments from 0 to 70 ka}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X17306027},
volume = {482},
year = {2018}
}
@article{Mieruch2014,
author = {Mieruch, S. and Schr{\"{o}}der, M. and No{\"{e}}l, S. and Schulz, J.},
doi = {10.1002/2014JD021588},
isbn = {2169-8996},
issn = {21698996},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {HOAPS,SCIAMACHY,autocorrelation,satellites,trends,water vapor},
number = {22},
pages = {12489--12499},
title = {{Comparison of decadal global water vapor changes derived from independent satellite time series}},
volume = {119},
year = {2014}
}
@article{doi:10.1002/2013GL057188,
abstract = {AbstractArctic air temperatures have increased in recent decades, along with documented reductions in sea ice, glacier size, and snow cover. However, the extent to which recent Arctic warming has been anomalous with respect to long-term natural climate variability remains uncertain. Here we use 145 radiocarbon dates on rooted tundra plants revealed by receding cold-based ice caps in the eastern Canadian Arctic to show that 5000 years of regional summertime cooling has been reversed, with average summer temperatures of the last {\~{}}100 years now higher than during any century in more than 44,000 years, including the peak warmth of the early Holocene when high-latitude summer insolation was 9{\%} greater than present. Reconstructed changes in snowline elevation suggest that summers cooled {\~{}}2.7°C over the past 5000 years, approximately twice the response predicted by Coupled Model Intercomparison Project Phase 5 climate models. Our results indicate that anthropogenic increases in greenhouse gases have led to unprecedented regional warmth.},
author = {Miller, Gifford H and Lehman, Scott J and Refsnider, Kurt A and Southon, John R and Zhong, Yafang},
doi = {10.1002/2013GL057188},
journal = {Geophysical Research Letters},
keywords = {Arctic,Arctic amplification,recent warming},
number = {21},
pages = {5745--5751},
title = {{Unprecedented recent summer warmth in Arctic Canada}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013GL057188},
volume = {40},
year = {2013}
}
@article{Miller2017,
abstract = {The response of the Northern Hemisphere cryosphere to the monotonic decline in summer insolation and variable radiative forcing during the Holocene has been one of irregular expansion culminating in the Little Ice Age, when most glaciers attained their maximum late Holocene dimensions. Although periods of intervening still-stand or ice-retreat can be reconstructed by direct dating of ice-recessional features, defining times of Neoglacial ice growth has been limited to indirect proxies preserved in distal archives. Here we report 45 precise radiocarbon dates on in situ plants emerging from beneath receding glaciers on Svalbard that directly date the onset of snowline descent and glacier expansion, entombing the plants. Persistent snowline lowering occurred between 4.0 and 3.4 ka, but with little additional persistent lowering until early in the first millennium AD. Populations of individual14C calendar age results and their aggregate calendar age probabilities define discrete episodes of vegetation kill and snowline lowering 240–340 AD, 410–540 AD and 670–750 AD, each with a lower snowline than the preceding episode, followed by additional snowline lowering between 1000 and 1220 AD, and between 1300 and 1450 AD. Snowline changes after 1450 AD, including the maximum ice extent of the Little Ice Age are not resolved by our collections, although snowlines remained lower than their 1450 AD level until the onset of modern warming. A time-distance diagram derived from a 250-m-long transect of dated ice-killed plants documents ice-margin advances ∼750, ∼1100 and after ∼1500 AD, concordant with distributed vegetation kill ages seen in the aggregate data set, supporting our central thesis that vegetation kill ages provide direct evidence of snowline lowering and cryospheric expansion. The mid- to late-Holocene history of snowline lowering on Svalbard is similar to ELA reconstructions of Norwegian and Svalbard cirque glaciers, and consistent with a cryospheric response to the secular decline of regional summertime insolation and stepped changes in nearby surface ocean environments. The widespread exposure of entombed plants dating from the first millennium AD suggests that Svalbard's average summer temperatures of the past century now exceed those of any century since at least 700 AD, including medieval times.},
author = {Miller, Gifford H. and Landvik, Jon Y. and Lehman, Scott J. and Southon, John R.},
doi = {10.1016/j.quascirev.2016.10.023},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Climate,Glacier,Holocene,Little Ice Age,Medieval,Neoglaciation,Radiocarbon,Recent warming,Svalbard},
pages = {67--78},
title = {{Episodic Neoglacial snowline descent and glacier expansion on Svalbard reconstructed from the 14C ages of ice-entombed plants}},
volume = {155},
year = {2017}
}
@article{Millereaaz1346,
abstract = {Using Pacific benthic foraminiferal $\delta$18O and Mg/Ca records, we derive a Cenozoic (66 Ma) global mean sea level (GMSL) estimate that records evolution from an ice-free Early Eocene to Quaternary bipolar ice sheets. These GMSL estimates are statistically similar to {\{}$\backslash$textquotedblleft{\}}backstripped{\{}$\backslash$textquotedblright{\}} estimates from continental margins accounting for compaction, loading, and thermal subsidence. Peak warmth, elevated GMSL, high CO2, and ice-free {\{}$\backslash$textquotedblleft{\}}Hothouse{\{}$\backslash$textquotedblright{\}} conditions (56 to 48 Ma) were followed by {\{}$\backslash$textquotedblleft{\}}Cool Greenhouse{\{}$\backslash$textquotedblright{\}} (48 to 34 Ma) ice sheets (10 to 30 m changes). Continental-scale ice sheets ({\{}$\backslash$textquotedblleft{\}}Icehouse{\{}$\backslash$textquotedblright{\}}) began {\~{}}34 Ma ({\textgreater}50 m changes), permanent East Antarctic ice sheets at 12.8 Ma, and bipolar glaciation at 2.5 Ma. The largest GMSL fall (27 to 20 ka; {\~{}}130 m) was followed by a {\textgreater}40 mm/yr rise (19 to 10 ka), a slowing (10 to 2 ka), and a stillstand until {\~{}}1900 CE, when rates began to rise. High long-term CO2 caused warm climates and high sea levels, with sea-level variability dominated by periodic Milankovitch cycles.},
author = {Miller, Kenneth G and Browning, James V and Schmelz, W John and Kopp, Robert E and Mountain, Gregory S and Wright, James D},
doi = {10.1126/sciadv.aaz1346},
journal = {Science Advances},
number = {20},
pages = {eaaz1346},
publisher = {American Association for the Advancement of Science},
title = {{Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records}},
url = {https://advances.sciencemag.org/content/6/20/eaaz1346},
volume = {6},
year = {2020}
}
@article{MILNE20082292,
author = {Milne, Glenn A and Mitrovica, Jerry X},
doi = {10.1016/j.quascirev.2008.08.018},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
number = {25},
pages = {2292--2302},
title = {{Searching for eustasy in deglacial sea-level histories}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379108001856},
volume = {27},
year = {2008}
}
@article{Mitchell2013,
abstract = {AbstractA strong link exists between stratospheric variability and anomalous weather patterns at the earth's surface. Specifically, during extreme variability of the Arctic polar vortex termed a “weak vortex event,” anomalies can descend from the upper stratosphere to the surface on time scales of weeks. Subsequently the outbreak of cold-air events have been noted in high northern latitudes, as well as a quadrupole pattern in surface temperature over the Atlantic and western European sectors, but it is currently not understood why certain events descend to the surface while others do not. This study compares a new classification technique of weak vortex events, based on the distribution of potential vorticity, with that of an existing technique and demonstrates that the subdivision of such events into vortex displacements and vortex splits has important implications for tropospheric weather patterns on weekly to monthly time scales. Using reanalysis data it is found that vortex splitting events are correl...},
author = {Mitchell, Daniel M. and Gray, Lesley J. and Anstey, James and Baldwin, Mark P. and Charlton-Perez, Andrew J.},
doi = {10.1175/JCLI-D-12-00030.1},
isbn = {0894-8755$\backslash$n1520-0442},
issn = {08948755},
journal = {Journal of Climate},
number = {8},
pages = {2668--2682},
title = {{The influence of stratospheric vortex displacements and splits on surface climate}},
volume = {26},
year = {2013}
}
@article{Mitchell2013a,
abstract = {The origin of the late preindustrial Holocene (LPIH) increase in atmospheric methane concentrations has been much debated. Hypotheses invoking changes in solely anthropogenic sources or solely natural sources have been proposed to explain the increase in concentrations. Here two high-resolution, high-precision ice core methane concentration records from Greenland and Antarctica are presented and are used to construct a high-resolution record of the methane inter-polar difference (IPD). The IPD record constrains the latitudinal distribution of emissions and shows that LPIH emissions increased primarily in the tropics, with secondary increases in the subtropical Northern Hemisphere. Anthropogenic and natural sources have different latitudinal characteristics, which are exploited to demonstrate that both anthropogenic and natural sources are needed to explain LPIH changes in methane concentration.},
author = {Mitchell, Logan and Brook, Ed and Lee, James E. and Buizert, Christo and Sowers, Todd},
doi = {10.1126/science.1238920},
issn = {10959203},
journal = {Science},
number = {6161},
pages = {964--966},
title = {{Constraints on the late Holocene anthropogenic contribution to the atmospheric methane budget (2013b)}},
volume = {342},
year = {2013}
}
@article{Moat2020,
author = {Moat, Ben I and Smeed, David A and Frajka-Williams, Eleanor and Desbruy{\`{e}}res, Damien G and Beaulieu, Claudie and Johns, William E and Rayner, Darren and Sanchez-Franks, Alejandra and Baringer, Molly O and Volkov, Denis and Jackson, Laura C and Bryden, Harry L},
doi = {10.5194/os-16-863-2020},
issn = {1812-0792},
journal = {Ocean Science},
month = {jul},
number = {4},
pages = {863--874},
publisher = {Copernicus Publications},
title = {{Pending recovery in the strength of the meridional overturning circulation at 26° N}},
url = {https://os.copernicus.org/articles/16/863/2020/ https://os.copernicus.org/articles/16/863/2020/os-16-863-2020.pdf},
volume = {16},
year = {2020}
}
@article{Moffa-Sanchez2019,
abstract = {Abstract The climate of the last two millennia was characterized by decadal to multicentennial variations, which were recorded in terrestrial records and had important societal impacts. The cause of these climatic events is still under debate, but changes in the North Atlantic circulation have often been proposed to play an important role. In this review we compile available high-resolution paleoceanographic data sets from the northern North Atlantic and Nordic Seas. The records are grouped into regions related to modern ocean conditions, and their variability is discussed. We additionally discuss our current knowledge from modeling studies, with a specific focus on the dynamical changes that are not well inferred from the proxy records. An illustration is provided through the analysis of two climate model ensembles and an individual simulation of the last millennium. This review thereby provides an up-to-date paleoperspective on the North Atlantic multidecadal to multicentennial ocean variability across the last two millennia.},
annote = {doi: 10.1029/2018PA003508},
author = {Moffa-S{\'{a}}nchez, P and Moreno-Chamarro, E and Reynolds, D J and Ortega, P and Cunningham, L and Swingedouw, D and Amrhein, D E and Halfar, J and Jonkers, L and Jungclaus, J H and Perner, K and Wanamaker, A and Yeager, S},
doi = {10.1029/2018PA003508},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {North Atlantic and Arctic climate variability,climate models,paleoceanography,past two millennia,proxies},
month = {aug},
number = {8},
pages = {1399--1436},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Variability in the Northern North Atlantic and Arctic Oceans Across the Last Two Millennia: A Review}},
url = {https://doi.org/10.1029/2018PA003508},
volume = {34},
year = {2019}
}
@article{Moffa-Sanchez2017,
abstract = {The subpolar North Atlantic is a key location for the Earth's climate system. In the Labrador Sea, intense winter air–sea heat exchange drives the formation of deep waters and the surface circulation of warm waters around the subpolar gyre. This process therefore has the ability to modulate the oceanic northward heat transport. Recent studies reveal decadal variability in the formation of Labrador Sea Water. Yet, crucially, its longer-term history and links with European climate remain limited. Here we present new decadally resolved marine proxy reconstructions, which suggest weakened Labrador Sea Water formation and gyre strength with similar timing to the centennial cold periods recorded in terrestrial climate archives and historical records over the last 3000 years. These new data support that subpolar North Atlantic circulation changes, likely forced by increased southward flow of Arctic waters, contributed to modulating the climate of Europe with important societal impacts as revealed in European history.},
author = {Moffa-S{\'{a}}nchez, Paola and Hall, Ian R},
doi = {10.1038/s41467-017-01884-8},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {1726},
title = {{North Atlantic variability and its links to European climate over the last 3000 years}},
url = {https://doi.org/10.1038/s41467-017-01884-8},
volume = {8},
year = {2017}
}
@article{Moffitt2015,
abstract = {Climate-driven Oxygen Minimum Zone (OMZ) expansions in the geologic record provide an opportunity to characterize the spatial and temporal scales of OMZ change. Here we investigate OMZ expansion through the global-scale warming event of the most recent deglaciation (18-11 ka), an event with clear relevance to understanding modern anthropogenic climate change. Deglacial marine sediment records were compiled to quantify the vertical extent, intensity, surface area and volume impingements of hypoxic waters upon continental margins. By integrating sediment records (183-2,309 meters below sea level; mbsl) containing one or more geochemical, sedimentary or microfossil oxygenation proxies integrated with analyses of eustatic sea level rise, we reconstruct the timing, depth and intensity of seafloor hypoxia. The maximum vertical OMZ extent during the deglaciation was variable by region: Subarctic Pacific ({\~{}}600-2,900 mbsl), California Current ({\~{}}330-1,500 mbsl), Mexico Margin ({\~{}}330-830 mbsl), and the Humboldt Current and Equatorial Pacific ({\~{}}110-3,100 mbsl). The timing of OMZ expansion is regionally coherent but not globally synchronous. Subarctic Pacific and California Current continental margins exhibit tight correlation to the oscillations of Northern Hemisphere deglacial events (Termination IA, B{\o}lling-Aller{\o}d, Younger Dryas and Termination IB). Southern regions (Mexico Margin and the Equatorial Pacific and Humboldt Current) exhibit hypoxia expansion prior to Termination IA ({\~{}}14.7 ka), and no regional oxygenation oscillations. Our analyses provide new evidence for the geographically and vertically extensive expansion of OMZs, and the extreme compression of upper-ocean oxygenated ecosystems during the geologically recent deglaciation.},
author = {Moffitt, Sarah E. and Moffitt, Russell A. and Sauthoff, Wilson and Davis, Catherine V. and Hewett, Kathryn and Hill, Tessa M.},
doi = {10.1371/journal.pone.0115246},
editor = {Hong, Yiguo},
issn = {1932-6203},
journal = {PLOS ONE},
month = {jan},
number = {1},
pages = {e0115246},
publisher = {Public Library of Science},
title = {{Paleoceanographic Insights on Recent Oxygen Minimum Zone Expansion: Lessons for Modern Oceanography}},
url = {https://dx.plos.org/10.1371/journal.pone.0115246},
volume = {10},
year = {2015}
}
@article{Mohajerani2018,
abstract = {Totten andMoscow University glaciers, in the marine-based sector of East Antarctica, contain enough ice to raise sea level by 5m. Obtaining precise measurements of their mass balance is challenging owing to large area of the basins and the small mass balance signal compared toWest Antarctic glaciers. Here we employ a locally optimized processing of Gravity Recovery and Climate Experiment (GRACE) harmonics to evaluate their mass balance at the sub-basin scale and compare the results with mass budget method (MBM) estimates using regional atmospheric climate model version 2.3 (RACMO2.3) or Mod{\`{e}}le Atmosph{\'{e}}rique R{\'{e}}gional version 3.6.4 (MAR3.6.4). The sub-basin mass loss estimate for April 2002 to November 2015 is 14.8 ± 4.3 Gt/yr, which is weakly affected by glacial isostatic adjustment uncertainties (±1.4 Gt/yr). This result agrees with MBM/RACMO2.3 (15.8 ± 2.0 Gt/yr), whereas MBM/MAR3.6.4 underes- timates the loss (6.6 ± 1.6 Gt/yr). For the entire drainage, the mass loss for April 2002 to August 2016 is 18.5 ± 6.6 Gt/yr, or 15 ± 4{\%}of its ice flux. These results provide unequivocal evidence for mass loss in this East Antarctic sector},
author = {Mohajerani, Yara and Velicogna, Isabella and Rignot, Eric},
doi = {10.1029/2018GL078173},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {East Antarctica,GRACE,Totten glacier,mass balance,mass budget,regional climate models},
number = {14},
pages = {7010--7018},
title = {{Mass Loss of Totten and Moscow University Glaciers, East Antarctica, Using Regionally Optimized GRACE Mascons}},
volume = {45},
year = {2018}
}
@article{Mohtadi2016,
author = {Mohtadi, Mahyar and Prange, Matthias and Steinke, Stephan},
doi = {10.1038/nature17450},
issn = {0028-0836},
journal = {Nature},
number = {7602},
pages = {191--199},
publisher = {Nature Publishing Group},
title = {{Review Palaeoclimatic insights into forcing and response of monsoon rainfall}},
url = {http://dx.doi.org/10.1038/nature17450},
volume = {533},
year = {2016}
}
@article{Mokeddem2014,
abstract = {The last interglacial, ∼125,000 y ago, was the last extended warm period the earth has known before our Common Era of the past 11,000 y. Its end came after ∼15,000 y, paced by the decline in northern summer insolation, and followed by a glacial age lasting 100,000 y. Yet the ocean dynamics contributing to this glacial initiation and its global propagation are not fully understood, nor are their general role in climate evolution understood. This study assesses the role of the ocean's gyre systems and fronts as dynamical components in large-scale climate change. Using microfossils, we document progressive southward advances of Arctic and polar hydrographic fronts into the subpolar North Atlantic Ocean, which trigger regional coolings and accelerate the transition into the glacial age.The last interglacial interval was terminated by the inception of a long, progressive glaciation that is attributed to astronomically influenced changes in the seasonal distribution of sunlight over the earth. However, the feedbacks, internal dynamics, and global teleconnections associated with declining northern summer insolation remain incompletely understood. Here we show that a crucial early step in glacial inception involves the weakening of the subpolar gyre (SPG) circulation of the North Atlantic Ocean. Detailed new records of microfossil foraminifera abundance and stable isotope ratios in deep sea sediments from Ocean Drilling Program site 984 south of Iceland reveal repeated, progressive cold water-mass expansions into subpolar latitudes during the last peak interglacial interval, marine isotope substage 5e. These movements are expressed as a sequence of progressively extensive southward advances and subsequent retreats of a hydrographic boundary that may have been analogous to the modern Arctic front, and associated with rapid changes in the strength of the SPG. This persistent millennial-scale oceanographic oscillation accompanied a long-term cooling trend at a time of slowly declining northern summer insolation, providing an early link in the propagation of those insolation changes globally, and resulting in a rapid transition from extensive regional warmth to the dramatic instability of the subsequent ∼100 ka.},
author = {Mokeddem, Zohra and McManus, Jerry F and Oppo, Delia W},
doi = {10.1073/pnas.1322103111},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {aug},
number = {31},
pages = {11263--11268},
title = {{Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1322103111},
volume = {111},
year = {2014}
}
@article{Mokeddem2016,
abstract = {Abstract Rapidly accumulating sediments from the Bj{\"{o}}rn drift deposit south of Iceland are studied for comparison of glacial/interglacial climate changes related to millennial variability of the subpolar surface and deep ocean circulation in the North Atlantic. High-resolution faunal, isotopic, and sedimentary analyses reveal a strong multimillennial climatic variability interpreted as oscillations in heat transport westward south of Iceland during marine isotope stage 6 (MIS 6), possibly related to the strength of the subpolar gyre (SPG). The oscillations persisted from MIS 6 through the following interglacial (MIS 5), although with diminished magnitude, and were respectively characterized by repeated advances of the polar front south of Iceland during MIS 6 and southward migrations of the Arctic front due to cold surface outflow through the East Greenland and East Iceland Currents during MIS 5. Incursions of cold, fresh surface waters, and drifting ice affected the dynamics of the SPG, episodically causing it to weaken and contract to the northwest. During these intervals of diminished SPG, the northward transport of subtropical heat and salt was strengthened and preferentially conveyed to the northeast past Iceland, enhancing deep-water formation in the Nordic Seas. By contrast, when the SPG was strong, more subtropical water and its associated heat were entrained within the relatively warm Irminger Current flowing westward south of Iceland. These oceanographic oscillations were associated with repeated multimillennial cooling and warming episodes during the glacial stage MIS 6, equivalent to the Dansgaard-Oeschger cycles of the last glaciation.},
annote = {doi: 10.1002/2015PA002813},
author = {Mokeddem, Zohra and McManus, Jerry F},
doi = {10.1002/2015PA002813},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {MIS 5,MIS 6,North Atlantic,stadial/interstadials},
month = {jun},
number = {6},
pages = {758--778},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Persistent climatic and oceanographic oscillations in the subpolar North Atlantic during the MIS 6 glaciation and MIS 5 interglacial}},
url = {https://doi.org/10.1002/2015PA002813},
volume = {31},
year = {2016}
}
@article{Mollier-Vogel2019,
author = {Mollier-Vogel, Elfi and Martinez, Philippe and Blanz, Thomas and Robinson, Rebecca and Desprat, St{\'{e}}phanie and Etourneau, Johan and Charlier, Karine and Schneider, Ralph R},
doi = {10.1016/j.gloplacha.2018.10.020},
journal = {Global and Planetary Change},
number = {October 2018},
pages = {365--373},
title = {{Mid-Holocene deepening of the Southeast Pacific oxycline}},
volume = {172},
year = {2019}
}
@article{Mollier-Vogel2013,
abstract = {We present a high-resolution marine record of sediment input from the Guayas River, Ecuador, that reflects changes in precipitation along western equatorial South America during the last 18ka. We use log (Ti/Ca) derived from X-ray Fluorescence (XRF) to document terrigenous input from riverine runoff that integrates rainfall from the Guayas River catchment. We find that rainfall-induced riverine runoff has increased during the Holocene and decreased during the last deglaciation. Superimposed on those long-term trends, we find that rainfall was probably slightly increased during the Younger Dryas, while the Heinrich event 1 was marked by an extreme load of terrigenous input, probably reflecting one of the wettest period over the time interval studied. When we compare our results to other Deglacial to Holocene rainfall records located across the tropical South American continent, different modes of variability become apparent. The records of rainfall variability imply that changes in the hydrological cycle at orbital and sub-orbital timescales were different from western to eastern South America. Orbital forcing caused an antiphase behavior in rainfall trends between eastern and western equatorial South America. In contrast, millennial-scale rainfall changes, remotely connected to the North Atlantic climate variability, led to homogenously wetter conditions over eastern and western equatorial South America during North Atlantic cold spells. These results may provide helpful diagnostics for testing the regional rainfall sensitivity in climate models and help to refine rainfall projections in South America for the next century. {\textcopyright} 2013 Elsevier Ltd.},
author = {Mollier-Vogel, Elfi and Leduc, Guillaume and B{\"{o}}schen, Tebke and Martinez, Philippe and Schneider, Ralph R.},
doi = {10.1016/j.quascirev.2013.06.021},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Deglaciation,Heinrich 1,Holocene,ITCZ,Speleothem,XRF,Younger Dryas},
pages = {29--38},
title = {{Rainfall response to orbital and millennial forcing in northern Peru over the last 18ka}},
volume = {76},
year = {2013}
}
@article{https://doi.org/10.1029/2001PA000663,
author = {Molnar, Peter and Cane, Mark A},
doi = {10.1029/2001PA000663},
journal = {Paleoceanography},
keywords = {El Ni{\~{n}}o,atmospheric heat transport,ice age,teleconnections},
number = {2},
pages = {11},
title = {{El Ni{\~{n}}o's tropical climate and teleconnections as a blueprint for pre-Ice Age climates}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2001PA000663},
volume = {17},
year = {2002}
}
@article{Monerie2019a,
abstract = {We assess the effect of the Atlantic multidecadal variability (AMV) on the global monsoon using idealized simulations. Warm AMV phases are associated with a significant strengthening of monsoon precipitation over Northern Africa and India, and anomalously weak monsoon precipitation over South America. Changes in monsoon precipitation are mediated by a change in atmospheric dynamics, primarily associated with a shift in the circulation related to both an enhanced interhemispheric thermal contrast and the remote impact of AMV on the Pacific Ocean, through changes in the Walker circulation. In contrast, the thermodynamic changes are less important. Further experiments show that the impact of AMV is largely due to the tropical component of the sea surface temperature anomalies. However, the extratropical Atlantic also plays a role, especially for northern Africa. Finally, we show that the effect of AMV on monsoons is not linearly related to the magnitude of warming.},
author = {Monerie, Paul Arthur and Robson, Jon and Dong, Buwen and Hodson, Dan L.R. and Klingaman, Nicholas P.},
doi = {10.1029/2018GL080903},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {North Altantic variability,climate simulation,experiments,global monsoon,internal variability,tropical precipitation},
number = {3},
pages = {1765--1775},
title = {{Effect of the Atlantic Multidecadal Variability on the Global Monsoon}},
volume = {46},
year = {2019}
}
@article{Montaggioni2008,
abstract = {The fringing reef at Pointe-au-Sable (Mauritius, Indian Ocean) was used to examine the effects of Holocene sea-level rise on coral growth. This reef is about 1000 m wide and comprises a forereef slope (30 m maximum depth), a narrow reef crest and a very shallow backreef (1{\textperiodcentered}5 m maximum depth). Four major coral communities were recognized, which developed within relatively narrow depth ranges: a Pachyseris/Oulophyllia community (deeper than 20 m), an Acropora 'tabulate'/Faviid community (20-6 m); a robust branching Acropora community (less than 6 m) and a Pavona community (less than 10 m). Three high-recovery cores show the Holocene reef sequence is a maximum of 19{\textperiodcentered}3 m thick and comprises four coral biofacies which are similar to counterparts identified in modern communities: robust branching, tabular-branching, robust branching-domal and foliaceous coral facies. A minimum sea-level curve for the past 7500 years was constructed. Using distribution patterns of coral biofacies and radiocarbon dates from corals, reconstruction of reef growth history indicates that both offshore and onshore reef zones were developing coevally, aggrading at rates of 4{\textperiodcentered}3 mm year-1 from 6900 years B.P. The reef caught up with sea-level only after sea-level stabilized. Changes in coral community and reef growth rates were driven principally by increasing water agitation due to the decrease in accommodation space. Based on the composition of the successive coral assemblages, the reef appears to have grown through successive equilibrium stages.},
author = {Montaggioni, Lucien F and Faure, G{\'{e}}rad},
doi = {10.1111/j.1365-3091.1997.tb02178.x},
issn = {00370746},
journal = {Sedimentology},
month = {jun},
number = {6},
pages = {1053--1070},
title = {{Response of reef coral communities to sea-level rise: a Holocene model from Mauritius (Western Indian Ocean)}},
volume = {44},
year = {2008}
}
@article{Montzka2021,
author = {Montzka, Stephen A. and Dutton, Geoffrey S. and Portmann, Robert W. and Chipperfield, Martyn P. and Davis, Sean and Feng, Wuhu and Manning, Alistair J. and Ray, Eric and Rigby, Matthew and Hall, Bradley D. and Siso, Carolina and Nance, J. David and Krummel, Paul B. and M{\"{u}}hle, Jens and Young, Dickon and O'Doherty, Simon and Salameh, Peter K. and Harth, Christina M. and Prinn, Ronald G. and Weiss, Ray F. and Elkins, James W. and Walter-Terrinoni, Helen and Theodoridi, Christina},
doi = {10.1038/s41586-021-03260-5},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7846},
pages = {428--432},
title = {{A decline in global CFC-11 emissions during 2018−2019}},
url = {http://www.nature.com/articles/s41586-021-03260-5},
volume = {590},
year = {2021}
}
@incollection{Montzka2018,
address = {Geneva, Switzerland},
author = {Montzka, S.A. and Velders, G.J.M. (Lead Authors) and Krummel, P.B. and M{\"{u}}hle, J. and Orkin, V.L. and Park, S. and Shah, N. and Walter-Terrinoni, H.},
booktitle = {Scientific Assessment of Ozone Depletion: 2018},
chapter = {2},
doi = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
pages = {2.1--2.56},
publisher = {World Meteorological Organization (WMO)},
series = {Global Ozone Research and Monitoring Project – Report No. 58},
title = {{Hydrofluorocarbons (HFCs)}},
url = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
year = {2018}
}
@article{Montzka2018a,
abstract = {The Montreal Protocol was designed to protect the stratospheric ozone layer by enabling reductions in the abundance of ozone-depleting substances such as chlorofluorocarbons (CFCs) in the atmosphere1–3. The reduction in the atmospheric concentration of trichlorofluoromethane (CFC-11) has made the second-largest contribution to the decline in the total atmospheric concentration of ozone-depleting chlorine since the 1990s1. However, CFC-11 still contributes one-quarter of all chlorine reaching the stratosphere, and a timely recovery of the stratospheric ozone layer depends on a sustained decline in CFC-11 concentrations1. Here we show that the rate of decline of atmospheric CFC-11 concentrations observed at remote measurement sites was constant from 2002 to 2012, and then slowed by about 50 per cent after 2012. The observed slowdown in the decline of CFC-11 concentration was concurrent with a 50 per cent increase in the mean concentration difference observed between the Northern and Southern Hemispheres, and also with the emergence of strong correlations at the Mauna Loa Observatory between concentrations of CFC-11 and other chemicals associated with anthropogenic emissions. A simple model analysis of our findings suggests an increase in CFC-11 emissions of 13 ± 5 gigagrams per year (25 ± 13 per cent) since 2012, despite reported production being close to zero4since 2006. Our three-dimensional model simulations confirm the increase in CFC-11 emissions, but indicate that this increase may have been as much as 50 per cent smaller as a result of changes in stratospheric processes or dynamics. The increase in emission of CFC-11 appears unrelated to past production; this suggests unreported new production, which is inconsistent with the Montreal Protocol agreement to phase out global CFC production by 2010.},
author = {Montzka, Stephen A. and Dutton, Geoff S. and Yu, Pengfei and Ray, Eric and Portmann, Robert W. and Daniel, John S. and Kuijpers, Lambert and Hall, Brad D. and Mondeel, Debra and Siso, Carolina and Nance, J. David and Rigby, Matt and Manning, Alistair J. and Hu, Lei and Moore, Fred and Miller, Ben R. and Elkins, James W.},
doi = {10.1038/s41586-018-0106-2},
isbn = {4158601801062},
issn = {1476-4687},
journal = {Nature},
number = {7705},
pages = {413--417},
title = {{An unexpected and persistent increase in global emissions of ozone-depleting CFC-11}},
url = {https://doi.org/10.1038/s41586-018-0106-2},
volume = {557},
year = {2018}
}
@article{Moore2013,
abstract = {The North Atlantic Oscillation (NAO) is one of the most important modes of variability in the global climate system and is characterized by a meridional dipole in the sea level pressure field, with centers of action near Iceland and the Azores. It has a profound influence on the weather, climate, ecosystems, and economies of Europe, Greenland, eastern North America, and North Africa. It has been proposed that around 1980, there was an eastward secular shift in the NAO's northern center of action that impacted sea ice export through Fram Strait. Independently, it has also been suggested that the location of its southern center of action is tied to the phase of the NAO. Both of these attributes of the NAO have been linked to anthropogenic climate change. Here the authors use both the one-point correlation map technique as well as empirical orthogonal function (EOF) analysis to show that the meridional dipole that is often seen in the sea level pressure field over the North Atlantic is not purely the result of the NAO (as traditionally defined) but rather arises through an interplay among the NAO and two other leading modes of variability in the North Atlantic region: the East Atlantic (EA) and the Scandinavian (SCA) patterns. This interplay has resulted in multidecadal mobility in the two centers of action of the meridional dipole since the late nineteenth century. In particular, an eastward movement of the dipole has occurred during the 1930s to 1950s as well as more recently. This mobility is not seen in the leading EOF of the sea level pressure field in the region.},
author = {Moore, G. W. K. and Renfrew, I. A. and Pickart, R. S.},
doi = {10.1175/JCLI-D-12-00023.1},
isbn = {0894-8755},
issn = {0894-8755},
journal = {Journal of Climate},
month = {apr},
number = {8},
pages = {2453--2466},
title = {{Multidecadal Mobility of the North Atlantic Oscillation}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-12-00023.1},
volume = {26},
year = {2013}
}
@article{Morales2020,
abstract = {South American (SA) societies are highly vulnerable to droughts and pluvials, but lack of long-term climate observations severely limits our understanding of the global processes driving climatic variability in the region. The number and quality of SA climate-sensitive tree ring chronologies have significantly increased in recent decades, now providing a robust network of 286 records for characterizing hydroclimate variability since 1400 CE. We combine this network with a self-calibrated Palmer Drought Severity Index (scPDSI) dataset to derive the South American Drought Atlas (SADA) over the continent south of 12°S. The gridded annual reconstruction of austral summer scPDSI is the most spatially complete estimate of SA hydroclimate to date, and well matches past historical dry/wet events. Relating the SADA to the Australia–New Zealand Drought Atlas, sea surface temperatures and atmospheric pressure fields, we determine that the El Ni{\~{n}}o–Southern Oscillation (ENSO) and the Southern Annular Mode (SAM) are strongly associated with spatially extended droughts and pluvials over the SADA domain during the past several centuries. SADA also exhibits more extended severe droughts and extreme pluvials since the mid-20th century. Extensive droughts are consistent with the observed 20th-century trend toward positive SAM anomalies concomitant with the weakening of midlatitude Westerlies, while low-level moisture transport intensified by global warming has favored extreme rainfall across the subtropics. The SADA thus provides a long-term context for observed hydroclimatic changes and for 21st-century Intergovernmental Panel on Climate Change (IPCC) projections that suggest SA will experience more frequent/severe droughts and rainfall events as a consequence of increasing greenhouse gas emissions.},
author = {Morales, Mariano S. and Cook, Edward R. and Barichivich, Jonathan and Christie, Duncan A. and Villalba, Ricardo and LeQuesne, Carlos and Srur, Ana M. and Ferrero, M. Eugenia and Gonz{\'{a}}lez-Reyes, {\'{A}}lvaro and Couvreux, Fleur and Matskovsky, Vladimir and Aravena, Juan C. and Lara, Antonio and Mundo, Ignacio A. and Rojas, Facundo and Prieto, Mar{\'{i}}a R. and Smerdon, Jason E. and Bianchi, Lucas O. and Masiokas, Mariano H. and Urrutia-Jalabert, Rocio and Rodriguez-Cat{\'{o}}n, Milagros and Mu{\~{n}}oz, Ariel A. and Rojas-Badilla, Moises and Alvarez, Claudio and Lopez, Lidio and Luckman, Brian H. and Lister, David and Harris, Ian and Jones, Philip D. and Williams, A. Park and Velazquez, Gonzalo and Aliste, Diego and Aguilera-Betti, Isabella and Marcotti, Eugenia and Flores, Felipe and Mu{\~{n}}oz, Tom{\'{a}}s and Cuq, Emilio and Boninsegna, Jos{\'{e}} A.},
doi = {10.1073/pnas.2002411117},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {29},
pages = {16816--16823},
title = {{Six hundred years of South American tree rings reveal an increase in severe hydroclimatic events since mid-20th century}},
volume = {117},
year = {2020}
}
@article{Moreno2018a,
author = {Moreno, P I and Vilanova, I and Villa-Mart{\'{i}}nez, R and Dunbar, R B and Mucciarone, D A and Kaplan, M R and Garreaud, R D and Rojas, M and Moy, C M and {De Pol-Holz}, R and Lambert, F},
doi = {10.1038/s41598-018-21836-6},
journal = {Scientific Reports},
number = {1},
pages = {3458},
title = {{Onset and evolution of southern annular mode-like changes at centennial timescale}},
volume = {8},
year = {2018}
}
@article{Moreno2014,
author = {Moreno, Patricio I. and Vilanova, I. and Villa-Mart{\'{i}}nez, R. and Garreaud, R D and Rojas, M and {De Pol-Holz}, R.},
doi = {10.1038/ncomms5375},
issn = {2041-1723},
journal = {Nature Communications},
month = {sep},
number = {1},
pages = {4375},
title = {{Southern Annular Mode-like changes in southwestern Patagonia at centennial timescales over the last three millennia}},
url = {http://www.nature.com/articles/ncomms5375},
volume = {5},
year = {2014}
}
@article{Morice2020,
author = {Morice, Colin P and Kennedy, John J. and Rayner, Nick A. and Winn, J.P. and Hogan, E. and Killick, R. E. and Dunn, Robert J.H. and Osborn, Timothy J. and Jones, P.D. and Simpson, I. R.},
doi = {10.1029/2019JD032361},
journal = {Journal of Geophysical Research: Atmospheres},
number = {3},
pages = {e2019JD032361},
title = {{An updated assessment of near-surface temperature change from 1850: the HadCRUT5 dataset}},
volume = {126},
year = {2021}
}
@article{Morioka2011a,
abstract = {AbstractUsing observational data and outputs from an ocean general circulation model, the growth and decay of the South Atlantic subtropical dipole (SASD) are studied. The SASD is the most dominant mode of interannual variability in the South Atlantic Ocean, and its sea surface temperature (SST) anomaly shows a dipole pattern that is oriented in the northeast?southwest direction. The positive (negative) pole develops because the warming of the mixed layer by the contribution from the climatological shortwave radiation is enhanced (suppressed) when the mixed layer is thinner (thicker) than normal. The mixed layer depth anomaly over the positive (negative) pole is due to the suppressed (enhanced) latent heat flux loss associated with the southward migration and strengthening of the subtropical high. During the decay phase, since the temperature difference between the mixed layer and the entrained water becomes anomalously large (small) as a result of the positive (negative) mixed layer temperature anomaly, the cooling of the mixed layer by the entrainment is enhanced (reduced). In addition, the cooling of the mixed layer by the contribution from the climatological latent heat flux is enhanced (suppressed) by the same thinner (thicker) mixed layer. This paper demonstrates the importance of taking into account the interannual variations of the mixed layer depth in discussing the growth and decay of SST anomalies associated with the SASD.},
annote = {doi: 10.1175/2011JCLI4010.1},
author = {Morioka, Yushi and Tozuka, Tomoki and Yamagata, Toshio},
doi = {10.1175/2011JCLI4010.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {apr},
number = {21},
pages = {5538--5554},
publisher = {American Meteorological Society},
title = {{On the Growth and Decay of the Subtropical Dipole Mode in the South Atlantic}},
url = {https://doi.org/10.1175/2011JCLI4010.1},
volume = {24},
year = {2011}
}
@article{MORLEY201418,
abstract = {Climate records of the mid-to-late Holocene transition, between 3–4 thousand years before present (ka), often exhibit a rapid change in response to the gradual change in orbital insolation. Here we investigate North Atlantic Central Water circulation as a possible mechanism regulating the latitudinal temperature gradient (LTG), which, in turn, amplifies climate sensitivity to small changes in solar irradiance. Through this mechanism, sharp climate events and transitions are the result of a positive feedback process that propagates and amplifies climate events in the North Atlantic region. We explore these linkages using an intermediate water temperature record reconstructed from Mg/Ca measurements of benthic foraminifera (Hyalinea balthica) from a sediment core off NW Africa (889 m depth) between 0 to 5.5 ka. Our results show that Eastern North Atlantic Central Waters (ENACW) cooled by ∼1°±0.7 °C and densities decreased by $\sigma$$\theta$=0.4±0.2 between 3.3 and 2.6 ka. This shift in ENACW hydrography illustrates a transition towards enhanced mid-latitude atmospheric circulation after 2.7 ka in particular during cold events of the late-Holocene. The presented records demonstrate the important role of ENACW circulation in propagating the climate signatures of the LTG by reducing the meridional heat transfer from high to low latitudes during the transition from the Holocene Thermal Maximum to the late-Holocene. In addition, the dynamic response of ENACW circulation to the gradual climate forcing of LTGs provides a prime example of an amplifying climate feedback mechanism.},
author = {Morley, Audrey and Rosenthal, Yair and DeMenocal, Peter and {Morley, A., Rosenthal, Y., deMenocal}, P.},
doi = {10.1016/j.epsl.2013.11.039},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Eastern North Atlantic Central water circulation,NAO,mid-Holocene climate optimum,ocean-atmosphere climate linkages,orbital insolation,paleoceanography},
pages = {18--26},
title = {{Ocean–atmosphere climate shift during the mid-to-late Holocene transition}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X13006730},
volume = {388},
year = {2014}
}
@article{Morlighem2017,
abstract = {Abstract Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.},
author = {Morlighem, M and Williams, C N and Rignot, E and An, L and Arndt, J E and Bamber, J L and Catania, G and Chauch{\'{e}}, N and Dowdeswell, J A and Dorschel, B and Fenty, I and Hogan, K and Howat, I and Hubbard, A and Jakobsson, M and Jordan, T M and Kjeldsen, K K and Millan, R and Mayer, L and Mouginot, J and No{\"{e}}l, B P Y and O'Cofaigh, C and Palmer, S and Rysgaard, S and Seroussi, H and Siegert, M J and Slabon, P and Straneo, F and van den Broeke, M R and Weinrebe, W and Wood, M and Zinglersen, K B},
doi = {10.1002/2017GL074954},
journal = {Geophysical Research Letters},
number = {21},
pages = {11051--11061},
title = {{BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation}},
volume = {44},
year = {2017}
}
@article{Morlighem2020a,
abstract = {The Antarctic ice sheet has been losing mass over past decades through the accelerated flow of its glaciers, conditioned by ocean temperature and bed topography. Glaciers retreating along retrograde slopes (that is, the bed elevation drops in the inland direction) are potentially unstable, while subglacial ridges slow down the glacial retreat. Despite major advances in the mapping of subglacial bed topography, significant sectors of Antarctica remain poorly resolved and critical spatial details are missing. Here we present a novel, high-resolution and physically based description of Antarctic bed topography using mass conservation. Our results reveal previously unknown basal features with major implications for glacier response to climate change. For example, glaciers flowing across the Transantarctic Mountains are protected by broad, stabilizing ridges. Conversely, in the marine basin of Wilkes Land, East Antarctica, we find retrograde slopes along Ninnis and Denman glaciers, with stabilizing slopes beneath Moscow University, Totten and Lambert glacier system, despite corrections in bed elevation of up to 1 km for the latter. This transformative description of bed topography redefines the high- and lower-risk sectors for rapid sea level rise from Antarctica; it will also significantly impact model projections of sea level rise from Antarctica in the coming centuries.},
author = {Morlighem, Mathieu and Rignot, Eric and Binder, Tobias and Blankenship, Donald and Drews, Reinhard and Eagles, Graeme and Eisen, Olaf and Ferraccioli, Fausto and Forsberg, Ren{\'{e}} and Fretwell, Peter and Goel, Vikram and Greenbaum, Jamin S and Gudmundsson, Hilmar and Guo, Jingxue and Helm, Veit and Hofstede, Coen and Howat, Ian and Humbert, Angelika and Jokat, Wilfried and Karlsson, Nanna B and Lee, Won Sang and Matsuoka, Kenichi and Millan, Romain and Mouginot, Jeremie and Paden, John and Pattyn, Frank and Roberts, Jason and Rosier, Sebastian and Ruppel, Antonia and Seroussi, Helene and Smith, Emma C and Steinhage, Daniel and Sun, Bo and van den Broeke, Michiel R and van Ommen, Tas D and van Wessem, Melchior and Young, Duncan A},
doi = {10.1038/s41561-019-0510-8},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {2},
pages = {132--137},
title = {{Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet}},
url = {https://doi.org/10.1038/s41561-019-0510-8},
volume = {13},
year = {2020}
}
@article{Morrill2018a,
author = {Morrill, Carrie and Lowry, Daniel P and Hoell, Andrew},
doi = {10.1002/2017GL075807},
journal = {Geophysical Research Letters},
pages = {335--345},
title = {{Thermodynamic and Dynamic Causes of Pluvial Conditions During the Last Glacial Maximum in Western North America}},
volume = {45},
year = {2018}
}
@article{Mortimer2020,
abstract = {{\textless}p{\textgreater}{\textless}![CDATA[Abstract. Nine gridded Northern Hemisphere snow water equivalent (SWE) products were evaluated as part of the European Space Agency (ESA) Satellite Snow Product Intercomparison and Evaluation Exercise (SnowPEx). Three categories of datasets were assessed: (1) those utilizing some form of reanalysis (the NASA Global Land Data Assimilation System version 2 – GLDAS-2; the European Centre for Medium-Range Weather Forecasts (ECMWF) interim land surface reanalysis – ERA-Interim/Land and ERA5; the NASA Modern-Era Retrospective Analysis for Research and Applications version 1 (MERRA) and version 2 (MERRA-2); the Crocus snow model driven by ERA-Interim meteorology – Crocus); (2) passive microwave remote sensing combined with daily surface snow depth observations (ESA GlobSnow v2.0); and (3) stand-alone passive microwave retrievals (NASA AMSR-E SWE versions 1.0 and 2.0) which do not utilize surface snow observations. Evaluation included validation against independent snow course measurements from Russia, Finland, and Canada and product intercomparison through the calculation of spatial and temporal correlations in SWE anomalies. The stand-alone passive microwave SWE products (AMSR-E v1.0 and v2.0 SWE) exhibit low spatial and temporal correlations to other products and RMSE nearly double the best performing product. Constraining passive microwave retrievals with surface observations (GlobSnow) provides performance comparable to the reanalysis-based products; RMSE over Finland and Russia for all but the AMSR-E products is ∼50 mm or less, with the exception of ERA-Interim/Land over Russia. Using a seven-dataset ensemble that excluded the stand-alone passive microwave products reduced the RMSE by 10 mm (20 {\%}) and increased the correlation from 0.67 to 0.78 compared to any individual product. The overall performance of the best multiproduct combinations is still at the margins of acceptable uncertainty for scientific and operational requirements; only through combined and integrated improvements in remote sensing, modeling, and observations will real progress in SWE product development be achieved.]]{\textgreater}{\textless}/p{\textgreater}},
author = {Mortimer, Colleen and Mudryk, Lawrence and Derksen, Chris and Luojus, Kari and Brown, Ross and Kelly, Richard and Tedesco, Marco},
doi = {10.5194/tc-14-1579-2020},
issn = {1994-0424},
journal = {The Cryosphere},
month = {may},
number = {5},
pages = {1579--1594},
title = {{Evaluation of long-term Northern Hemisphere snow water equivalent products}},
url = {https://tc.copernicus.org/articles/14/1579/2020/},
volume = {14},
year = {2020}
}
@article{Mortin2016,
abstract = {The timing of melt onset affects the surface energy uptake throughout the melt season. Yet the processes triggering melt and causing its large interannual variability are not well understood. Here we show that melt onset over Arctic sea ice is initiated by positive anomalies of water vapor, clouds, and air temperatures that increase the downwelling longwave radiation (LWD) to the surface. The earlier melt onset occurs; the stronger are these anomalies. Downwelling shortwave radiation (SWD) is smaller than usual at melt onset, indicating that melt is not triggered by SWD. When melt occurs early, an anomalously opaque atmosphere with positive LWD anomalies preconditions the surface for weeks preceding melt. In contrast, when melt begins late, clearer than usual conditions are evident prior to melt. Hence, atmospheric processes are imperative for melt onset. It is also found that spring LWD increased during recent decades, consistent with trends toward an earlier melt onset.},
author = {Mortin, Jonas and Svensson, Gunilla and Graversen, Rune G. and Kapsch, Marie Luise and Stroeve, Julienne C. and Boisvert, Linette N.},
doi = {10.1002/2016GL069330},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {Arctic sea ice,climate variability,melt onset,polar meteorology,remote sensing},
number = {12},
pages = {6636--6642},
title = {{Melt onset over Arctic sea ice controlled by atmospheric moisture transport}},
volume = {43},
year = {2016}
}
@article{MOUCHA201772,
abstract = {Global backwards-in time models of mantle convection have resulted in vastly different interpretations of the transient state of dynamic topography on the U.S. Atlantic passive margin (Moucha et al., 2008; Spasojevi{\'{c}} et al., 2008; Rowley et al., 2013; Rovere et al., 2015). However, reconciling these geodynamic models with the observed offshore sedimentary record directly is complex because the sedimentary record integrates changes in climate, sea level, lithology, and tectonics. To circumvent this, we instead focus on modeling the observed deformation of the Orangeburg scarp, a well-documented 3.5millionyear old mid-Pliocene shoreline (e.g. Rovere et al., 2015). Herein, we present results from a new landscape evolution model and demonstrate that flexural effects along this margin are comparable to changes in dynamic topography (Rowley et al., 2013) and are required to fully explain deformation of the Orangeburg scarp. Moreover, using the Orangeburg scarp as a datum subject to glacial isostatic adjustment, we demonstrate that a 15m mid-Pliocene sea level above present-day is most consistent with interspersed coastal plain sediment and surface deformation derived from mantle convection and flexural-isostasy.},
author = {Moucha, Robert and Ruetenik, Gregory A},
doi = {10.1016/j.gloplacha.2017.01.004},
issn = {0921-8181},
journal = {Global and Planetary Change},
pages = {72--78},
title = {{Interplay between dynamic topography and flexure along the U.S. Atlantic passive margin: Insights from landscape evolution modeling}},
url = {http://www.sciencedirect.com/science/article/pii/S0921818116300388},
volume = {149},
year = {2017}
}
@article{Mouginot9239,
abstract = {We reconstruct the mass balance of the Greenland Ice Sheet for the past 46 years by comparing glacier ice discharge into the ocean with interior accumulation of snowfall from regional atmospheric climate models over 260 drainage basins. The mass balance started to deviate from its natural range of variability in the 1980s. The mass loss has increased sixfold since the 1980s. Greenland has raised sea level by 13.7 mm since 1972, half during the last 8 years.We reconstruct the mass balance of the Greenland Ice Sheet using a comprehensive survey of thickness, surface elevation, velocity, and surface mass balance (SMB) of 260 glaciers from 1972 to 2018. We calculate mass discharge, D, into the ocean directly for 107 glaciers (85{\%} of D) and indirectly for 110 glaciers (15{\%}) using velocity-scaled reference fluxes. The decadal mass balance switched from a mass gain of +47 {\{}$\backslash$textpm{\}} 21 Gt/y in 1972{\{}$\backslash$textendash{\}}1980 to a loss of 51 {\{}$\backslash$textpm{\}} 17 Gt/y in 1980{\{}$\backslash$textendash{\}}1990. The mass loss increased from 41 {\{}$\backslash$textpm{\}} 17 Gt/y in 1990{\{}$\backslash$textendash{\}}2000, to 187 {\{}$\backslash$textpm{\}} 17 Gt/y in 2000{\{}$\backslash$textendash{\}}2010, to 286 {\{}$\backslash$textpm{\}} 20 Gt/y in 2010{\{}$\backslash$textendash{\}}2018, or sixfold since the 1980s, or 80 {\{}$\backslash$textpm{\}} 6 Gt/y per decade, on average. The acceleration in mass loss switched from positive in 2000{\{}$\backslash$textendash{\}}2010 to negative in 2010{\{}$\backslash$textendash{\}}2018 due to a series of cold summers, which illustrates the difficulty of extrapolating short records into longer-term trends. Cumulated since 1972, the largest contributions to global sea level rise are from northwest (4.4 {\{}$\backslash$textpm{\}} 0.2 mm), southeast (3.0 {\{}$\backslash$textpm{\}} 0.3 mm), and central west (2.0 {\{}$\backslash$textpm{\}} 0.2 mm) Greenland, with a total 13.7 {\{}$\backslash$textpm{\}} 1.1 mm for the ice sheet. The mass loss is controlled at 66 {\{}$\backslash$textpm{\}} 8{\%} by glacier dynamics (9.1 mm) and 34 {\{}$\backslash$textpm{\}} 8{\%} by SMB (4.6 mm). Even in years of high SMB, enhanced glacier discharge has remained sufficiently high above equilibrium to maintain an annual mass loss every year since 1998.},
author = {Mouginot, J{\'{e}}r{\'{e}}mie and Rignot, Eric and Bj{\o}rk, Anders A and van den Broeke, Michiel and Millan, Romain and Morlighem, Mathieu and No{\"{e}}l, Brice and Scheuchl, Bernd and Wood, Michael},
doi = {10.1073/pnas.1904242116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {19},
pages = {9239--9244},
publisher = {National Academy of Sciences},
title = {{Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018}},
url = {https://www.pnas.org/content/116/19/9239},
volume = {116},
year = {2019}
}
@article{Munoz2017,
abstract = {The P{\'{a}}ramo de Frontino (3460 m elevation) in Colombia is located approximately halfway between the Pacific and Atlantic oceans. It contains a 17 kyr long, stratigraphically continuous sedimentary sequence dated by 30 AMS 14C ages. Our study covers the last 11,500 cal yr and focuses on the biotic (pollen) and abiotic (microfluorescence-X or $\mu$XRF) components of this high mountain ecosystem. The pollen record provides a proxy for temperature and humidity with a resolution of 20–35 yr, and $\mu$XRF of Ti and Fe is a proxy for rainfall with a sub-annual (ca. 6-month) resolution. Temperature and humidity display rapid and significant changes over the Holocene. The rapid transition from a cold (mean annual temperature (MAT) 3.5 °C lower than today) and wet Younger Dryas to a warm and dry early Holocene is dated at 11,410 cal yr BP. During the Holocene, MAT varied from ca. 2.5 °C below to 3.5° above present-day temperature. Warm periods (11,410–10,700, 9700–6900, 4000–2400 cal yr BP) were separated by colder intervals. The last 2.4 kyr of the record is affected by human impact. The Holocene remained dry until 7500 cal yr BP. Then, precipitations increased to reach a maximum between 5000 and 4500 cal yr BP. A rapid decrease occurred until 3500 cal yr BP and the late Holocene was dry. Spectral analysis of $\mu$XRF data show rainfall cyclicity at millennial scale throughout the Holocene, and at centennial down to ENSO scale in more specific time intervals. The highest rainfall intervals correlate with the highest activity of ENSO. Variability in solar output is possibly the main cause for this millennial to decadal cyclicity. We interpret ENSO and ITCZ as the main climate change-driving mechanisms in Frontino. Comparison with high-resolution XRF data from the Caribbean Cariaco Basin (a proxy for rainfall in the coastal Venezuelian cordilleras) demonstrates that climate in Frontino was Pacific-driven (ENSO-dominated) during the YD and early Holocene, whereas it was Atlantic-driven in Cariaco (ITCZ-dominated). From ca. 8000 cal yr BP, climate in both areas was under the dual influence of ENSO and ITCZ, thereby showing existing teleconnections between the tropical Pacific and Atlantic oceans. The Frontino record is to date the highest-resolution Holocene study in NW Colombia. An implication of these results is that new records should be analyzed with multiproxy tools, in particular those providing high resolution time series, such as $\mu$XRF.},
author = {Mu{\~{n}}oz, Paula and Gorin, Georges and Parra, Norberto and Vel{\'{a}}squez, Cesar and Lemus, Diego and Monsalve, M. Carlos and Jojoa, Marcela},
doi = {10.1016/j.quascirev.2016.11.021},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Humidity,Iron,Palaeoenvironmemt,Pollen,Rainfall,Temperature,Titanium,Wavelet analysis,X-ray fluorescence,Younger Dryas},
pages = {159--178},
title = {{Holocene climatic variations in the Western Cordillera of Colombia: A multiproxy high-resolution record unravels the dual influence of ENSO and ITCZ}},
volume = {155},
year = {2017}
}
@article{Mudryk2020,
abstract = {{\textless}p{\textgreater}{\textless}![CDATA[Abstract. This paper presents an analysis of observed and simulated historical snow cover extent and snow mass, along with future snow cover projections from models participating in the World Climate Research Programme Coupled Model Intercomparison Project Phase 6 (CMIP6). Where appropriate, the CMIP6 output is compared to CMIP5 results in order to assess progress (or absence thereof) between successive model generations. An ensemble of six observation-based products is used to produce a new time series of historical Northern Hemisphere snow extent anomalies and trends; a subset of four of these products is used for snow mass. Trends in snow extent over 1981–2018 are negative in all months and exceed -50×103 km2 yr−1 during November, December, March, and May. Snow mass trends are approximately −5 Gt yr−1 or more for all months from December to May. Overall, the CMIP6 multi-model ensemble better represents the snow extent climatology over the 1981–2014 period for all months, correcting a low bias in CMIP5. Simulated snow extent and snow mass trends over the 1981–2014 period are stronger in CMIP6 than in CMIP5, although large inter-model spread remains in the simulated trends for both variables. There is a single linear relationship between projected spring snow extent and global surface air temperature (GSAT) changes, which is valid across all CMIP6 Shared Socioeconomic Pathways. This finding suggests that Northern Hemisphere spring snow extent will decrease by about 8 {\%} relative to the 1995–2014 level per degree Celsius of GSAT increase. The sensitivity of snow to temperature forcing largely explains the absence of any climate change pathway dependency, similar to other fast-response components of the cryosphere such as sea ice and near-surface permafrost extent.]]{\textgreater}{\textless}/p{\textgreater}},
author = {Mudryk, Lawrence and Santolaria-Ot{\'{i}}n, Mar{\'{i}}a and Krinner, Gerhard and M{\'{e}}n{\'{e}}goz, Martin and Derksen, Chris and Brutel-Vuilmet, Claire and Brady, Mike and Essery, Richard},
doi = {10.5194/tc-14-2495-2020},
issn = {1994-0424},
journal = {The Cryosphere},
month = {jul},
number = {7},
pages = {2495--2514},
title = {{Historical Northern Hemisphere snow cover trends and projected changes in the CMIP6 multi-model ensemble}},
url = {https://tc.copernicus.org/articles/14/2495/2020/},
volume = {14},
year = {2020}
}
@article{Muglia2018,
abstract = {Circulation changes have been suggested to play an important role in the sequestration of atmospheric CO2 in the glacial ocean. However, previous studies have resulted in contradictory results regarding the strength of the Atlantic Meridional Overturning Circulation (AMOC) and three-dimensional, quantitative reconstructions of the glacial ocean constrained by multiple proxies remain scarce. Here we simulate the modern and glacial ocean using a coupled physical-biogeochemical, global, three-dimensional model constrained simultaneously by $\delta$13C, radiocarbon, and $\delta$15N to explore the effects of AMOC differences and Southern Ocean iron fertilization on the distributions of these isotopes and ocean carbon storage. We show that $\delta$13C and radiocarbon data sparsely sampled at the locations of existing glacial sediment cores can be used to reconstruct the modern AMOC accurately. Applying this method to the glacial ocean we find that a surprisingly weak (6–9 Sv or about half of today's) and shallow AMOC maximizes carbon storage and best reproduces the sediment isotope data. Increasing the atmospheric soluble iron flux in the model's Southern Ocean intensifies export production, carbon storage, and further improves agreement with $\delta$13C and $\delta$15N reconstructions. Our best fitting simulation is a significant improvement compared with previous studies, and suggests that both circulation and export production changes were necessary to maximize carbon storage in the glacial ocean.},
author = {Muglia, Juan and Skinner, Luke C and Schmittner, Andreas},
doi = {10.1016/j.epsl.2018.05.038},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Last Glacial Maximum,carbon cycle,ocean circulation},
pages = {47--56},
title = {{Weak overturning circulation and high Southern Ocean nutrient utilization maximized glacial ocean carbon}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X18303212},
volume = {496},
year = {2018}
}
@article{Murphy2014,
abstract = {The record of winter fast-ice in the South Orkney Islands, northern Weddell Sea, Antarctica, is over a century long and provides the longest observational record of sea-ice variability in the Southern Hemisphere. Here we present analyses of the series of fast-ice formation and breakout dates from 1903 to 2008. We show that over the satellite era (post-1979), the timing of both final autumn formation and complete spring breakout of fast-ice is representative of the regional sea-ice concentrations (SIC) in the northern Weddell Sea, and associated with atmospheric conditions in the Amundsen Sea region to the west of the Antarctic Peninsula. Variation in the fast-ice breakout date is influenced by the intensity of the westerly/north-westerly winds associated with the Southern Annular Mode (SAM). In contrast, the date of ice formation displays correlations with regional oceanic and sea-ice conditions over the previous 18 months, which indicate a preconditioning during the previous summer and winter, and exhibits variability associated with variation in tropical Pacific sea-surface temperature (i.e., the El Ni{\~{n}}o-Southern Oscillation, ENSO). A reduction in fast-ice duration at the South Orkney Islands around the 1950s was associated with both later formation and earlier breakout. However, there were marked changes in variability (with periodicities of 3–5, 7–9, and 20 years) in each of the series and in their relationships with ENSO and SAM, indicating the need for caution in interpreting changes in ice conditions based on shorter-term satellite series.},
author = {Murphy, E. J. and Clarke, A. and Abram, N. J. and Turner, J.},
doi = {10.1002/2013JC009511},
isbn = {2169-9275},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
keywords = {ENSO,Southern Annular Mode,Southern Ocean,fast-ice,sea-ice},
number = {7},
pages = {4549--4572},
title = {{Variability of sea-ice in the northern Weddell Sea during the 20th century}},
volume = {119},
year = {2014}
}
@article{Myers-Smith2020,
abstract = {As the Arctic warms, vegetation is responding, and satellite measures indicate widespread greening at high latitudes. This ‘greening of the Arctic' is among the world's most important large-scale ecological responses to global climate change. However, a consensus is emerging that the underlying causes and future dynamics of so-called Arctic greening and browning trends are more complex, variable and inherently scale-dependent than previously thought. Here we summarize the complexities of observing and interpreting high-latitude greening to identify priorities for future research. Incorporating satellite and proximal remote sensing with in-situ data, while accounting for uncertainties and scale issues, will advance the study of past, present and future Arctic vegetation change.},
author = {Myers-Smith, Isla H. and Kerby, Jeffrey T. and Phoenix, Gareth K. and Bjerke, Jarle W. and Epstein, Howard E. and Assmann, Jakob J. and John, Christian and Andreu-Hayles, Laia and Angers-Blondin, Sandra and Beck, Pieter S. A. and Berner, Logan T. and Bhatt, Uma S. and Bjorkman, Anne D. and Blok, Daan and Bryn, Anders and Christiansen, Casper T. and Cornelissen, J. Hans C. and Cunliffe, Andrew M. and Elmendorf, Sarah C. and Forbes, Bruce C. and Goetz, Scott J. and Hollister, Robert D. and de Jong, Rogier and Loranty, Michael M. and Macias-Fauria, Marc and Maseyk, Kadmiel and Normand, Signe and Olofsson, Johan and Parker, Thomas C. and Parmentier, Frans-Jan W. and Post, Eric and Schaepman-Strub, Gabriela and Stordal, Frode and Sullivan, Patrick F. and Thomas, Haydn J. D. and T{\o}mmervik, Hans and Treharne, Rachael and Tweedie, Craig E. and Walker, Donald A. and Wilmking, Martin and Wipf, Sonja},
doi = {10.1038/s41558-019-0688-1},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {106--117},
title = {{Complexity revealed in the greening of the Arctic}},
url = {http://www.nature.com/articles/s41558-019-0688-1},
volume = {10},
year = {2020}
}
@book{NAP24696,
address = {Washington, DC, USA},
author = {{NA SEM}},
doi = {10.17226/24696},
isbn = {978-0-309-45603-6},
pages = {82},
publisher = {National Academies of Sciences, Engineering, and Medicine. The National Academies Press},
title = {{Antarctic Sea Ice Variability in the Southern Ocean-Climate System: Proceedings of a Workshop}},
url = {https://www.nap.edu/catalog/24696/antarctic-sea-ice-variability-in-the-southern-ocean-climate-system},
year = {2017}
}
@article{Naik2015,
abstract = {Abstract Here we present the first boron isotope-based pCO2sw (pCO2 of seawater) reconstruction from the eastern Arabian Sea using the planktic foraminifera species Globigerinoides ruber. Our results from sediment core AAS9/21 show that pCO2sw varied between {\~{}}160 and 300?µatm during the last 23?kyr. The ?pCO2, the sea-air pCO2 difference, is relatively small during the last glacial maximum and becomes more negative toward the Holocene, with the exception of a significant excess during the last deglaciation centered on the B?lling-{\AA}ller?d. Throughout the record, ?pCO2 is predominantly negative, probably as a result of enhanced biological productivity (and higher nutrient and carbon utilization) during the southwest monsoon. A reduction in ?pCO2 during the last glacial maximum is therefore consistent with a reduction in the strength of this monsoon system.},
annote = {doi: 10.1002/2015GL063089},
author = {Naik, Sushant S and {Divakar Naidu}, P and Foster, Gavin L and Mart{\'{i}}nez-Bot{\'{i}}, Miguel A},
doi = {10.1002/2015GL063089},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Arabian Sea,Globigerinoides ruber,boron isotopes,monsoon,$\Delta$pCO2},
month = {mar},
number = {5},
pages = {1450--1458},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Tracing the strength of the southwest monsoon using boron isotopes in the eastern Arabian Sea}},
url = {https://doi.org/10.1002/2015GL063089},
volume = {42},
year = {2015}
}
@article{NAIR201993,
abstract = {The present study documents the interactions between Southern Hemisphere high-latitude (Antarctica {\&} Southern Ocean), southern Indian Ocean subtropics (Agulhas leakage) and Asian summer monsoon. The study uses SST and sea-ice reconstructions along with diatom absolute abundances and diatom biometry from two sediment cores located at the Subantarctic Front (SAF) and Antarctic Polar Front (APF) in the southwest Indian sector of the Southern Ocean. Sea-ice records suggest the presence of the mean winter sea ice limit at around the modern APF location during MIS 2 and MIS 4 and episodic and unconsolidated winter sea ice far north as ∼43°S during LGM, when the SSTs were lowest. Higher diatom productivity and larger mean sizes of F. kerguelensis and T. lentiginosa recorded at the northern core site during the glacial stages suggest a northward shift of the APF. A decrease in diatom productivity and sizes at the southern core site highlights stratified Permanent Open Ocean Zone (POOZ) surface waters in response to longer sea-ice presence during the glacial stages. The comparative study between the records of Southern Hemisphere high-latitude and Asian summer monsoon climate variability revealed that the Asian summer monsoon variability could have been more likely forced by low latitude insolation gradient changes and supported by Antarctic climate changes via meridional shifts of the fronts and sea ice. The past changes in the intensity of Asian summer monsoon along with the Southern Ocean frontal variation might have influenced the Southern Indian Ocean surface circulation by changing the Agulhas leakage intensity.},
author = {Nair, Abhilash and Mohan, Rahul and Crosta, Xavier and Manoj, M C and Thamban, Meloth and Marieu, Vincent},
doi = {10.1016/j.quascirev.2019.04.007},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Agulhas,Antarctica,Diatom,Indian Ocean,Polar front,Teleconnection},
pages = {93--104},
title = {{Southern Ocean sea ice and frontal changes during the Late Quaternary and their linkages to Asian summer monsoon}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379119300125},
volume = {213},
year = {2019}
}
@article{9000883,
abstract = {Uncertainty in snow properties impacts the accuracy of Arctic sea ice thickness estimates from radar altimetry. On first-year sea ice (FYI), spatiotemporal variations in snow properties can cause the Ku-band main radar scattering horizon to appear above the snow/sea ice interface. This can increase the estimated sea ice freeboard by several centimeters, leading to FYI thickness overestimations. This article examines the expected changes in Ku-band main scattering horizon and its impact on FYI thickness estimates, with variations in snow temperature, salinity, and density derived from ten naturally occurring Arctic FYI Cases encompassing saline/nonsaline, warm/cold, simple/complexly layered snow (4-45 cm) overlying FYI (48-170 cm). Using a semi-empirical modeling approach, snow properties from these Cases are used to derive layer-wise brine volume and dielectric constant estimates, to simulate the Ku-band main scattering horizon and delays in radar propagation speed. Differences between modeled and observed FYI thickness are calculated to assess sources of error. Under both cold and warm conditions, saline snow covers are shown to shift the main scattering horizon above from the snow/sea ice interface, causing thickness retrieval errors. Overestimates in FYI thicknesses of up to 65{\%} are found for warm, saline snow overlaying thin sea ice. Our simulations exhibited a distinct shift in the main scattering horizon when the snow layer densities became greater than 440 kg/m3, especially under warmer snow conditions. Our simulations suggest a mean Ku-band propagation delay for snow of 39{\%}, which is higher than 25{\%}, suggested in previous studies.},
author = {Nandan, V and Scharien, R K and Geldsetzer, T and Kwok, R and Yackel, J J and Mahmud, M S and R{\"{o}}sel, A and Tonboe, R and Granskog, M and Willatt, R and Stroeve, J and Nomura, D and Frey, M},
doi = {10.1109/JSTARS.2020.2966432},
issn = {2151-1535},
journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
keywords = {oceanographic regions;oceanographic techniques;rad},
pages = {1082--1096},
title = {{Snow Property Controls on Modeled Ku-Band Altimeter Estimates of First-Year Sea Ice Thickness: Case Studies From the Canadian and Norwegian Arctic}},
volume = {13},
year = {2020}
}
@article{Nash2016a,
abstract = {The African continent is characterised by a wide range of hydroclimate regimes, ranging from humid equatorial West Africa to the arid deserts in the northern and southern subtropics. The livelihoods of much of its population are also vulnerable to future climate change, mainly through variability in rainfall affecting water resource availability. A growing number of data sources indicate that such hydroclimatic variability is an intrinsic component of Africa's natural environment. This paper, co-authored by members of the PAGES Africa 2k Working Group, presents an extensive assessment and discussion of proxy, historical and instrumental evidence for hydroclimatic variability across the African continent, spanning the last two millennia. While the African palaeoenvironmental record is characterised by spatially disjunctive datasets, with often less-than-optimal temporal resolution and chronological control, the available evidence allows the assessment of prominent spatial patterns of palaeomoisture variability through time. In this study, we focus sequentially on data for six major time windows: the first millennium CE, the Medieval Climate Anomaly (900–1250 CE), the Little Ice Age (1250–1750 CE), the end of the LIA (1750–1850 CE), the Early Modern Period (1850–1950), and the period of recent warming (1950 onwards). This results in a continent-wide synthesis of regional moisture-balance trends through history, allowing consideration of possible driving mechanisms, and suggestions for future research.},
author = {Nash, David J. and {De Cort}, Gijs and Chase, Brian M. and Verschuren, Dirk and Nicholson, Sharon E. and Shanahan, Timothy M. and Asrat, Asfawossen and L{\'{e}}zine, Anne Marie and Grab, Stefan W.},
doi = {10.1016/j.quascirev.2016.10.012},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Africa,Holocene,Little Ice Age,Medieval Climate Anomaly,Palaeoclimatology},
pages = {1--22},
title = {{African hydroclimatic variability during the last 2000 years}},
volume = {154},
year = {2016}
}
@misc{Neely2016,
author = {{Neely III}, Ryan R. and Schmidt, Anja},
doi = {10.5285/76ebdc0b-0eed-4f70-b89e-55e606bcd568},
publisher = {Centre for Environmental Data Analysis, 04 February 2016},
title = {{VolcanEESM: Global volcanic sulphur dioxide (SO2) emissions database from 1850 to present – Version 1.0}},
year = {2016}
}
@article{Nerem2018a,
abstract = {Satellite altimetry has shown that global mean sea level has been rising at a rate of ∼3 ± 0.4 mm/y since 1993. Using the altimeter record coupled with careful consideration of interannual and decadal variability as well as potential instrument errors, we show that this rate is accelerating at 0.084 ± 0.025 mm/y2, which agrees well with climate model projections. If sea level continues to change at this rate and acceleration, sea-level rise by 2100 (∼65 cm) will be more than double the amount if the rate was constant at 3 mm/y.

Using a 25-y time series of precision satellite altimeter data from TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3, we estimate the climate-change–driven acceleration of global mean sea level over the last 25 y to be 0.084 ± 0.025 mm/y2. Coupled with the average climate-change–driven rate of sea level rise over these same 25 y of 2.9 mm/y, simple extrapolation of the quadratic implies global mean sea level could rise 65 ± 12 cm by 2100 compared with 2005, roughly in agreement with the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5) model projections.},
author = {Nerem, R. S. and Beckley, B. D. and Fasullo, J. T. and Hamlington, B. D. and Masters, D. and Mitchum, G. T.},
doi = {10.1073/pnas.1717312115},
isbn = {0027-8424},
issn = {0027-8424, 1091-6490},
journal = {Proceedings of the National Academy of Sciences},
month = {feb},
pages = {201717312},
pmid = {29440401},
title = {{Climate-change–driven accelerated sea-level rise detected in the altimeter era}},
volume = {115},
year = {2018}
}
@article{Neu2013a,
author = {Neu, U and Akperov, M G and Bellenbaum, N and Benestad, R and Blender, R and Caballero, R and Cocozza, A and Dacre, H and Feng, Y and Fraedrich, K and Grieger, J and Gulev, S and Hanley, J and Hewson, T and Inatsu, M and Keay, K and Kew, S F and Kindem, I and Leckebusch, G C and Liberato, M L R and Lionello, P and Mokhov, I I and Pinto, J G and Raible, C C and Reale, M and Rudeva, I and Schuster, M and Simmonds, I and Sinclair, M and Sprenger, M and Tilinina, N D and Trigo, I F and Ulbrich, S and Ulbrich, U and Wang, X L and Wernli, H},
doi = {10.1175/BAMS-D-11-00154.1},
journal = {Bulletin of the American Meteorological Society},
pages = {529--547},
title = {{IMILAST: A Community Effort to Intercompare Extratropical Cyclone Detection and Tracking Algorithms}},
volume = {94},
year = {2013}
}
@article{Neukom2014,
author = {Neukom, Raphael and Gergis, Jo{\"{e}}lle and Karoly, David J and Wanner, Heinz and Curran, Mark and Elbert, Julie and Gonz{\'{a}}lez-Rouco, Fidel and Linsley, Braddock K and Moy, Andrew D and Mundo, Ignacio and Raible, Christoph C and Steig, Eric J and van Ommen, Tas and Vance, Tessa and Villalba, Ricardo and Zinke, Jens and Frank, David},
doi = {10.1038/nclimate2174},
journal = {Nature Climate Change},
month = {mar},
pages = {362},
publisher = {Nature Publishing Group},
title = {{Inter-hemispheric temperature variability over the past millennium}},
url = {http://dx.doi.org/10.1038/nclimate2174 http://10.0.4.14/nclimate2174 https://www.nature.com/articles/nclimate2174{\#}supplementary-information},
volume = {4},
year = {2014}
}
@article{Neukom2019,
author = {Neukom, Raphael and Steiger, Nathan and G{\'{o}}mez-Navarro, Juan Jos{\'{e}} and Wang, Jianghao and Werner, Johannes P.},
doi = {10.1038/s41586-019-1401-2},
issn = {0028-0836},
journal = {Nature},
month = {jul},
number = {7766},
pages = {550--554},
title = {{No evidence for globally coherent warm and cold periods over the preindustrial Common Era}},
url = {http://www.nature.com/articles/s41586-019-1401-2},
volume = {571},
year = {2019}
}
@article{Newby2014a,
author = {Newby, Paige E. and Shuman, Bryan N and Donnelly, Jeffrey P and Karnauskas, Kristopher B and Marsicek, Jeremiah},
doi = {10.1002/2014GL060183},
journal = {Geophysical Research Letters},
keywords = {10.1002/2014GL060183 and Holocene,drought,ground-penetrating radar,lake levels,northeast U.S,paleohydrology},
pages = {4300--4307},
title = {{Centennial-to-millennial hydrologic trends and variability along the North Atlantic Coast, USA, during the Holocene}},
volume = {41},
year = {2014}
}
@article{Newman2016a,
abstract = {Abstract The quasi-biennial oscillation (QBO) is a tropical lower stratospheric, downward propagating zonal wind variation, with an average period of {\~{}}28 months. The QBO has been constantly documented since 1953. Here we describe the evolution of the QBO during the Northern Hemisphere winter of 2015–2016 using radiosonde observations and meteorological reanalyses. Normally, the QBO would show a steady downward propagation of the westerly phase. In 2015–2016, there was an anomalous upward displacement of this westerly phase from {\~{}}30 hPa to 15 hPa. These westerlies impinge on or “cutoff” the normal downward propagation of the easterly phase. In addition, easterly winds develop at 40 hPa. Comparisons to tropical wind statistics for the 1953 to present record demonstrate that this 2015–2016 QBO disruption is unprecedented.},
author = {Newman, P A and Coy, L and Pawson, S and Lait, L R},
doi = {10.1002/2016GL070373},
journal = {Geophysical Research Letters},
number = {16},
pages = {8791--8797},
title = {{The anomalous change in the QBO in 2015–2016}},
volume = {43},
year = {2016}
}
@article{Newman2016,
abstract = {The Pacific decadal oscillation (PDO), the dominant year-round pattern of monthly North Pacific sea surface temperature (SST) variability, is an important target of ongoing research within the meteorological and climate dynamics communities and is central to the work of many geologists, ecologists, natural resource managers, and social scientists. Research over the last 15 years has led to an emerging consensus: the PDO is not a single phenomenon, but is instead the result of a combination of different physical processes, including both remote tropical forcing and local North Pacific atmosphere–ocean interactions, which operate on different time scales to drive similar PDO-like SST anomaly patterns. How these processes combine to generate the observed PDO evolution, including apparent regime shifts, is shown using simple autoregressive models of increasing spatial complexity. Simulations of recent climate in coupled GCMs are able to capture many aspects of the PDO, but do so based on a balance of processes often more independent of the tropics than is observed. Finally, it is suggested that the assessment of PDO-related regional climate impacts, reconstruction of PDO-related variability into the past with proxy records, and diagnosis of Pacific variability within coupled GCMs should all account for the effects of these different processes, which only partly represent the direct forcing of the atmosphere by North Pacific Ocean SSTs.},
author = {Newman, Matthew and Alexander, Michael A. and Ault, Toby R. and Cobb, Kim M. and Deser, Clara and {Di Lorenzo}, Emanuele and Mantua, Nathan J. and Miller, Arthur J. and Minobe, Shoshiro and Nakamura, Hisashi and Schneider, Niklas and Vimont, Daniel J. and Phillips, Adam S. and Scott, James D. and Smith, Catherine A.},
doi = {10.1175/JCLI-D-15-0508.1},
isbn = {0916-8370},
issn = {0894-8755},
journal = {Journal of Climate},
keywords = {Atm/Ocean structure/Phenomena,Atmosphere-ocean interaction,Climate classification/regimes,Model evaluation/performance,Models and modeling,Pacific decadal oscillation,Paleoclimate,Physical meteorology and climatology,Variability},
month = {jun},
number = {12},
pages = {4399--4427},
pmid = {4},
title = {{The Pacific Decadal Oscillation, Revisited}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-15-0508.1},
volume = {29},
year = {2016}
}
@article{Nguyen2018,
author = {Nguyen, Phu and Thorstensen, Andrea and Sorooshian, Soroosh and Hsu, Kuolin and AghaKouchak, Amir and Ashouri, Hamed and Tran, Hoang and Braithwaite, Dan},
doi = {10.1175/BAMS-D-17-0065.1},
issn = {00030007},
journal = {Bulletin of the American Meteorological Society},
number = {4},
pages = {689--697},
title = {{Global precipitation trends across spatial scales using satellite observations}},
volume = {99},
year = {2018}
}
@article{Nguyen2013a,
abstract = {Analysis of the annual cycle of intensity, extent, and width of the Hadley circulation across a 31-yr period (1979–2009) from all existent reanalyses reveals a good agreement among the datasets. All datasets show that intensity is at a maximum in the winter hemisphere and at a minimum in the summer hemisphere. Maximum and minimum values of meridional extent are reached in the respective autumn and spring hemispheres. While considering the horizontal momentum balance, where a weakening of the Hadley cell (HC) is expected in association with a widening, it is shown here that there is no direct relationship between intensity and extent on a monthly time scale.},
author = {Nguyen, H. and Evans, A. and Lucas, C. and Smith, I. and Timbal, B.},
doi = {10.1175/JCLI-D-12-00224.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {may},
number = {10},
pages = {3357--3376},
title = {{The Hadley Circulation in Reanalyses: Climatology, Variability, and Change}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-12-00224.1},
volume = {26},
year = {2013}
}
@article{Nguyen2015,
author = {Nguyen, H and Lucas, C and Evans, A and Timbal, B and Hanson, L},
doi = {10.1175/JCLI-D-15-0139.1},
journal = {Journal of Climate},
pages = {8067--8077},
title = {{Expansion of the Southern Hemisphere Hadley Cell in Response to Greenhouse Gas Forcing}},
volume = {28},
year = {2015}
}
@article{Niedermeyer2014a,
abstract = {The Indo-Pacific Warm Pool (IPWP) is the largest source of atmospheric water vapor, and region of highest rainfall, on Earth. At irregular intervals, this high-rainfall regime weakens, causing severe droughts with massive consequences for the local population. Research into the underlying mechanisms is limited by the temporal coverage of climate data. We produced a record of rainfall over the western IPWP covering the past 24,000 years. Our data indicate that topography and coastline position govern regional IPWP hydrology on glacial−interglacial timescales. During the Holocene, western IPWP rainfall is linked to that of East Africa through a precipitation dipole. Fluctuations of this dipole identified in our study serve as an impetus for future studies to advance our understanding of IPWP dynamics.The Indo-Pacific Warm Pool (IPWP) is a key site for the global hydrologic cycle, and modern observations indicate that both the Indian Ocean Zonal Mode (IOZM) and the El Ni{\~{n}}o Southern Oscillation exert strong influence on its regional hydrologic characteristics. Detailed insight into the natural range of IPWP dynamics and underlying climate mechanisms is, however, limited by the spatial and temporal coverage of climate data. In particular, long-term (multimillennial) precipitation patterns of the western IPWP, a key location for IOZM dynamics, are poorly understood. To help rectify this, we have reconstructed rainfall changes over Northwest Sumatra (western IPWP, Indian Ocean) throughout the past 24,000 y based on the stable hydrogen and carbon isotopic compositions ($\delta$D and $\delta$13C, respectively) of terrestrial plant waxes. As a general feature of western IPWP hydrology, our data suggest similar rainfall amounts during the Last Glacial Maximum and the Holocene, contradicting previous claims that precipitation increased across the IPWP in response to deglacial changes in sea level and/or the position of the Intertropical Convergence Zone. We attribute this discrepancy to regional differences in topography and different responses to glacioeustatically forced changes in coastline position within the continental IPWP. During the Holocene, our data indicate considerable variations in rainfall amount. Comparison of our isotope time series to paleoclimate records from the Indian Ocean realm reveals previously unrecognized fluctuations of the Indian Ocean precipitation dipole during the Holocene, indicating that oscillations of the IOZM mean state have been a constituent of western IPWP rainfall over the past ten thousand years.},
author = {Niedermeyer, Eva M and Sessions, Alex L and Feakins, Sarah J and Mohtadi, Mahyar},
doi = {10.1073/pnas.1323585111},
journal = {Proceedings of the National Academy of Sciences},
month = {jul},
number = {26},
pages = {9402},
title = {{Hydroclimate of the western Indo-Pacific Warm Pool during the past 24,000 years}},
url = {http://www.pnas.org/content/111/26/9402.abstract},
volume = {111},
year = {2014}
}
@article{Nielsen2013,
author = {Nielsen, Tove and Kuijpers, Antoon},
doi = {10.1038/srep01875},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {1875},
title = {{Only 5 southern Greenland shelf edge glaciations since the early Pliocene}},
volume = {3},
year = {2013}
}
@article{Nitze2017,
abstract = {Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here, we present a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM, ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69{\%}), Western Alaska (-2.82{\%}), and Kolyma Lowland (-0.51{\%}) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48{\%}, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e., upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.},
author = {Nitze, Ingmar and Grosse, Guido and Jones, Benjamin M. and Arp, Christopher D. and Ulrich, Mathias and Fedorov, Alexander and Veremeeva, Alexandra},
doi = {10.3390/rs9070640},
isbn = {2072-4292},
issn = {20724292},
journal = {Remote Sensing},
keywords = {Alaska,Lake change,Lake dynamics,Landsat,Machine-learning,Permafrost region,Siberia,Thermokarst,Trend analysis},
number = {7},
pages = {640},
title = {{Landsat-based trend analysis of lake dynamics across Northern Permafrost Regions}},
volume = {9},
year = {2017}
}
@article{Nnamchi2016a,
abstract = {AbstractEquatorial Atlantic variability is dominated by the Atlantic Ni{\~{n}}o peaking during the boreal summer. Studies have shown robust links of the Atlantic Ni{\~{n}}o to fluctuations of the St. Helena subtropical anticyclone and Benguela Ni{\~{n}}o events. Furthermore, the occurrence of opposite sea surface temperature (SST) anomalies in the eastern equatorial and southwestern extratropical South Atlantic Ocean (SAO), also peaking in boreal summer, has recently been identified and termed the SAO dipole (SAOD). However, the extent to which and how the Atlantic Ni{\~{n}}o and SAOD are related remain unclear. Here, an analysis of historical observations reveals the Atlantic Ni{\~{n}}o as a possible intrinsic equatorial arm of the SAOD. Specifically, the observed sporadic equatorial warming characteristic of the Atlantic Ni{\~{n}}o ({\~{}}0.4 K) is consistently linked to southwestern cooling ({\~{}}?0.4 K) of the Atlantic Ocean during the boreal summer. Heat budget calculations show that the SAOD is largely driven by the surface net heat flux anomalies while ocean dynamics may be of secondary importance. Perturbations of the St. Helena anticyclone appear to be the dominant mechanism triggering the surface heat flux anomalies. A weakening of the anticyclone will tend to weaken the prevailing northeasterlies and enhance evaporative cooling over the southwestern Atlantic Ocean. In the equatorial region, the southeast trade winds weaken, thereby suppressing evaporation and leading to net surface warming. Thus, it is hypothesized that the wind?evaporation?SST feedback may be responsible for the growth of the SAOD events linking southern extratropics and equatorial Atlantic variability via surface net heat flux anomalies.},
annote = {doi: 10.1175/JCLI-D-15-0894.1},
author = {Nnamchi, Hyacinth C and Li, Jianping and Kucharski, Fred and Kang, In-Sik and Keenlyside, Noel S and Chang, Ping and Farneti, Riccardo},
doi = {10.1175/JCLI-D-15-0894.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {mar},
number = {20},
pages = {7295--7311},
publisher = {American Meteorological Society},
title = {{An Equatorial–Extratropical Dipole Structure of the Atlantic Ni{\~{n}}o}},
url = {https://doi.org/10.1175/JCLI-D-15-0894.1},
volume = {29},
year = {2016}
}
@article{Nnamchi2017a,
abstract = {Abstract Two variants of sea-surface temperature (SST) dipole indices for the South Atlantic Ocean (SAO) has been previously described representing: (1) the South Atlantic subtropical dipole (SASD) supposedly peaking in austral summer and (2) the SAO dipole (SAOD) in winter. In this study, we present the analysis of observational data sets (1985?2014) showing the SASD and SAOD as largely constituting the same mode of ocean?atmosphere interaction reminiscent of the SAOD structure peaking in winter. Indeed, winter is the only season in which the inverse correlation between the northern and southern poles of both indices is statistically significant. The observed SASD and SAOD indices exhibit robust correlations (P ≤ 0.001) in all seasons and these are reproduced by 54 of the 63 different models of the Coupled Models Intercomparison Project analysed. Their robust correlations notwithstanding the SASD and SAOD indices appear to better capture different aspects of SAO climate variability and teleconnections.},
annote = {doi: 10.1002/asl.781},
author = {Nnamchi, Hyacinth C and Kucharski, Fred and Keenlyside, Noel S and Farneti, Riccardo},
doi = {10.1002/asl.781},
issn = {1530-261X},
journal = {Atmospheric Science Letters},
keywords = {CMIP3/5,SST dipole,South Atlantic Ocean,seasonal evolution},
month = {oct},
number = {10},
pages = {396--402},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Analogous seasonal evolution of the South Atlantic SST dipole indices}},
url = {https://doi.org/10.1002/asl.781},
volume = {18},
year = {2017}
}
@article{https://doi.org/10.1029/2019JC015834,
abstract = {Abstract Observations during the satellite era 1979–2018 only depict small sea surface temperature (SST) trends over the Equatorial Atlantic cold tongue region in boreal summer. This lack of surface warming of the cold tongue, termed warming hole here, denotes an 11{\%} amplification of the mean SST annual cycle. The warming hole is driven by a shoaling of the equatorial thermocline, linked to increased wind stress forcing, and damped by the surface turbulent heat fluxes. The satellite era warming deficit is not unusual during the twentieth century—similar weak trends were also observed during the 1890s–1910s and 1940s–1960s. The tendency for surface cooling appears to reflect an interaction of external forcing, which controls the timing and magnitude of the cooling, with the intrinsic variability of the climate system. The hypothesis for externally forced modulation of internal variability is supported by climate model simulations forced by the observed time-varying concentrations of atmospheric greenhouse gases and natural aerosols. These show that increased greenhouse forcing warmed the cold tongue and aerosols cooled it during the satellite era. However, internal variability, as derived from control integrations with fixed, preindustrial values of greenhouse gases and aerosols, can potentially cause larger cooling than observed during the satellite era. Large uncertainties remain on the relative roles of external forcing and intrinsic variability in both observations and coupled climate models.},
annote = {e2019JC015834 2019JC015834},
author = {Nnamchi, Hyacinth C and Latif, Mojib and Keenlyside, Noel S and Park, Wonsun},
doi = {https://doi.org/10.1029/2019JC015834},
journal = {Journal of Geophysical Research: Oceans},
keywords = {CMIP5,Equatorial Atlantic,External forcing,Intrinsic variability,Thermocline feedback,Warming hole},
number = {4},
pages = {e2019JC015834},
title = {{A Satellite Era Warming Hole in the Equatorial Atlantic Ocean}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015834},
volume = {125},
year = {2020}
}
@article{https://doi.org/10.1029/2019RG000663,
abstract = {Abstract The Antarctic Ice Sheet (AIS) is out of equilibrium with the current anthropogenic-enhanced climate forcing. Paleoenvironmental records and ice sheet models reveal that the AIS has been tightly coupled to the climate system during the past and indicate the potential for accelerated and sustained Antarctic ice mass loss into the future. Modern observations by contrast suggest that the AIS has only just started to respond to climate change in recent decades. The maximum projected sea level contribution from Antarctica to 2100 has increased significantly since the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report, although estimates continue to evolve with new observational and theoretical advances. This review brings together recent literature highlighting the progress made on the known processes and feedbacks that influence the stability of the AIS. Reducing the uncertainty in the magnitude and timing of the future sea level response to AIS change requires a multidisciplinary approach that integrates knowledge of the interactions between the ice sheet, solid Earth, atmosphere, and ocean systems and across time scales of days to millennia. We start by reviewing the processes affecting AIS mass change, from atmospheric and oceanic processes acting on short time scales (days to decades), through to ice processes acting on intermediate time scales (decades to centuries) and the response to solid Earth interactions over longer time scales (decades to millennia). We then review the evidence of AIS changes from the Pliocene to the present and consider the projections of global sea level rise and their consequences. We highlight priority research areas required to improve our understanding of the processes and feedbacks governing AIS change.},
annote = {e2019RG000663 2019RG000663},
author = {Noble, T L and Rohling, E J and Aitken, A R A and Bostock, H C and Chase, Z and Gomez, N and Jong, L M and King, M A and Mackintosh, A N and McCormack, F S and McKay, R M and Menviel, L and Phipps, S J and Weber, M E and Fogwill, C J and Gayen, B and Golledge, N R and Gwyther, D E and Hogg, A McC. and Martos, Y M and Pena-Molino, B and Roberts, J and van de Flierdt, T and Williams, T},
doi = {10.1029/2019RG000663},
journal = {Reviews of Geophysics},
keywords = {Antarctic Ice Sheet,climate,interaction,past,processes,sea level},
number = {4},
pages = {e2019RG000663},
title = {{The Sensitivity of the Antarctic Ice Sheet to a Changing Climate: Past, Present, and Future}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019RG000663},
volume = {58},
year = {2020}
}
@article{NoetzliJBiskabornBChristiansenHHIsaksenKSchroeneichPSmithSVieiraGZhaoL2019,
author = {Noetzli, J. and Biskaborn, B. K. and Christiansen, H. H. and Isaksen, K. and Schoeneich, P. and Smith, S. and Vieira, G. and Zhao, L. and Streletskiy, D. A.},
doi = {10.1175/2019BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {9},
pages = {S21--S22},
title = {{Permafrost Thermal State [in “State of the Climate in 2018”]}},
volume = {100},
year = {2019}
}
@article{NoetzliJChristiansenHHIsaksenKSmithSZhaoL2020,
author = {Noetzli, J. and Christiansen, H. H. and Isaksen, K. and Smith, S. and Zhao, L. and Streletskiy, D. A.},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S34--S36},
title = {{Permafrost Thermal State [in “State of the Climate in 2019”]}},
volume = {101},
year = {2020}
}
@article{Nogueira2020,
abstract = {This study presents a comprehensive inter-comparison between two widely used rainfall datasets – the Global Precipitation Climatology Project (GPCP) and the ERA-Interim reanalysis – and the recently released ERA-5, which will replace ERA-Interim as the main European Centre for Medium-Range Weather and Forecasting (ECMWF) reanalysis by 2020. Systematic and random error components were computed for the reanalysis datasets over the 1979–2018 period using GPCP as reference. The analysis was taken at monthly timescale at 2.5° spatial resolution, limited by GPCP. Despite its resolution limitations and complex algorithms, GPCP has been extensively used for model evaluation due to its global and long-term (over 40 years) coverage. Over most of the tropics, and over localized mid-latitude regions, ERA-5 showed lower bias and unbiased root-mean squared error (ubRMSE), as well as higher correlations, compared to ERA-Interim. Throughout the rest of the globe, these error metrics displayed similar values between both reanalysis, except over localized regions of the eastern tropical Pacific, the Andes and the Himalayas, where ERA-Interim outperformed ERA-5. A process-based analysis revealed that ERA-Interim tended to overestimate deep convection and moisture flux convergence over the tropical oceans and land, leading to excessive rainfall. Similarly, ERA-Interim showed significant rainfall underestimation over the mid-latitude oceans due to underestimation of deep convection and moisture flux convergence. Both cases were significantly improved in ERA-5, likely due to its improved parameterizations and higher resolution. Indeed, the differences in monthly rainfall between the two reanalysis were mainly due to improved dynamical (circulation) rather than thermodynamical (Clausius-Clapeyron) processes or surface evaporation changes. Nonetheless, the results also revealed improved representation of the moisture sink/source patterns over the tropical oceans in ERA-5. Finally, there were significant differences in the long-term rainfall trend patterns amongst the three datasets (with differences reaching {\~{}}30{\%}/decade), that can extend even to the sign of the trend, with the most notorious differences occurring over tropical Africa. Furthermore, ERA-5 didn't show improved representation of these trends. In fact, the trend of global-mean rainfall in ERA-Interim was closer to GPCP than ERA-5.},
author = {Nogueira, Miguel},
doi = {10.1016/j.jhydrol.2020.124632},
issn = {00221694},
journal = {Journal of Hydrology},
keywords = {Climate,Dynamics,Rainfall datasets,Rainfall variability,Reanalysis},
number = {January},
pages = {124632},
publisher = {Elsevier},
title = {{Inter-comparison of ERA-5, ERA-interim and GPCP rainfall over the last 40 years: Process-based analysis of systematic and random differences}},
url = {https://doi.org/10.1016/j.jhydrol.2020.124632},
volume = {583},
year = {2020}
}
@article{Nolan2018a,
abstract = {Terrestrial ecosystems will be transformed by current anthropogenic change, but the extent of this change remains a challenge to predict. Nolan et al. looked at documented vegetational and climatic changes at almost 600 sites worldwide since the last glacial maximum 21,000 years ago. From this, they determined vegetation responses to temperature changes of 4° to 7°C. They went on to estimate the extent of ecosystem changes under current similar (albeit more rapid) scenarios of warming. Without substantial mitigation efforts, terrestrial ecosystems are at risk of major transformation in composition and structure. Science , this issue p. [920][1] Impacts of global climate change on terrestrial ecosystems are imperfectly constrained by ecosystem models and direct observations. Pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was comparable in magnitude to warming projected for the next century under high-emission scenarios. We reviewed 594 published paleoecological records to examine compositional and structural changes in terrestrial vegetation since the last glacial period and to project the magnitudes of ecosystem transformations under alternative future emission scenarios. Our results indicate that terrestrial ecosystems are highly sensitive to temperature change and suggest that, without major reductions in greenhouse gas emissions to the atmosphere, terrestrial ecosystems worldwide are at risk of major transformation, with accompanying disruption of ecosystem services and impacts on biodiversity. [1]: /lookup/volpage/361/920?iss=6405},
author = {Nolan, Connor and Overpeck, Jonathan T. and Allen, Judy R.M. and Anderson, Patricia M. and Betancourt, Julio L. and Binney, Heather A. and Brewer, Simon and Bush, Mark B. and Chase, Brian M. and Cheddadi, Rachid and Djamali, Morteza and Dodson, John and Edwards, Mary E. and Gosling, William D. and Haberle, Simon and Hotchkiss, Sara C. and Huntley, Brian and Ivory, Sarah J. and Kershaw, A. Peter and Kim, Soo Hyun and Latorre, Claudio and Leydet, Michelle and L{\'{e}}zine, Anne Marie and Liu, Kam Biu and Liu, Yao and Lozhkin, A. V. and McGlone, Matt S. and Marchant, Robert A. and Momohara, Arata and Moreno, Patricio I. and M{\"{u}}ller, Stefanie and Otto-Bliesner, Bette L. and Shen, Caiming and Stevenson, Janelle and Takahara, Hikaru and Tarasov, Pavel E. and Tipton, John and Vincens, Annie and Weng, Chengyu and Xu, Qinghai and Zheng, Zhuo and Jackson, Stephen T.},
doi = {10.1126/science.aan5360},
issn = {10959203},
journal = {Science},
number = {6405},
pages = {920--923},
title = {{Past and future global transformation of terrestrial ecosystems under climate change}},
volume = {361},
year = {2018}
}
@article{Norris2016,
abstract = {Clouds substantially affect Earth's energy budget by reflecting solar radiation back to space and by restricting emission of thermal radiation to space1. They are perhaps the largest uncertainty in our understanding of climate change, owing to disagreement among climate models and observational datasets over what cloud changes have occurred during recent decades and will occur in response to global warming2,3. This is because observational systems originally designed for monitoring weather have lacked sufficient stability to detect cloud changes reliably over decades unless they have been corrected to remove artefacts4,5. Here we show that several independent, empirically corrected satellite records exhibit large- scale patterns of cloud change between the 1980s and the 2000s that are similar to those produced by model simulations of climate with recent historical external radiative forcing. Observed and simulated cloud change patterns are consistent with poleward retreat of mid-latitude storm tracks, expansion of subtropical dry zones, and increasing height of the highest cloud tops at all latitudes. The primary drivers of these cloud changes appear to be increasing greenhouse gas concentrations and a recovery from volcanic radiative cooling. These results indicate that the cloud changes most consistently predicted by global climate models are currently occurring in nature.},
author = {Norris, Joel R. and Allen, Robert J. and Evan, Amato T. and Zelinka, Mark D. and O'Dell, Christopher W. and Klein, Stephen A.},
doi = {10.1038/nature18273},
isbn = {1476-4687},
issn = {14764687},
journal = {Nature},
number = {7614},
pages = {72--75},
pmid = {27398619},
publisher = {Nature Publishing Group},
title = {{Evidence for climate change in the satellite cloud record}},
volume = {536},
year = {2016}
}
@article{Notz2014,
abstract = {Abstract. We examine how the evaluation of modelled sea-ice coverage against reality is affected by uncertainties in the retrieval of sea-ice coverage from satellite, by the usage of sea-ice extent to overcome these uncertainties, and by internal variability. We find that for Arctic summer sea ice, model biases in sea-ice extent can be qualitatively different from biases in sea-ice area. This is because about half of the CMIP5 models and satellite retrievals based on the Bootstrap and the ASI algorithm show a compact ice cover in summer with large areas of high-concentration sea ice, while the other half of the CMIP5 models and satellite retrievals based on the NASA Team algorithm show a loose ice cover. For the Arctic winter sea-ice cover, differences in grid geometry can cause synthetic biases in sea-ice extent that are larger than the observational uncertainty. Comparing the uncertainty arising directly from the satellite retrievals with those that arise from internal variability, we find that the latter by far dominates the uncertainty estimate for trends in sea-ice extent and area: most of the differences between modelled and observed trends can simply be explained by internal variability. For absolute sea-ice area and sea-ice extent, however, internal variability cannot explain the difference between model and observations for about half the CMIP5 models that we analyse here. All models that we examined have regional biases, as expressed by the root-mean-square error in concentration, that are larger than the differences between individual satellite algorithms.},
author = {Notz, D.},
doi = {10.5194/tc-8-229-2014},
issn = {19940416},
journal = {Cryosphere},
number = {1},
pages = {229--243},
title = {{Sea-ice extent and its trend provide limited metrics of model performance}},
volume = {8},
year = {2014}
}
@article{OLeary2013,
author = {O'Leary, Michael J and Hearty, Paul J and Thompson, William G and Raymo, Maureen E and Mitrovica, Jerry X and Webster, Jody M},
doi = {10.1038/ngeo1890},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {9},
pages = {796--800},
title = {{Ice sheet collapse following a prolonged period of stable sea level during the last interglacial}},
url = {https://doi.org/10.1038/ngeo1890},
volume = {6},
year = {2013}
}
@article{OMara2019,
abstract = {Variability of North Pacific sea surface temperatures (SSTs) on multidecadal timescales plays an important role in modulating global climate and regional hydroclimate. The principle modern phenomenon associated with this variability is the Pacific Decadal Oscillation (PDO); however, our understanding of the PDO and multidecadal SST variability more broadly is limited to SST observations from the historical era and land-based proxy reconstructions. Here, we reconstruct multidecadal Pacific Ocean SST variability with an 1,800-year, continuous, high-resolution alkenone-derived SST reconstruction from Baja California, a region sensitive to changes in the PDO, and compare the record with a reconstruction of Southwestern North American hydroclimate. Our SST reconstruction displays persistent multicentennial and discontinuous intervals of multidecadal variability with periodicities similar to instrumental PDO observations. The most severe droughts in Southwestern North America during the last two millennia are coeval with strong multidecadal variability, suggesting that multidecadal SST variability plays an important role in regional megadroughts.},
author = {O'Mara, Nicholas A. and Cheung, Anson H. and Kelly, Christopher S. and Sandwick, Samantha and Herbert, Timothy D. and Russell, James M. and Abella‐Guti{\'{e}}rrez, Jose and Dee, Sylvia G. and Swarzenski, Peter W. and Herguera, Juan Carlos},
doi = {10.1029/2019GL084828},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Pacific Decadal Oscillation,alkenone paleothermometry,megadrought,multicentennial,multidecadal,sea surface temperature},
month = {dec},
number = {24},
pages = {14662--14673},
title = {{Subtropical Pacific Ocean Temperature Fluctuations in the Common Era: Multidecadal Variability and Its Relationship With Southwestern North American Megadroughts}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2019GL084828},
volume = {46},
year = {2019}
}
@incollection{doi:10.1061/9780784482599.074,
abstract = {Long-term measurements (1991–2016) from 17 thaw tubes in the Mackenzie Delta region were analyzed to investigate changes in thaw penetration (TP), ground surface (GS) elevation relative to a stable benchmark, and active-layer thickness (ALT). TP increased significantly during the study period at 10 of the sites, at a median rate of 0.5 cm a-1 (min: 0.2, max: 1.5 cm a-1). Significant subsidence occurred at 10 sites, at a median rate of 0.4 cm a-1 (min: 0.2, max: 0.8 cm a-1). These results indicate long-term regional permafrost degradation and surface subsidence in the western Canadian Arctic. About 5 to 38 cm of permafrost have thawed over 25 years at the sites, and {\~{}}5 to 20 cm of excess ground ice have melted. ALT increased significantly at only 5 of the sites and decreased at 4 sites. In ice-rich ground, increases in TP can more than double increases in ALT. For example, at a site near Inuvik, ALT increased by only 19 cm between 1994 and 2016, but TP increased by about 40 cm and was accompanied by 20 cm of surface subsidence. At sites in ice-poor ground, negligible settlement occurs, and increases in TP and ALT are similar. In ice-rich terrain, the degradation of permafrost cannot be detected by probing for active-layer thickness alone.},
author = {O'Neill, H Brendan and Smith, S L and Duchesne, C},
booktitle = {Cold Regions Engineering 2019},
doi = {10.1061/9780784482599.074},
pages = {643--651},
title = {{Long-Term Permafrost Degradation and Thermokarst Subsidence in the Mackenzie Delta Area Indicated by Thaw Tube Measurements}},
url = {https://ascelibrary.org/doi/abs/10.1061/9780784482599.074},
year = {2019}
}
@article{doi:10.1002/joc.3529,
abstract = {Abstract El Ni{\~{n}}o and La Ni{\~{n}}a exhibit significant asymmetry in their duration. El Ni{\~{n}}o tends to turn rapidly into La Ni{\~{n}}a after the mature, while La Ni{\~{n}}a tends to persist for up to 2 years. Reconstructed historical sea surface temperatures (SST) show a significantly increase in the intensity of El Ni{\~{n}}o-Southern Oscillation (ENSO) asymmetry, particularly El Ni{\~{n}}o transitivity, during the last six decades. Atmospheric observational data have shown that the relationship between El Ni{\~{n}}o and surface zonal wind anomalies over the equatorial Western Pacific (WP) has strengthened, and anomalous WP easterlies have appeared after the 1970s climate regime shift. To investigate the dependency of ENSO transitivity on its amplitude, a suite of idealized experiments using an atmospheric general circulation model (AGCM) is performed by imposing 12 different ENSO-related SST anomalies exhibiting equal spatiotemporal distribution but different amplitude. Our AGCM experiments show strong nonlinearity in the WP zonal wind against the amplitude of the warm phase. In the strong (weak) El Ni{\~{n}}o state, the WP response tends to accelerate (prevent) the transition from El Ni{\~{n}}o to La Ni{\~{n}}a; however, this relationship is not applicable to the La Ni{\~{n}}a phase. The asymmetry in transitivity/persistency is found to differ in terms of their sensitivity to the ENSO amplitude; this difference is also detected in the long-term control simulation of Geophysical Fluid Dynamics Laboratory-Climate Model version 2.1. The long-term variation in El Ni{\~{n}}o transitivity in this model correlates strongly with the decadal variation in the ENSO amplitude and Indo-Pacific interbasin coupling. However, this result is not apparent in the opposite phase. The results of this study indicate that the decadal change in ENSO amplitude and Indian Ocean feedback could be significantly related to the decadal change in the cyclic nature of ENSO and should be discussed separately for El Ni{\~{n}}o and La Ni{\~{n}}a. Copyright {\textcopyright} 2012 Royal Meteorological Society},
author = {Ohba, Masamichi},
doi = {10.1002/joc.3529},
journal = {International Journal of Climatology},
keywords = {AGCM,ENSO asymmetry,ENSO transition,Indian Ocean,long-term variation},
number = {6},
pages = {1495--1509},
title = {{Important factors for long-term change in ENSO transitivity}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.3529},
volume = {33},
year = {2013}
}
@article{Okamoto2005a,
author = {Okamoto, Ken and Ushio, Tomoo and Iguchi, Toshio and Takahashi, N and Iwanami, K},
doi = {10.1109/IGARSS.2005.1526575},
isbn = {0780390504},
journal = {Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05.},
number = {3},
pages = {3414--3416},
publisher = {IEEE},
title = {{The Global Satellite Mapping of Precipitation (GSMaP) Project}},
volume = {5},
year = {2005}
}
@article{Olden2006a,
abstract = {Ongoing species invasions and extinctions are changing biological diversity in differ- ent ways at different spatial scales. Biotic homogenization (or BH) refers to the pro- cess by which the genetic, taxonomic or functional similarities of regional biotas increase over time. It is a multifaceted process that encompasses species invasions, extinctions and environmental alterations, focusing on how the identities of species (or their genetic or functional attributes) change over space and time. Despite the increasing use of the term BH in conservation biology, it is often used erroneously as a synonym for patterns of species invasions, loss of native species or changes in spe- cies richness through time. This reflects the absence of an agreed-upon, cogent defi- nition of BH. Here, we offer an operational definition for BH and review the various methodologies used to study this process. We identify the strengths and weaknesses of these approaches, and make explicit recommendations for future studies. We conclude by citing the need for researchers to: (1) consider carefully the definition of BH by recognizing the genetic, taxonomic and functional realms of this process; (2) recognize that documenting taxonomic homogenization requires tracking the identity of species (not species richness) comprising biotas through space and time; and (3) employ more rigorous methods for quantifying BH.},
author = {Olden, Julian D. and Rooney, Thomas P.},
doi = {10.1111/j.1466-822X.2006.00214.x},
issn = {1466822X},
journal = {Global Ecology and Biogeography},
keywords = {Beta-diversity,Biological impoverishment,Community change,Extinction,Invasion,Species richness,Taxonomic homogenization},
number = {2},
pages = {113--120},
title = {{On defining and quantifying biotic homogenization}},
volume = {15},
year = {2006}
}
@article{Oliveira2014,
author = {Oliveira, Flavio N M and Carvalho, Leila M V and Ambrizzi, Tercio},
doi = {10.1002/joc.3795},
issn = {0899-8418},
journal = {International Journal of Climatology},
month = {apr},
number = {5},
pages = {1676--1692},
title = {{A new climatology for Southern Hemisphere blockings in the winter and the combined effect of ENSO and SAM phases}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.3795},
volume = {34},
year = {2014}
}
@article{Olsen2012a,
author = {Olsen, Jesper and Anderson, N John and Knudsen, Mads F},
doi = {10.1038/ngeo1589},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {nov},
number = {11},
pages = {808--812},
publisher = {Nature Publishing Group},
title = {{Variability of the North Atlantic Oscillation over the past 5,200 years}},
url = {http://www.nature.com/articles/ngeo1589},
volume = {5},
year = {2012}
}
@article{Oltmans2013,
abstract = {Longer-term (i.e., 20-40 years) tropospheric ozone (O3) time series obtained from surface and ozonesonde observations have been analyzed to assess possible changes with time through 2010. The time series have been selected to reflect relatively broad geographic regions and where possible minimize local scale influences, generally avoiding sites close to larger urban areas. Several approaches have been used to describe the changes with time, including application of a time series model, running 15-year trends, and changes in the distribution by month in the O3 mixing ratio. Changes have been investigated utilizing monthly averages, as well as exposure metrics that focus on specific parts of the distribution of hourly average concentrations (e.g., low-, mid-, and high-level concentration ranges). Many of the longer time series (∼30 years) in mid-latitudes of the Northern Hemisphere, including those in Japan, show a pattern of significant increase in the earlier portion of the record, with a flattening over the last 10-15 years. It is uncertain if the flattening of the O3 change over Japan reflects the impact of O3 transported from continental East Asia in light of reported O3 increases in China. In the Canadian Arctic, declines from the beginning of the ozonesonde record in 1980 have mostly rebounded with little overall change over the period of record. The limited data in the tropical Pacific suggest very little change over the entire record. In the southern hemisphere subtropics and mid-latitudes, the significant increase observed in the early part of the record has leveled off in the most recent decade. At the South Pole, a decline observed during the first half of the 35-year record has reversed, and O3 has recovered to levels similar to the beginning of the record. Our understanding of the causes of the longer-term changes is limited, although it appears that in the mid-latitudes of the northern hemisphere, controls on O3 precursors have likely been a factor in the leveling off or decline from earlier O3 increases. {\textcopyright} 2012 Elsevier Ltd.},
author = {Oltmans, S. J. and Lefohn, A. S. and Shadwick, D. and Harris, J. M. and Scheel, H. E. and Galbally, I. and Tarasick, D. W. and Johnson, B. J. and Brunke, E. G. and Claude, H. and Zeng, G. and Nichol, S. and Schmidlin, F. and Davies, J. and Cuevas, E. and Redondas, A. and Naoe, H. and Nakano, T. and Kawasato, T.},
doi = {10.1016/j.atmosenv.2012.10.057},
isbn = {1352-2310},
issn = {13522310},
journal = {Atmospheric Environment},
keywords = {Changes in concentration distribution,Trends,Troposphere ozone},
pages = {331--351},
title = {{Recent tropospheric ozone changes – A pattern dominated by slow or no growth}},
volume = {67},
year = {2013}
}
@article{Oppo2003a,
abstract = {The conversion of surface water to deep water in the North Atlantic results in the release of heat from the ocean to the atmosphere, which may have amplified millennial-scale climate variability during glacial times1 and could even have contributed to the past 11,700 years of relatively mild climate (known as the Holocene epoch)2,3,4. Here we investigate changes in the carbon-isotope composition of benthic foraminifera throughout the Holocene and find that deep-water production varied on a centennial–millennial timescale. These variations may be linked to surface and atmospheric events that hint at a contribution to climate change over this period.},
author = {Oppo, Delia W and McManus, Jerry F and Cullen, James L},
doi = {10.1038/422277b},
issn = {1476-4687},
journal = {Nature},
number = {6929},
pages = {277},
title = {{Deepwater variability in the Holocene epoch}},
url = {https://doi.org/10.1038/422277b},
volume = {422},
year = {2003}
}
@article{Ordonez2016a,
abstract = {Climatic conditions are changing at different rates and in different directions1,2 , potentially causing the emergence of novel species assemblages3 . Here we identify areas where recent (1901–2013) changes in temperature and precipitation are likely to be producing novel species assemblages through three distinct mechanisms: emergence of novel climatic combinations4,5 , rapid displacement of climatic isoclines1,2,6–8 and local divergences between temperature and precipita- tion vectors1,2 . Novel climates appear in the tropics, while displacement is faster at higher latitudes and divergence is high in the subtropics and mountainous regions. Globally, novel climate combinations so far are rare (3.4{\%} of evaluated cells), mean displacement is 3.7km decade−1 and divergence is high ({\textgreater}60◦ ) for 67{\%} of evaluated cells. Via at least one of the proposed mechanisms, novel species assemblages are likely to be forming in the North American Great Plains and temperate forests, Amazon, South American grasslands, Australia, boreal Asia andAfrica. In these areas, temperature- and moisture-sensitive species may be affected by new climates emerging, differential biotic lags to rapidly changing climates or by being pulled in opposite directions along local spatial gradients. These results provide spatially explicit hypotheses about where and why novel communities are likely to emerge due to recent climate change.},
author = {Ordonez, Alejandro and Williams, John W. and Svenning, Jens Christian},
doi = {10.1038/nclimate3127},
isbn = {1758-678X},
issn = {17586798},
journal = {Nature Climate Change},
pages = {1104--1109},
title = {{Mapping climatic mechanisms likely to favour the emergence of novel communities}},
volume = {6},
year = {2016}
}
@article{Orme2017a,
author = {Orme, L. C. and Charman, D. J. and Reinhardt, L. and Jones, R. T. and Mitchell, F. J. G. and Stefanini, B. S. and Grosvenor, M.},
doi = {10.1130/G38521.1},
journal = {Geology},
number = {4},
pages = {335--338},
title = {{Past changes in the North Atlantic storm track driven by insolation and sea-ice forcing}},
volume = {45},
year = {2017}
}
@article{Ortega2015,
author = {Ortega, Pablo and Lehner, Flavio and Swingedouw, Didier and Masson-delmotte, Valerie and Raible, Christoph C and Casado, Mathieu and Yiou, Pascal},
doi = {10.1038/nature14518},
journal = {Nature},
number = {7558},
pages = {71--74},
title = {{A model-tested North Atlantic Oscillation reconstruction for the past millennium}},
volume = {523},
year = {2015}
}
@article{https://doi.org/10.1029/2019JD032352,
abstract = {Abstract Climatic Research Unit temperature version 5 (CRUTEM5) is an extensive revision of our land surface air temperature data set. We have expanded the underlying compilation of monthly temperature records from 5,583 to 10,639 stations, of which those with sufficient data to be used in the gridded data set has grown from 4,842 to 7,983. Many station records have also been extended or replaced by series that have been homogenized by national meteorological and hydrological services. We have improved the identification of potential outliers in these data to better capture outliers during the reference period; to avoid classifying some real regional temperature extremes as outliers; and to reduce trends in outlier counts arising from climatic warming. Due to these updates, the gridded data set shows some regional increases in station density and regional changes in temperature anomalies. Nonetheless, the global-mean timeseries of land air temperature is only slightly modified compared with previous versions and previous conclusions are not altered. The standard gridding algorithm and comprehensive error model are the same as for the previous version, but we have explored an alternative gridding algorithm that removes the under-representation of high latitude stations. The alternative gridding increases estimated global-mean land warming by about 0.1°C over the course of the whole record. The warming from 1861–1900 to the mean of the last 5 years is 1.6°C using the standard gridding (with a 95{\%} confidence interval for errors on individual annual means of −0.11 to +0.10°C in recent years), while the alternative gridding gives a change of 1.7°C.},
annote = {e2019JD032352 2019JD032352},
author = {Osborn, T J and Jones, P D and Lister, D H and Morice, C P and Simpson, I R and Winn, J P and Hogan, E and Harris, I C},
doi = {10.1029/2019JD032352},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {CRUTEM,climate change,global temperature,global warming,instrumental climate data,land air temperature},
number = {2},
pages = {e2019JD032352},
title = {{Land Surface Air Temperature Variations Across the Globe Updated to 2019: The CRUTEM5 Data Set}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JD032352},
volume = {126},
year = {2021}
}
@techreport{Osborne2018,
author = {Osborne, E.B. and Richter-Menge, J. and Jeffries, M.},
doi = {https://arctic.noaa.gov/Report-Card/Report-Card-2018},
editor = {Osborne, E and Richter-Menge, J and Jeffries, M},
keywords = {NOAA,arctic,report card},
pages = {113},
publisher = {National Oceanic and Atmospheric Administration (NOAA)},
title = {{Arctic Report Card 2018}},
url = {https://arctic.noaa.gov/Report-Card/Report-Card-2018},
year = {2018}
}
@article{Osborne2020b,
abstract = {Oceanic uptake of CO2 can mitigate climate change, but also results in global ocean acidification. Ocean acidification-related changes to the marine carbonate system can disturb ecosystems and hinder calcification by some organisms. Here, we use the calcification response of planktonic foraminifera as a tool to reconstruct the progression of ocean acidification in the California Current Ecosystem through the twentieth century. Measurements of nearly 2,000 fossil foraminifera shell weights and areas preserved in a marine sediment core showed a 20{\%} reduction in calcification by a surface-dwelling foraminifera species. Using modern calibrations, this response translates to an estimated 35{\%} reduction in carbonate ion concentration, a biologically important chemical component of the carbonate system. Assuming other aspects of the carbonate system, this represents a 0.21 decline in pH, exceeding the estimated global average decline by more than a factor of two. Our proxy record also shows considerable variability that is significantly correlated with Pacific Decadal Oscillation and decadal-scale changes in upwelling strength, a relationship that until now has been obscured by the relatively short observational record. This modulation suggests that climatic variations will play an important role in amplifying or alleviating the anthropogenic signal and progression of ocean acidification in this region.},
author = {Osborne, Emily B and Thunell, Robert C and Gruber, Nicolas and Feely, Richard A and Benitez-Nelson, Claudia R},
doi = {10.1038/s41561-019-0499-z},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {1},
pages = {43--49},
title = {{Decadal variability in twentieth-century ocean acidification in the California Current Ecosystem}},
url = {https://doi.org/10.1038/s41561-019-0499-z},
volume = {13},
year = {2020}
}
@article{Osterberg2017,
abstract = {Future changes in North Pacific wintertime climate will be largely determined by the response of the Aleutian Low (ALow) pressure system to anthropogenic forcing. Although the ALow has intensified over the twentieth century, global climate model projections of future ALow variability are equivocal. In order to evaluate decadal to centennial ALow forcing mechanisms and provide context for the modern intensification, here we combine a new Denali ice core (Alaska) sea-salt sodium record with the Mount Logan ice core (Yukon) sodium record to develop a composite 1200 year record of ALow variability. The composite record indicates that the recent secular ALow intensification began circa 1741 and is unprecedented in magnitude and duration over the past millennium. North Pacific ice core snow accumulation and stable isotope records are consistent with this interpretation. The ALow intensification is associated with warming tropical Pacific sea surface temperatures, consistent with dynamic theory and instrumental correlations.},
author = {Osterberg, E. C. and Winski, D. A. and Kreutz, K. J. and Wake, C. P. and Ferris, D. G. and Campbell, S. and Introne, D. and Handley, M. and Birkel, S.},
doi = {10.1002/2017GL073697},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {Aleutian Low,Denali,ice core},
number = {14},
pages = {7447--7454},
title = {{The 1200 year composite ice core record of Aleutian Low intensification}},
volume = {44},
year = {2017}
}
@article{cp-2019-174,
author = {Otto-Bliesner, Bette L and Brady, Esther C and Zhao, Anni and Brierley, Chris M. and Axford, Yarrow and Capron, Emilie and Govin, Aline and Hoffman, Jeremy S. and Isaacs, Elizabeth and Kageyama, Masa and Scussolini, Paolo and Tzedakis, Polychronis C and Williams, Charles J. R. and Wolff, Eric and Abe-Ouchi, Ayako and Braconnot, Pascale and {Ramos Buarque}, Silvana and Cao, Jian and de Vernal, Anne and Guarino, Maria Vittoria and Guo, Chuncheng and LeGrande, Allegra N and Lohmann, Gerrit and Meissner, Katrin J. and Menviel, Laurie and Morozova, Polina A. and Nisancioglu, Kerim H. and O'ishi, Ryouta and {Salas y M{\'{e}}lia}, David and Shi, Xiaoxu and Sicard, Marie and Sime, Louise and Stepanek, Christian and Tomas, Robert and Volodin, Evgeny and Yeung, Nicholas K. H. and Zhang, Qiong and Zhang, Zhongshi and Zheng, Weipeng},
doi = {10.5194/cp-17-63-2021},
issn = {1814-9332},
journal = {Climate of the Past},
month = {jan},
number = {1},
pages = {63--94},
title = {{Large-scale features of Last Interglacial climate: results from evaluating the lig127k simulations for the Coupled Model Intercomparison Project (CMIP6)–Paleoclimate Modeling Intercomparison Project (PMIP4)}},
url = {https://cp.copernicus.org/articles/17/63/2021/},
volume = {17},
year = {2021}
}
@article{otto-bliesner_amplified_2017,
author = {Otto-Bliesner, Bette L and Jahn, Alexandra and Feng, Ran and Brady, Esther C and Hu, Aixue and L{\"{o}}fverstr{\"{o}}m, Marcus},
doi = {10.1002/2016GL071805},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jan},
number = {2},
pages = {957--964},
shorttitle = {Amplified {\{}North{\}} {\{}Atlantic{\}} warming in the late {\{}}},
title = {{Amplified North Atlantic warming in the late Pliocene by changes in Arctic gateways: Arctic Gateways and Pliocene Climate}},
url = {http://doi.wiley.com/10.1002/2016GL071805},
volume = {44},
year = {2017}
}
@article{Ouellet2011,
abstract = {Remotely sensed data were used to derive simple ecosystem indicators for four regions of the Northwest Atlantic to test the hypothesis that sea surface temperatures (SSTs) and spring phytoplankton bloom characteristics (initiation, timing, intensity, and duration) have a significant influence on larval survival and recruitment of northern shrimp (Pandalus borealis). For all years (1998-2007) and regions, hatching was after the initiation of the bloom and before or after the bloom reached its maximum intensity. The results suggest that the best survival of larvae is associated with high warming rates of SST following hatching, but in very cold environments, warm temperatures at hatching seem to be important for larval survival. The analyses also indicate that larval survival is supported by an early, long phytoplankton bloom which attains high concentrations of chlorophyll a. The results demonstrate the potential of remotely sensed data for deriving simple population-specific ecosystem indicators for potential use in building operational recruitment models for predicting changes in northern shrimp abundance. Crown Copyright {\textcopyright} 2010. Published by Oxford journals on behalf of the International Council for the Exploration of the Sea. All rights reserved.},
author = {Ouellet, Patrick and Fuentes-Yaco, C{\'{e}}sar and Savard, Louise and Platt, Trevor and Sathyendranath, Shubha and Koeller, Peter and Orr, David and Siegstad, Helle},
doi = {10.1093/icesjms/fsq174},
issn = {10543139},
journal = {ICES Journal of Marine Science},
keywords = {Northern shrimp,Phytoplankton bloom,Recruitment,Remote sensing,SST},
month = {dec},
number = {4},
pages = {737--744},
title = {{Ocean surface characteristics influence recruitment variability of populations of northern shrimp (Pandalus borealis) in the Northwest Atlantic}},
url = {https://doi.org/10.1093/icesjms/fsq174},
volume = {68},
year = {2011}
}
@article{Overland2015,
abstract = {AbstractThe last decade shows increased variability in the Arctic Oscillation (AO) index for December. Over eastern North America such increased variability depended on amplification of the climatological longwave atmospheric circulation pattern. Recent negative magnitudes of the AO have increased geopotential thickness west of Greenland and cold weather in the central and eastern United States. Although the increased variance in the AO is statistically significant based on 9-yr running standard deviations from 1950 to 2014, one cannot necessarily robustly attribute the increase to steady changes in external sources (sea temperatures, sea ice) rather than a chaotic view of internal atmospheric variability; this is due to a relatively short record and a review of associated atmospheric dynamics. Although chaotic internal variability dominates the dynamics of atmospheric circulation, Arctic thermodynamic influence can reinforce the regional geopotential height pattern. Such reinforcement suggests a conditio...},
author = {Overland, James E. and Wang, Muyin},
doi = {10.1175/JCLI-D-15-0395.1},
issn = {08948755},
journal = {Journal of Climate},
number = {18},
pages = {7297--7305},
title = {{Increased variability in the early winter subarctic North American atmospheric circulation}},
volume = {28},
year = {2015}
}
@article{Pagani2011,
abstract = {Earth's modern climate, characterized by polar ice sheets and large equator-to-pole temperature gradients, is rooted in environmental changes that promoted Antarctic glaciation {\~{}}33.7 million years ago. Onset of Antarctic glaciation reflects a critical tipping point for Earth's climate and provides a framework for investigating the role of atmospheric carbon dioxide (CO2) during major climatic change. Previously published records of alkenone-based CO2 from high- and low-latitude ocean localities suggested that CO2 increased during glaciation, in contradiction to theory. Here, we further investigate alkenone records and demonstrate that Antarctic and subantarctic data overestimate atmospheric CO2 levels, biasing long-term trends. Our results show that CO2 declined before and during Antarctic glaciation and support a substantial CO2 decrease as the primary agent forcing Antarctic glaciation, consistent with model-derived CO2 thresholds.},
author = {Pagani, Mark and Huber, Matthew and Liu, Zhonghui and Bohaty, Steven M. and Henderiks, Jorijntje and Sijp, Willem and Krishnan, Srinath and DeConto, Robert M.},
doi = {10.1126/science.1203909},
issn = {10959203},
journal = {Science},
number = {6060},
pages = {1261--1264},
title = {{The Role of Carbon Dioxide During the Onset of Antarctic Glaciation}},
volume = {334},
year = {2011}
}
@article{PAGES2kConsortium2017,
author = {{PAGES 2k Consortium}},
doi = {10.1038/sdata.2017.88},
journal = {Scientific Data},
month = {jul},
pages = {170088},
publisher = {The Author(s)},
title = {{A global multiproxy database for temperature reconstructions of the Common Era}},
url = {http://dx.doi.org/10.1038/sdata.2017.88 http://10.0.4.14/sdata.2017.88 https://www.nature.com/articles/sdata201788{\#}supplementary-information},
volume = {4},
year = {2017}
}
@article{Neukom2019a,
abstract = {Multidecadal surface temperature changes may be forced by natural as well as anthropogenic factors, or arise unforced from the climate system. Distinguishing these factors is essential for estimating sensitivity to multiple climatic forcings and the amplitude of the unforced variability. Here we present 2,000-year-long global mean temperature reconstructions using seven different statistical methods that draw from a global collection of temperature-sensitive palaeoclimate records. Our reconstructions display synchronous multidecadal temperature fluctuations that are coherent with one another and with fully forced millennial model simulations from the Coupled Model Intercomparison Project Phase 5 across the Common Era. A substantial portion of pre-industrial (1300–1800 ce) variability at multidecadal timescales is attributed to volcanic aerosol forcing. Reconstructions and simulations qualitatively agree on the amplitude of the unforced global mean multidecadal temperature variability, thereby increasing confidence in future projections of climate change on these timescales. The largest warming trends at timescales of 20 years and longer occur during the second half of the twentieth century, highlighting the unusual character of the warming in recent decades.},
author = {{PAGES 2k Consortium}},
doi = {10.1038/s41561-019-0400-0},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {8},
pages = {643--649},
title = {{Consistent multidecadal variability in global temperature reconstructions and simulations over the Common Era}},
url = {https://doi.org/10.1038/s41561-019-0400-0},
volume = {12},
year = {2019}
}
@article{PAGES2kConsortium2013a,
abstract = {Temperature change over the past 2,000 years has shown pronounced regional variability. An assessment of all available continental temperature reconstructions shows a clear twentieth century warming trend, but no evidence of a coherent Little Ice Age or Medieval Warm Period.},
author = {{PAGES 2k Consortium}},
doi = {10.1038/ngeo1797},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {5},
pages = {339--346},
title = {{Continental-scale temperature variability during the past two millennia}},
url = {https://doi.org/10.1038/ngeo1797},
volume = {6},
year = {2013}
}
@article{Palchan2019,
abstract = {Northern and eastern Africa were exposed to significantly wetter conditions relative to present during the early Holocene period known as the African Humid Period (AHP), although the latitudinal extent of the northward expansion of the tropical rain belt remains poorly constrained. New records of 230Thxs-normalized accumulation rates in marine sediment cores from the Red Sea and Gulf of Aden are combined with existing records of western Africa dust and terrestrial records across the Sahara Desert, revealing that fluxes of dust transported east from the Sahara decreased by at least 50{\%} during the AHP, due to the development of wetter conditions as far north as {\~{}}22°N. These results provide the first quantitative record of sediment and dust accumulation rates in the Red Sea and the Gulf of Aden over the past 20 kyrs and challenge the paradigm of vast vegetative cover across the north and northeastern Sahara Desert during the AHP.},
author = {Palchan, Daniel and Torfstein, Adi},
doi = {10.1038/s41467-019-11701-z},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {3803},
title = {{A drop in Sahara dust fluxes records the northern limits of the African Humid Period}},
url = {https://doi.org/10.1038/s41467-019-11701-z},
volume = {10},
year = {2019}
}
@article{Palmeiro2015,
abstract = {Sudden Stratospheric Warmings (SSWs) are characterized by a pronounced increase of the stratospheric polar temperature during the winter season. Different definitions have been used in the literature to diagnose the occurrence of SSWs, yielding discrepancies in the detected events. The aim of this paper is to compare the SSW climatologies obtained by different methods using reanalysis data. We have identified the occurrence of Northern Hemisphere SSWs during the extended-winter season and the 1958-2014 period for a suite of eight representative definitions and three different reanalyses. Overall, and despite the differences in the number and exact dates of occurrence of SSWs, the main climatological signatures of SSWs are not sensitive to the considered reanalysis.The mean frequency of SSWs is 6.7 events decade-1, but it ranges from 4 to 10 events, depending on the method. The seasonal cycle of events is statistically indistinguishable across definitions, with a common peak in January. However, the multi-decadal variability is method-dependent, with only two definitions displaying minimum frequencies in the 1990s. An analysis of the mean signatures of SSWs in the stratosphere revealed negligible differences among methods compared to the large case-to-case variability within a given definition.The stronger and more coherent tropospheric signals before and after SSWs are associated with major events, which are detected by most methods. The tropospheric signals of minor SSWs are less robust, representing the largest source of discrepancy across definitions. Therefore, to obtain robust results, future studies on stratosphere-troposphere coupling should aim to minimize the detection of minor warmings.},
author = {Palmeiro, Froila M. and Barriopedro, David and Garcia-Herrera, Ricardo and Calvo, Natalia},
doi = {10.1175/JCLI-D-15-0004.1},
issn = {08948755},
journal = {Journal of Climate},
number = {17},
pages = {6823--6840},
title = {{Comparing sudden stratospheric warming definitions in reanalysis data}},
volume = {28},
year = {2015}
}
@article{10.1088/1748-9326/abdaec,
abstract = {We present an ensemble approach to quantify historical global mean sea-level (GMSL) rise based on tide gauge reconstructions. This approach combines the maximum internal uncertainty across the ensemble with an estimate of structural uncertainty to provide a conservative estimate of the total uncertainty. Comparisons of GMSL rise over the 20th century based on deltas and linear trends (and their respective uncertainties) are consistent with past Intergovernmental Panel on Climate Change (IPCC) assessments and show good agreement with satellite altimeter timeseries. Sensitivity tests show that our estimates of GMSL rise are robust to the choice of reference period and central estimate timeseries. The methods proposed in this study are generic and could be easily applied to other global or regional climate change indicators.},
author = {Palmer, Matthew D and Domingues, Catia M and Slangen, Aim{\'{e}}e B A and {Boeira Dias}, F},
doi = {10.1088/1748-9326/abdaec},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {apr},
number = {4},
pages = {044043},
title = {{An ensemble approach to quantify global mean sea-level rise over the 20th century from tide gauge reconstructions}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/abdaec},
volume = {16},
year = {2021}
}
@article{doi:10.1175/JTECH-D-17-0129.1,
abstract = { AbstractTime-varying biases in expendable bathythermograph (XBT) instruments have emerged as a key uncertainty in estimates of historical ocean heat content variability and change. One of the challenges in the development of XBT bias corrections is the lack of metadata in ocean profile databases. Approximately 50{\%} of XBT profiles in the World Ocean database (WOD) have no information about manufacturer or probe type. Building on previous research efforts, this paper presents a deterministic algorithm for assigning missing XBT manufacturer and probe type for individual temperature profiles based on 1) the reporting country, 2) the maximum reported depth, and 3) the record date. The criteria used are based on bulk analysis of known XBT profiles in the WOD for the period 1966–2015. A basic skill assessment demonstrates a 77{\%} success rate at correctly assigning manufacturer and probe type for profiles where this information is available. The skill rate is lowest during the early 1990s, which is also a period when metadata information is particularly poor. The results suggest that substantive improvements could be made through further data analysis and that future algorithms may benefit from including a larger number of predictor variables. },
author = {Palmer, Matthew D and Boyer, Tim and Cowley, Rebecca and Kizu, Shoichi and Reseghetti, Franco and Suzuki, Toru and Thresher, Ann},
doi = {10.1175/JTECH-D-17-0129.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {3},
pages = {429--440},
title = {{An Algorithm for Classifying Unknown Expendable Bathythermograph (XBT) Instruments Based on Existing Metadata}},
url = {https://doi.org/10.1175/JTECH-D-17-0129.1},
volume = {35},
year = {2018}
}
@article{Palmer2015a,
author = {Palmer, Jonathan G and Cook, Edward R and Turney, Chris S M and Allen, Kathy and Fenwick, Pavla and Cook, Benjamin I and O'Donnell, Alison and Lough, Janice and Grierson, Pauline and Baker, Patrick},
doi = {10.1088/1748-9326/10/12/124002},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {124002},
publisher = {IOP Publishing},
title = {{Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500–2012) modulated by the Interdecadal Pacific Oscillation}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/10/12/124002},
volume = {10},
year = {2015}
}
@article{Palmer2003,
abstract = {The oceans play a major role in defining atmospheric carbon dioxide (CO2) levels, and although the geographical distribution of CO2 uptake and release in the modern ocean is understood, little is known about past distributions. Boron isotope studies of planktonic foraminifera from the western equatorial Pacific show that this area was a strong source of CO2 to the atmosphere between approximately 13,800 and 15,600 years ago. This observation is most compatible with increased frequency of La Ni{\~{n}}a conditions during this interval. Hence, increased upwelling in the eastern equatorial Pacific may have played an important role in the rise in atmospheric CO2 during the last deglaciation.},
author = {Palmer, M R and Pearson, P N},
doi = {10.1126/science.1080796},
journal = {Science},
month = {apr},
number = {5618},
pages = {480--482},
title = {{A 23,000-Year Record of Surface Water pH and PCO2 in the Western Equatorial Pacific Ocean}},
url = {http://science.sciencemag.org/content/300/5618/480.abstract},
volume = {300},
year = {2003}
}
@article{Palmer2010,
abstract = {We report here the results of a multi-proxy study to reconstruct surface water pCO2 concentrations in the northern Arabian Sea. Our results show that $\delta$11B and Mg/Ca measurements of the planktonic foraminifer Globigerinoides sacculifer yield consistent pCO2 values with those reconstructed from the $\delta$13C of alkenones when used in conjunction with foraminifera $\delta$13C and Cd/Ca values. They reveal that this area of the oceans has been a constant source of CO2 to the atmosphere during the interval 5–29ka, and that the intensity of this source was greatest between 11 and 17ka, when atmospheric CO2 levels were rising rapidly. We interpret our data as reflecting variation in the strength of the Asian Summer Monsoon (ASM), thus indicating that the strength of the ASM varied in phase with summer insolation over the Tibetan plateau between 5 and 29ka. In contrast to a previous study (Clemens and Prell, 2003), we observe no significant lag between the rise in insolation and the response of the ASM. Rather, our data support a recent study by Rohling et al. (2009) that northern hemisphere climatic forcing factors play a greater role in controlling the intensity of the ASM during times of intense monsoon activity, and that the southern hemisphere forcing is more important during times of weak monsoons.},
author = {Palmer, M R and Brummer, G J and Cooper, M J and Elderfield, H and Greaves, M J and Reichart, G J and Schouten, S and Yu, J M},
doi = {10.1016/j.epsl.2010.03.023},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Arabian Sea,carbon dioxide,monsoon,palaeoceanography},
number = {1},
pages = {49--57},
title = {{Multi-proxy reconstruction of surface water pCO2 in the northern Arabian Sea since 29ka}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X10002049},
volume = {295},
year = {2010}
}
@article{Pan2018,
abstract = {Global vegetation dynamics are of critical importance for understanding changes in ecosystem structure and functioning and their responses to different natural and anthropogenic drivers. Under the background of rapid global warming, it is still unclear whether there were significant changes in the extent and intensity of global vegetation browning during the past three decades. Taking satellite-derived normalized difference vegetation index (NDVI) as the proxy of vegetation growth, we investigated spatiotemporal variances in global vegetation trends during the period 1982–2013 using the ensemble empirical mode decomposition (EEMD) method and two piecewise linear regression models. Our study suggests that increasing global vegetation browning is masked by overall vegetation greening. A {\textgreater}60{\%} increase in browning area was found during the study period, and the results consistently indicate that the expansion of browning trends has accelerated since 1994. After the late 1990s, browning trends increased in all latitudinal bands in the Northern Hemisphere. This increase was particularly pronounced in the northern mid-low latitudes, where the greening trends stalled or even reversed. Areas with browning trends increased in all land cover types, although the increase processes varied substantially. During 1982–2013, although most vegetated lands exhibited overall greening trends, greening-to-browning reversals occurred on all continents and occupied a much larger area than browning-to-greening reversals. Greening trends prevailed before the turning points, and browning trends largely expanded and enhanced thereafter. The increased browning trends resulted in a slowdown of the increase in global mean NDVI since the early 1990s. Since drought is likely the main cause of the increasing browning trends, global vegetation growth is at risk of reversal from long-term greening to long-term browning in the warmer future.},
author = {Pan, Naiqing and Feng, Xiaoming and Fu, Bojie and Wang, Shuai and Ji, Fei and Pan, Shufen},
doi = {10.1016/j.rse.2018.05.018},
issn = {00344257},
journal = {Remote Sensing of Environment},
keywords = {GIMMS3g NDVI,Spatiotemporal pattern,Time series analysis,Trend shift,Vegetation browning},
pages = {59--72},
title = {{Increasing global vegetation browning hidden in overall vegetation greening: Insights from time-varying trends (2018a)}},
volume = {214},
year = {2018}
}
@article{Pan2018a,
abstract = {Yorke Peninsula in southern Australia is an important region for reconstructing relative sea-level histories due to its location on the eastern margin of the tectonically stable Gawler Craton and in one of the world's geographically most remote far-field locations from the Pleistocene ice sheets. Richly fossiliferous, skeletal carbonate sands of the last interglacial (125 ka) Glanville Formation crop out in the coastal cliffs along large sectors of southern Yorke Peninsula. Sedimentary facies include deepening-upward intertidal to shallow subtidal facies, relict storm beach facies and cobble and boulder beach deposits in more exposed, higher energy locations. During deposition of the Glanville Formation, southern Yorke Peninsula had a different coastal geography with two prominent marine corridors extending across the southern-most portion of the entire peninsula. In a 3 km long coastal cliff section in southern Hardwicke Bay, the Glanville Formation crops out as an upward-deepening intertidal-subtidal succession capped by supratidal and subaerially-exposed sediments with pervasive calcrete development. The sedimentary succession passes upwards from a basal unit of intertidal sand flat facies with abundant gastropods (Batillaria diemenensis) near the upper bounding (disconformity) surface, upwards into richly fossiliferous shelly sands (coquina) representing a shallow subtidal facies formed by sediment aggradation in response to a relative sea-level rise. The subtidal facies is dominated by the bivalve molluscs Katelysia sp. and Amesodesma angusta, signifying a water deepening event. The subtidal facies is in turn overlain by pedogenically modified skeletal carbonate sands with pervasive calcrete development signifying a relative sea level fall at the end of the Last Interglacial Maximum. The upper-bounding surface of the shallow-water subtidal facies ranges from 2.4 to 3.0 m Australian Height Datum (AHD) and by analogy with modern sedimentary environments suggests a maximum palaeo-sea level of 4.8 ± 1.0 m during the Last Interglacial Maximum. Uranium-series ages of 127.3 ± 2.1 to 115.0 ± 5.4 ka on specimens of the solitary coral Plesiastrea versipora from the subtidal facies confirm that the succession was deposited during the Last Interglacial Maximum, and are consistent with the independent stratigraphical evidence that the highstand event was represented by a single phase of relative sea-level rise. Correlation with other occurrences of the Glanville Formation in southern Australia has also been confirmed by aminostratigraphy.},
author = {Pan, Tsun-You and Murray-Wallace, Colin V and Dosseto, Anthony and Bourman, Robert P},
doi = {10.1016/j.margeo.2018.01.012},
issn = {0025-3227},
journal = {Marine Geology},
keywords = {Amino acid racemization dating,Last interglacial maximum,MIS 5e,Sea level,Southern Australia,Uranium-series dating},
pages = {126--136},
title = {{The last interglacial (MIS 5e) sea level highstand from a tectonically stable far-field setting, Yorke Peninsula, southern Australia (2018b)}},
url = {http://www.sciencedirect.com/science/article/pii/S0025322717303298},
volume = {398},
year = {2018}
}
@article{Park2021,
author = {Park, Sunyoung and Western, Luke M. and Saito, Takuya and Redington, Alison L. and Henne, Stephan and Fang, Xuekun and Prinn, Ronald G. and Manning, Alistair J. and Montzka, Stephen A. and Fraser, Paul J. and Ganesan, Anita L. and Harth, Christina M. and Kim, Jooil and Krummel, Paul B. and Liang, Qing and M{\"{u}}hle, Jens and O'Doherty, Simon and Park, Hyeri and Park, Mi-Kyung and Reimann, Stefan and Salameh, Peter K. and Weiss, Ray F. and Rigby, Matthew},
doi = {10.1038/s41586-021-03277-w},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7846},
pages = {433--437},
title = {{A decline in emissions of CFC-11 and related chemicals from eastern China}},
url = {http://www.nature.com/articles/s41586-021-03277-w},
volume = {590},
year = {2021}
}
@article{Park2016,
abstract = {Monitoring and understanding climate-induced changes in the boreal and arctic vegetation is critical$\backslash$nto aid in prognosticating their future. We used a 33 year (1982–2014) long record of satellite$\backslash$nobservations to robustly assess changes in metrics of growing season (onset: SOS, end: EOS and$\backslash$nlength: LOS) and seasonal total gross primary productivity. Particular attention was paid to$\backslash$nevaluating the accuracy of these metrics by comparing them to multiple independent direct and$\backslash$nindirect growing season and productivity measures. These comparisons reveal that the derived metrics$\backslash$ncapture the spatio-temporal variations and trends with acceptable significance level (generally p$\backslash$n{\textless} 0.05). We find that LOS has lengthened by 2.60 d dec −1 ( p {\textless} 0.05) due to an earlier onset of$\backslash$nSOS (−1.61 d dec −1 , p {\textless} 0.05) and a delayed EOS (0.67 d dec −1 , p {\textless} 0.1) at the circumpolar scale$\backslash$nover the past three decades. Relatively greater rates of changes in growing season were observed in$\backslash$nEurasia (EA) and in boreal regions than in North America (NA) and the arctic regions. However, this$\backslash$ntendency of earlier SOS and delayed EOS was prominent only during the earlier part of the data$\backslash$nrecord (1982–1999). During the later part (2000–2014), this tendency was reversed, i.e. delayed SOS$\backslash$nand earlier EOS. As for seasonal total productivity, we find that 42.0{\%} of northern vegetation shows$\backslash$na statistically significant ( p {\textless} 0.1) greening trend over the last three decades. This greening$\backslash$ntranslates to a 20.9{\%} gain in productivity since 1982. In contrast, only 2.5{\%} of northern vegetation$\backslash$nshows browning, or a 1.2{\%} loss of productivity. These trends in productivity were continuous through$\backslash$nthe period of record, unlike changes in growing season metrics. Similarly, we find relatively$\backslash$ngreater increasing rates of productivity in EA and in arctic regions than in NA and the boreal$\backslash$nregions. These results highlight spatially and temporally varying vegetation dynamics and are$\backslash$nreflective of biome-specific responses of northern vegetation during last three decades.},
author = {Park, Taejin and Ganguly, Sangram and T{\o}mmervik, Hans and Euskirchen, Eug{\'{e}}nie S. and H{\o}gda, Kjell-Arild and Karlsen, Stein Rune and Brovkin, Victor and Nemani, Ramakrishna R. and Myneni, Ranga B.},
doi = {10.1088/1748-9326/11/8/084001},
isbn = {1748-9326},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {AVHRR,MODIS,boreal and arctic,climate change,gross primary productivity,photosynthetically active growing season,remote sensing},
month = {aug},
number = {8},
pages = {084001},
title = {{Changes in growing season duration and productivity of northern vegetation inferred from long-term remote sensing data}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/11/8/084001},
volume = {11},
year = {2016}
}
@article{Parkes2018,
abstract = {Global-mean sea-level rise (GMSLR) during the twentieth century was primarily caused by glacier and ice-sheet mass loss, thermal expansion of ocean water and changes in terrestrial water storage1. Whether based on observations2 or results of climate models3,4, however, the sum of estimates of each of these contributions tends to fall short of the observed GMSLR. Current estimates of the glacier contribution to GMSLR rely on the analysis of glacier inventory data, which are known to undersample the smallest glacier size classes5,6. Here we show that from 1901 to 2015, missing and disappeared glaciers produced a sea-level equivalent (SLE) of approximately 16.7 to 48.0 millimetres. Missing glaciers are those small glaciers that we expect to exist today, owing to regional analyses and theoretical scaling relationships, but that are not represented in the inventories. These glaciers contributed approximately 12.3 to 42.7 millimetres to the historical SLE. Additionally, disappeared glaciers (those that existed in 1901 but had melted away by 2015, and that therefore cannot be included in modern global glacier inventories) made an estimated contribution of between 4.4 and 5.3 millimetres. Failure to consider these uncharted glaciers may be an important cause of difficulties in closing the GMSLR budget during the twentieth century: their contribution is on average between 0.17 and 0.53 millimetres of SLE per year, compared to a budget discrepancy of about 0.5 millimetres of GMSLR per year between 1901 and 1990. Although the uncharted glaciers will have a minimal role in sea-level rise in the future, and are less important after 1990, these findings imply that undiscovered physical processes are not required to close the historical sea-level budget.},
author = {Parkes, David and Marzeion, Ben},
doi = {10.1038/s41586-018-0687-9},
issn = {1476-4687},
journal = {Nature},
number = {7732},
pages = {551--554},
title = {{Twentieth-century contribution to sea-level rise from uncharted glaciers}},
url = {https://doi.org/10.1038/s41586-018-0687-9},
volume = {563},
year = {2018}
}
@article{Parkinson2014,
abstract = {Satellite data are used to determine the number of days having sea ice coverage in each year 1979–2013 and to map the trends in these ice-season lengths. Over the majority of the Arctic seasonal sea ice zone, the ice season shortened at an average rate of at least 5 days/decade between 1979 and 2013, and in a small area in the northeastern Barents Sea the rate of shortening reached over 65 days/decade. The only substantial non-coastal area with lengthening sea ice seasons is the Bering Sea, where the ice season lengthened by 5–15 days/decade. Over the Arctic as a whole, the area with ice seasons shortened by at least 5 days/decade is 12.4×106km2, while the area with ice seasons lengthened by at least 5 days/decade is only 1.1×106km2. The contrast is even greater, percentage-wise, for higher rates.},
author = {Parkinson, Claire L.},
doi = {10.1002/2014GL060434},
isbn = {3016145715},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {12},
pages = {4316--4322},
pmid = {25821265},
title = {{Spatially mapped reductions in the length of the Arctic sea ice season}},
volume = {41},
year = {2014}
}
@article{Parkinson14414,
abstract = {A newly completed 40-y record of satellite observations is used to quantify changes in Antarctic sea ice coverage since the late 1970s. Sea ice spreads over vast areas and has major impacts on the rest of the climate system, reflecting solar radiation and restricting ocean/atmosphere exchanges. The satellite record reveals that a gradual, decades-long overall increase in Antarctic sea ice extents reversed in 2014, with subsequent rates of decrease in 2014{\{}$\backslash$textendash{\}}2017 far exceeding the more widely publicized decay rates experienced in the Arctic. The rapid decreases reduced the Antarctic sea ice extents to their lowest values in the 40-y record, both on a yearly average basis (record low in 2017) and on a monthly basis (record low in February 2017).Following over 3 decades of gradual but uneven increases in sea ice coverage, the yearly average Antarctic sea ice extents reached a record high of 12.8 {\{}$\backslash$texttimes{\}} 106 km2 in 2014, followed by a decline so precipitous that they reached their lowest value in the 40-y 1979{\{}$\backslash$textendash{\}}2018 satellite multichannel passive-microwave record, 10.7 {\{}$\backslash$texttimes{\}} 106 km2, in 2017. In contrast, it took the Arctic sea ice cover a full 3 decades to register a loss that great in yearly average ice extents. Still, when considering the 40-y record as a whole, the Antarctic sea ice continues to have a positive overall trend in yearly average ice extents, although at 11,300 {\{}$\backslash$textpm{\}} 5,300 km2.y-1, this trend is only 50{\%} of the trend for 1979{\{}$\backslash$textendash{\}}2014, before the precipitous decline. Four of the 5 sectors into which the Antarctic sea ice cover is divided all also have 40-y positive trends that are well reduced from their 2014{\{}$\backslash$textendash{\}}2017 values. The one anomalous sector in this regard, the Bellingshausen/Amundsen Seas, has a 40-y negative trend, with the yearly average ice extents decreasing overall in the first 3 decades, reaching a minimum in 2007, and exhibiting an overall upward trend since 2007 (i.e., reflecting a reversal in the opposite direction from the other 4 sectors and the Antarctic sea ice cover as a whole).},
author = {Parkinson, Claire L},
doi = {10.1073/pnas.1906556116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {29},
pages = {14414--14423},
publisher = {National Academy of Sciences},
title = {{A 40-y record reveals gradual Antarctic sea ice increases followed by decreases at rates far exceeding the rates seen in the Arctic}},
url = {https://www.pnas.org/content/116/29/14414},
volume = {116},
year = {2019}
}
@article{Parmesan2015,
abstract = {BACKGROUND: Anthropogenic climate change (ACC) will influence all aspects of plant biology over coming decades. Many changes in wild species have already been well-documented as a result of increased atmospheric CO2 concentrations, warming climate and changing precipitation regimes. A wealth of available data has allowed the use of meta-analyses to examine plant-climate interactions on more sophisticated levels than before. These analyses have revealed major differences in plant response among groups, e.g. with respect to functional traits, taxonomy, life-history and provenance. Interestingly, these meta-analyses have also exposed unexpected mismatches between theory, experimental, and observational studies. SCOPE: We reviewed the literature on species' responses to ACC, finding {\~{}}42 {\%} of 4000 species studied globally are plants (primarily terrestrial). We review impacts on phenology, distributions, ecophysiology, regeneration biology, plant-plant and plant-herbivore interactions, and the roles of plasticity and evolution. We focused on apparent deviations from expectation, and highlighted cases where more sophisticated analyses revealed that unexpected changes were, in fact, responses to ACC. CONCLUSIONS: We found that conventionally expected responses are generally well-understood, and that it is the aberrant responses that are now yielding greater insight into current and possible future impacts of ACC. We argue that inconclusive, unexpected, or counter-intuitive results should be embraced in order to understand apparent disconnects between theory, prediction, and observation. We highlight prime examples from the collection of papers in this Special Issue, as well as general literature. We found use of plant functional groupings/traits had mixed success, but that some underutilized approaches, such as Grime's C/S/R strategies, when incorporated, have improved understanding of observed responses. Despite inherent difficulties, we highlight the need for ecologists to conduct community-level experiments in systems that replicate multiple aspects of ACC. Specifically, we call for development of coordinating experiments across networks of field sites, both natural and man-made. Copyright {\textcopyright} The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.},
author = {Parmesan, C and Hanley, M. E.},
doi = {10.1093/aob/mcv169},
issn = {0305-7364},
journal = {Annals of Botany},
month = {nov},
number = {6},
pages = {849--864},
title = {{Plants and climate change: complexities and surprises}},
url = {https://academic.oup.com/aob/article-lookup/doi/10.1093/aob/mcv169},
volume = {116},
year = {2015}
}
@article{Pascolini-Campbell2015,
abstract = {We investigate the various methods currently available for distinguishing between the Central Pacific (CP) El Ni{\~{n}}o (or ``El Ni{\~{n}}o Modoki'') and the canonical El Ni{\~{n}}o by considering nine different methods and five sea surface temperature (SST) datasets from 1880 to 2010. This is aimed to demonstrate the variety which exists between different classification methods as well as to help identify years which can be more confidently classified as CP events. Classifying CP El Ni{\~{n}}os based on the greatest convergence between methods and between SST datasets provides a more robust identification of these events. Analysis of the SST patterns of the CP years identified demonstrates several misclassifications, stressing the importance of not relying solely on indices. After removal, 14 years which are classified the most consistently as CP events include the following: 1885/1886, 1914/1915, 1940/1941, 1958/1959, 1963/1964, 1968/1969, 1977/1978, 1986/1987, 1990/1991, 1991/1992, 1994/1995, 2002/2003, 2003/2004, and 2004/2005. Our findings also indicate the intermittent appearance of CP events throughout the time period investigated, inciting the role of multidecadal natural climate variability in generating CP El Ni{\~{n}}os.},
author = {Pascolini-Campbell, M and Zanchettin, D and Bothe, O and Timmreck, C and Matei, D and Jungclaus, J H and Graf, H.-F.},
doi = {10.1007/s00704-014-1114-2},
issn = {1434-4483},
journal = {Theoretical and Applied Climatology},
month = {jan},
number = {1},
pages = {379--389},
title = {{Toward a record of Central Pacific El Ni{\~{n}}o events since 1880}},
url = {https://doi.org/10.1007/s00704-014-1114-2},
volume = {119},
year = {2015}
}
@article{Paulot2018,
author = {Paulot, Fabien and Paynter, David and Ginoux, Paul and Naik, Vaishali and Horowitz, Larry W.},
doi = {10.5194/acp-18-13265-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {sep},
number = {17},
pages = {13265--13281},
title = {{Changes in the aerosol direct radiative forcing from 2001 to 2015: observational constraints and regional mechanisms}},
url = {https://www.atmos-chem-phys.net/18/13265/2018/},
volume = {18},
year = {2018}
}
@article{Pearson2009a,
author = {Pearson, Paul N and Foster, Gavin L and Wade, Bridget S},
doi = {10.1038/nature08447},
journal = {Nature},
month = {sep},
pages = {1110},
publisher = {Macmillan Publishers Limited. All rights reserved},
title = {{Atmospheric carbon dioxide through the Eocene–Oligocene climate transition}},
volume = {461},
year = {2009}
}
@article{Pecl2017,
abstract = {Climate change is causing geographical redistribution of plant and animal species globally. These distributional shifts are leading to new ecosystems and ecological communities, changes that will affect human society. Pecl et al. review these current and future impacts and assess their implications for sustainable development goals. Science , this issue p. [eaai9214][1] {\#}{\#}{\#} BACKGROUND The success of human societies depends intimately on the living components of natural and managed systems. Although the geographical range limits of species are dynamic and fluctuate over time, climate change is impelling a universal redistribution of life on Earth. For marine, freshwater, and terrestrial species alike, the first response to changing climate is often a shift in location, to stay within preferred environmental conditions. At the cooler extremes of their distributions, species are moving poleward, whereas range limits are contracting at the warmer range edge, where temperatures are no longer tolerable. On land, species are also moving to cooler, higher elevations; in the ocean, they are moving to colder water at greater depths. Because different species respond at different rates and to varying degrees, key interactions among species are often disrupted, and new interactions develop. These idiosyncrasies can result in novel biotic communities and rapid changes in ecosystem functioning, with pervasive and sometimes unexpected consequences that propagate through and affect both biological and human communities. {\#}{\#}{\#} ADVANCES At a time when the world is anticipating unprecedented increases in human population growth and demands, the ability of natural ecosystems to deliver ecosystem services is being challenged by the largest climate-driven global redistribution of species since the Last Glacial Maximum. We demonstrate the serious consequences of this species redistribution for economic development, livelihoods, food security, human health, and culture, and we document feedbacks on climate itself. As with other impacts of climate change, species range shifts will leave “winners” and “losers” in their wake, radically reshaping the pattern of human well-being between regions and different sectors and potentially leading to substantial conflict. The pervasive impacts of changes in species distribution transcend single systems or dimensions, with feedbacks and linkages between multiple interacting scales and through whole ecosystems, inclusive of humans. We argue that the negative effects of climate change cannot be adequately anticipated or prepared for unless species responses are explicitly included in decision-making and global strategic frameworks. {\#}{\#}{\#} OUTLOOK Despite mounting evidence for the pervasive and substantial impacts of a climate-driven redistribution of Earth's species, current global goals, policies, and international agreements fail to account for these effects. With the predicted intensification of species movements and their diverse societal and environmental impacts, awareness of species “on the move” should be incorporated into local, regional, and global assessments as standard practice. This will raise hope that future targets—whether they be global sustainability goals, plans for regional biodiversity maintenance, or local fishing or forestry harvest strategies—can be achievable and that society is prepared for a world of universal ecological change. Human society has yet to appreciate the implications of unprecedented species redistribution for life on Earth, including for human lives. Even if greenhouse gas emissions stopped today, the responses required in human systems to adapt to the most serious effects of climate-driven species redistribution would be massive. Meeting these challenges requires governance that can anticipate and adapt to changing conditions, as well as minimize negative consequences. ![Figure][2]{\textless}/img{\textgreater} As the global climate changes, human well-being, ecosystem function, and even climate itself are increasingly affected by the shifting geography of life. Climate-driven changes in species distributions, or range shifts, affect human well-being both directly (for example, through emerging diseases and changes in food supply) and indirectly (by degrading ecosystem health). Some range shifts even create feedbacks (positive or negative) on the climate system, altering the pace of climate change. Distributions of Earth's species are changing at accelerating rates, increasingly driven by human-mediated climate change. Such changes are already altering the composition of ecological communities, but beyond conservation of natural systems, how and why does this matter? We review evidence that climate-driven species redistribution at regional to global scales affects ecosystem functioning, human well-being, and the dynamics of climate change itself. Production of natural resources required for food security, patterns of disease transmission, and processes of carbon sequestration are all altered by changes in species distribution. Consideration of these effects of biodiversity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals. [1]: /lookup/doi/10.1126/science.aai9214 [2]: pending:yes},
author = {Pecl, Gretta T. and Ara{\'{u}}jo, Miguel B. and Bell, Johann D. and Blanchard, Julia and Bonebrake, Timothy C. and Chen, I. Ching and Clark, Timothy D. and Colwell, Robert K. and Danielsen, Finn and Eveng{\aa}rd, Birgitta and Falconi, Lorena and Ferrier, Simon and Frusher, Stewart and Garcia, Raquel A. and Griffis, Roger B. and Hobday, Alistair J. and Janion-Scheepers, Charlene and Jarzyna, Marta A. and Jennings, Sarah and Lenoir, Jonathan and Linnetved, Hlif I. and Martin, Victoria Y. and McCormack, Phillipa C. and McDonald, Jan and Mitchell, Nicola J. and Mustonen, Tero and Pandolfi, John M. and Pettorelli, Nathalie and Popova, Ekaterina and Robinson, Sharon A. and Scheffers, Brett R. and Shaw, Justine D. and Sorte, Cascade J.B. and Strugnell, Jan M. and Sunday, Jennifer M. and Tuanmu, Mao Ning and Verg{\'{e}}s, Adriana and Villanueva, Cecilia and Wernberg, Thomas and Wapstra, Erik and Williams, Stephen E.},
doi = {10.1126/science.aai9214},
issn = {10959203},
journal = {Science},
number = {6332},
pages = {eaai9214},
title = {{Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being}},
volume = {355},
year = {2017}
}
@article{Pedlar2015,
abstract = {? 2015 American Meteorological Society.This study produced annual spatial models (or grids) of 27 growing-season variables for Canada that span two centuries (1901-2100). Temporal gaps in the availability of daily climate data-the typical and preferred source for calculating growing-season variables-necessitated the use of two approaches for generating these growing-season grids. The first approach, used only for the 1950-2010 period, employed a computer script to directly calculate the suite of growing-season variables from existing daily climate grids. Since daily grids were not available for the remaining years, a second approach, which employed a machine-learning method called boosted regression trees (BRT), was used to generate statistical models that related each growing-season variable to a suite of climate and water-related predictors. These BRT models were used to generate grids of growing-season variables for each year of the study period, including the 1950-2010 period to allow comparison between the two approaches. Mean absolute errors associated with the BRT-based grids were approximately 30{\%} higher than those associated with the daily-based grids. The two approaches were also compared by calculating trends in growing-season length over the 1950-2010 period. Significant increases in growing-season length were obtained for nearly all ecozones across Canada, and there were no significant differences in the trends obtained from the two approaches. Although the daily-based approach tended to have lower errors, the BRT approach produced comparable map products that should be valuable for periods and regions for which daily data are not available.},
author = {Pedlar, John H. and McKenney, Daniel W. and Lawrence, Kevin and Papadopol, Pia and Hutchinson, Michael F. and Price, David},
doi = {10.1175/JAMC-D-14-0045.1},
issn = {15588432},
journal = {Journal of Applied Meteorology and Climatology},
keywords = {Agriculture,Crop growth,Interpolation schemes,Model evaluation/performance,North America,Statistical techniques},
number = {2},
pages = {506--518},
title = {{A comparison of two approaches for generating spatial models of growing-season variables for Canada}},
volume = {54},
year = {2015}
}
@article{Peeters2004,
abstract = {The magnitude of heat and salt transfer between the Indian and Atlantic oceans through ‘Agulhas leakage' is considered important for balancing the global thermohaline circulation1,2,3. Increases or reductions of this leakage lead to strengthening or weakening of the Atlantic meridional overturning and associated variation of North Atlantic Deep Water formation4,5,6. Here we show that modern Agulhas waters, which migrate into the south Atlantic Ocean in the form of an Agulhas ring, contain a characteristic assemblage of planktic foraminifera. We use this assemblage as a modern analogue to investigate the Agulhas leakage history over the past 550,000 years from a sediment record in the Cape basin. Our reconstruction indicates that Indian–Atlantic water exchange was highly variable: enhanced during present and past interglacials and largely reduced during glacial intervals. Coherent variability of Agulhas leakage with northern summer insolation suggests a teleconnection to the monsoon system. The onset of increased Agulhas leakage during late glacial conditions took place when glacial ice volume was maximal, suggesting a crucial role for Agulhas leakage in glacial terminations, timing of interhemispheric climate change7 and the resulting resumption of the Atlantic meridional overturning circulation6.},
author = {Peeters, Frank J C and Acheson, Ruth and Brummer, Geert-Jan A and de Ruijter, Wilhelmus P M and Schneider, Ralph R and Ganssen, Gerald M and Ufkes, Els and Kroon, Dick},
doi = {10.1038/nature02785},
issn = {1476-4687},
journal = {Nature},
number = {7000},
pages = {661--665},
title = {{Vigorous exchange between the Indian and Atlantic oceans at the end of the past five glacial periods}},
url = {https://doi.org/10.1038/nature02785},
volume = {430},
year = {2004}
}
@article{https://doi.org/10.1002/2014JB011176,
author = {Peltier, W R and Argus, D F and Drummond, R},
doi = {10.1002/2014JB011176},
journal = {Journal of Geophysical Research: Solid Earth},
keywords = {glacial isostasy,mantle dynamics,space geodesy},
number = {1},
pages = {450--487},
title = {{Space geodesy constrains ice age terminal deglaciation: The global ICE-6G{\_}C (VM5a) model}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JB011176},
volume = {120},
year = {2015}
}
@article{Pena-Ortiz2013,
author = {Pena-Ortiz, C and Gallego, D and Ribera, P and Ordonez, P and Alvarez-Castro, M D C},
doi = {10.1002/jgrd.50305.},
journal = {Journal of Geophysical Research: Atmospheres},
pages = {2702--2713},
title = {{Observed trends in the global jet stream characteristics during the second half of the 20th century}},
volume = {118},
year = {2013}
}
@article{Pendleton2019a,
abstract = {Arctic temperatures are increasing faster than the Northern Hemisphere average due to strong positive feedbacks unique to polar regions. However, the degree to which recent Arctic warming is unprecedented remains debated. Ages of entombed plants in growth position preserved by now receding ice caps in Arctic Canada help to address this issue by placing recent conditions in a multi-millennial context. Here we show that pre-Holocene radiocarbon dates on plants collected at the margins of 30 ice caps in Arctic Canada suggest those locations were continuously ice covered for {\textgreater} 40 kyr, but are now ice-free. We use in situ (14)C inventories in rocks from nine locations to explore the possibility of brief exposure during the warm early Holocene. Modeling the evolution of in situ (14)C confirms that Holocene exposure is unlikely at all but one of the sites. Viewed in the context of temperature records from Greenland ice cores, our results suggest that summer warmth of the past century exceeds now any century in {\~{}}115,000 years.},
author = {Pendleton, Simon L and Miller, Gifford H and Lifton, Nathaniel and Lehman, Scott J and Southon, John and Crump, Sarah E and Anderson, Robert S},
doi = {10.1038/s41467-019-08307-w},
issn = {2041-1723},
journal = {Nature communications},
month = {jan},
number = {1},
pages = {445},
publisher = {Nature Publishing Group UK},
title = {{Rapidly receding Arctic Canada glaciers revealing landscapes continuously ice-covered for more than 40,000 years}},
volume = {10},
year = {2019}
}
@article{PenduffT.G.SerazinS.LerouxS.CloseJ.-M.MolinesB.BarnierL.BessieresL.Terray2018,
author = {Penduff, Thierry and S{\'{e}}razin, Guillaume and Leroux, St{\'{e}}phanie and Close, Sally and Molines, Jean-Marc and Barnier, Bernard and Bessi{\`{e}}res, Laurent and Terray, Laurent and Maze, Guillaume},
doi = {10.5670/oceanog.2018.210},
journal = {Oceanography},
number = {2},
pages = {63--71},
title = {{Chaotic variability of ocean heat content: Climate-relevant features and observational implications}},
volume = {31},
year = {2018}
}
@article{Peng2018,
abstract = {Information on the timing of Arctic snow and ice melt onset, sea ice opening, retreat, advance, and closing, can be beneficial to a variety of stakeholders. Sea ice modelers can use information on the evolution of the ice cover through the rest of the summer to improve their seasonal sea ice forecasts. The length of the open water season (as derived from retreat/advance dates) is important for human activities and for wildlife. Long-term averages and variability of these dates as climate indicators are beneficial to business strategic planning and climate monitoring. In this study, basic characteristics of temporal means and variability of Arctic sea ice climate indicators derived from a satellite-based climate data record from March 1979 to February 2017 melt and freeze seasons are described. Our results show that, over the Arctic region, anomalies of snow and ice melt onset, ice opening and retreat dates are getting earlier in the year at a rate of more than 5 days per decade, while that of ice advance and closing dates are getting later at a rate of more than 5 days per decade. These significant trends resulted in significant upward trends for anomalies of inner and outer ice-free periods at a rate of nearly 12 days per decade. Small but significant downward trends of seasonal ice loss and gain period anomalies were also observed at a rate of −1.48 and −0.53 days per decade, respectively. Our analyses also demonstrated that the means of these indicators and their trends are sensitive to valid data masks and regional averaging methods.},
author = {Peng, Ge and Steele, Michael and Bliss, Angela C. and Meier, Walter N. and Dickinson, Suzanne},
doi = {10.3390/rs10091328},
issn = {20724292},
journal = {Remote Sensing},
keywords = {Arctic sea ice,Climate data record,Climate indicator,Decadal trend,Melt onset,Sea ice freeze-up,Sea ice retreat,Variability},
number = {9},
pages = {1328},
title = {{Temporal means and variability of Arctic sea ice melt and freeze season climate indicators using a satellite climate data record}},
volume = {10},
year = {2018}
}
@article{Penman2014,
abstract = {The Paleocene-Eocene ThermalMaximum(PETM) has been associated with the release of several thousands of petagrams of carbon (PgC) asmethane and/or carbon dioxide into the ocean-atmosphere system within {\~{}}10 kyr, on the basis of the co-occurrence of a carbon isotope excursion (CIE), widespread dissolution of deep sea carbonates, and globalwarming. In theory, this rapid carbon release should have severely acidified the surface ocean, though no geochemical evidence has yet been presented.Using boron-based proxies for surface ocean carbonate chemistry, we present the first observational evidence for a drop in the pH of surface and thermocline seawater during the PETM. Planktic foraminifers froma drill site in the North Pacific (Ocean Drilling Program Site 1209) show a {\~{}}0.8‰decrease in boron isotopic composition ($\delta$11B) at the onset of the event, alongwitha30–40{\%}reduction in shell B/Ca. Similar trends in $\delta$11B are present in two lower-resolution records from the South Atlantic and Equatorial Pacific. These observations are consistent with significant, global acidification of the surface ocean lasting at least 70 kyr and requiring sustained carbon release. The anomalies in the B records are consistent with an initial surface pH drop of {\~{}}0.3 units, at the upper range ofmodel-based estimates of acidification},
author = {Penman, Donald E. and H{\"{o}}nisch, B{\"{a}}rbel and Zeebe, Richard E. and Thomas, Ellen and Zachos, James C.},
doi = {10.1002/2014PA002621},
issn = {19449186},
journal = {Paleoceanography},
number = {5},
pages = {357--369},
publisher = {Blackwell Publishing Ltd},
title = {{Rapid and sustained surface ocean acidification during the Paleocene-Eocene Thermal Maximum}},
volume = {29},
year = {2014}
}
@article{Pepler2018b,
author = {Pepler, A S and {Di Luca}, A and Evans, J P},
doi = {10.1002/joc.5245},
journal = {International Journal of Climatology},
number = {3},
pages = {1314--1327.},
title = {{Independently assessing the representation of midlatitude cyclones in high-resolution reanalyses using satellite observed winds}},
volume = {38},
year = {2018}
}
@article{Perez2018b,
abstract = {There has been about a forty per cent reduction in the transport of carbonate ions to the deep North Atlantic Ocean since preindustrial times, severely endangering cold-water corals.},
author = {Perez, Fiz F and Fontela, Marcos and Garc{\'{i}}a-Ib{\'{a}}{\~{n}}ez, Maribel I and Mercier, Herl{\'{e}} and Velo, Anton and Lherminier, Pascale and Zunino, Patricia and de la Paz, Mercedes and Alonso-P{\'{e}}rez, Fernando and Guallart, Elisa F and Padin, Xose A},
doi = {10.1038/nature25493},
issn = {1476-4687},
journal = {Nature},
number = {7693},
pages = {515--518},
title = {{Meridional overturning circulation conveys fast acidification to the deep Atlantic Ocean}},
url = {https://doi.org/10.1038/nature25493},
volume = {554},
year = {2018}
}
@article{PerovichD.W.MeierM.TschudiK.WoodS.FarrellS.HendricksS.GerlandL.KaleschkeR.RickerX.Tian-Kunze2020,
author = {Perovich, D. and Meier, W. and Tschudi, M. and Wood, K. and Farrell, S. and Hendricks, S. and Gerland, S. and Kaleschke, L. and Ricker, R. and Tian-Kunze, X. and Webster, M.},
doi = {10.1175/BAMS-D-20-0086.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S251--S253},
title = {{The Arctic: Sea ice [in “State of the Climate in 2019”]}},
volume = {101},
year = {2020}
}
@article{Petherick2013,
author = {Petherick, L and Bostock, H and Cohen, T J and Fitzsimmons, K and Tibby, J and Fletcher, M and Dosseto, A},
doi = {10.1016/j.quascirev.2012.12.012},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {58--77},
publisher = {Elsevier Ltd},
title = {{Climatic records over the past 30 ka from temperate Australia e a synthesis from the Oz-INTIMATE workgroup}},
url = {http://dx.doi.org/10.1016/j.quascirev.2012.12.012},
volume = {74},
year = {2013}
}
@article{Philipona2018,
abstract = {Abstract Since the mid-twentieth century, radiosonde and satellite measurements show that the troposphere has warmed and the stratosphere has cooled. These changes are primarily due to increasing concentrations of well-mixed greenhouse gases and the depletion of stratospheric ozone. In response to continued greenhouse gas increases and stratospheric ozone depletion, climate models project continued tropospheric warming and stratospheric cooling over the coming decades. Global average satellite observations of lower stratospheric temperatures exhibit no significant trends since the turn of the century. In contrast, an analysis of vertically resolved radiosonde measurements from 60 stations shows an increase of lower stratospheric temperature since the turn of the century at altitudes between 15 and 30 km and over most continents. Trend estimates are somewhat sensitive to homogeneity assessment choices, but all investigated radiosonde data sets suggest a change from late twentieth century cooling to early 21st century warming in the lower stratosphere, which is consistent with a reversal from ozone depletion to recovery from the effects of ozone-depleting substances. In comparison, satellite observations at the radiosonde locations show only minor early 21st century warming, possibly due to the compensating effects of continued cooling above the radiosonde altitude range.},
author = {Philipona, Rolf and Mears, Carl and Fujiwara, Masatomo and Jeannet, Pierre and Thorne, Peter and Bodeker, Greg and Haimberger, Leopold and Hervo, Maxime and Popp, Christoph and Romanens, Gonzague and Steinbrecht, Wolfgang and St{\"{u}}bi, Rene and {Van Malderen}, Roeland},
doi = {10.1029/2018JD028901},
journal = {Journal of Geophysical Research: Atmospheres},
number = {22},
pages = {12509--512522},
title = {{Radiosondes Show That After Decades of Cooling, the Lower Stratosphere Is Now Warming}},
volume = {123},
year = {2018}
}
@misc{Piao2018,
abstract = {No consensus has yet been reached on the major factors driving the observed increase in the seasonal amplitude of atmospheric CO2 in the northern latitudes. In this study, we used atmospheric CO2 records from 26 northern hemisphere stations with a temporal coverage longer than 15 years, and an atmospheric transport model prescribed with net biome productivity (NBP) from an ensemble of nine terrestrial ecosystem models, to attribute change in the seasonal amplitude of atmospheric CO2. We found significant (p {\textless}.05) increases in seasonal peak-to-trough CO2 amplitude (AMPP-T) at nine stations, and in trough-to-peak amplitude (AMPT-P) at eight stations over the last three decades. Most of the stations that recorded increasing amplitudes are in Arctic and boreal regions ({\textgreater}50°N), consistent with previous observations that the amplitude increased faster at Barrow (Arctic) than at Mauna Loa (subtropics). The multi-model ensemble mean (MMEM) shows that the response of ecosystem carbon cycling to rising CO2 concentration (eCO2) and climate change are dominant drivers of the increase in AMPP-T and AMPT-P in the high latitudes. At the Barrow station, the observed increase of AMPP-T and AMPT-P over the last 33 years is explained by eCO2 (39{\%} and 42{\%}) almost equally than by climate change (32{\%} and 35{\%}). The increased carbon losses during the months with a net carbon release in response to eCO2 are associated with higher ecosystem respiration due to the increase in carbon storage caused by eCO2 during carbon uptake period. Air-sea CO2 fluxes (10{\%} for AMPP-T and 11{\%} for AMPT-P) and the impacts of land-use change (marginally significant 3{\%} for AMPP-T and 4{\%} for AMPT-P) also contributed to the CO2 measured at Barrow, highlighting the role of these factors in regulating seasonal changes in the global carbon cycle.},
author = {Piao, Shilong and Liu, Zhuo and Wang, Yilong and Ciais, Philippe and Yao, Yitong and Peng, Shushi and Chevallier, Fr{\'{e}}d{\'{e}}ric and Friedlingstein, Pierre and Janssens, Ivan A. and Pe{\~{n}}uelas, Josep and Sitch, Stephen and Wang, Tao},
booktitle = {Global Change Biology},
doi = {10.1111/gcb.13909},
issn = {13652486},
keywords = {CO2 fertilization effect,amplitude of atmospheric CO2,attribution,climate change,detection,land-use change},
number = {2},
pages = {608--616},
title = {{On the causes of trends in the seasonal amplitude of atmospheric CO2}},
volume = {24},
year = {2018}
}
@article{Piao2020,
abstract = {Vegetation greenness has been increasing globally since at least 1981, when satellite technology enabled large-scale vegetation monitoring. The greening phenomenon, together with warming, sea-level rise and sea-ice decline, represents highly credible evidence of anthropogenic climate change. In this Review, we examine the detection of the greening signal, its causes and its consequences. Greening is pronounced over intensively farmed or afforested areas, such as in China and India, reflecting human activities. However, strong greening also occurs in biomes with low human footprint, such as the Arctic, where global change drivers play a dominant role. Vegetation models suggest that CO2 fertilization is the main driver of greening on the global scale, with other factors being notable at the regional scale. Modelling indicates that greening could mitigate global warming by increasing the carbon sink on land and altering biogeophysical processes, mainly evaporative cooling. Coupling high temporal and fine spatial resolution remote-sensing observations with ground measurements, increasing sampling in the tropics and Arctic, and modelling Earth systems in more detail will further our insights into the greening of Earth.},
author = {Piao, Shilong and Wang, Xuhui and Park, Taejin and Chen, Chi and Lian, Xu and He, Yue and Bjerke, Jarle W and Chen, Anping and Ciais, Philippe and T{\o}mmervik, Hans and Nemani, Ramakrishna R and Myneni, Ranga B},
doi = {10.1038/s43017-019-0001-x},
issn = {2662-138X},
journal = {Nature Reviews Earth {\&} Environment},
number = {1},
pages = {14--27},
title = {{Characteristics, drivers and feedbacks of global greening}},
url = {https://doi.org/10.1038/s43017-019-0001-x},
volume = {1},
year = {2020}
}
@article{10.1093/gji/ggz447,
abstract = {Locally, the elevation of last interglacial (LIG; ∼122 ka) sea level markers is modulated by processes of vertical displacement, such as tectonic uplift or glacial isostatic adjustment, and these processes must be accounted for in deriving estimates of global ice volumes from geological sea level records. The impact of sediment loading on LIG sea level markers is generally not accounted for in these corrections, as it is assumed that the impact is negligible except in extremely high depositional settings, such as the world's largest river deltas. Here we perform a generalized test to assess the extent to which sediment loading may impact global variability in the present-day elevation of LIG sea level markers. We numerically simulate river sediment deposition using a diffusive model that incorporates a migrating shoreline to construct a global history of sedimentation over the last glacial cycle. We then calculate sea level changes due to this sediment loading using a gravitationally self-consistent model of glacial isostatic adjustment, and compare these predictions to a global compilation of LIG sea level data. We perform a statistical analysis, which accounts for spatial autocorrelation, across a global compilation of 1287 LIG sea level markers. Though limited by uncertainties in the LIG sea level database and the precise history of river deposition, this analysis suggests there is not a statistically significant global signal of sediment loading in LIG sea level markers. Nevertheless, at sites where LIG sea level markers have been measured, local sea level predicted using our simulated sediment loading history is perturbed up to 16 m. More generally, these predictions establish the relative sensitivity of different regions to sediment loading. Finally, we consider the implications of our results for estimates of tectonic uplift rates derived from LIG marine terraces; we predict that sediment loading causes 5–10 m of subsidence over the last glacial cycle at specific locations along active margin regions such as California and Barbados, where deriving long-term tectonic uplift rates from LIG shorelines is a common practice.},
author = {Pico, T},
doi = {10.1093/gji/ggz447},
issn = {0956-540X},
journal = {Geophysical Journal International},
number = {1},
pages = {384--392},
title = {{Towards assessing the influence of sediment loading on Last Interglacial sea level}},
url = {https://doi.org/10.1093/gji/ggz447},
volume = {220},
year = {2020}
}
@article{Piecuch2015,
author = {Piecuch, Christopher G and Ponte, Rui M},
doi = {10.1002/2015GL064580},
journal = {Geophysical Research Letters},
number = {14},
pages = {5918--5925},
publisher = {Wiley Online Library},
title = {{Inverted barometer contributions to recent sea level changes along the northeast coast of North America}},
volume = {42},
year = {2015}
}
@article{Piecuch2016,
author = {Piecuch, Christopher G and Dangendorf, S{\"{o}}nke and Ponte, Rui M and Marcos, Marta},
doi = {10.1175/JCLI-D-16-0048.1},
journal = {Journal of Climate},
number = {13},
pages = {4801--4816},
title = {{Annual sea level changes on the North American Northeast Coast: influence of local winds and barotropic motions}},
volume = {29},
year = {2016}
}
@article{Piecuch2020,
author = {Piecuch, Christopher G},
doi = {10.1038/s41467-020-17761-w},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {3973},
title = {{Likely weakening of the Florida Current during the past century revealed by sea-level observations}},
url = {https://doi.org/10.1038/s41467-020-17761-w},
volume = {11},
year = {2020}
}
@article{Pimm2014a,
abstract = {Recent studies clarify where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. We assess key statistics about species, their distribution, and their status. Most are undescribed. Those we know best have large geographical ranges and are often common within them. Most known species have small ranges. The numbers of small-ranged species are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. Current rates of extinction are about 1000 times the likely background rate of extinction. Future rates depend on many factors and are poised to increase. Although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity.},
archivePrefix = {arXiv},
arxivId = {1132},
author = {Pimm, S. L. and Jenkins, C. N. and Abell, R. and Brooks, T. M. and Gittleman, J. L. and Joppa, L. N. and Raven, P. H. and Roberts, C. M. and Sexton, J. O.},
doi = {10.1126/science.1246752},
eprint = {1132},
isbn = {1095-9203 (Electronic)$\backslash$n0036-8075 (Linking)},
issn = {10959203},
journal = {Science},
number = {6187},
pages = {1246752},
pmid = {24876501},
title = {{The biodiversity of species and their rates of extinction, distribution, and protection}},
volume = {344},
year = {2014}
}
@article{doi:10.1146/annurev-marine-010419-010916,
abstract = { The geographic distributions of marine species are changing rapidly, with leading range edges following climate poleward, deeper, and in other directions and trailing range edges often contracting in similar directions. These shifts have their roots in fine-scale interactions between organisms and their environment—including mosaics and gradients of temperature and oxygen—mediated by physiology, behavior, evolution, dispersal, and species interactions. These shifts reassemble food webs and can have dramatic consequences. Compared with species on land, marine species are more sensitive to changing climate but have a greater capacity for colonization. These differences suggest that species cope with climate change at different spatial scales in the two realms and that range shifts across wide spatial scales are a key mechanism at sea. Additional research is needed to understand how processes interact to promote or constrain range shifts, how the dominant responses vary among species, and how the emergent communities of the future ocean will function. },
annote = {PMID: 31505130},
author = {Pinsky, Malin L and Selden, Rebecca L and Kitchel, Zo{\"{e}} J},
doi = {10.1146/annurev-marine-010419-010916},
journal = {Annual Review of Marine Science},
number = {1},
pages = {153--179},
title = {{Climate-Driven Shifts in Marine Species Ranges: Scaling from Organisms to Communities}},
url = {https://doi.org/10.1146/annurev-marine-010419-010916},
volume = {12},
year = {2020}
}
@article{https://doi.org/10.1002/wcc.150,
abstract = {Abstract The North Atlantic oscillation (NAO) is under current climate conditions the leading mode of atmospheric circulation variability over the North Atlantic region. While the pattern is present during the entire year, it is most important during winter, explaining a large part of the variability of the large-scale pressure field, being thus largely determinant for the weather conditions over the North Atlantic basin and over Western Europe. In this study, a review of recent literature on the basic understanding of the NAO, its variability on different time scales and driving physical mechanisms is presented. In particular, the observed NAO variations and long-term trends are put into a long term perspective by considering paleo-proxy evidence. A representative number of recently released NAO reconstructions are discussed. While the reconstructions agree reasonably well with observations during the instrumental overlapping period, there is a rather high uncertainty between the different reconstructions for the pre-instrumental period, which leads to partially incoherent results, that is, periods where the NAO reconstructions do not agree even in sign. Finally, we highlight the future need of a broader definition of the NAO, the assessment of the stability of the teleconnection centers over time, the analysis of the relations to other relevant variables like temperature and precipitation, as well as on the relevant processes involved. WIREs Clim Change 2012, 3:79–90. doi: 10.1002/wcc.150 This article is categorized under: Paleoclimates and Current Trends {\textgreater} Earth System Behavior},
author = {Pinto, Joaquim G and Raible, Christoph C},
doi = {10.1002/wcc.150},
journal = {WIREs Climate Change},
number = {1},
pages = {79--90},
title = {{Past and recent changes in the North Atlantic oscillation}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/wcc.150},
volume = {3},
year = {2012}
}
@article{Platt2003,
abstract = {The different factors that influence the prevalent decline in fish stocks are currently subject to urgent and intense scrutiny. Here we combine the use of remote-sensing satellite data with a long-term data set of haddock recruitment off the eastern continental shelf of Nova Scotia, Canada, to show that the survival of the larval fish depends on the timing of the local spring bloom of phytoplankton. This link has been suspected for more than 100 years, but its verification has had to wait for technology with sufficient spatial and temporal resolution.},
author = {Platt, Trevor and Fuentes-Yaco, Csar and Frank, Kenneth T},
doi = {10.1038/423398b},
issn = {1476-4687},
journal = {Nature},
number = {6938},
pages = {398--399},
title = {{Spring algal bloom and larval fish survival}},
url = {https://doi.org/10.1038/423398b},
volume = {423},
year = {2003}
}
@article{doi:10.1175/JCLI-D-15-0556.1,
abstract = { AbstractThe ECMWF twentieth century reanalysis (ERA-20C; 1900–2010) assimilates surface pressure and marine wind observations. The reanalysis is single-member, and the background errors are spatiotemporally varying, derived from an ensemble. The atmospheric general circulation model uses the same configuration as the control member of the ERA-20CM ensemble, forced by observationally based analyses of sea surface temperature, sea ice cover, atmospheric composition changes, and solar forcing. The resulting climate trend estimations resemble ERA-20CM for temperature and the water cycle. The ERA-20C water cycle features stable precipitation minus evaporation global averages and no spurious jumps or trends. The assimilation of observations adds realism on synoptic time scales as compared to ERA-20CM in regions that are sufficiently well observed. Comparing to nighttime ship observations, ERA-20C air temperatures are 1 K colder. Generally, the synoptic quality of the product and the agreement in terms of climate indices with other products improve with the availability of observations. The MJO mean amplitude in ERA-20C is larger than in 20CR version 2c throughout the century, and in agreement with other reanalyses such as JRA-55. A novelty in ERA-20C is the availability of observation feedback information. As shown, this information can help assess the product's quality on selected time scales and regions. },
author = {Poli, Paul and Hersbach, Hans and Dee, Dick P and Berrisford, Paul and Simmons, Adrian J and Vitart, Fr{\'{e}}d{\'{e}}ric and Laloyaux, Patrick and Tan, David G H and Peubey, Carole and Th{\'{e}}paut, Jean-No{\"{e}}l and Tr{\'{e}}molet, Yannick and H{\'{o}}lm, El{\'{i}}as V and Bonavita, Massimo and Isaksen, Lars and Fisher, Michael},
doi = {10.1175/JCLI-D-15-0556.1},
journal = {Journal of Climate},
number = {11},
pages = {4083--4097},
title = {{ERA-20C: An Atmospheric Reanalysis of the Twentieth Century}},
url = {https://doi.org/10.1175/JCLI-D-15-0556.1},
volume = {29},
year = {2016}
}
@article{Polo2015,
abstract = {Previous observational and model studies have shown that a warm (cold) event in the equatorial Atlantic during the boreal summer are related to the development of a Pacific La Ni{\~{n}}a (El Ni{\~{n}}o) event, that is fully developed in the following winter. Although the connection takes place via atmospheric bridge, the processes at work have not been clarified for such a remote and lagged relationship. The present paper uses a partially coupled atmosphere–ocean model to infer a mechanism by which a Pacific El Ni{\~{n}}o event can be developed. In this way, enhanced equatorial convection in the equatorial Atlantic during a warm event results in enhanced subsidence and surface wind divergence over the equatorial Pacific around the dateline. This wind anomaly contributes to pile up water in the western equatorial Pacific, triggering a perturbation in the depth of the oceanic thermocline, which propagates eastward as an equatorial Kelvin wave from autumn to winter. The thermocline shallowing as the wave propagates allows for cooling of the oceanic mixed layer through anomalous temperature advection by anomalous zonal currents and by mean vertical entrainment velocity. Zonal advective and thermocline feedbacks reinforce the surface winds anomalies over the central eastern equatorial Pacific setting up the conditions for the development of a cold event in this ocean. The sequence during an Atlantic cold event is similar with the appropriate change in signs. These findings are relevant to ENSO predictability at seasonal timescales.},
author = {Polo, Irene and Martin-Rey, Marta and Rodriguez-Fonseca, Belen and Kucharski, Fred and Mechoso, Carlos Roberto},
doi = {10.1007/s00382-014-2354-7},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {1},
pages = {115--131},
title = {{Processes in the Pacific La Ni{\~{n}}a onset triggered by the Atlantic Ni{\~{n}}o}},
url = {https://doi.org/10.1007/s00382-014-2354-7},
volume = {44},
year = {2015}
}
@article{Polo2013a,
abstract = {In response to a substantial weakening of the Atlantic Meridional Overturning Circulation (AMOC)—from a coupled ocean–atmosphere general circulation model experiment—significant changes in the interannual variability are found over the tropical Atlantic, characterized by an increase of variance (by {\~{}}150 {\%}) in boreal late spring-early summer and a decrease of variance (by {\~{}}60 {\%}) in boreal autumn. This study focuses on understanding physical mechanisms responsible for these changes in interannual variability in the tropical Atlantic. It demonstrates that the increase of variability in spring is a consequence of an increase in the variance of the El Ni{\~{n}}o-Southern Oscillation, which has a large impact on the tropical Atlantic via anomalous surface heat fluxes. Winter El Ni{\~{n}}o (La Ni{\~{n}}a) affects the eastern equatorial Atlantic by decreasing (increasing) cloud cover and surface wind speed which is associated with anomalous downward (upward) short wave radiation and reduced (enhanced) upward latent heat fluxes, creating anomalous positive (negative) sea surface temperature (SST) anomalies over the region from winter to spring. On the other hand, the decrease of SST variance in autumn is due to a deeper mean thermocline which weakens the impact of the thermocline movement on SST variation. The comparison between the model results and observations is not straightforward owing to the influence of model biases and the lack of a major MOC weakening event in the instrumental record. However, it is argued that the basic physical mechanisms found in the model simulations are likely to be robust and therefore have relevance to understanding tropical Atlantic variability in the real world, perhaps with modified seasonality.},
author = {Polo, Irene and Dong, Buwen W and Sutton, Rowan T},
doi = {10.1007/s00382-013-1716-x},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {9},
pages = {2765--2784},
title = {{Changes in tropical Atlantic interannual variability from a substantial weakening of the meridional overturning circulation}},
url = {https://doi.org/10.1007/s00382-013-1716-x},
volume = {41},
year = {2013}
}
@article{https://doi.org/10.1029/2007GL031745,
abstract = {A 9-year time series of SeaWiFS remotely-sensed ocean color data is used to examine temporal trends in the ocean's most oligotrophic waters, those with surface chlorophyll not exceeding 0.07 mg chl/m3. In the North and South Pacific, North and South Atlantic, outside the equatorial zone, the areas of low surface chlorophyll waters have expanded at average annual rates from 0.8 to 4.3{\%}/yr and replaced about 0.8 million km2/yr of higher surface chlorophyll habitat with low surface chlorophyll water. It is estimated that the low surface chlorophyll areas in these oceans combined have expanded by 6.6 million km2 or by about 15.0{\%} from 1998 through 2006. In both hemispheres, evidence shows a more rapid expansion of the low surface chlorophyll waters during the winter. The North Atlantic, which has the smallest oligotrophic gyre is expanding most rapidly, both annually at 4.3{\%}/yr and seasonally, in the first quarter at 8.5{\%}/yr. Mean sea surface temperature in each of these 4 subtropical gyres also increased over the 9-year period. The expansion of the low chlorophyll waters is consistent with global warming scenarios based on increased vertical stratification in the mid-latitudes, but the rates of expansion we observe already greatly exceed recent model predictions.},
author = {Polovina, Jeffrey J and Howell, Evan A and Abecassis, Melanie},
doi = {10.1029/2007GL031745},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {chlorophyll,oligotrophic gyres},
month = {feb},
number = {3},
pages = {L03618},
title = {{Ocean's least productive waters are expanding}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2007GL031745 http://doi.wiley.com/10.1029/2007GL031745},
volume = {35},
year = {2008}
}
@article{Polson2017a,
abstract = {The wet-gets-wetter, dry-gets-drier paradigm (WWDD) is widely used to summarize the expected response of the hydrological cycle to global warming. While some studies find that changes in observations and climate models support the WWDD paradigm, others find that it is more complicated at local scales and over land. This discrepancy is partly explained by differences in model climatologies and by movement of the wet and dry regions. Here we show that by tracking changes in wet and dry regions as they shift over the tropics and vary in models, mean precipitation changes follow the WWDD pattern in observations and models over land and ocean. However, this signal is reduced and disappears in model dry regions, when these factors are not accounted for. Accounting for seasonal and interannual shifts of the regions and climatological differences between models reduces uncertainty in predictions of future precipitation changes and makes these changes detectable earlier.},
author = {Polson, D. and Hegerl, G. C.},
doi = {10.1002/2016GL071194},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {climate change,climate models,precipitation,satellite observations,tropics},
number = {1},
pages = {365--373},
title = {{Strengthening contrast between precipitation in tropical wet and dry regions}},
volume = {44},
year = {2017}
}
@article{Poluianov2016,
abstract = {Abstract New consistent and precise computations of the production of five cosmogenic radioisotopes, 7Be, 10Be, 14C, 22Na, and 36Cl, in the Earth's atmosphere by cosmic rays are presented in the form of tabulated yield functions. For the first time, a detailed set of the altitude profiles of the production functions is provided which makes it possible to apply the results directly as input for atmospheric transport models. Good agreement with most of the earlier published works for columnar and global isotopic production rates is shown. Altitude profiles of the production are important, in particular for such tasks as studies of strong solar particle events in the past, precise reconstructions of solar activity on long-term scale, tracing air mass dynamics using cosmogenic radioisotopes, etc. As an example, computations of the 10Be deposition flux in the polar region are shown for the last decades and also for a period around 780 A.D. and confronted with the actual measurements in Greenland and Antarctic ice cores.},
author = {Poluianov, S V and Kovaltsov, G A and Mishev, A L and Usoskin, I G},
doi = {10.1002/2016JD025034},
journal = {Journal of Geophysical Research: Atmospheres},
number = {13},
pages = {8125--8136},
title = {{Production of cosmogenic isotopes 7Be, 10Be, 14C, 22Na, and 36Cl in the atmosphere: Altitudinal profiles of yield functions}},
volume = {121},
year = {2016}
}
@article{Polyak2018,
abstract = {The magnitude and trajectory of sea-level change during marine isotope stage (MIS) 5e of the last interglacial period is uncertain. In general, sea level may have been 6–9 m above present sea level, with one or more oscillations of up to several metres superimposed. Here we present a well-dated relative sea-level record from the island of Mallorca in the western Mediterranean Sea for MIS-5e, based on the occurrence of phreatic overgrowths on speleothems forming near sea level. We find that relative sea-level in this region was within a range of 2.15 ± 0.75 m above present levels between 126,600 ± 400 and 116,000 ± 800 years ago, although centennial-scale excursions cannot be excluded due to some gaps in the speleothem record. We corrected our relative sea-level record for glacio-isostatic adjustment using nine different glacial isostatic models. Together, these models suggest that ice-equivalent sea-level in Mallorca peaked at the start of MIS-5e then gradually decreased and stabilized by 122,000 years ago, until the highstand termination 116,000 years ago. Our sea-level record does not support the hypothesis of rapid sea-level fluctuations within MIS-5e. Instead, we suggest that melting of the polar ice sheets occurred early in the interglacial period, followed by gradual ice-sheet growth.},
author = {Polyak, Victor J and Onac, Bogdan P and Forn{\'{o}}s, Joan J and Hay, Carling and Asmerom, Yemane and Dorale, Jeffrey A and Gin{\'{e}}s, Joaqu{\'{i}}n and Tuccimei, Paola and Gin{\'{e}}s, Angel},
doi = {10.1038/s41561-018-0222-5},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {11},
pages = {860--864},
title = {{A highly resolved record of relative sea level in the western Mediterranean Sea during the last interglacial period}},
url = {https://doi.org/10.1038/s41561-018-0222-5},
volume = {11},
year = {2018}
}
@article{Polyakov2005a,
abstract = {Abstract Substantial changes occurred in the North Atlantic during the twentieth century. Here the authors demonstrate, through the analysis of a vast collection of observational data, that multidecadal fluctuations on time scales of 50?80 yr are prevalent in the upper 3000 m of the North Atlantic Ocean. Spatially averaged temperature and salinity from the 0?300- and 1000?3000-m layers vary in opposition: prolonged periods of cooling and freshening (warming and salinification) in one layer are generally associated with opposite tendencies in the other layer, consistent with the notion of thermohaline overturning circulation. In the 1990s, widespread cooling and freshening was a dominant feature in the 1000?3000-m layer, whereas warming and salinification generally dominated in the upper 300 m, except for the subpolar North Atlantic where complex exchanges with the Arctic Ocean occur. The single-signed basin-scale pattern of multidecadal variability is evident from decadal 1000?3000-m temperature and salinity fields, whereas upper-ocean temperature and salinity distributions have a more complicated spatial pattern. Results suggest a general warming trend of 0.012° ± 0.009°C decade?1 in the upper-3000-m North Atlantic over the last 55 yr of the twentieth century, although during this time there are periods in which short-term trends are strongly amplified by multidecadal variability. Since warming (cooling) is generally associated with salinification (freshening) for these large-scale fluctuations, qualitatively tracking the mean temperature?salinity relationship, vertical displacement of isotherms appears to play an important role in this warming and in other observed fluctuations. Finally, since the North Atlantic Ocean plays a crucial role in establishing and regulating global thermohaline circulation, the multidecadal fluctuations of the heat and freshwater balance discussed here should be considered when assessing long-term climate change and variability, both in the North Atlantic and at global scales.},
annote = {doi: 10.1175/JCLI3548.1},
author = {Polyakov, I V and Bhatt, U S and Simmons, H L and Walsh, D and Walsh, J E and Zhang, X},
doi = {10.1175/JCLI3548.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {nov},
number = {21},
pages = {4562--4581},
publisher = {American Meteorological Society},
title = {{Multidecadal Variability of North Atlantic Temperature and Salinity during the Twentieth Century}},
url = {https://doi.org/10.1175/JCLI3548.1},
volume = {18},
year = {2005}
}
@article{Pontes2020,
abstract = {Thermodynamic arguments imply that global mean rainfall increases in a warmer atmosphere; however, dynamical effects may result in more significant diversity of regional precipitation change. Here we investigate rainfall changes in the mid-Pliocene Warm Period ({\~{}} 3 Ma), a time when temperatures were 2–3{\textordmasculine}C warmer than the pre-industrial era, using output from the Pliocene Model Intercomparison Projects phases 1 and 2 and sensitivity climate model experiments. In the Mid-Pliocene simulations, the higher rates of warming in the northern hemisphere create an interhemispheric temperature gradient that enhances the southward cross-equatorial energy flux by up to 48{\%}. This intensified energy flux reorganizes the atmospheric circulation leading to a northward shift of the Inter-Tropical Convergence Zone and a weakened and poleward displaced Southern Hemisphere Subtropical Convergences Zones. These changes result in drier-than-normal Southern Hemisphere tropics and subtropics. The evaluation of the mid-Pliocene adds a constraint to possible future warmer scenarios associated with differing rates of warming between hemispheres.},
author = {Pontes, Gabriel M. and Wainer, Ilana and Taschetto, Andr{\'{e}}a S. and {Sen Gupta}, Alex and Abe-Ouchi, Ayako and Brady, Esther C. and Chan, Wing-Le and Chandan, Deepak and Contoux, Camille and Feng, Ran and Hunter, Stephen J. and Kame, Yoichi and Lohmann, Gerrit and Otto-Bliesner, Bette L. and Peltier, W. Richard and Stepanek, Christian and Tindall, Julia and Tan, Ning and Zhang, Qiong and Zhang, Zhongshi},
doi = {10.1038/s41598-020-68884-5},
isbn = {0123456789},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {13458},
pmid = {32778702},
publisher = {Nature Publishing Group UK},
title = {{Drier tropical and subtropical Southern Hemisphere in the mid-Pliocene Warm Period}},
url = {https://doi.org/10.1038/s41598-020-68884-5 http://www.nature.com/articles/s41598-020-68884-5},
volume = {10},
year = {2020}
}
@article{Pottapinjara2019a,
abstract = {AbstractPrevious studies have talked about the existence of a relation between the Atlantic meridional mode (AMM) and Atlantic zonal mode (AZM) via the meridional displacement of the intertropical convergence zone (ITCZ) in the Atlantic during boreal spring and the resulting cross-equatorial zonal winds. However, why the strong relation between the ITCZ (or AMM) and zonal winds does not translate into a strong relation between the ITCZ and AZM has not been explained. This question is addressed here, and it is found that there is a skewness in the relation between ITCZ and AZM: while a northward migration of ITCZ during spring in general leads to a cold AZM event in the ensuing summer, the southward migration of the ITCZ is less likely to lead to a warm event. This is contrary to what the previous studies imply. The skewness is attributed to the Atlantic seasonal cycle and to the strong seasonality of the AZM. All those cold AZM events preceded by a northward ITCZ movement during spring are found to strictly adhere to typical timings and evolution of the different Bjerknes feedback components involved. It is also observed that the causative mechanisms of warm events are more diverse than those of the cold events. These results can be expected to enhance our understanding of the AZM as well as that of chronic model biases and contribute to the predictability of the Indian summer monsoon through the links between the two as shown in our earlier studies.},
annote = {doi: 10.1175/JCLI-D-18-0614.1},
author = {Pottapinjara, Vijay and Girishkumar, M S and Murtugudde, R and Ashok, K and Ravichandran, M},
doi = {10.1175/JCLI-D-18-0614.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {may},
number = {15},
pages = {4767--4781},
publisher = {American Meteorological Society},
title = {{On the Relation between the Boreal Spring Position of the Atlantic Intertropical Convergence Zone and Atlantic Zonal Mode}},
url = {https://doi.org/10.1175/JCLI-D-18-0614.1},
volume = {32},
year = {2019}
}
@article{doi:10.1175/2011JCLI4101.1,
abstract = {AbstractThe Walker circulation (WC) is one of the world's most prominent and important atmospheric systems. The WC weakened during the twentieth century, reaching record low levels in recent decades. This weakening is thought to be partly due to global warming and partly due to internally generated natural variability. There is, however, no consensus in the literature on the relative contribution of external forcing and natural variability to the observed weakening of the WC. This paper examines changes in the strength of the WC using an index called Box$\Delta$P, which is equal to the difference in mean sea level pressure across the equatorial Pacific. Change in both the observations and in World Climate Research Programme (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) climate models are examined. The annual average Box$\Delta$P declines in the observations and in 15 out of 23 models during the twentieth century (results that are significant at or above the 95{\%} level), consistent with earlier work. However, the magnitude of the multimodel ensemble mean (MMEM) 1901–99 trend (−0.10 Pa yr−1) is much smaller than the magnitude of the observed trend (−0.52 Pa yr−1). While a wide range of trends is evident in the models with approximately 90{\%} of the model trends in the range (−0.25 to +0.1 Pa yr−1), even this range is too narrow to encompass the magnitude of the observed trend. Twenty-first-century changes in Box$\Delta$P under the Special Report on Emissions Scenarios (SRES) A1B and A2 are also examined. Negative trends (i.e., weaker WCs) are evident in all seasons. However, the MMEM trends for the A1B and A2 scenarios are smaller in magnitude than the magnitude of the observed trend. Given that external forcing linked to greenhouse gases is much larger in the twenty-first-century scenarios than twentieth-century forcing, this, together with the twentieth-century results mentioned above, would seem to suggest that external forcing has not been the primary driver of the observed weakening of the WC. However, 9 of the 23 models are unable to account for the observed change unless the internally generated component of the trend is very large. But indicators of observed variability linked to El Ni{\~{n}}o–Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation have modest trends, suggesting that internally variability has been modest. Furthermore, many of the nine “inconsistent” models tend to have poorer simulations of climatic features linked to ENSO. In addition, the externally forced component of the trend tends to be larger in magnitude and more closely matches the observed trend in the models that are better able to reproduce ENSO-related variability. The “best” four models, for example, have a MMEM of −0.2 Pa yr−1 (i.e., approximately 40{\%} of the observed change), suggesting a greater role for external forcing in driving the observed trend. These and other considerations outlined below lead the authors to conclude that (i) both external forcing and internally generated variability contributed to the observed weakening of the WC over the twentieth century and (ii) external forcing accounts for approximately 30{\%}–70{\%} of the observed weakening with internally generated climate variability making up the rest.},
author = {Power, Scott B and Kociuba, Greg},
doi = {10.1175/2011JCLI4101.1},
journal = {Journal of Climate},
number = {24},
pages = {6501--6514},
title = {{What Caused the Observed Twentieth-Century Weakening of the Walker Circulation?}},
url = {https://doi.org/10.1175/2011JCLI4101.1},
volume = {24},
year = {2011}
}
@article{Prakash2018,
abstract = {Accurate estimates of long-term land surface temperature (Ts) and near-surface air temperature (Ta) at finer spatio-temporal resolutions are crucial for surface energy budget studies, for environmental applications, for land surface model data assimilation, and for climate change assessment and its associated impacts. The Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard the Aqua satellite provide a unique opportunity to estimate both temperatures twice daily at the global scale. In this study, differences between Ta and Ts were assessed locally over regions of North America from 2009 to 2013 using ground-based observations covering a wide range of geographical, topographical, and land cover types. The differences between Ta and Ts during non-precipitating conditions are generally 2--3 times larger than precipitating conditions. However, these differences show noticeable diurnal and seasonal variations. The differences between Ta and Ts were also investigated at the global scale using the AIRS estimates under clear-sky conditions for the period 2003--2015. The tropical regions showed about 5--20 {\{}$\backslash$textdegree{\}}C warmer Ts than Ta during the day-time, whereas opposite characteristics (about 2--5 {\{}$\backslash$textdegree{\}}C cooler Ts than Ta) are found over most parts of the globe during the night-time. Additionally, Ts estimates from the AIRS and the MODIS sensors were inter-compared. Although large-scale features of Ts were essentially similar for both sensors, considerable differences in magnitudes were observed ({\textgreater}{\{}$\backslash$thinspace{\}}6 {\{}$\backslash$textdegree{\}}C over mountainous regions). Finally, Ta and Ts estimates from the AIRS and MODIS sensors were validated against ground-based observations for the period of 2009--2013. The error characteristics notably varied with ground stations and no clear evidence of their dependency on land cover types or elevation was detected. However, the MODIS-derived Ts estimates generally showed larger biases and higher errors compared to the AIRS-derived estimates. The biases and errors increased steadily when the spatial resolution of the MODIS estimates changed from finer to coarser. These results suggest that representativeness error should be properly accounted for when validating satellite-based temperature estimates with point observations.},
author = {Prakash, Satya and Shati, Farjana and Norouzi, Hamid and Blake, Reginald},
doi = {10.1007/s00704-018-2623-1},
issn = {1434-4483},
journal = {Theoretical and Applied Climatology},
month = {sep},
number = {1-2},
pages = {587--600},
title = {{Observed differences between near-surface air and skin temperatures using satellite and ground-based data}},
url = {https://doi.org/10.1007/s00704-018-2623-1},
volume = {137},
year = {2018}
}
@article{Prentice2000a,
abstract = {BIOME 6000 is an international project to map vegetation globally at mid-Holocene (6000 14 C yr bp) and last glacial maximum (LGM, 18,000 14 C yr bp), with a view to evaluating coupled climate-biosphere model results. Primary palaeoecological data are assigned to biomes using an explicit algorithm based on plant functional types. This paper introduces the second Special Feature on BIOME 6000. Site-based global biome maps are shown with data from North America, Eurasia (except South and Southeast Asia) and Africa at both time periods. A map based on surface samples shows the method's skill in reconstructing present-day biomes. Cold and dry conditions at LGM favoured extensive tundra and steppe. These biomes intergraded in northern Eurasia. Northern hemisphere forest biomes were displaced south- ward. Boreal evergreen forests (taiga) and temperate deciduous forests were fragmented, while European and East Asian steppes were greatly extended. Tropical moist forests (i.e. tropical rain forest and tropical seasonal forest) in Africa were reduced. In south-western North America, desert and steppe were replaced by open conifer woodland, opposite to the general arid trend but consistent with modelled southward displacement of the jet stream. The Arctic forest limit was shifted slighly north at 6000 14 C yr bp in some sectors, but not in all. Northern temperate forest zones were generally shifted greater distances north. Warmer winters as well as summers in several regions are required to explain these shifts. Temperate deciduous forests in Europe were greatly extended, into the Mediterranean region as well as to the north. Steppe encroached on forest biomes in interior North America, but not in central Asia. Enhanced monsoons extended forest biomes in China inland and Sahelian vegetation into the Sahara while the African tropical rain forest was also reduced, consistent with a modelled northward shift of the ITCZ and a more seasonal climate in the equatorial zone. Palaeobiome maps show the outcome of separate, independent migrations of plant taxa in response to climate change. The average composition of biomes at LGM was often markedly different from today. Refugia for the temperate deciduous and tropical rain forest biomes may have existed offshore at LGM, but their characteristic taxa also persisted as components of other biomes. Examples include temperate deciduous trees that survived in cool mixed forest in eastern Europe, and tropical evergreen trees that survived in tropical seasonal forest in Africa. The sequence of biome shifts dur- ing a glacial-interglacial cycle may help account for some disjunct distributions of plant taxa. For example, the now-arid Saharan mountains may have linked Mediterranean and African tropical montane floras during enhanced monsoon regimes. Major changes in physical land-surface conditions, shown by the palaeobiome data, have implications for the global climate. The data can be used directly to evaluate the output of coupled atmosphere-biosphere models. The data could also be objectively generalized to yield realistic gridded land-surface maps, for use in sensitivity experiments with atmospheric models. Recent analyses of vegetation-climate feedbacks have focused on the hypothesized positive feedback effects of climate-induced vegetation changes in the Sahara/Sahel region and the Arctic during the mid-Holocene. However, a far wider spectrum of interactions potentially exists and could be investigated, using these data, both for 6000 14 C yr bp and for the LGM.},
author = {Prentice, I. Colin and Jolly, Dominique and Afanas'eva, N. B. and Ager, T. A. and Anderson, K. and Anderson, P. M. and Andrieu, V. and Andreev, A. A. and Ballouche, A. and Bartlein, P. J. and de Beaulieu, J. L. and Bengo, M. and Berezina, N. A. and Bezusko, L. G. and Bezusko, T. V. and Bigelow, N. H. and Blyakharchuk, T. A. and Bolikhovskaya, N. S. and Bonnefille, R. and Bottema, S. and Br{\'{e}}nac, P. and Brubaker, L. B. and Buchet, G. and Burney, D. and Bykova, G. V. and Cheddadi, R. and Chen, X. and Chernavskaya, M. M. and Chernova, G. M. and Cwynar, L. C. and Dorofeyuk, N. I. and Dirksen, V. G. and Edorh, T. and Edwards, M. E. and Eisner, W. R. and Elenga, H. and Elina, G. A. and Elmoutaki, S. and Filimonova, L. V. and Glebov, F. Z. and Guiot, J. and Gunova, V. S. and Hamilton, A. C. and Han, H. and Harrison, S. P. and Hu, F. S. and Huang, C. and Huntley, B. and Jolly, D. and Jonson, H. and Ke, M. and Khomutova, V. I. and Kong, Z. and Kvavadze, E. V. and Laarif, F. and Lamb, H. E. and L{\'{e}}zine, A. M. and Li, S. and Li, W. and Liew, P. and Liu, G. and Liu, J. and Liu, Q. and Liu, K. B. and Lozhkin, A. V. and Maley, J. and Marchant, R. and Mbenza, M. and MacDonald, G. M. and Miyoshi, N. and Mock, C. J. and Morita, Y. and Newby, P. and Ni, J. and Osipova, I. R. and Panova, N. K. and Perez-Obiol, R. and Peyron, O. and Prentice, I. C. and Qiu, W. and Reille, M. and Ren, G. and Reynaud-Farrera, I. and Richard, P. J.H. and Riollet, G. and Ritchie, J. C. and Roche, E. and Saarse, L. and Scott, L. and Sevastyanov, D. V. and Sher, A. V. and Song, C. and Spear, R. W. and Ssemmanda, I. and Straka, H. and Sugita, S. and Sun, X. and Takahara, H. and Tang, L. and Tarasov, P. E. and Taylor, D. and Thompson, R. S. and Uchiyama, T. and {Van Campo}, E. and Vilimumbalo, S. and Vincens, A. and Volkova, V. S. and Waller, M. and Webb, T. and Williams, J. W. and Xia, Y. and Xu, Q. and Yan, S. and Yang, X. and Yu, G. and Zernitskaya, V. P. and Zhao, J. and Zheng, Z.},
doi = {10.1046/j.1365-2699.2000.00425.x},
issn = {03050270},
journal = {Journal of Biogeography},
keywords = {Biogeography,Biomes,Climate change,Land-surface characteristics,Last glacial maximum,Mid-Holocene,Plant functional data,Plant functional types,Pollen data,Vegetation changes,Vegetation distribution},
number = {3},
pages = {507--519},
title = {{Mid-Holocene and glacial-maximum vegetation geography of the northern continents and Africa}},
volume = {27},
year = {2000}
}
@article{Prigent2020,
abstract = {A prominent weakening in equatorial Atlantic sea surface temperature (SST) variability, occurring around the year 2000, is investigated by means of observations, reanalysis products and the linear recharge oscillator (ReOsc) model. Compared to the time period 1982–1999, during 2000–2017 the May–June–July SST variability in the eastern equatorial Atlantic has decreased by more than 30{\%}. Coupled air–sea feedbacks, namely the positive Bjerknes feedback and the negative net heat flux damping are important drivers for the equatorial Atlantic interannual SST variability. We find that the Bjerknes feedback weakened after 2000 while the net heat flux damping increased. The weakening of the Bjerknes feedback does not appear to be fully explainable by changes in the mean state of the tropical Atlantic. The increased net heat flux damping is related to an enhanced response of the latent heat flux to the SST anomalies (SSTa). Strengthened trade winds as well as warmer SSTs are suggested to increase the air–sea specific humidity difference and hence, enhancing the latent heat flux response to SSTa. A combined effect of those two processes is proposed to be responsible for the weakened SST variability in the eastern equatorial Atlantic. The ReOsc model supports the link between reduced SST variability, weaker Bjerknes feedback and stronger net heat flux damping.},
author = {Prigent, Arthur and L{\"{u}}bbecke, Joke F and Bayr, Tobias and Latif, Mojib and Wengel, Christian},
doi = {10.1007/s00382-020-05138-0},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {5},
pages = {2731--2744},
title = {{Weakened SST variability in the tropical Atlantic Ocean since 2000}},
url = {https://doi.org/10.1007/s00382-020-05138-0},
volume = {54},
year = {2020}
}
@article{https://doi.org/10.1029/2020GL089348,
abstract = {Abstract Observations and reanalysis products are used to investigate the substantial weakening in the southeastern tropical Atlantic sea surface temperature (SST) variability since 2000. Relative to 1982–1999, the March-April-May SST variability in the Angola-Benguela area (ABA) has decreased by more than 30{\%}. Both equatorial remote forcing and local forcing are known to play an important role in driving SST variability in the ABA. Compared to 1982–1999, since 2000, equatorial remote forcing had less influence on ABA SSTs, whereas local forcing has become more important. In particular, the robust correlation that existed between the equatorial zonal wind stress and the ABA SSTs has substantially weakened, suggesting less influence of Kelvin waves on ABA SSTs. Moreover, the strong correlation linking the South Atlantic Anticyclone and the ABA SSTs has reduced. Finally, multidecadal surface warming of the ABA could also have played a role in the weakening of the interannual SST variability.},
annote = {e2020GL089348 2020GL089348},
author = {Prigent, Arthur and {Imbol Koungue}, Rodrigue Anicet and L{\"{u}}bbecke, Joke F and Brandt, Peter and Latif, Mojib},
doi = {10.1029/2020GL089348},
journal = {Geophysical Research Letters},
keywords = {Benguela upwelling system,interannual SST variability,local atmospheric forcing,multidecadal surface warming,remote equatorial forcing,stratification},
number = {20},
pages = {e2020GL089348},
title = {{Origin of Weakened Interannual Sea Surface Temperature Variability in the Southeastern Tropical Atlantic Ocean}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL089348},
volume = {47},
year = {2020}
}
@article{Prytherch2015,
author = {Prytherch, John and Kent, Elizabeth C and Fangohr, Susanne and Berry, David I},
doi = {10.1002/joc.4150},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {accepted 9 august 2014,air,i,marine climatology,received 14 may 2013,revised 22 july 2014,satellite observations,sea interaction,specific humidity,ssm,surface humidity},
month = {jul},
number = {9},
pages = {2359--2381},
title = {{A comparison of SSM/I-derived global marine surface-specific humidity datasets}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.4150},
volume = {35},
year = {2015}
}
@article{Pulliainen2020,
author = {Pulliainen, Jouni and Luojus, Kari and Derksen, Chris and Mudryk, Lawrence and Lemmetyinen, Juha and Salminen, Miia and Ikonen, Jaakko and Takala, Matias and Cohen, Juval and Smolander, Tuomo and Norberg, Johannes},
doi = {10.1038/s41586-020-2258-0},
issn = {0028-0836},
journal = {Nature},
month = {may},
number = {7808},
pages = {294--298},
title = {{Patterns and trends of Northern Hemisphere snow mass from 1980 to 2018}},
url = {http://www.nature.com/articles/s41586-020-2258-0},
volume = {581},
year = {2020}
}
@article{Punyu2014a,
abstract = {The top 1m radiocarbon dated section of a 5.6m long sediment core retrieved from the Equatorial Indian Ocean is studied for productivity changes in response to climate variability that have taken place during the last {\~{}}33kyr. The robust indicators of marine productivity such as phytol and brassicasterol exhibit distinctly higher contents (av. 5.8ng/g and 4.8ng/g respectively) during the LGM (25–17kyBP) as compared to the succeeding period (16–5kyBP: av. 1.9ng/g each) and preceding period (33–25kyBP: av. 1.8 and 0.8ng/g respectively) which suggest increased productivity during the cold and dry climate of the LGM. The Corg content is also relatively higher during this period than the warmer Holocene. However, marginally higher C/N ratios ({\~{}}7.8) and enrichment of $\delta$13Corg ({\~{}}−19.8‰) during the LGM than the Holocene (C/N {\~{}}6.4 and $\delta$13Corg{\~{}}−21.5‰), and also the higher carbon preference index (CPI) of n-alkanes and n-alkanols together suggest the presence of terrestrial organic matter in the sediment. The increased equatorial productivity and terrestrial organic matter input together during the LGM may indicate intensified inter-monsoon equatorial Westerly Jets resulting in elevated productivity.},
author = {Punyu, Vikesano R and Banakar, Virupaxa K and Garg, Anita},
doi = {10.1016/j.margeo.2013.11.010},
issn = {0025-3227},
journal = {Marine Geology},
keywords = {Equatorial Indian Ocean,Last Glacial Maximum,Westerly Jets,biomarkers,palaeoproductivity},
pages = {44--51},
title = {{Equatorial Indian Ocean productivity during the last 33kyr and possible linkage to Westerly Jet variability}},
url = {http://www.sciencedirect.com/science/article/pii/S0025322713002508},
volume = {348},
year = {2014}
}
@article{doi:10.1175/2010JCLI3682.1,
abstract = { Abstract Abyssal global and deep Southern Ocean temperature trends are quantified between the 1990s and 2000s to assess the role of recent warming of these regions in global heat and sea level budgets. The authors 1) compute warming rates with uncertainties along 28 full-depth, high-quality hydrographic sections that have been occupied two or more times between 1980 and 2010; 2) divide the global ocean into 32 basins, defined by the topography and climatological ocean bottom temperatures; and then 3) estimate temperature trends in the 24 sampled basins. The three southernmost basins show a strong statistically significant abyssal warming trend, with that warming signal weakening to the north in the central Pacific, western Atlantic, and eastern Indian Oceans. Eastern Atlantic and western Indian Ocean basins show statistically insignificant abyssal cooling trends. Excepting the Arctic Ocean and Nordic seas, the rate of abyssal (below 4000 m) global ocean heat content change in the 1990s and 2000s is equivalent to a heat flux of 0.027 (±0.009) W m−2 applied over the entire surface of the earth. Deep (1000–4000 m) warming south of the Subantarctic Front of the Antarctic Circumpolar Current adds 0.068 (±0.062) W m−2. The abyssal warming produces a 0.053 (±0.017) mm yr−1 increase in global average sea level and the deep warming south of the Subantarctic Front adds another 0.093 (±0.081) mm yr−1. Thus, warming in these regions, ventilated primarily by Antarctic Bottom Water, accounts for a statistically significant fraction of the present global energy and sea level budgets. },
author = {Purkey, Sarah G and Johnson, Gregory C},
doi = {10.1175/2010JCLI3682.1},
journal = {Journal of Climate},
number = {23},
pages = {6336--6351},
title = {{Warming of Global Abyssal and Deep Southern Ocean Waters between the 1990s and 2000s: Contributions to Global Heat and Sea Level Rise Budgets}},
url = {https://doi.org/10.1175/2010JCLI3682.1},
volume = {23},
year = {2010}
}
@article{Putnam2017a,
author = {Putnam, Aaron E and Broecker, Wallace S},
doi = {10.1126/sciadv.1600871},
issn = {2375-2548},
journal = {Science Advances},
month = {may},
number = {5},
pages = {e1600871},
title = {{Human-induced changes in the distribution of rainfall}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.1600871},
volume = {3},
year = {2017}
}
@article{Qi2017b,
abstract = {The uptake of anthropogenic CO2 by the ocean decreases seawater pH and carbonate mineral aragonite saturation state ($\Omega$arag), a process known as Ocean Acidification (OA). This can be detrimental to marine organisms and ecosystems. The Arctic Ocean is particularly sensitive to climate change and aragonite is expected to become undersaturated ($\Omega$arag {\textless} 1) there sooner than in other oceans. However, the extent and expansion rate of OA in this region are still unknown. Here we show that, between the 1990s and 2010, low $\Omega$arag waters have expanded northwards at least 5°, to 85° N, and deepened 100 m, to 250 m depth. Data from trans-western Arctic Ocean cruises show that $\Omega$arag {\textless} 1 water has increased in the upper 250 m from 5{\%} to 31{\%} of the total area north of 70° N. Tracer data and model simulations suggest that increased Pacific Winter Water transport, driven by an anomalous circulation pattern and sea-ice retreat, is primarily responsible for the expansion, although local carbon recycling and anthropogenic CO2 uptake have also contributed. These results indicate more rapid acidification is occurring in the Arctic Ocean than the Pacific and Atlantic oceans, with the western Arctic Ocean the first open-ocean region with large-scale expansion of acidified' water directly observed in the upper water column.},
author = {Qi, Di and Chen, Liqi and Chen, Baoshan and Gao, Zhongyong and Zhong, Wenli and Feely, Richard A. and Anderson, Leif G. and Sun, Heng and Chen, Jianfang and Chen, Min and Zhan, Liyang and Zhang, Yuanhui and Cai, Wei-Jun},
doi = {10.1038/nclimate3228},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {mar},
number = {3},
pages = {195--199},
title = {{Increase in acidifying water in the western Arctic Ocean}},
url = {http://www.nature.com/articles/nclimate3228},
volume = {7},
year = {2017}
}
@article{Quade2017,
author = {Quade, J and Kaplan, M R},
doi = {10.1016/j.quascirev.2017.10.006},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {173--188},
publisher = {Elsevier Ltd},
title = {{Lake-level stratigraphy and geochronology revisited at Lago (Lake) Cardiel, Argentina, and changes in the Southern Hemispheric Westerlies over the last 25 ka}},
url = {https://doi.org/10.1016/j.quascirev.2017.10.006},
volume = {177},
year = {2017}
}
@article{Quade2018,
abstract = {The Sahara was wetter and greener during multiple interglacial periods of the Quaternary, when some have suggested it featured very large (mega) lakes, ranging in surface area from 30,000 to 350,000 km 2 . In this paper, we review the physical and biological evidence for these large lakes, especially during the African Humid Period (AHP) 11–5 ka. Megalake systems from around the world provide a checklist of diagnostic features, such as multiple well-defined shoreline benches, wave-rounded beach gravels where coarse material is present, landscape smoothing by lacustrine sediment, large-scale deltaic deposits, and in places, tufas encrusting shorelines. Our survey reveals no clear evidence of these features in the Sahara, except in the Chad basin. Hydrologic modeling of the proposed megalakes requires mean annual rainfall ≥1.2 m/yr and a northward displacement of tropical rainfall belts by ≥1000 km. Such a profound displacement is not supported by other paleo-climate proxies and comprehensive climate models, challenging the existence of megalakes in the Sahara. Rather than megalakes, isolated wetlands and small lakes are more consistent with the Sahelo-Sudanian paleoenvironment that prevailed in the Sahara during the AHP. A pale-green and discontinuously wet Sahara is the likelier context for human migrations out of Africa during the late Quaternary.},
author = {Quade, Jay and Dente, Elad and Armon, Moshe and {Ben Dor}, Y. and Morin, Efrat and Adam, Ori and Enzel, Yehouda},
doi = {10.1017/qua.2018.46},
issn = {0033-5894},
journal = {Quaternary Research},
keywords = {lake chad,lake victoria,megalakes,paleohydrology,paleolakes,paleowetlands,sahara},
month = {sep},
number = {2},
pages = {253--275},
title = {{Megalakes in the Sahara? A Review}},
url = {https://www.cambridge.org/core/product/identifier/S0033589418000467/type/journal{\_}article},
volume = {90},
year = {2018}
}
@article{Queste2018,
abstract = {Abstract At suboxic oxygen concentrations, key biogeochemical cycles change and denitrification becomes the dominant remineralization pathway. Earth system models predict oxygen loss across most ocean basins in the next century; oxygen minimum zones near suboxia may become suboxic and therefore denitrifying. Using an ocean glider survey and historical data, we show oxygen loss in the Gulf of Oman (from 6?12 to {\textless}2 ?mol kg?1) not represented in climatologies. Because of the nonlinearity between denitrification and oxygen concentration, resolutions of current Earth system models are too coarse to accurately estimate denitrification. We develop a novel physical proxy for oxygen from the glider data and use a high-resolution physical model to show eddy stirring of oxygen across the Gulf of Oman. We use the model to investigate spatial and seasonal differences in the ratio of oxic and suboxic water across the Gulf of Oman and waters exported to the wider Arabian Sea.},
annote = {doi: 10.1029/2017GL076666},
author = {Queste, Bastien Y and Vic, Cl{\'{e}}ment and Heywood, Karen J and Piontkovski, Sergey A},
doi = {10.1029/2017GL076666},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Arabian sea,Oman,denitrifcation,deoxygenation,eddies,glider},
month = {may},
number = {9},
pages = {4143--4152},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Physical Controls on Oxygen Distribution and Denitrification Potential in the North West Arabian Sea}},
url = {https://doi.org/10.1029/2017GL076666},
volume = {45},
year = {2018}
}
@article{cp-12-1889-2016,
author = {R{\"{a}}s{\"{a}}nen, T A and Lindgren, V and Guillaume, J H A and Buckley, B M and Kummu, M},
doi = {10.5194/cp-12-1889-2016},
journal = {Climate of the Past},
number = {9},
pages = {1889--1905},
title = {{On the spatial and temporal variability of ENSO precipitation and drought teleconnection in mainland Southeast Asia}},
url = {https://cp.copernicus.org/articles/12/1889/2016/},
volume = {12},
year = {2016}
}
@article{Rosel2018a,
author = {R{\"{o}}sel, Anja and Itkin, Polona and King, Jennifer and Divine, Dmitry and Wang, Caixin and Granskog, Mats A. and Krumpen, Thomas and Gerland, Sebastian},
doi = {10.1002/2017JC012865},
isbn = {2169-9291},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
number = {2},
pages = {1156--1176},
pmid = {26213675},
title = {{Thin Sea Ice, Thick Snow, and Widespread Negative Freeboard Observed During N-ICE2015 North of Svalbard}},
volume = {123},
year = {2018}
}
@article{Røthe2019,
abstract = {New time series of long-term hydroclimate variability in the Arctic are urgently needed in order to better understand the response patterns to external forcing and changes in boundary conditions for global climate models. Here, we present a high-resolution record of mass-wasting events based on analyses of sediments deposited in Lake Svartvatnet. Based on novel methods such as x-ray computed tomography (CT), the volume of inorganic layers in Svartvatnet is calculated and allows us to investigate the frequency of mass-wasting events during the last 9000 years in Arctic Norway. The results show an increasing activity over the late Holocene with three main phases of an increased number of mass-wasting events at 6700–5200, 4500–2800 and 1700–500 cal. yr BP. We infer that the frequency of mass-wasting events is driven by wintertime precipitation with possible links to variations in North Atlantic Oscillation (NAO) index and changes in the zonal flow regime affecting the transport of moist air masses by the westerlies over Arctic Norway. Thus, we suggest that positive NAO conditions dominated in periods with high mass-wasting activity in the mid-Holocene and late Holocene and were separated by quiescent periods at 5200–4200 and 2700–1800 cal. yr BP that represent less dominant westerlies over Arctic Norway.},
author = {R{\o}the, Torgeir O and Bakke, Jostein and St{\o}ren, Eivind WN and Dahl, Svein O},
doi = {10.1177/0959683619846983},
issn = {0959-6836},
journal = {The Holocene},
month = {aug},
number = {8},
pages = {1305--1321},
title = {{Wintertime extreme events recorded by lake sediments in Arctic Norway}},
url = {http://journals.sagepub.com/doi/10.1177/0959683619846983},
volume = {29},
year = {2019}
}
@article{Racault2017a,
abstract = {Oceanic phytoplankton respond rapidly to a complex spectrum of climate-driven perturbations, confounding attempts to isolate the principal causes of observed changes. A dominant mode of variability in the Earth-climate system is that generated by the El Ni{\~{n}}o phenomenon. Marked variations are observed in the centroid of anomalous warming in the Equatorial Pacific under El Ni{\~{n}}o, associated with quite different alterations in environmental and biological properties. Here, using observational and reanalysis datasets, we differentiate the regional physical forcing mechanisms, and compile a global atlas of associated impacts on oceanic phytoplankton caused by two extreme types of El Ni{\~{n}}o. We find robust evidence that during Eastern Pacific (EP) and Central Pacific (CP) types of El Ni{\~{n}}o, impacts on phytoplankton can be felt everywhere, but tend to be greatest in the tropics and subtropics, encompassing up to 67{\%} of the total affected areas, with the remaining 33{\%} being areas located in high-latitudes. Our analysis also highlights considerable and sometimes opposing regional effects. During EP El Ni{\~{n}}o, we estimate decreases of −56 TgC/y in the tropical eastern Pacific Ocean, and −82 TgC/y in the western Indian Ocean, and increase of +13 TgC/y in eastern Indian Ocean, whereas during CP El Ni{\~{n}}o, we estimate decreases −68 TgC/y in the tropical western Pacific Ocean and −10 TgC/y in the central Atlantic Ocean. We advocate that analysis of the dominant mechanisms forcing the biophysical under El Ni{\~{n}}o variability may provide a useful guide to improve our understanding of projected changes in the marine ecosystem in a warming climate and support development of adaptation and mitigation plans.},
author = {Racault, Marie-Fanny and Sathyendranath, Shubha and Brewin, Robert J W and Raitsos, Dionysios E and Jackson, Thomas and Platt, Trevor},
doi = {10.3389/fmars.2017.00133},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {may},
pages = {133},
title = {{Impact of El Ni{\~{n}}o Variability on Oceanic Phytoplankton}},
url = {http://journal.frontiersin.org/article/10.3389/fmars.2017.00133/full},
volume = {4},
year = {2017}
}
@article{Racault2012,
abstract = {In recent years, phytoplankton phenology has been proposed as an indicator to monitor systematically the state of the pelagic ecosystem and to detect changes triggered by perturbation of the environmental conditions. Here we describe the phenology of phytoplankton growth for the world ocean using remote-sensing ocean colour data, and analyse its variability between 1998 and 2007. Generally, the tropics and subtropics present long growing period (≈15–20 weeks) of low amplitude ({\textless}0.5mgChlm−3), whereas the high-latitudes show short growing period ({\textless}10weeks) of high amplitude (up to 7mgChlm−3). Statistical analyses suggest a close coupling between the development of the growing period and the seasonal increase in insolation in the North Atlantic and Southern Ocean. In the tropics and subtropics, variability in light is low, and the growing period is controlled by nutrient supply occurring when mixing increases. Large interannual variability in the duration of the growing period is observed over the decade 1998–2007, with positive anomalies following the major 1997–1998 El Ni{\~{n}}o-La Ni{\~{n}}a events, and generally negative anomalies from 2003 to 2007. Warmer Sea-Surface Temperature (SST) over the duration of the growing period is associated with longer duration at high-latitudes indicating an extension of the growing period over summer months. The opposite is observed in the tropics and subtropics, where the duration is shorter when the SST is warmer, indicating increased stratification. Positive phases of North Atlantic Oscillation and Southern Annular Mode and negative phases of Multivariate El Ni{\~{n}}o-Southern Oscillation index (El Ni{\~{n}}o conditions), associated with enhanced water mixing and nutrients supply, generally sustain longer growth. On the basis of the results, perspectives are drawn on the utility of phenology as an organising principle for the analysis of pelagic ecosystem.},
author = {Racault, Marie-Fanny and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Buitenhuis, Erik and Sathyendranath, Shubha and Platt, Trevor},
doi = {10.1016/j.ecolind.2011.07.010},
issn = {1470-160X},
journal = {Ecological Indicators},
keywords = {Climate forcing,Ecological indicator,Interannual variability,Phytoplankton phenology,Remote sensing},
number = {1},
pages = {152--163},
title = {{Phytoplankton phenology in the global ocean}},
url = {http://www.sciencedirect.com/science/article/pii/S1470160X11002160},
volume = {14},
year = {2012}
}
@article{Racault2017,
abstract = {Phenology relates to the study of timing of periodic events in the life cycle of plants or animals as influenced by environmental conditions and climatic forcing. Phenological metrics provide information essential to quantify variations in the life cycle of these organisms. The metrics also allow us to estimate the speed at which living organisms respond to environmental changes. At the surface of the oceans, microscopic plant cells, so-called phytoplankton, grow and sometimes form blooms, with concentrations reaching up to 100 million cells per litre and extending over many square kilometres. These blooms can have a huge collective impact on ocean colour, because they contain chlorophyll and other auxiliary pigments, making them visible from space. Phytoplankton populations have a high turnover rate and can respond within hours to days to environmental perturbations. This makes them ideal indicators to study the first-level biological response to environmental changes. In the Earth's climate system, the El Ni{\~{n}}o–Southern Oscillation (ENSO) dominates large-scale inter-annual variations in environmental conditions. It serves as a natural experiment to study and understand how phytoplankton in the ocean (and hence the organisms at higher trophic levels) respond to climate variability. Here, the ENSO influence on phytoplankton is estimated through variations in chlorophyll concentration, primary production and timings of initiation, peak, termination and duration of the growing period. The phenological variabilities are used to characterise phytoplankton responses to changes in some physical variables: sea surface temperature, sea surface height and wind. It is reported that in oceanic regions experiencing high annual variations in the solar cycle, such as in high latitudes, the influence of ENSO may be readily measured using annual mean anomalies of physical variables. In contrast, in oceanic regions where ENSO modulates a climate system characterised by a seasonal reversal of the wind forcing, such as the monsoon system in the Indian Ocean, phenology-based mean anomalies of physical variables help refine evaluation of the mechanisms driving the biological responses and provide a more comprehensive understanding of the integrated processes.},
author = {Racault, M.-F. and Sathyendranath, S and Menon, N and Platt, T},
doi = {10.1007/s10712-016-9391-1},
issn = {1573-0956},
journal = {Surveys in Geophysics},
number = {1},
pages = {277--293},
title = {{Phenological Responses to ENSO in the Global Oceans (2017a)}},
url = {https://doi.org/10.1007/s10712-016-9391-1},
volume = {38},
year = {2017}
}
@article{Radeloff2015a,
abstract = {Rapid and ongoing change creates novelty in ecosystems everywhere, both when comparing contemporary systems to their historical baselines, and predicted future systems to the present. However, the level of novelty varies greatly among places. Here we propose a formal and quantifiable definition of abiotic and biotic novelty in ecosystems, map abiotic novelty globally, and discuss the implications of novelty for the science of ecology and for biodiversity conservation. We define novelty as the degree of dissimilarity of a system, measured in one or more dimensions relative to a reference baseline, usually defined as either the present or a time window in the past. In this conceptualization, novelty varies in degree, it is multidimensional, can be measured, and requires a temporal and spatial reference. This definition moves beyond prior categorical definitions of novel ecosystems, and does not include human agency, self-perpetuation, or irreversibility as criteria. Our global assessment of novelty was based on abiotic factors (temperature, precipitation, and nitrogen deposition) plus human population, and shows that there are already large areas with high novelty today relative to the early 20th century, and that there will even be more such areas by 2050. Interestingly, the places that are most novel are often not the places where absolute changes are largest; highlighting that novelty is inherently different from change. For the ecological sciences, highly novel ecosystems present new opportunities to test ecological theories, but also challenge the predictive ability of ecological models and their validation. For biodiversity conservation, increasing novelty presents some opportunities, but largely challenges. Conservation action is necessary along the entire continuum of novelty, by redoubling efforts to protect areas where novelty is low, identifying conservation opportunities where novelty is high, developing flexible yet strong regulations and policies, and establishing long-term experiments to test management approaches. Meeting the challenge of novelty will require advances in the science of ecology, and new and creative. conservation approaches.},
author = {Radeloff, Volker C. and Williams, John W. and Bateman, Brooke L. and Burke, Kevin D. and Carter, Sarah K. and Childress, Evan S. and Cromwell, Kara J. and Gratton, Claudio and Hasley, Andrew O. and Kraemer, Benjamin M. and Latzka, Alexander W. and Marin-Spiotta, Erika and Meine, Curt D. and Munoz, Samuel E. and Neeson, Thomas M. and Pidgeon, Anna M. and Rissman, Adena R. and Rivera, Ricardo J. and Szymanski, Laura M. and Usinowicz, Jacob},
doi = {10.1890/14-1781.1},
isbn = {6082634349},
issn = {19395582},
journal = {Ecological Applications},
keywords = {Anthropocene,Biodiversity,Centennial Paper,Conservation,Global change,No-analog,Novel climates,Novel ecosystems,Novelty},
number = {8},
pages = {2051--2068},
pmid = {26910939},
title = {{The rise of novelty in ecosystems}},
volume = {25},
year = {2015}
}
@article{Rae2018a,
abstract = {The cause of changes in atmospheric carbon dioxide (CO2) during the recent ice ages is yet to be fully explained. Most mechanisms for glacial–interglacial CO2 change have centred on carbon exchange with the deep ocean, owing to its large size and relatively rapid exchange with the atmosphere1. The Southern Ocean is thought to have a key role in this exchange, as much of the deep ocean is ventilated to the atmosphere in this region2. However, it is difficult to reconstruct changes in deep Southern Ocean carbon storage, so few direct tests of this hypothesis have been carried out. Here we present deep-sea coral boron isotope data that track the pH—and thus the CO2 chemistry—of the deep Southern Ocean over the past forty thousand years. At sites closest to the Antarctic continental margin, and most influenced by the deep southern waters that form the ocean's lower overturning cell, we find a close relationship between ocean pH and atmospheric CO2: during intervals of low CO2, ocean pH is low, reflecting enhanced ocean carbon storage; and during intervals of rising CO2, ocean pH rises, reflecting loss of carbon from the ocean to the atmosphere. Correspondingly, at shallower sites we find rapid (millennial- to centennial-scale) decreases in pH during abrupt increases in CO2, reflecting the rapid transfer of carbon from the deep ocean to the upper ocean and atmosphere. Our findings confirm the importance of the deep Southern Ocean in ice-age CO2 change, and show that deep-ocean CO2 release can occur as a dynamic feedback to rapid climate change on centennial timescales.},
author = {Rae, J. W.B. and Burke, A. and Robinson, L. F. and Adkins, J. F. and Chen, T. and Cole, C. and Greenop, R. and Li, T. and Littley, E. F.M. and Nita, D. C. and Stewart, J. A. and Taylor, B. J.},
doi = {10.1038/s41586-018-0614-0},
issn = {14764687},
journal = {Nature},
month = {oct},
number = {7728},
pages = {569--573},
publisher = {Nature Publishing Group},
title = {{CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales}},
volume = {562},
year = {2018}
}
@article{Rae2021,
abstract = {Throughout Earth's history, CO 2 is thought to have exerted a fundamental control on environmental change. Here we review and revise CO 2 reconstructions from boron isotopes in carbonates and carbon isotopes in organic matter over the Cenozoic—the past 66 million years. We find close coupling between CO 2 and climate throughout the Cenozoic, with peak CO 2 levels of ∼1,500 ppm in the Eocene greenhouse, decreasing to ∼500 ppm in the Miocene, and falling further into the ice age world of the Plio–Pleistocene. Around two-thirds of Cenozoic CO 2 drawdown is explained by an increase in the ratio of ocean alkalinity to dissolved inorganic carbon, likely linked to a change in the balance of weathering to outgassing, with the remaining one-third due to changing ocean temperature and major ion composition. Earth system climate sensitivity is explored and may vary between different time intervals. The Cenozoic CO 2 record highlights the truly geological scale of anthropogenic CO 2 change: Current CO 2 levels were last seen around 3 million years ago, and major cuts in emissions are required to prevent a return to the CO 2 levels of the Miocene or Eocene in the coming century.},
author = {Rae, James W.B. and Zhang, Yi Ge and Liu, Xiaoqing and Foster, Gavin L. and Stoll, Heather M. and Whiteford, Ross D.M.},
doi = {10.1146/annurev-earth-082420-063026},
issn = {0084-6597},
journal = {Annual Review of Earth and Planetary Sciences},
month = {may},
number = {1},
pages = {609--641},
title = {{Atmospheric CO2 over the Past 66 Million Years from Marine Archives}},
url = {https://www.annualreviews.org/doi/10.1146/annurev-earth-082420-063026},
volume = {49},
year = {2021}
}
@article{Rahmstorf2015,
abstract = {Possible changes in Atlantic meridional overturning circulation (AMOC) provide a key source of uncertainty regarding future climate change. Maps of temperature trends over the twentieth century show a conspicuous region of cooling in the northern Atlantic. Here we present multiple lines of evidence suggesting that this cooling may be due to a reduction in the AMOC over the twentieth century and particularly after 1970. Since 1990 the AMOC seems to have partly recovered. This time evolution is consistently suggested by an AMOC index based on sea surface temperatures, by the hemispheric temperature difference, by coral-based proxies and by oceanic measurements. We discuss a possible contribution of the melting of the Greenland Ice Sheet to the slowdown. Using a multi-proxy temperature reconstruction for the AMOC index suggests that the AMOC weakness after 1975 is an unprecedented event in the past millennium (p{\textgreater}0.99). Further melting of Greenland in the coming decades could contribute to further weakening of the AMOC.},
author = {Rahmstorf, Stefan and Box, Jason E. and Feulner, Georg and Mann, Michael E. and Robinson, Alexander and Rutherford, Scott and Schaffernicht, Erik J.},
doi = {10.1038/nclimate2554},
isbn = {1758-678X$\backslash$r1758-6798},
issn = {17586798},
journal = {Nature Climate Change},
pages = {475--480},
pmid = {25925475},
title = {{Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation}},
volume = {5},
year = {2015}
}
@article{https://doi.org/10.1002/wcc.680,
abstract = {Abstract Extratropical cyclones, a major phenomenon of the mid-latitude atmospheric dynamics, show strong variability over a range of time scales. Future projections hint at an increase of cyclonic intensity and the associated precipitation, an important fact to be considered when developing future risk assessments. This review presents a first overview of studies which (a) puts the current variability and projected future climate changes of extratropical cyclone characteristics in a long-term perspective, (b) shows connections to natural external forcings, and (c) deepens our understanding of cyclone intensification processes for past climate periods. We summarize the current state of knowledge for two periods in the past—the last millennium and the Last Glacial Maximum (LGM, 21,000 years ago). For these two periods, the sparse information from paleo proxy archives are compared to climate modeling results on global and regional scales. For example, strong changes of the climate mean state, induced by orbital forcing and associated feedbacks, show strong effects on different cyclone characteristics, for example, a southward shift of the storm tracks over the North Atlantic during the LGM. Other findings indicate that dynamic processes could play at least an equally important role as thermodynamic processes for the variations of cyclone-induced precipitation. This is in contrast to the projected future changes in cyclone-related precipitation, which are driven primarily by thermodynamic processes. The review demonstrates how a paleoclimatic view can foster an extended process understanding and be instrumental to better understand future changes in extratropical cyclones and associated characteristics. This article is categorized under: Paleoclimates and Current Trends {\textgreater} Modern Climate Change},
author = {Raible, Christoph C and Pinto, Joaquim G and Ludwig, Patrick and Messmer, Martina},
doi = {10.1002/wcc.680},
journal = {WIREs Climate Change},
keywords = {Last Glacial Maximum,Last Millennium,climate change,extratropical cyclones,internal climate variability},
number = {1},
pages = {e680},
title = {{A review of past changes in extratropical cyclones in the northern hemisphere and what can be learned for the future}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/wcc.680},
volume = {12},
year = {2021}
}
@article{RAITZSCH2018138,
abstract = {The boron isotopic composition of planktonic foraminiferal shell calcite ($\delta$11BCc) provides valuable information on the pH of ambient water at the time of calcification. Hence, $\delta$11BCc of fossil surface-dwelling planktonic foraminifera can be used to reconstruct ancient aqueous pCO2 if information on a second carbonate system parameter, temperature and salinity is available. However, pH and pCO2 of surface waters may vary seasonally, largely due to changes in temperature, DIC, and alkalinity. As also the shell fluxes of planktonic foraminifera show species-specific seasonal patterns that are linked to intra-annual changes in temperature, it is obvious that $\delta$11BCc of a certain species reflects the pH and thus pCO2 biased towards a specific time period within a year. This is important to consider for the interpretation of fossil $\delta$11BCc records that may mirror seasonal pH signals. Here we present new Multi-Collector Inductively Coupled Mass Spectrometry (MC-ICPMS) $\delta$11BCc coretop data for the planktonic foraminifera species Globigerina bulloides, Globigerinoides ruber, Trilobatus sacculifer and Orbulina universa and compare them with $\delta$11Bborate derived from seasonally resolved carbonate system parameters. We show that the inferred season-adjusted $\delta$11BCc/$\delta$11Bborate relationships are similar to existing calibrations and can be combined with published $\delta$11BCc field and culture data to augment paleo-pH calibrations. To test the applicability of these calibrations, we used a core drilled on the Walvis Ridge in the Southeast Atlantic spanning the last 330,000 years to reconstruct changes in surface-water pCO2. The reconstruction based on G. bulloides, which reflects the austral spring season, was shown to yield values that closely resemble the Vostok ice-core data indicating that surface-water pCO2 was close to equilibrium with the atmosphere during the cooler spring season. In contrast, pCO2 estimated from $\delta$11BCc of O. universa, T. sacculifer and G. ruber that predominantly lived during the warmer seasons, exhibits up to ∼50 ppmv higher values than the Vostok ice-core data. This is probably due to the higher austral summer and fall temperatures, as shown by Mg/Ca to be on average ∼4 °C higher than during the cooler spring season, accounting for an increase in pCO2 of ∼4{\%} per 1 °C. Our results demonstrate that paleo-pH estimates based on $\delta$11BCc contain a significant seasonal signal reflecting the habitat preference of the recording foraminifera species.},
author = {Raitzsch, Markus and Bijma, Jelle and Benthien, Albert and Richter, Klaus-Uwe and Steinhoefel, Grit and Ku{\v{c}}era, Michal},
doi = {10.1016/j.epsl.2018.02.002},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {boron isotopes,planktonic foraminifera,seasonality},
pages = {138--150},
title = {{Boron isotope-based seasonal paleo-pH reconstruction for the Southeast Atlantic – A multispecies approach using habitat preference of planktonic foraminifera}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X1830058X},
volume = {487},
year = {2018}
}
@article{doi:10.1175/JCLI-D-15-0629.1,
abstract = {AbstractTemperature trends in the middle and upper stratosphere are evaluated using measurements from the Stratospheric Sounding Unit (SSU), combined with data from the Aura Microwave Limb Sounder (MLS) and Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) instruments. Data from MLS and SABER are vertically integrated to approximate the SSU weighting functions and combined with SSU to provide a data record spanning 1979–2015. Vertical integrals are calculated using empirically derived Gaussian weighting functions, which provide improved agreement with high-latitude SSU measurements compared to previously derived weighting functions. These merged SSU data are used to evaluate decadal-scale trends, solar cycle variations, and volcanic effects from the lower to the upper stratosphere. Episodic warming is observed following the volcanic eruptions of El Chich{\'{o}}n (1982) and Mt. Pinatubo (1991), focused in the tropics in the lower stratosphere and in high latitudes in the middle and upper stratosphere. Solar cycle variations are centered in the tropics, increasing in amplitude from the lower to the upper stratosphere. Linear trends over 1979–2015 show that cooling increases with altitude from the lower stratosphere (from {\~{}}−0.1 to −0.2 K decade−1) to the middle and upper stratosphere (from {\~{}}−0.5 to −0.6 K decade−1). Cooling in the middle and upper stratosphere is relatively uniform in latitudes north of about 30°S, but trends decrease to near zero over the Antarctic. Mid- and upper-stratospheric temperatures show larger cooling over the first half of the data record (1979–97) compared to the second half (1998–2015), reflecting differences in upper-stratospheric ozone trends between these periods.},
author = {Randel, William J and Smith, Anne K and Wu, Fei and Zou, Cheng-Zhi and Qian, Haifeng},
doi = {10.1175/JCLI-D-15-0629.1},
journal = {Journal of Climate},
number = {13},
pages = {4843--4859},
title = {{Stratospheric Temperature Trends over 1979–2015 Derived from Combined SSU, MLS, and SABER Satellite Observations}},
url = {https://doi.org/10.1175/JCLI-D-15-0629.1},
volume = {29},
year = {2016}
}
@article{doi:10.1029/2018JD028355,
abstract = {Abstract Several groups routinely produce gridded land surface air temperature (LSAT) data sets using station measurements to assess the status and impact of climate change. The Intergovernmental Panel on Climate Change Fifth Assessment Report suggests that estimated global and hemispheric mean LSAT trends of different data sets are consistent. However, less attention has been paid to the intercomparison at local/regional scales, which is important for local/regional studies. In this study we comprehensively compare four data sets at different spatial and temporal scales, including Berkley Earth Surface Temperature land surface air temperature data set (BEST-LAND), Climate Research Unit Temperature Data Set version 4 (CRU-TEM4v), National Aeronautics and Space Administration Goddard Institute for Space Studies data (NASA-GISS), and data provided by National Oceanic and Atmospheric Administration National Center for Environmental Information (NOAA-NCEI). The mean LSAT anomalies are remarkably different because of the data coverage differences, with the magnitude nearly 0.4°C for the global and Northern Hemisphere and 0.6°C for the Southern Hemisphere. This study additionally finds that on the regional scale, northern high latitudes, southern middle-to-high latitudes, and the equator show the largest differences nearly 0.8°C. These differences cause notable differences for the trend calculation at regional scales. At the local scale, four data sets show significant variations over South America, Africa, Maritime Continent, central Australia, and Antarctica, which leads to remarkable differences in the local trend analysis. For some areas, different data sets produce conflicting results of whether warming exists. Our analysis shows that the differences across scales are associated with the availability of stations and the use of infilling techniques. Our results suggest that conventional LSAT data sets using only station observations have large uncertainties across scales, especially over station-sparse areas. In developing future LSAT data sets, the data uncertainty caused by limited and unevenly distributed station observations must be reduced.},
author = {Rao, Yuhan and Liang, Shunlin and Yu, Yunyue},
doi = {10.1029/2018JD028355},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {intercomparison,land surface air temperature,surface warming,warming hiatus},
number = {11},
pages = {5881--5900},
title = {{Land Surface Air Temperature Data Are Considerably Different Among BEST-LAND, CRU-TEM4v, NASA-GISS, and NOAA-NCEI}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD028355},
volume = {123},
year = {2018}
}
@article{doi:10.1175/JCLI-D-13-00431.1,
abstract = {AbstractRemote effects modulating the austral summer precipitation over southern Africa during El Ni{\~{n}}o/El Ni{\~{n}}o Modoki events are investigated by analyzing the observed events during December–February of the years from 1982/83 to 2010/11. Based on the composite analyses, it is found that southern Africa experiences significantly below normal precipitation during El Ni{\~{n}}o events compared to El Ni{\~{n}}o Modoki events. During these latter events, precipitation anomalies are not so significant although southern Africa as a whole receives below normal precipitations. The differences in the spatial distribution of precipitation over southern Africa are seen to be related to the sea surface temperature (SST) anomalies of the equatorial Pacific through atmospheric teleconnections.The low-level (850 hPa) Matsuno–Gill response to anomalously high precipitation over the Pacific during El Ni{\~{n}}o events results in an anomalous anticyclone extending from the equatorial to the subtropical South Indian Ocean. These anomalous anticyclonic winds weaken the tropical moisture flow into the southern Africa landmass. Rossby wave activity flux analysis of the upper-level (300 hPa) circulation shows an anomalous tropospheric stationary wave from the Pacific propagating toward southern Africa and maintaining an anomalous anticyclone over southern Africa. The anomalous Matsuno–Gill response and the anomalous tropospheric stationary wave response are intense during El Ni{\~{n}}o events, causing drought over southern Africa. During El Ni{\~{n}}o Modoki events, these processes are weaker compared to El Ni{\~{n}}o events.},
author = {Ratnam, J V and Behera, S K and Masumoto, Y and Yamagata, T},
doi = {10.1175/JCLI-D-13-00431.1},
journal = {Journal of Climate},
number = {10},
pages = {3802--3815},
title = {{Remote Effects of El Ni{\~{n}}o and Modoki Events on the Austral Summer Precipitation of Southern Africa}},
url = {https://doi.org/10.1175/JCLI-D-13-00431.1},
volume = {27},
year = {2014}
}
@article{Ray2017,
abstract = {{\textcopyright} 2017. American Geophysical Union. Sulfur hexafluoride (SF 6 ) is a greenhouse gas with one of the highest radiative efficiencies in the atmosphere as well as an important indicator of transport time scales in the stratosphere. The current widely used estimate of the atmospheric lifetime of SF 6 is 3200 years. In this study we use in situ measurements in the 2000 Arctic polar vortex that sampled air with up to 50{\%} SF 6 loss to calculate an SF 6 lifetime. Comparison of these measurements with output from the Whole Atmosphere Community Climate Model (WACCM) shows that WACCM transport into the vortex is accurate and that an important SF 6 loss mechanism, believed to be electron attachment, is missing in the model. Based on the measurements and estimates of the size of the vortex, we calculate an SF 6 lifetime of 850 years with an uncertainty range of 580-1400 years. The amount of SF 6 loss is shown to be consistent with that of HFC-227ea, which has a lifetime of 670-780 years, adding independent support to our new SF 6 lifetime estimate. Based on the revised lifetime the global warming potential of SF 6 will decrease only slightly for short time horizons ( {\textless} 100 years) but will decrease substantially for time horizons longer than 2000 years. Also, the use of SF 6 measurements as an indicator of transport time scales in the stratosphere clearly must account for potential influence from polar vortex air. Plain Language Summary We have calculated an atmospheric lifetime of the molecule SF 6 based on trace gas measurements in the stratospheric polar vortex. This lifetime is 3 times shorter than the commonly used lifetime over the past 20 years. Since SF 6 is a greenhouse gas this adjustment has implications for long-term climate effects.},
author = {Ray, Eric A. and Moore, Fred L. and Elkins, James W. and Rosenlof, Karen H. and Laube, Johannes C. and R{\"{o}}ckmann, Thomas and Marsh, Daniel R. and Andrews, Arlyn E.},
doi = {10.1002/2016JD026198},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {apr},
number = {8},
pages = {4626--4638},
title = {{Quantification of the SF6 lifetime based on mesospheric loss measured in the stratospheric polar vortex}},
url = {http://doi.wiley.com/10.1002/2016JD026198},
volume = {122},
year = {2017}
}
@article{RAY2011496,
author = {Ray, Richard D and Douglas, Bruce C},
doi = {10.1016/j.pocean.2011.07.021},
issn = {0079-6611},
journal = {Progress in Oceanography},
number = {4},
pages = {496--515},
title = {{Experiments in reconstructing twentieth-century sea levels}},
url = {http://www.sciencedirect.com/science/article/pii/S0079661111000759},
volume = {91},
year = {2011}
}
@article{Raymo2012,
abstract = {The magnitude of sea level rise during marine isotope stage 11 (about 400,000 years ago) is shown to have been probably only 6 to 13 metres, in contrast to some earlier estimates of up to 20 metres.},
author = {Raymo, Maureen E and Mitrovica, Jerry X},
doi = {10.1038/nature10891},
issn = {1476-4687},
journal = {Nature},
number = {7390},
pages = {453--456},
title = {{Collapse of polar ice sheets during the stage 11 interglacial}},
url = {https://doi.org/10.1038/nature10891},
volume = {483},
year = {2012}
}
@article{doi:10.1029/2002JD002670,
abstract = {We present the Met Office Hadley Centre's sea ice and sea surface temperature (SST) data set, HadISST1, and the nighttime marine air temperature (NMAT) data set, HadMAT1. HadISST1 replaces the global sea ice and sea surface temperature (GISST) data sets and is a unique combination of monthly globally complete fields of SST and sea ice concentration on a 1° latitude-longitude grid from 1871. The companion HadMAT1 runs monthly from 1856 on a 5° latitude-longitude grid and incorporates new corrections for the effect on NMAT of increasing deck (and hence measurement) heights. HadISST1 and HadMAT1 temperatures are reconstructed using a two-stage reduced-space optimal interpolation procedure, followed by superposition of quality-improved gridded observations onto the reconstructions to restore local detail. The sea ice fields are made more homogeneous by compensating satellite microwave-based sea ice concentrations for the impact of surface melt effects on retrievals in the Arctic and for algorithm deficiencies in the Antarctic and by making the historical in situ concentrations consistent with the satellite data. SSTs near sea ice are estimated using statistical relationships between SST and sea ice concentration. HadISST1 compares well with other published analyses, capturing trends in global, hemispheric, and regional SST well, containing SST fields with more uniform variance through time and better month-to-month persistence than those in GISST. HadMAT1 is more consistent with SST and with collocated land surface air temperatures than previous NMAT data sets.},
author = {Rayner, N A and Parker, D E and Horton, E B and Folland, C K and Alexander, L V and Rowell, D P and Kent, E C and Kaplan, A},
doi = {10.1029/2002JD002670},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {bias correction,climate change,climate data reconstruction,night marine air temperature,sea ice,sea surface temperature},
number = {D14},
title = {{Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2002JD002670},
volume = {108},
year = {2003}
}
@article{Rayner2020,
abstract = {Day-to-day variations in surface air temperature affect society in many ways, but daily surface air temperature measurements are not available everywhere. Therefore, a global daily picture cannot be achieved with measurements made in situ alone and needs to incorporate estimates from satellite retrievals.This article presents the science developed in the EU Horizon 2020-funded EUSTACE project (2015-2019, https://www.eustaceproject.org) to produce global and European, multi-decadal ensembles of daily analyses of surface air temperature complementary to those from dynamical reanalyses, integrating different ground-based and satellite-borne data types. Relationships between surface air temperature measurements and satellite-based estimates of surface skin temperature over all surfaces of Earth (land, ocean, ice and lakes) are quantified. Information contained in the satellite retrievals then helps to estimate air temperature and create global fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place; this needs efficient statistical analysis methods to cope with the considerable data volumes. Daily fields are presented as ensembles to enable propagation of uncertainties through applications. Estimated temperatures and their uncertainties are evaluated against independent measurements and other surface temperature data sets.Achievements in the EUSTACE project have also included fundamental preparatory work useful to others, for example: gathering user requirements; identifying inhomogeneities in daily surface air temperature measurement series from weather stations; carefully quantifying uncertainties in satellite skin and air temperature estimates; exploring the interaction between air temperature and lakes; developing statistical models relevant to non-Gaussian variables; and methods for efficient computation.The main goals and activities of the EUSTACE project are discussed along with some key results, including a global, multi-decadal daily air temperature record from satellite and in situ measurements.},
author = {Rayner, Nick A and Auchmann, Renate and Bessembinder, Janette and Br{\"{o}}nnimann, Stefan and Brugnara, Yuri and Capponi, Francesco and Carrea, Laura and Dodd, Emma M A and Ghent, Darren and Good, Elizabeth and H{\o}yer, Jacob L and Kennedy, John J and Kent, Elizabeth C and Killick, Rachel E and van der Linden, Paul and Lindgren, Finn and Madsen, Kristine S and Merchant, Christopher J and Mitchelson, Joel R and Morice, Colin P and Nielsen-Englyst, Pia and Ortiz, Patricio F and Remedios, John J and van der Schrier, Gerard and Squintu, Antonello A and Stephens, Ag and Thorne, Peter W and Tonboe, Rasmus T and Trent, Tim and Veal, Karen L and Waterfall, Alison M and Winfield, Kate and Winn, Jonathan and Woolway, R Iestyn},
doi = {10.1175/BAMS-D-19-0095.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
month = {jun},
pages = {1--79},
title = {{The EUSTACE project: delivering global, daily information on surface air temperature}},
url = {https://doi.org/10.1175/BAMS-D-19-0095.1},
year = {2020}
}
@article{Reboita2015a,
author = {Reboita, M S and da Rocha, R P and Ambrizzi, T and Gouveia, C D},
doi = {10.1007/s00382-014-2447-3},
journal = {Climate Dynamics},
pages = {1929--1944},
title = {{Trend and teleconnection patterns in the climatology of extratropical cyclones over the Southern Hemisphere}},
volume = {45},
year = {2015}
}
@article{Rehfeld2018,
author = {Rehfeld, Kira and M{\"{u}}nch, Thomas and Ho, Sze Ling and Laepple, Thomas},
doi = {10.1038/nature25454},
journal = {Nature},
month = {feb},
pages = {356},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Global patterns of declining temperature variability from the Last Glacial Maximum to the Holocene}},
url = {http://dx.doi.org/10.1038/nature25454 http://10.0.4.14/nature25454 https://www.nature.com/articles/nature25454{\#}supplementary-information},
volume = {554},
year = {2018}
}
@article{Reichler2012,
abstract = {The stratosphere is connected to tropospheric weather and climate. In particular, extreme stratospheric circulation events are known to exert a dynamical feedback on the troposphere. However, it is unclear whether the state of the stratosphere also affects the ocean and its circulation. A co-variability of decadal stratospheric flow variations and conditions in the North Atlantic Ocean has been suggested, but such findings are based on short simulations with only one climate model. Here we assess ocean reanalysis data and find that, over the previous 30 years, the stratosphere and the Atlantic thermohaline circulation experienced low-frequency variations that were similar to each other. Using climate models, we demonstrate that this similarity is consistent with the hypothesis that variations in the sequence of stratospheric circulation anomalies, combined with the persistence of individual anomalies, significantly affect the North Atlantic Ocean. Our analyses identify a previously unknown source for decadal climate variability and suggest that simulations of deep layers of the atmosphere and the ocean are needed for realistic predictions of climate.},
author = {Reichler, Thomas and Kim, Junsu and Manzini, Elisa and Kr{\"{o}}ger, J{\"{u}}rgen},
doi = {10.1038/ngeo1586},
isbn = {1752-0894},
issn = {17520894},
journal = {Nature Geoscience},
number = {11},
pages = {783--787},
publisher = {Nature Publishing Group},
title = {{A stratospheric connection to Atlantic climate variability}},
volume = {5},
year = {2012}
}
@article{ReidP.andMassom2015,
author = {Reid, P. and Massom, R.A.},
doi = {10.1175/2015BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {7},
pages = {S163--S164},
title = {{Successive Antarctic sea ice extent records during 2012, 2013 and 2014 [in “State of the Climate in 2014”]}},
volume = {96},
year = {2015}
}
@article{ReidP.S.StammerjohnR.A.MassomS.BarreiraT.Scambos2020,
author = {Reid, P. and Stammerjohn, S. and Massom, R. A. and Barreira, S. and Scambos, T. and Lieser, J. L.},
doi = {10.1175/BAMS-D-20-0090.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S304--S306},
title = {{Sea ice extent, concentration, and seasonality [in “State of the Climate in 2019"]}},
volume = {101},
year = {2020}
}
@article{Reid2015,
abstract = {Observations of Southern Hemisphere sea ice from passive microwave satellite measurements show that a new record maximum extent of 19.58 x 10 6 km 2 was reached on 30 September 2013; the extent is just over two standard deviations above the 1979-2012 mean and follows a similar record (19.48x 10 6 km 2 ) in 2012. On the record day in 2013, sea-ice extent was greater than the 30 year average (1981-2010) in nearly all Southern Ocean regions. For the year as a whole, Southern Hemisphere sea-ice area and extent were well above average, and numerous monthly and daily records were broken. Analysis of anomaly patterns and the atmospheric and oceanic events suggests that a sequence of regional wind and cold-freshened surface waters is likely responsible for the record maximum and the generally high 2013 extent. In particular, the Ross Sea sector experienced a combination of cold southerly winds associated with the position and depth of the Amundsen Sea low, and lower than normal sea surface temperatures (up to 2°C below normal). The resulting very high anomaly in ice extent in this region was a major component of the overall record maximum.},
author = {Reid, Phil and Stammerjohn, Sharon and Massom, Rob and Scambos, Ted and Lieser, Jan},
doi = {10.3189/2015AoG69A892},
isbn = {02603055 (ISSN)},
issn = {0260-3055},
journal = {Annals of Glaciology},
keywords = {Atmosphere/ice/ocean interactions,Climate change,Sea ice},
month = {jul},
number = {69},
pages = {99--106},
title = {{The record 2013 Southern Hemisphere sea-ice extent maximum}},
url = {https://www.cambridge.org/core/product/identifier/S0260305500261296/type/journal{\_}article},
volume = {56},
year = {2015}
}
@article{Reinhold2019,
author = {Reinhold, T. and Shapiro, A.I. and Solanki, S.K. and Montet, B.T. and Krivova, N.A. and Cameron, R.H. and Amazo-G{\'{o}}mez, E.M.},
doi = {10.1126/science.aay3821},
journal = {Science},
number = {6490},
pages = {518--521},
title = {{The Sun is less active than other solar-type stars}},
volume = {368},
year = {2019}
}
@article{Remmelzwaal2019a,
abstract = {Abstract Over the past several decades, oxygen minimum zones have rapidly expanded due to rising temperatures raising concerns about the impacts of future climate change. One way to better understand the drivers behind this expansion is to evaluate the links between climate and seawater deoxygenation in the past especially in times of geologically abrupt climate change such as the Palaeocene-Eocene Thermal Maximum (PETM), a well-characterized period of rapid warming {\~{}}56 Ma. We have developed and applied the novel redox proxies of foraminiferal Cr isotopes ($\delta$53Cr) and Ce anomalies (Ce/Ce*) to assess changes in paleoredox conditions arising from changes in oxygen availability. Both $\delta$53Cr and Cr concentrations decrease notably over the PETM at intermediate to upper abyssal water depths, indicative of widespread reductions in dissolved oxygen concentrations. An apparent correlation between the sizes of $\delta$53Cr and benthic $\delta$18O excursions during the PETM suggests temperature is one of the main controlling factors of deoxygenation in the open ocean. Ocean Drilling Program Sites 1210 in the Pacific and 1263 in the Southeast Atlantic suggest that deoxygenation is associated with warming and circulation changes, as supported by Ce/Ce* data. Our geochemical data are supported by simulations from an intermediate complexity climate model (cGENIE), which show that during the PETM anoxia was mostly restricted to the Tethys Sea, while hypoxia was more widespread as a result of increasing atmospheric CO2 (from 1 to 6 times preindustrial values).},
annote = {doi: 10.1029/2018PA003372},
author = {Remmelzwaal, Serginio R C and Dixon, Sophie and Parkinson, Ian J and Schmidt, Daniela N and Monteiro, Fanny M and Sexton, Philip and Fehr, Manuela A and Peacock, Caroline and Donnadieu, Yannick and James, Rachael H},
doi = {10.1029/2018PA003372},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {PETM,cerium,chromium,deoxygenation,foraminifera,hypoxia},
month = {jun},
number = {6},
pages = {917--929},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Investigating Ocean Deoxygenation During the PETM Through the Cr Isotopic Signature of Foraminifera}},
url = {https://doi.org/10.1029/2018PA003372},
volume = {34},
year = {2019}
}
@article{Renner2014a,
abstract = {The Arctic sea ice cover is rapidly shrinking, but a direct, longer-term assessment of the ice thinning remains challenging. A new time series constructed from in situ measurements of sea ice thickness at the end of the melt season in Fram Strait shows a thinning by over 50{\%} during 2003–2012. The modal and mean ice thickness along 79◦N decreased at a rate of 0.3 and 0.2myr−1, respectively, with long-term averages of 2.5 and 3m. Airborne observations reveal an east-west thickness gradient across the strait in spring but not in summer due to advection from more different source regions. There is no clear relationship between interannual ice thickness variability and the source regions of the ice. The observed thinning is therefore likely a result of Arctic-wide reduction in ice thickness with a potential shift in exported ice types playing a minor role.},
author = {Renner, Angelika H H and Gerland, Sebastian and Haas, Christian and Spreen, Gunnar and Beckers, Justin F. and Hansen, Edmond and Nicolaus, Marcel and Goodwin, Harvey},
doi = {10.1002/2014GL060369},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {14},
pages = {5029--5036},
title = {{Evidence of Arctic sea ice thinning from direct observations}},
volume = {41},
year = {2014}
}
@article{Rennie2014,
abstract = {Described herein is the first version release of monthly temperature holdings of a new Global Land Surface Meteorological Databank. Organized under the auspices of the International Surface Temperature Initiative (ISTI), an international group of scientists have spent three years collating and merging data from numerous sources to create a merged holding. This release in its recommended form consists of over 30 000 individual station records, some of which extend over the past 300 years. This article describes the sources, the chosen merge methodology, and the resulting databank characteristics. Several variants of the databank have also been released that reflect the structural uncertainty in merging datasets. Variants differ in, for example, the order in which sources are considered and the degree of congruence required in station geolocation for consideration as a merged or unique record. Also described is a version control protocol that will be applied in the event of updates. Future updates are envisaged with the addition of new data sources, and with changes in processing, where public feedback is always welcomed. Major updates, when necessary, will always be accompanied by a new journal paper. This databank release forms the foundation for the construction of new global land surface air temperature analyses by the global research community and their assessment by the ISTI's benchmarking and assessment working group.},
author = {Rennie, J J and Lawrimore, J H and Gleason, B E and Thorne, P W and Morice, C P and Menne, M J and Williams, C N and de Almeida, W Gambi and Christy, J R and Flannery, M and Ishihara, M and Kamiguchi, K and Klein-Tank, A M G and Mhanda, A and Lister, D H and Razuvaev, V and Renom, M and Rusticucci, M and Tandy, J and Worley, S J and Venema, V and Angel, W and Brunet, M and Dattore, B and Diamond, H and Lazzara, M A and {Le Blancq}, F and Luterbacher, J and M{\"{a}}chel, H and Revadekar, J and Vose, R S and Yin, X},
doi = {10.1002/gdj3.8},
journal = {Geoscience Data Journal},
number = {2},
pages = {75--102},
title = {{The international surface temperature initiative global land surface databank: monthly temperature data release description and methods}},
volume = {1},
year = {2014}
}
@article{Renwick2015,
abstract = {Aim Range shifts associated with 20th-century warming have been documented for a wide range of taxa, but many species are not migrating fast enough to keep pace with the rapidly changing climate. Tree species can experience particularly long time lags in their migration response, resulting in altered forest composition and potentially delaying the migration of other obligate species. Here we review potential causes of these time lags and develop a conceptual framework for understanding how migration timing affects the observed rate of change. Location Global forest ecosystems. Methods We synthesize evidence from present-day tree species migrations to determine how different migration constraints can delay tree species range shifts. Results The rate of present-day tree migrations is frequently slower than expected, and many factors may contribute to observed migration lags. Migration constraints can be overcome given the right combination of circumstances, resulting in episodic range shifts that create temporal variability in migration rates. Given projected increases in forest disturbances and extreme climatic events, episodic range shifts are likely. Main conclusions Recent efforts to explain the slow rate of tree migration have primarily focused on dispersal limitation and niche-based constraints such as competition and other biotic interactions. We argue that these constraints cannot be fully understood without considering the temporal context of tree migration. Attempts to forecast and manage future distribution shifts must consequently consider how migration timing may affect observed patterns of change.},
author = {Renwick, Katherine M. and Rocca, Monique E.},
doi = {10.1111/geb.12240},
issn = {14668238},
journal = {Global Ecology and Biogeography},
keywords = {Climate change,Migration lag,Natural resource management,Range shift,Temporal context,Tree species,Vegetation shifts},
number = {1},
pages = {44--51},
title = {{Temporal context affects the observed rate of climate-driven range shifts in tree species}},
volume = {24},
year = {2015}
}
@article{Resplandy2019,
abstract = {The ocean is the main source of thermal inertia in the climate system. Ocean heat uptake during recent decades has been quantified using ocean temperature measurements. However, these estimates all use the same imperfect ocean dataset and share additional uncertainty due to sparse coverage, especially before 2007. Here, we provide an independent estimate by using measurements of atmospheric oxygen (O2) and carbon dioxide (CO2) – levels of which increase as the ocean warms and releases gases – as a whole ocean thermometer. We show that the ocean gained 1.29 ± 0.79 × 1022 Joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.80 ± 0.49 W watts per square metre of Earth's surface. We also find that the ocean-warming effect that led to the outgassing of O2 and CO2 can be isolated from the direct effects of anthropogenic emissions and CO2 sinks. Our result – which relies on high-precision O2 atmospheric measurements dating back to 1991 – leverages an integrative Earth system approach and provides much needed independent confirmation of heat uptake estimated from ocean data.},
author = {Resplandy, L and Keeling, R F and Eddebbar, Y and Brooks, M and Wang, R and Bopp, L and Long, M C and Dunne, J P and Koeve, W and Oschlies, A},
doi = {10.1038/s41598-019-56490-z},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {20244},
title = {{Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition}},
url = {https://doi.org/10.1038/s41598-019-56490-z},
volume = {9},
year = {2019}
}
@article{amt-13-789-2020,
author = {Reuter, M and Buchwitz, M and Schneising, O and No{\"{e}}l, S and Bovensmann, H and Burrows, J P and Boesch, H and {Di Noia}, A and Anand, J and Parker, R J and Somkuti, P and Wu, L and Hasekamp, O P and Aben, I and Kuze, A and Suto, H and Shiomi, K and Yoshida, Y and Morino, I and Crisp, D and O'Dell, C W and Notholt, J and Petri, C and Warneke, T and Velazco, V A and Deutscher, N M and Griffith, D W T and Kivi, R and Pollard, D F and Hase, F and Sussmann, R and T{\'{e}}, Y V and Strong, K and Roche, S and Sha, M K and {De Mazi{\`{e}}re}, M and Feist, D G and Iraci, L T and Roehl, C M and Retscher, C and Schepers, D},
doi = {10.5194/amt-13-789-2020},
journal = {Atmospheric Measurement Techniques},
number = {2},
pages = {789--819},
title = {{Ensemble-based satellite-derived carbon dioxide and methane column-averaged dry-air mole fraction data sets (2003–2018) for carbon and climate applications}},
url = {https://amt.copernicus.org/articles/13/789/2020/},
volume = {13},
year = {2020}
}
@article{Reynhout2019a,
author = {Reynhout, Scott A and Sagredo, Esteban A and Kaplan, Michael R and Carlos, Juan and Martini, Mateo A and Moreno, Patricio I and Rojas, Maisa and Schwartz, Roseanne and Schaefer, Joerg M},
doi = {10.1016/j.quascirev.2019.05.029},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {178--187},
publisher = {Elsevier Ltd},
title = {{Holocene glacier fluctuations in Patagonia are modulated by summer insolation intensity and paced by Southern Annular Mode-like variability}},
volume = {220},
year = {2019}
}
@article{doi:10.1029/2018PA003366,
abstract = {Abstract Our understanding of North Atlantic Ocean variability within the coupled climate system is limited by the brevity of instrumental records and a deficiency of absolutely dated marine proxies. Here we demonstrate that a spatial network of marine stable oxygen isotope series derived from molluscan sclerochronologies ($\delta$18Oshell) can provide skillful annually resolved reconstructions of key components of North Atlantic Ocean variability with absolute dating precision. Analyses of the common $\delta$18Oshell variability, using principal component analysis, highlight strong connections with tropical North Atlantic and subpolar gyre (SPG) sea surface temperatures and sea surface salinity in the North Atlantic Current (NAC) region. These analyses suggest that low-frequency variability is dominated by the tropical Atlantic signal while decadal variability is dominated by variability in the SPG and salinity transport in the NAC. Split calibration and verification statistics indicate that the composite series produced using the principal component analysis can provide skillful quantitative reconstructions of tropical North Atlantic and SPG sea surface temperatures and NAC sea surface salinities over the industrial period (1864–2000). The application of these techniques with extended individual $\delta$18Oshell series provides powerful baseline records of past North Atlantic variability into the unobserved preindustrial period. Such records are essential for developing our understanding of natural climate variability in the North Atlantic Ocean and the role it plays in the wider climate system, especially on multidecadal to centennial time scales, potentially enabling reduction of uncertainties in future climate predictions.},
author = {Reynolds, D J and Hall, I R and Slater, S M and Mette, M J and Wanamaker, A D and Scourse, J D and Garry, F K and Halloran, P R},
doi = {10.1029/2018PA003366},
journal = {Paleoceanography and Paleoclimatology},
keywords = {North Atlantic Current,North Atlantic Ocean,proxy network,sclerochronology,subpolar gyre,tropical North Atlantic},
number = {10},
pages = {1086--1098},
title = {{Isolating and Reconstructing Key Components of North Atlantic Ocean Variability From a Sclerochronological Spatial Network}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018PA003366},
volume = {33},
year = {2018}
}
@misc{RGIConsortium2017,
abstract = {The Randolph Glacier Inventory (RGI 6.0) is a global inventory of glacier outlines. It is supplemental to the Global Land Ice Measurements from Space initiative (GLIMS). Production of the RGI was motivated by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). Future updates will be made to the RGI and the GLIMS Glacier Database in parallel during a transition period. As all these data are incorporated into the GLIMS Glacier Database and as download tools are developed to obtain GLIMS data in the RGI data format, the RGI will evolve into a downloadable subset of GLIMS, offering complete one-time coverage, version control, and a standard set of attributes.},
address = {CO, USA},
author = {{RGI Consortium}},
doi = {10.7265/N5-RGI-60},
keywords = {RGI Consortium},
publisher = {Technical Report, Global Land Ice Measurements from Space},
title = {{Randolph Glacier Inventory – A Dataset of Global Glacier Outlines: Version 6.0}},
url = {https:doi.org/10.7265/N5-RGI-60},
year = {2017}
}
@article{Rhein2017,
annote = {doi: 10.1098/rsta.2016.0321},
author = {Rhein, Monika and Steinfeldt, Reiner and Kieke, Dagmar and Stendardo, Ilaria and Yashayaev, Igor},
doi = {10.1098/rsta.2016.0321},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {sep},
number = {2102},
pages = {20160321},
publisher = {Royal Society},
title = {{Ventilation variability of Labrador Sea Water and its impact on oxygen and anthropogenic carbon: a review}},
url = {https://doi.org/10.1098/rsta.2016.0321},
volume = {375},
year = {2017}
}
@article{Rhodes2017,
abstract = {{\textcopyright} 2017. American Geophysical Union.In order to understand atmospheric methane (CH4) biogeochemistry now and in the future, we must apprehend its natural variability, without anthropogenic influence. Samples of ancient air trapped within ice cores provide the means to do this. Here we analyze the ultrahigh-resolution CH4 record of the West Antarctic Ice Sheet Divide ice core 67.2-9.8ka and find novel, atmospheric CH4 variability at centennial time scales throughout the record. This signal is characterized by recurrence intervals within a broad 80-500year range, but we find that age-scale uncertainties complicate the possible isolation of any periodic frequency. Lower signal amplitudes in the Last Glacial relative to the Holocene may be related to incongruent effects of firn-based signal smoothing processes. Within interstadial and stadial periods, the peak-to-peak signal amplitudes vary in proportion to the underlying millennial-scale oscillations in CH4 concentration-the relative amplitude change is constant. We propose that the centennial CH4 signal is related to tropical climate variability that influences predominantly low-latitude wetland CH4 emissions.},
author = {Rhodes, Rachael H. and Brook, Edward J. and McConnell, Joseph R. and Blunier, Thomas and Sime, Louise C. and Fa{\"{i}}n, Xavier and Mulvaney, Robert},
doi = {10.1002/2016GB005570},
issn = {19449224},
journal = {Global Biogeochemical Cycles},
keywords = {Last Glacial Period,atmospheric composition,centennial variability,ice cores,methane,paleoclimate},
number = {3},
pages = {575--590},
title = {{Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period}},
volume = {31},
year = {2017}
}
@article{Rhodes2015b,
abstract = {The causal mechanisms responsible for the abrupt climate changes of the Last Glacial Period remain unclear. One major difficulty is dating ice-rafted debris deposits associated with Heinrich events: Extensive iceberg influxes into the North Atlantic Ocean linked to global impacts on climate and biogeochemistry. In a new ice core record of atmospheric methane with ultrahigh temporal resolution, we find abrupt methane increases within Heinrich stadials 1, 2, 4, and 5 that, uniquely, have no counterparts in Greenland temperature proxies. Using a heuristic model of tropical rainfall distribution, we propose that Hudson Strait Heinrich events caused rainfall intensification over Southern Hemisphere land areas, thereby producing excess methane in tropical wetlands. Our findings suggest that the climatic impacts of Heinrich events persisted for 740 to 1520 years.},
author = {Rhodes, Rachael H. and Brook, Edward J. and Chiang, John C.H. and Blunier, Thomas and Maselli, Olivia J. and McConnell, Joseph R. and Romanini, Daniele and Severinghaus, Jeffrey P.},
doi = {10.1126/science.1262005},
isbn = {1223326500},
issn = {10959203},
journal = {Science},
number = {6238},
pages = {1016--1019},
pmid = {26023138},
title = {{Enhanced tropical methane production in response to iceberg discharge in the North Atlantic}},
volume = {348},
year = {2015}
}
@article{Rhodes2013,
abstract = {Ancient air trapped inside bubbles in ice cores can now be analysed for methane concentration utilising a laser spectrometer coupled to a continuous melter system. We present a new ultra-high resolution record of atmospheric methane variability over the last 1800yr obtained from continuous analysis of a shallow ice core from the North Greenland Eemian project (NEEM-2011-S1) during a 4-week laboratory-based measurement campaign. Our record faithfully replicates the form and amplitudes of multi-decadal oscillations previously observed in other ice cores and demonstrates the detailed depth resolution (5.3cm), rapid acquisition time (30mday-1) and good long-term reproducibility (2.6{\%}, 2$\sigma$) of the continuous measurement technique.In addition, we report the detection of high frequency ice core methane signals of non-atmospheric origin. Firstly, measurements of air from the firn-ice transition region and an interval of ice core dating from 1546-1560 AD (gas age) resolve apparently quasi-annual scale methane oscillations. Traditional gas chromatography measurements on discrete ice samples confirm these signals and indicate peak-to-peak amplitudes of ca. 22 parts per billion (ppb). We hypothesise that these oscillations result from staggered bubble close-off between seasonal layers of contrasting density during time periods of sustained multi-year atmospheric methane change. Secondly, we report the detection of abrupt (20-100. cm depth interval), high amplitude (35-80. ppb excess) methane spikes in the NEEM ice that are reproduced by discrete measurements. We show for the first time that methane spikes present in thin and infrequent layers in polar, glacial ice are accompanied by elevated concentrations of carbon- and nitrogen-based chemical impurities, and suggest that biological in-situ production may be responsible. {\textcopyright} 2013 Elsevier B.V.},
author = {Rhodes, Rachael H. and Fa{\"{i}}n, Xavier and Stowasser, Christopher and Blunier, Thomas and Chappellaz, J{\'{e}}r{\^{o}}me and McConnell, Joseph R. and Romanini, Daniele and Mitchell, Logan E. and Brook, Edward J.},
doi = {10.1016/j.epsl.2013.02.034},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {Cryobiology,Firn,Greenland,Ice core,Late Holocene climate,Methane},
pages = {9--19},
title = {{Continuous methane measurements from a late Holocene Greenland ice core: Atmospheric and in-situ signals}},
volume = {368},
year = {2013}
}
@article{Ribeiro2018,
abstract = {In this study a set of 157 collocated XBT (DB/T7 type) and CTD stations distributed across three different regions of the Southern Ocean is explored using the manufacturer's fall-rate equation (FRE), which is a classic correction method, and new correction methods to investigate how the regional environment characteristics may impact a probe's descent and the corresponding depth estimates. Regional coefficients were estimated for all three basins and for the Southern Ocean as a whole. The manufacturer's FRE proved to perform better in high latitudes than in the rest of the World Ocean, overestimating the true depth by only 2{\%}. The overall depth bias was positive, further supporting the hypothesis of a regional dependence of the XBT fall rate on water temperature, which leads to a general overestimation of ocean heat content in the upper layer ({\$}{\~{}}{\$}4.79 × 109 J or {\$}{\~{}}{\$}10{\%}). The pure thermal bias was found to be mostly negative, which is likely to be related to temperature errors. However, the Southern Ocean region is notoriously undersampled when compared to the rest of the World Ocean as well, as it is associated with strong spatial and temporal variability, thus raising the overall uncertainty on that estimate. Moreover, although the manufacturer's FRE has a satisfying performance in the Southern Ocean, the current community's recommended correction method still leads to improved temperature values in those waters. Finally, more studies are needed in order to fully understand the XBT regional bias and its implications for climate studies in the region.},
author = {Ribeiro, Natalia and Mata, Mauricio M and {De Azevedo}, Jos{\'{e}} Luiz L and Cirano, Mauro},
doi = {10.1175/JTECH-D-17-0086.1},
issn = {15200426},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {4},
pages = {911--926},
title = {{An assessment of the XBT fall-rate equation in the Southern Ocean}},
volume = {35},
year = {2018}
}
@article{Richardson2016,
author = {Richardson, Mark and Cowtan, Kevin and Hawkins, Ed and Stolpe, Martin B.},
doi = {10.1038/nclimate3066},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {931--935},
title = {{Reconciled climate response estimates from climate models and the energy budget of Earth}},
url = {http://www.nature.com/articles/nclimate3066},
volume = {6},
year = {2016}
}
@article{1748-9326-13-5-054004,
abstract = {The Paris Agreement on climate change aims to limit ‘global average temperature' rise to ‘well below 2 °C' but reported temperature depends on choices about how to blend air and water temperature data, handle changes in sea ice and account for regions with missing data. Here we use CMIP5 climate model simulations to estimate how these choices affect reported warming and carbon budgets consistent with the Paris Agreement. By the 2090s, under a low-emissions scenario, modelled global near-surface air temperature rise is 15{\%} higher (5{\%}–95{\%} range 6{\%}–21{\%}) than that estimated by an approach similar to the HadCRUT4 observational record. The difference reduces to 8{\%} with global data coverage, or 4{\%} with additional removal of a bias associated with changing sea-ice cover. Comparison of observational datasets with different data sources or infilling techniques supports our model results regarding incomplete coverage. From high-emission simulations, we find that a HadCRUT4 like definition means higher carbon budgets and later exceedance of temperature thresholds, relative to global near-surface air temperature. 2 °C warming is delayed by seven years on average, to 2048 (2035–2060), and CO 2 emissions budget for a {\textgreater}50{\%} chance of {\textless}2 °C warming increases by 67 GtC (246 GtCO 2 ).},
author = {Richardson, Mark and Cowtan, Kevin and Millar, Richard J},
doi = {10.1088/1748-9326/aab305},
journal = {Environmental Research Letters},
number = {5},
pages = {54004},
title = {{Global temperature definition affects achievement of long-term climate goals}},
url = {http://stacks.iop.org/1748-9326/13/i=5/a=054004},
volume = {13},
year = {2018}
}
@article{Ricker2015,
abstract = {Radar altimetry measurements of the current satellite mission CryoSat-2 show an increase of Arctic sea ice thickness in autumn 2013, compared to previous years but also related to March 2013. Such an increase over the melting season seems unlikely and needs to be investigated. Recent studies show that the influence of the snow cover is not negligible and can highly affect the CryoSat-2 range retrievals if it is assumed that the main scattering horizon is given by the snow-ice interface. Our analysis of Arctic ice mass balance buoy records and coincident CryoSat-2 data between 2012 and 2014 adds observational evidence to these findings. Linear trends of snow and ice freeboard measurements from buoys and nearby CryoSat-2 freeboard retrievals are calculated during accumulation events. We find a positive correlation between buoy snow freeboard and CryoSat-2 freeboard estimates, revealing that early snow accumulation might have caused a bias in CryoSat-2 sea ice thickness in autumn 2013.},
author = {Ricker, Robert and Hendricks, Stefan and Perovich, Donald K. and Helm, Veit and Gerdes, R{\"{u}}diger},
doi = {10.1002/2015GL064081},
isbn = {0094-8276},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {CryoSat-2,ice mass balance,radar altimetry,sea ice freeboard,sea ice thickness,snow depth},
number = {11},
pages = {4447--4455},
title = {{Impact of snow accumulation on CryoSat-2 range retrievals over Arctic sea ice: An observational approach with buoy data}},
volume = {42},
year = {2015}
}
@article{Rigby2019a,
abstract = {The recovery of the stratospheric ozone layer relies on the continued decline in the atmospheric concentrations of ozone-depleting gases such as chlorofluorocarbons1. The atmospheric concentration of trichlorofluoromethane (CFC-11), the second-most abundant chlorofluorocarbon, has declined substantially since the mid-1990s2. A recently reported slowdown in the decline of the atmospheric concentration of CFC-11 after 2012, however, suggests that global emissions have increased3,4. A concurrent increase in CFC-11 emissions from eastern Asia contributes to the global emission increase, but the location and magnitude of this regional source are unknown3. Here, using high-frequency atmospheric observations from Gosan, South Korea, and Hateruma, Japan, together with global monitoring data and atmospheric chemical transport model simulations, we investigate regional CFC-11 emissions from eastern Asia. We show that emissions from eastern mainland China are 7.0 ± 3.0 (±1 standard deviation) gigagrams per year higher in 2014–2017 than in 2008–2012, and that the increase in emissions arises primarily around the northeastern provinces of Shandong and Hebei. This increase accounts for a substantial fraction (at least 40 to 60 per cent) of the global rise in CFC-11 emissions. We find no evidence for a significant increase in CFC-11 emissions from any other eastern Asian countries or other regions of the world where there are available data for the detection of regional emissions. The attribution of any remaining fraction of the global CFC-11 emission rise to other regions is limited by the sparsity of long-term measurements of sufficient frequency near potentially emissive regions. Several considerations suggest that the increase in CFC-11 emissions from eastern mainland China is likely to be the result of new production and use, which is inconsistent with the Montreal Protocol agreement to phase out global chlorofluorocarbon production by 2010.},
author = {Rigby, M. and Park, S. and Saito, T. and Western, L. M. and Redington, A. L. and Fang, X. and Henne, S. and Manning, A. J. and Prinn, R. G. and Dutton, G. S. and Fraser, P. J. and Ganesan, A. L. and Hall, B. D. and Harth, C. M. and Kim, J. and Kim, K. R. and Krummel, P. B. and Lee, T. and Li, S. and Liang, Q. and Lunt, M. F. and Montzka, S. A. and M{\"{u}}hle, J. and O'Doherty, S. and Park, M. K. and Reimann, S. and Salameh, P. K. and Simmonds, P. and Tunnicliffe, R. L. and Weiss, R. F. and Yokouchi, Y. and Young, D.},
doi = {10.1038/s41586-019-1193-4},
issn = {14764687},
journal = {Nature},
number = {7757},
pages = {546--550},
title = {{Increase in CFC-11 emissions from eastern China based on atmospheric observations}},
volume = {569},
year = {2019}
}
@article{Rignot1095,
abstract = {We use updated drainage inventory, ice thickness, and ice velocity data to calculate the grounding line ice discharge of 176 basins draining the Antarctic Ice Sheet from 1979 to 2017. We compare the results with a surface mass balance model to deduce the ice sheet mass balance. The total mass loss increased from 40 ± 9 Gt/y in 1979–1990 to 50 ± 14 Gt/y in 1989–2000, 166 ± 18 Gt/y in 1999–2009, and 252 ± 26 Gt/y in 2009–2017. In 2009–2017, the mass loss was dominated by the Amundsen/Bellingshausen Sea sectors, in West Antarctica (159 ± 8 Gt/y), Wilkes Land, in East Antarctica (51 ± 13 Gt/y), and West and Northeast Peninsula (42 ± 5 Gt/y). The contribution to sea-level rise from Antarctica averaged 3.6 ± 0.5 mm per decade with a cumulative 14.0 ± 2.0 mm since 1979, including 6.9 ± 0.6 mm from West Antarctica, 4.4 ± 0.9 mm from East Antarctica, and 2.5 ± 0.4 mm from the Peninsula (i.e., East Antarctica is a major participant in the mass loss). During the entire period, the mass loss concentrated in areas closest to warm, salty, subsurface, circumpolar deep water (CDW), that is, consistent with enhanced polar westerlies pushing CDW toward Antarctica to melt its floating ice shelves, destabilize the glaciers, and raise sea level.},
author = {Rignot, Eric and Mouginot, J{\'{e}}r{\'{e}}mie and Scheuchl, Bernd and van den Broeke, Michiel and van Wessem, Melchior J. and Morlighem, Mathieu},
doi = {10.1073/pnas.1812883116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {4},
pages = {1095--1103},
publisher = {National Academy of Sciences},
title = {{Four decades of Antarctic Ice Sheet mass balance from 1979–2017}},
url = {https://www.pnas.org/content/116/4/1095},
volume = {116},
year = {2019}
}
@article{Ritz2013,
abstract = {The Atlantic meridional overturning circulation is a key component of the climate system. Data and climate model reconstructions reveal a decline in the strength of the overturning circulation during the Heinrich1 and Younger Dryas cold events of the last glacial period.},
author = {Ritz, Stefan P and Stocker, Thomas F and Grimalt, Joan O and Menviel, Laurie and Timmermann, Axel},
doi = {10.1038/ngeo1723},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {3},
pages = {208--212},
title = {{Estimated strength of the Atlantic overturning circulation during the last deglaciation}},
url = {https://doi.org/10.1038/ngeo1723},
volume = {6},
year = {2013}
}
@article{Roberts2012,
author = {Roberts, N. and Moreno, A. and Valero-Garces, B. L. and Corella, J. P. and Jones, M. and Allcock, S. and Woodbridge, J. and Morell{\'{o}}n, M. and Luterbachere, J. and Xoplaki, E. and T{\"{u}}rkes, M.},
doi = {10.1016/j.gloplacha.2011.11.002},
journal = {Global and Planetary Change},
number = {s1},
pages = {23--34},
title = {{Palaeolimnological evidence for an east–west climate see-saw in the Mediterranean since AD 900}},
volume = {84-85},
year = {2012}
}
@article{Roberts2019a,
author = {Roberts, J Brent and Clayson, C A and Robertson, Franklin R},
doi = {10.1029/2018EA000436},
issn = {2333-5084},
journal = {Earth and Space Science},
month = {jul},
number = {7},
pages = {1220--1233},
title = {{Improving Near‐Surface Retrievals of Surface Humidity Over the Global Open Oceans From Passive Microwave Observations}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2018EA000436},
volume = {6},
year = {2019}
}
@article{Robertson2016a,
author = {Robertson, Franklin R and Bosilovich, Michael G. and Roberts, J B},
doi = {10.1175/JCLI-D-16-0379.1},
journal = {Journal of Climate},
pages = {8625--8646},
title = {{Reconciling Land – Ocean Moisture Transport Variability in Reanalyses with P - ET in Observationally Driven Land Surface Models}},
volume = {29},
year = {2016}
}
@article{Robertson2020,
abstract = {Four state-of-the-art satellite-based estimates of ocean surface latent heat fluxes (LHFs) extending over three decades are analyzed, focusing on the interannual variability and trends of near-global averages and regional patterns. Detailed inter-comparisons are made with other datasets including: (i) reduced observation reanalyses (RedObs) whose exclusion of satellite data renders them an important independent diagnostic tool; (ii) a moisture budget residual LHF estimate using reanalysis moisture transport, atmospheric storage and satellite precipitation; (iii) the ECMWF Reanalysis 5 (ERA5); (iv) Remote Sensing Systems (RSS) single-sensor passive microwave and scatterometer wind speed retrievals, and (v) several sea-surface temperature (SST) datasets.Large disparities remain in near-global satellite LHF trends and their regional expression over the 1990-2010 period, during which time the Interdecadal Pacific Oscillation changed sign. The budget residual diagnostics support the smaller RedObs LHF trends. The satellites, ERA5 and RedObs are reasonably consistent in identifying contributions by the 10m wind speed variations to the LHF trend patterns. However, contributions by the near-surface vertical humidity gradient from satellites and ERA5 trend upward in time with respect to the RedObs ensemble and show less agreement in trend patterns.Problems with wind speed retrievals from Special Sensor Microwave Imager / Sounder satellite sensors, excessive upward trends in trends in Optimal Interpolation Sea Surface Temperature (OISST AVHRR-Only) data used in most satellite LHF estimates and uncertainties associated with poor satellite coverage before the mid-1990s are noted. Possibly erroneous trends are also identified in ERA5 LHF associated with the onset of scatterometer wind data assimilation in the early 1990s.},
author = {Robertson, Franklin R. and Roberts, Jason B. and Bosilovich, Michael G. and Bentamy, Abderrahim and Clayson, Carol Anne and Fennig, Karsten and Schr{\"{o}}der, Marc and Tomita, Hiroyuki and Compo, Gilbert P. and Gutenstein, Marloes and Hersbach, Hans and Kobayashi, Chiaki and Ricciardulli, Lucrezia and Sardeshmukh, Prashant and Slivinski, Laura C.},
doi = {10.1175/jcli-d-19-0954.1},
issn = {0894-8755},
journal = {Journal of Climate},
pages = {8415--8437},
title = {{Uncertainties in Ocean Latent Heat Flux Variations Over Recent Decades in Satellite-Based Estimates and Reduced Observation Reanalyses}},
volume = {33},
year = {2020}
}
@article{Robertson2014,
author = {Robertson, F. R. and Bosilovich, M. G. and Roberts, J. B. and Reichle, R. H. and Adler, R. and Ricciardulli, L. and Berg, W. and Huffman, G. J.},
doi = {10.1175/JCLI-D-13-00384.1},
journal = {Journal of Climate},
pages = {6135--6154},
title = {{Consistency of Estimated Global Water Cycle Variations over the Satellite Era}},
volume = {27},
year = {2014}
}
@article{Robson2016,
author = {Robson, Jon and Ortega, Pablo and Sutton, Rowan},
doi = {10.1038/ngeo2727},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {513--517},
publisher = {Nature Publishing Group},
title = {{A reversal of climatic trends in the North Atlantic since 2005}},
url = {http://dx.doi.org/10.1038/ngeo2727},
volume = {9},
year = {2016}
}
@article{Rodysill2018,
abstract = {This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators, including vegetation, lake water elevation, stream flow and runoff, cave drip rates, biological productivity, assemblages of living organisms, and salinity. Centennial-scale hydroclimate anomalies are obtained by iteratively sampling the proxy data on each of thousands of age model realizations and determining the fractions of possible time series indicating that the century-smoothed data was anomalously wet or dry relative to the 100 BCE to 1900 CE mean. Results suggest regionally asynchronous wet and dry periods over multidecadal to centennial timescales and frequent periods of extended regional drought. Most sites indicate drying during previously documented multicentennial periods of warmer Northern Hemisphere temperatures, particularly in the western U.S., central U.S., and Canada. Two widespread droughts were documented by the NAHS: from 50 BCE to 450 CE and from 800 to 1100 CE. Major hydroclimate reorganizations occurred out of sync with Northern Hemisphere temperature variations and widespread wet and dry anomalies occurred during both warm and cool periods. We present a broad assessment of paleoclimate relationships that highlights the potential influences of internal variability and external forcing and supports a prominent role for Pacific and Atlantic Ocean dynamics on century-scale continental hydroclimate.},
author = {Rodysill, Jessica R. and Anderson, Lesleigh and Cronin, Thomas M. and Jones, Miriam C. and Thompson, Robert S. and Wahl, David B. and Willard, Debra A. and Addison, Jason A. and Alder, Jay R. and Anderson, Katherine H. and Anderson, Lysanna and Barron, John A. and Bernhardt, Christopher E. and Hostetler, Steven W. and Kehrwald, Natalie M. and Khan, Nicole S. and Richey, Julie N. and Starratt, Scott W. and Strickland, Laura E. and Toomey, Michael R. and Treat, Claire C. and Wingard, G. Lynn},
doi = {10.1016/j.gloplacha.2017.12.025},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Common Era,Drought,North America,Paleoclimate},
number = {December 2017},
pages = {175--198},
title = {{A North American Hydroclimate Synthesis (NAHS) of the Common Era}},
volume = {162},
year = {2018}
}
@article{10.3389/fmars.2019.00439,
author = {Roemmich, Dean and Alford, Matthew H and Claustre, Herv{\'{e}} and Johnson, Kenneth and King, Brian and Moum, James and Oke, Peter and Owens, W Brechner and Pouliquen, Sylvie and Purkey, Sarah and Scanderbeg, Megan and Suga, Toshio and Wijffels, Susan and Zilberman, Nathalie and Bakker, Dorothee and Baringer, Molly and Belbeoch, Mathieu and Bittig, Henry C and Boss, Emmanuel and Calil, Paulo and Carse, Fiona and Carval, Thierry and Chai, Fei and Conchubhair, Diarmuid {\'{O}} and D'Ortenzio, Fabrizio and Dall'Olmo, Giorgio and Desbruyeres, Damien and Fennel, Katja and Fer, Ilker and Ferrari, Raffaele and Forget, Gael and Freeland, Howard and Fujiki, Tetsuichi and Gehlen, Marion and Greenan, Blair and Hallberg, Robert and Hibiya, Toshiyuki and Hosoda, Shigeki and Jayne, Steven and Jochum, Markus and Johnson, Gregory C and Kang, KiRyong and Kolodziejczyk, Nicolas and K{\"{o}}rtzinger, Arne and Traon, Pierre-Yves Le and Lenn, Yueng-Djern and Maze, Guillaume and Mork, Kjell Arne and Morris, Tamaryn and Nagai, Takeyoshi and Nash, Jonathan and Garabato, Alberto Naveira and Olsen, Are and Pattabhi, Rama Rao and Prakash, Satya and Riser, Stephen and Schmechtig, Catherine and Schmid, Claudia and Shroyer, Emily and Sterl, Andreas and Sutton, Philip and Talley, Lynne and Tanhua, Toste and Thierry, Virginie and Thomalla, Sandy and Toole, John and Troisi, Ariel and Trull, Thomas W and Turton, Jon and Velez-Belchi, Pedro Joaquin and Walczowski, Waldemar and Wang, Haili and Wanninkhof, Rik and Waterhouse, Amy F and Waterman, Stephanie and Watson, Andrew and Wilson, Cara and Wong, Annie P S and Xu, Jianping and Yasuda, Ichiro},
doi = {10.3389/fmars.2019.00439},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
pages = {439},
title = {{On the Future of Argo: A Global, Full-Depth, Multi-Disciplinary Array}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00439},
volume = {6},
year = {2019}
}
@article{Rohde2013b,
author = {Rohde, Robert A. and Muller, Richard and Jacobsen, Robert and Perlmutter, Saul and Rosenfeld, Arthur and Wurtele, Jonathan and Curry, Judith and Wickham, Charlotte and Mosher, Steven},
doi = {10.4172/gigs.1000103},
journal = {Geoinformatics {\&} Geostatistics: An Overview},
number = {2},
title = {{Berkeley Earth Temperature Averaging Process}},
volume = {1},
year = {2013}
}
@article{essd-12-3469-2020,
author = {Rohde, R A and Hausfather, Z},
doi = {10.5194/essd-12-3469-2020},
journal = {Earth System Science Data},
number = {4},
pages = {3469--3479},
title = {{The Berkeley Earth Land/Ocean Temperature Record}},
url = {https://essd.copernicus.org/articles/12/3469/2020/},
volume = {12},
year = {2020}
}
@article{ROHLING20171,
abstract = {Studies of past glacial cycles yield critical information about climate and sea-level (ice-volume) variability, including the sensitivity of climate to radiative change, and impacts of crustal rebound on sea-level reconstructions for past interglacials. Here we identify significant differences between the last and penultimate glacial maxima (LGM and PGM) in terms of global volume and distribution of land ice, despite similar temperatures and radiative forcing. Our analysis challenges conventional views of relationships between global ice volume, sea level, seawater oxygen isotope values, and deep-sea temperature, and supports the potential presence of large floating Arctic ice shelves during the PGM. The existence of different glacial ‘modes' calls for focussed research on the complex processes behind ice-age development. We present a glacioisostatic assessment to demonstrate how a different PGM ice-sheet configuration might affect sea-level estimates for the last interglacial. Results suggest that this may alter existing last interglacial sea-level estimates, which often use an LGM-like ice configuration, by several metres (likely upward).},
author = {Rohling, Eelco J and Hibbert, Fiona D and Williams, Felicity H and Grant, Katharine M and Marino, Gianluca and Foster, Gavin L and Hennekam, Rick and de Lange, Gert J and Roberts, Andrew P and Yu, Jimin and Webster, Jody M and Yokoyama, Yusuke},
doi = {10.1016/j.quascirev.2017.09.009},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Arctic ice shelf,Glacioisostatic adjustment,Ice volume,Last Glacial Maximum,Last Interglacial,Penultimate Glacial Maximum,Sea level,$\delta$O},
pages = {1--28},
title = {{Differences between the last two glacial maxima and implications for ice-sheet, $\delta$18O, and sea-level reconstructions}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379117303906},
volume = {176},
year = {2017}
}
@article{Rohling2007,
abstract = {This paper concerns the use of stable oxygen isotope ratios ({\$}\delta{\$} 18O) and stable hydrogen isotope ratios ({\$}\delta{\$} 2H or {\$}\delta{\$}D) to derive paleosalinity. First, I evaluate the potential and limitations of existing methods based on {\$}\delta{\$}18O and {\$}\delta{\$}D separately. Next, I propose a new theoretical framework for the combined use of {\$}\Delta{\$}18o and {\$}\delta{\$}D to constrain the impact of the hydrological cycle on the surface waters and to thus characterize changes in surface water salinity. This new method is accompanied by an error propagation exercise to demonstrate its limitations and areas of potential improvement. A feasible strategy is outlined for achieving reconstructions of paleosalinity change with an uncertainty of 1 practical salinity unit or less with the newly proposed method (especially in regions with high deuterium excess values. Copyright 2007 by the American Geophysical Union.},
author = {Rohling, Eelco J},
doi = {10.1029/2007PA001437},
issn = {08838305},
journal = {Paleoceanography},
keywords = {hydrogen isotopes,oxygen isotopes,paleosalinity},
month = {sep},
number = {3},
pages = {PA3215},
title = {{Progress in paleosalinity: Overview and presentation of a new approach}},
url = {http://doi.wiley.com/10.1029/2007PA001437},
volume = {22},
year = {2007}
}
@article{Rohling2019,
abstract = {The last interglacial (LIG; {\~{}}130 to {\~{}}118 thousand years ago, ka) was the last time global sea level rose well above the present level. Greenland Ice Sheet (GrIS) contributions were insufficient to explain the highstand, so that substantial Antarctic Ice Sheet (AIS) reduction is implied. However, the nature and drivers of GrIS and AIS reductions remain enigmatic, even though they may be critical for understanding future sea-level rise. Here we complement existing records with new data, and reveal that the LIG contained an AIS-derived highstand from {\~{}}129.5 to {\~{}}125 ka, a lowstand centred on 125–124 ka, and joint AIS + GrIS contributions from {\~{}}123.5 to {\~{}}118 ka. Moreover, a dual substructure within the first highstand suggests temporal variability in the AIS contributions. Implied rates of sea-level rise are high (up to several meters per century; m c−1), and lend credibility to high rates inferred by ice modelling under certain ice-shelf instability parameterisations.},
author = {Rohling, Eelco J and Hibbert, Fiona D and Grant, Katharine M and Galaasen, Eirik V and Irvalı, Nil and Kleiven, Helga F and Marino, Gianluca and Ninnemann, Ulysses and Roberts, Andrew P and Rosenthal, Yair and Schulz, Hartmut and Williams, Felicity H and Yu, Jimin},
doi = {10.1038/s41467-019-12874-3},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {5040},
title = {{Asynchronous Antarctic and Greenland ice-volume contributions to the last interglacial sea-level highstand}},
url = {https://doi.org/10.1038/s41467-019-12874-3},
volume = {10},
year = {2019}
}
@article{Rohrer2018,
abstract = {Atmospheric circulation types, blockings, and cyclones are central features of the extratropical flow and key to understanding the climate system. This study intercompares the representation of these features in 10 reanalyses and in an ensemble of 30 climate model simulations between 1980 and 2005. Both modern, full-input reanalyses and century-long, surface-input reanalyses are examined. Modern full-input reanalyses agree well on key statistics of blockings, cyclones, and circulation types. However, the intensity and depth of cyclones vary among them. Reanalyses with higher horizontal resolution show higher cyclone center densities and more intense cyclones. For blockings, no strict relationship is found between frequency or intensity and horizontal resolution. Full-input reanalyses contain more intense blocking, compared to surface-input reanalyses. Circulation-type classifications over central Europe show that both versions of the Twentieth Century Reanalysis dataset contain more easterlies and...},
author = {Rohrer, Marco and Br{\"{o}}nnimann, Stefan and Martius, Olivia and Raible, Christoph C. and Wild, Martin and Compo, Gilbert P.},
doi = {10.1175/JCLI-D-17-0350.1},
issn = {08948755},
journal = {Journal of Climate},
number = {8},
pages = {3009--3031},
title = {{Representation of extratropical cyclones, blocking anticyclones, and alpine circulation types in multiple reanalyses and model simulations}},
volume = {31},
year = {2018}
}
@article{RomanovskyVESmithSLIsaksenKNylandKEKholodovALShiklomanovNIStreletskiyDAFarquharsonLMDrozdovDSMalkovaGV2020,
author = {Romanovsky, VE and Smith, SL and Isaksen, K and Nyland, KE and Kholodov, AL and Shiklomanov, NI and Streletskiy, DA and Farquharson, LM and Drozdov, DS and Malkova, GV and Christiansen, HH},
doi = {10.1175/BAMS-D-20-0086.1},
journal = {Bulletin of the American Meteorological Society},
number = {8},
pages = {S265--S269},
title = {{The Arctic: Terrestrial Permafrost [in “State of the Climate in 2019”]}},
volume = {101},
year = {2020}
}
@incollection{RomanovskyV.E.SmithS.L.IsaksenK.ShiklomanovN.I.StreletskiyD.A.KholodovA.L.ChristiansenH.H.DrozdovD.S.MalkovaG.V.Marchenko2017,
author = {Romanovsky, V. E. and Smith, S. L. and Isaksen, K. and Shiklomanov, N. I. and Streletskiy, D. A. and Kholodov, A. L. and Christiansen, H. H. and Drozdov, D. S. and Malkova, G. V. and Marchenko1, S. S.},
booktitle = {Arctic Report Card 2017},
doi = {https://arctic.noaa.gov/Report-Card/Report-Card-2017},
pages = {54--59},
publisher = {National Oceanic and Atmospheric Administration (NOAA)},
title = {{Terrestrial Permafrost}},
url = {https://arctic.noaa.gov/Report-Card/Report-Card-2017},
year = {2017}
}
@incollection{RomanovskyV.IsaksenK.DrozdovD.AnisimovO.InstanesA.LeibmanM.McGuireA.D.ShiklomanovN.SmithS.L.Walker2017,
address = {Oslo, Norway},
author = {Romanovsky, V.E. and Isaksen, K. and Drozdov, D. and Anisimov, O. and Instanes, A. and Leibman, M. and McGuire, A. D. and Shiklomanov, N. and Smith, S. L. and Walker, D.},
booktitle = {Snow, Water, Ice and Permafrost in the Arctic (SWIPA) 2017},
doi = {https://www.amap.no/documents/doc/snow-water-ice-and-permafrost-in-the-arctic-swipa-2017/1610},
isbn = {978-82-7971-101-8},
pages = {65--102},
publisher = {Arctic Monitoring and Assessment Program (AMAP)},
title = {{Changing permafrost and its impacts}},
url = {https://www.amap.no/documents/doc/snow-water-ice-and-permafrost-in-the-arctic-swipa-2017/1610},
year = {2017}
}
@article{Rosenthal617,
abstract = {Global warming is popularly viewed only as an atmospheric process, when, as shown by marine temperature records covering the last several decades, most heat uptake occurs in the ocean. How did subsurface ocean temperatures vary during past warm and cold intervals? Rosenthal et al. (p. 617) present a temperature record of western equatorial Pacific subsurface and intermediate water masses over the past 10,000 years that shows that heat content varied in step with both northern and southern high-latitude oceans. The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future.Observed increases in ocean heat content (OHC) and temperature are robust indicators of global warming during the past several decades. We used high-resolution proxy records from sediment cores to extend these observations in the Pacific 10,000 years beyond the instrumental record. We show that water masses linked to North Pacific and Antarctic intermediate waters were warmer by 2.1 {\{}$\backslash$textpm{\}} 0.4{\{}$\backslash$textdegree{\}}C and 1.5 {\{}$\backslash$textpm{\}} 0.4{\{}$\backslash$textdegree{\}}C, respectively, during the middle Holocene Thermal Maximum than over the past century. Both water masses were {\~{}}0.9{\{}$\backslash$textdegree{\}}C warmer during the Medieval Warm period than during the Little Ice Age and {\~{}}0.65{\{}$\backslash$textdegree{\}} warmer than in recent decades. Although documented changes in global surface temperatures during the Holocene and Common era are relatively small, the concomitant changes in OHC are large.},
author = {Rosenthal, Yair and Linsley, Braddock K and Oppo, Delia W},
doi = {10.1126/science.1240837},
issn = {0036-8075},
journal = {Science},
number = {6158},
pages = {617--621},
publisher = {American Association for the Advancement of Science},
title = {{Pacific Ocean Heat Content During the Past 10,000 Years}},
url = {https://science.sciencemag.org/content/342/6158/617},
volume = {342},
year = {2013}
}
@article{RosenthalY.KalanskyJ.MorleyA.Linsley2017,
author = {Rosenthal, Yair and Kalansky, Julie and Morley, Audrey and Linsley, Braddock},
doi = {10.1016/j.quascirev.2016.10.017},
journal = {Quaternary Science Reviews},
pages = {1--12},
title = {{A paleo-perspective on ocean heat content: Lessons from the Holocene and Common Era}},
volume = {155},
year = {2017}
}
@article{Ross2020,
abstract = {Abstract Anthropogenic climate change is causing our oceans to lose oxygen and become more acidic at an unprecedented rate, threatening marine ecosystems and their associated animals. In deep-sea environments, where conditions have typically changed over geological timescales, the associated animals, adapted to these stable conditions, are expected to be highly vulnerable to any change or direct human impact. Our study coalesces one of the longest deep-sea observational oceanographic time series, reaching back to the 1960s, with a modern visual survey that characterizes almost two vertical kilometers of benthic seamount ecosystems. Based on our new and rigorous analysis of the Line P oceanographic monitoring data, the upper 3,000 m of the Northeast Pacific (NEP) has lost 15{\%} of its oxygen in the last 60 years. Over that time, the oxygen minimum zone (OMZ), ranging between approximately 480 and 1,700 m, has expanded at a rate of 3.0 ± 0.7 m/year (due to deepening at the bottom). Additionally, carbonate saturation horizons above the OMZ have been shoaling at a rate of 1?2 m/year since the 1980s. Based on our visual surveys of four NEP seamounts, these deep-sea features support ecologically important taxa typified by long life spans, slow growth rates, and limited mobility, including habitat-forming cold water corals and sponges, echinoderms, and fish. By examining the changing conditions within the narrow realized bathymetric niches for a subset of vulnerable populations, we resolve chemical trends that are rapid in comparison to the life span of the taxa and detrimental to their survival. If these trends continue as they have over the last three to six decades, they threaten to diminish regional seamount ecosystem diversity and cause local extinctions. This study highlights the importance of mitigating direct human impacts as species continue to suffer environmental changes beyond our immediate control.},
annote = {doi: 10.1111/gcb.15307},
author = {Ross, Tetjana and {Du Preez}, Cherisse and Ianson, Debby},
doi = {10.1111/gcb.15307},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {benthic ecosystems,climate change,cold water corals,ecosystem-based management,ocean acidification,ocean biogeochemistry,ocean deoxygenation,vulnerable marine ecosystems},
month = {nov},
number = {11},
pages = {6424--6444},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Rapid deep ocean deoxygenation and acidification threaten life on Northeast Pacific seamounts}},
url = {https://doi.org/10.1111/gcb.15307 https://onlinelibrary.wiley.com/doi/10.1111/gcb.15307},
volume = {26},
year = {2020}
}
@article{https://doi.org/10.1029/2020GL087456,
annote = {e2020GL087456 2020GL087456},
author = {Rossby, T and Chafik, L{\'{e}}on and Houpert, Lo{\"{i}}c},
doi = {10.1029/2020GL087456},
journal = {Geophysical Research Letters},
keywords = {AMV,Hydrography,Nordic Seas,Norr{\"{o}}na,Volume and heat transport},
number = {12},
pages = {e2020GL087456},
title = {{What can Hydrography Tell Us About the Strength of the Nordic Seas MOC Over the Last 70 to 100 Years?}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087456},
volume = {47},
year = {2020}
}
@article{Rouault2018a,
abstract = {A Benguela Ni{\~{n}}o developed in November 2010 and lasted for 5months along the Angolan and Namibian coastlines. Maximum amplitude was reached in January 2011 with an interannual monthly Sea Surface Temperature anomaly larger than 4°C at the Angola Benguela Front. It was the warmest event since 1995. Consistent with previous Benguela Ni{\~{n}}os, this event was generated by a relaxation of the trade winds in the western equatorial Atlantic, which triggered a strong equatorial Kelvin wave propagating eastward along the equator and then southward along the southwest African coast. In the equatorial band, the associated ocean sub-surface temperature anomaly clearly shows up in data from the PIRATA mooring array. The dynamical signature is also detected by altimetry derived Sea Surface Height and is well reproduced by an Ocean Linear Model. In contrast to previous Benguela Ni{\~{n}}os, the initial propagation of sub-surface temperature anomalies along the equator started in October and the associated warming in the Angolan Benguela Front Zone followed on as early as November 2010. The warming was then advected further south in the Northern Benguela upwelling system as far as 25°S by an anomalously strong poleward sub-surface current. Demise of the event was triggered by stronger than normal easterly winds along the Equator in April and May 2011 leading to above normal shoaling of the thermocline along the Equator and the south-west African coastline off Angola and an associated abnormal equatorward current at the Angola Benguela Front in April and May 2011.},
author = {Rouault, Mathieu and Illig, Serena and L{\"{u}}bbecke, Joke and Koungue, Rodrigue Anicet Imbol},
doi = {10.1016/j.jmarsys.2017.07.007},
issn = {0924-7963},
journal = {Journal of Marine Systems},
keywords = {Angola Current,Benguela Current,Benguela Ni{\~{n}}o,Benguela upwelling,PIRATA,Tropical Atlantic},
pages = {39--48},
title = {{Origin, development and demise of the 2010–2011 Benguela Ni{\~{n}}o}},
url = {http://www.sciencedirect.com/science/article/pii/S0924796316303876},
volume = {188},
year = {2018}
}
@article{Routson2019b,
author = {Routson, Cody C and Nicholas, P and Kaufman, Darrell S and Michael, P and Goosse, Hugues and Shuman, Bryan N and Rodysill, Jessica R and Ault, Toby},
doi = {10.1038/s41586-019-1060-3},
isbn = {4158601910603},
issn = {1476-4687},
journal = {Nature},
pages = {83--87},
publisher = {Springer US},
title = {{Mid-latitude net precipitation decreased with Arctic warming during the Holocene}},
url = {http://dx.doi.org/10.1038/s41586-019-1060-3},
volume = {568},
year = {2019}
}
@article{10.1093/gji/ggx156,
author = {Roy, Keven and Peltier, W R},
doi = {10.1093/gji/ggx156},
issn = {0956-540X},
journal = {Geophysical Journal International},
number = {2},
pages = {1115--1142},
title = {{Space-geodetic and water level gauge constraints on continental uplift and tilting over North America: regional convergence of the ICE-6G{\_}C (VM5a/VM6) models}},
url = {https://doi.org/10.1093/gji/ggx156},
volume = {210},
year = {2017}
}
@article{essd-11-473-2019,
author = {Rubino, M and Etheridge, D M and Thornton, D P and Howden, R and Allison, C E and Francey, R J and Langenfelds, R L and Steele, L P and Trudinger, C M and Spencer, D A and Curran, M A J and van Ommen, T D and Smith, A M},
doi = {10.5194/essd-11-473-2019},
journal = {Earth System Science Data},
number = {2},
pages = {473--492},
title = {{Revised records of atmospheric trace gases CO2, CH4, N2O, and $\delta$13C-CO2 over the last 2000 years from Law Dome, Antarctica}},
url = {https://www.earth-syst-sci-data.net/11/473/2019/},
volume = {11},
year = {2019}
}
@article{Rubino2020a,
abstract = {On global and hemispheric scales, sea-surface temperature (SST) anomalies are assumed to be good surrogates for near-surface marine air temperature (MAT) anomalies. In fact, global gridded temperature datasets commonly blend SST and near-surface air temperature anomalies to overcome the lack of geographically homogeneous and reliable MAT observations. Here, we show that SST and MAT anomalies differ regarding crucial statistical properties such as multiannual trends and probabilistic distributions of daily and monthly averages. We provide evidence of the lack of interchangeability from an array of moored buoys in the tropical Pacific Ocean. We identify statistically significant discrepancies between SST and MAT anomalies for single as well as groups of such buoys. Thus, caution is required when characterizing and interpreting MAT variability through SST observations, especially at shorter than decadal timescale.},
author = {Rubino, Angelo and Zanchettin, Davide and {De Rovere}, Francesco and McPhaden, Michael J},
doi = {10.1038/s41598-020-64167-1},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {7433},
title = {{On the interchangeability of sea-surface and near-surface air temperature anomalies in climatologies}},
url = {https://doi.org/10.1038/s41598-020-64167-1},
volume = {10},
year = {2020}
}
@article{Rumpf2018b,
author = {Rumpf, Sabine B. and H{\"{u}}lber, Karl and Zimmermann, Niklaus E. and Dullinger, Stefan},
doi = {10.1111/geb.12865},
isbn = {1466-822X},
issn = {14668238},
journal = {Global Ecology and Biogeography},
keywords = {climate change,elevation,leading edge,mountains,range dynamics,range limit,rear edge,trailing edge},
number = {4},
pages = {533--543},
title = {{Elevational rear edges shifted at least as much as leading edges over the last century}},
volume = {28},
year = {2018}
}
@article{Rupp2013,
abstract = {Significant declines in spring Northern Hemisphere (NH) snow cover extent (SCE) have been observed over the last five decades. As one step toward understanding the causes of this decline, an optimal finger- printing technique is used to look for consistency in the temporal pattern of spring NH SCE between ob- servations and simulations from 15 global climate models (GCMs) that form part of phase 5 of the Coupled Model Intercomparison Project. The authors examined simulations from 15GCMsthat included both natural and anthropogenic forcing and simulations from 7 GCMs that included only natural forcing. The decline in observedNHSCE could be largely explained by the combined natural and anthropogenic forcing but not by natural forcing alone. However, the 15 GCMs, taken as a whole, underpredicted the combined forcing re- sponse by a factor of 2. How much of this underprediction was due to underrepresentation of the sensitivity to external forcing of theGCMs or to their underrepresentation of internal variability has yet to be determined.},
author = {Rupp, David E. and Mote, Philip W. and Bindoff, Nathaniel L. and Stott, Peter A. and Robinson, David A.},
doi = {10.1175/JCLI-D-12-00563.1},
issn = {08948755},
journal = {Journal of Climate},
number = {18},
pages = {6904--6914},
title = {{Detection and attribution of observed changes in northern hemisphere spring snow cover}},
volume = {26},
year = {2013}
}
@article{Rustic1537,
abstract = {How have eastern equatorial Pacific sea surface temperatures varied over the past 1000 years? Today, the tropical Pacific Ocean has a large influence on global climate, through processes such as El Ni{\~{n}}o. Researchers would thus like to know how the ocean varied in the past. Although good records exist from the western ocean, the same has not been true for the eastern side. Rustic et al. analyzed marine sediments recovered from near the Galapagos Islands. They conclude that the tropical Pacific Ocean changed state about 500 years ago, near the transition between the warm Medieval Climate Anomaly and the cold Little Ice Age.Science, this issue p. 1537Tropical Pacific Ocean dynamics during the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA) are poorly characterized due to a lack of evidence from the eastern equatorial Pacific. We reconstructed sea surface temperature, El Ni{\~{n}}o{\{}$\backslash$textendash{\}}Southern Oscillation (ENSO) activity, and the tropical Pacific zonal gradient for the past millennium from Gal{\'{a}}pagos ocean sediments. We document a mid-millennium shift (MMS) in ocean-atmosphere circulation around 1500{\{}$\backslash$textendash{\}}1650 CE, from a state with dampened ENSO and strong zonal gradient to one with amplified ENSO and weak gradient. The MMS coincided with the deepest LIA cooling and was probably caused by a southward shift of the intertropical convergence zone. The peak of the MCA (900{\{}$\backslash$textendash{\}}1150 CE) was a warm period in the eastern Pacific, contradicting the paradigm of a persistent La Ni{\~{n}}a pattern.},
author = {Rustic, Gerald T and Koutavas, Athanasios and Marchitto, Thomas M and Linsley, Braddock K},
doi = {10.1126/science.aac9937},
issn = {0036-8075},
journal = {Science},
number = {6267},
pages = {1537--1541},
publisher = {American Association for the Advancement of Science},
title = {{Dynamical excitation of the tropical Pacific Ocean and ENSO variability by Little Ice Age cooling}},
url = {http://science.sciencemag.org/content/350/6267/1537},
volume = {350},
year = {2015}
}
@misc{ryu2020icno,
abstract = {The continuous growth of atmospheric nitrous oxide (N2O) is of concern for its potential role in global warming and future stratospheric ozone destruction. Climate feedbacks that enhance N2O emissions in response to global warming are not well understood, and past records of N2O from ice cores are not sufficiently well resolved to examine the underlying climate-N2O feedbacks on societally relevant time scales. Here, we present a new high-resolution and high-precision N2O reconstruction obtained from the Greenland NEEM (North Greenland Eemian Ice Drilling) and the Antarctic Styx Glacier ice cores. Covering the N2O history of the past two millennia, our reconstruction shows a centennial-scale variability of {\{}$\backslash$textasciitilde{\}}10 ppb. A pronounced minimum at {\{}$\backslash$textasciitilde{\}}600 CE coincides with the reorganizations of tropical hydroclimate and ocean productivity changes. Comparisons with proxy records suggest association of centennial- to millennial-scale variations in N2O with changes in tropical and subtropical land hydrology and marine productivity.},
author = {Ryu, Yeongjun and Ahn, Jinho and Yang, Ji-Woong and Brook, Edward J and Timmermann, Axel and Blunier, Thomas and Hur, Soondo and Kim, Seong-Joong},
doi = {10.1594/PANGAEA.923434},
publisher = {PANGAEA},
title = {{Ice core nitrous oxide over the past 2000 years}},
type = {data set},
url = {10.1594/PANGAEA.923434},
year = {2020}
}
@article{sanchez-montes_late_2019,
abstract = {Abstract.The initiation and evolution of the Cordilleran Ice Sheet is relatively poorly constrained. International Ocean Discovery Program (IODP) Expedition 341 recovered marine sediments at Site U1417 in the Gulf of Alaska (GOA). Here we present alkenone-derived sea surface temperature (SST) analyses alongside ice rafted debris (IRD), pollen, terrigenous and marine organic matter (OM) inputs to the GOA through the late Pliocene and early Pleistocene. The first IRD contribution from tidewater glaciers in southwest Alaska is recorded at 2.9{\&}thinsp;Ma, indicating that the Cordilleran ice sheet extent increased in the late Pliocene. A higher occurrence of IRD and higher sedimentation rates in the GOA during the early Pleistocene, at 2.5{\&}thinsp;Ma, occur in synchrony with SSTs warming on the order of 1{\&}thinsp;°C relative to the Pliocene. All records show a high degree of variability in the early Pleistocene, indicating highly efficient ocean-climate-ice interactions through warm SST-ocean evaporation-orographic precipitation-ice growth mechanisms. A climatic shift towards ocean circulation in the subarctic Pacific similar to the pattern observed during negative Pacific Decadal Oscillation (PDO) conditions today appears to be a necessary pre-requisite to develop the Cordilleran glaciation and increase moisture supply to the subarctic Pacific. The drop in atmospheric CO{\$}{\_}{\{}\backslashtextrm{\{}2{\}}{\}}{\$} concentrations since 2.8{\&}thinsp;Ma is suggested as one of the main forcing mechanisms driving the Cordilleran glaciation.},
author = {S{\'{a}}nchez-Montes, Maria Luisa and McClymont, Erin L and Lloyd, Jeremy M and M{\"{u}}ller, Juliane and Cowan, Ellen A and Zorzi, Coralie},
doi = {10.5194/cp-2019-29},
issn = {1814-9359},
journal = {Climate of the Past},
month = {mar},
number = {1},
pages = {299--313},
title = {{Late Pliocene Cordilleran Ice Sheet development with warm Northeast Pacific sea surface temperatures}},
url = {https://www.clim-past-discuss.net/cp-2019-29/},
volume = {16},
year = {2020}
}
@article{Sanchez-Velasco2019,
abstract = {Abstract The present state of deoxygenation in the northern limits of the shallow oxygen minimum zone off Mexico is examined in order to detect its effects on larval fish habitats and consider the sensitivity of fish larvae to decreased dissolved oxygen. A series of cruises between 2000 and 2017 indicated a significant vertical expansion of low oxygen waters. The upper limit of suboxic conditions ({\textless}4.4 ?mol/kg) has risen {\~{}}100 m at 19.5°N off Cabo Corrientes and {\~{}}50 m at 25°N in the mouth of the Gulf of California. The larval habitat distribution was related to the geographic variability of dissolved oxygen and water masses between these two latitudes. One recurrent larval habitat, with Bregmaceros bathymaster larvae as the indicator species, extended throughout the water column off Cabo Corrientes from Subtropical Subsurface Water (suboxic conditions) to the surface (220 ?mol/kg). The second recurrent habitat was located between the oxycline ({\textgreater}44 ?mol/kg) and the surface in association with the Gulf of California Water, with Benthosema panamense as the indicator species. During the warm El Ni{\~{n}}o event of 2015?2016, a tropical larval fish habitat (Auxis spp.) associated with Tropical Surface Water appeared to change the larval habitat distributions. These results indicate that some species are resilient to changes of dissolved oxygen and temperature generated by El Ni{\~{n}}o events and by continuing deoxygenation, although other species with more limited environmental windows could be affected by deoxygenation, probably leading to a change of the pelagic ecosystem over time.},
annote = {doi: 10.1029/2019JC015414},
author = {S{\'{a}}nchez-Velasco, Laura and God{\'{i}}nez, V{\'{i}}ctor M and Ruvalcaba-Aroche, Erick D and M{\'{a}}rquez-Artavia, Amaru and Beier, Emilio and Barton, Eric D and Jim{\'{e}}nez-Rosenberg, S Patricia A},
doi = {10.1029/2019JC015414},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {deoxygenation,eastern tropical North Pacific,fish larvae,shallow oxygen minimum zones},
month = {dec},
number = {12},
pages = {9690--9705},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Larval Fish Habitats and Deoxygenation in the Northern Limit of the Oxygen Minimum Zone off Mexico}},
url = {https://doi.org/10.1029/2019JC015414},
volume = {124},
year = {2019}
}
@article{Sejourne2015,
abstract = {As observed in most regions in the Arctic, the thawing of ice-rich permafrost (thermokarst) has been developing in Central Yakutia. However, the relationship between thermokarst development and climate variations is not well understood in this region, in particular the development rate of thaw slumps. The objective of this paper is to understand the current development of thermokarst by studying the evolution of the banks of thermokarst lakes. We studied retrogressive thaw slumps and highly degraded ice-wedge polygons (baydjarakhs), indicative of thermokarst, using high resolution satellite images taken in 2011-2013 and conducting field studies. The retrogressive thaw slump activity results in the formation of thermocirque with a minimum and maximum average headwall retreat of 0.5 and 3.16m{\textperiodcentered}yr-1 respectively. The thermocirques and the baydjarakhs are statistically more concentrated on the south- to southwest-facing banks of thermokarst lakes. Moreover, the rate of headwall retreat of the thermocirques is the most important on the south-facing banks of the lakes. These observations indicate a control of the current permafrost thaw on the banks of thermokarst lakes by insolation. In the context of recent air temperature increase in Central Yakutia, the rate of thermocirque development may increase in the future.},
author = {S{\'{e}}journ{\'{e}}, A. and Costard, F. and Fedorov, A. and Gargani, J. and Skorve, J. and Mass{\'{e}}, M. and M{\`{e}}ge, D.},
doi = {10.1016/j.geomorph.2015.03.033},
issn = {0169555X},
journal = {Geomorphology},
keywords = {Ground ice,Periglacial,Siberia,Slump,Thermokarst},
month = {jul},
pages = {31--40},
title = {{Evolution of the banks of thermokarst lakes in Central Yakutia (Central Siberia) due to retrogressive thaw slump activity controlled by insolation}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0169555X15001841},
volume = {241},
year = {2015}
}
@article{Sachs2018,
author = {Sachs, J P and Blois, J and Mcgee, T and Wolhowe, M and Haberle, S and Clark, G and Atahan, P},
doi = {10.1029/2018PA003469},
journal = {Paleoceanography and Paleoclimatology},
pages = {1383--1395},
title = {{Southward Shift of the Pacific ITCZ During the Holocene}},
volume = {33},
year = {2018}
}
@article{Sadekov2013,
abstract = {The El Ni{\~{n}}o-Southern Oscillation (ENSO) is one of the most important components of the global climate system, but its potential response to an anthropogenic increase in atmospheric CO2 remains largely unknown. One of the major limitations in ENSO prediction is our poor understanding of the relationship between ENSO variability and long-term changes in Tropical Pacific oceanography. Here we investigate this relationship using palaeorecords derived from the geochemistry of planktonic foraminifera. Our results indicate a strong negative correlation between ENSO variability and zonal gradient of sea-surface temperatures across the Tropical Pacific during the last 22 ky. This strong correlation implies a mechanistic link that tightly couples zonal sea-surface temperature gradient and ENSO variability during large climate changes and provides a unique insight into potential ENSO evolution in the future by suggesting enhanced ENSO variability under a global warming scenario.},
author = {Sadekov, Aleksey Yu and Ganeshram, Raja and Pichevin, Laetitia and Berdin, Rose and McClymont, Erin and Elderfield, Henry and Tudhope, Alexander W},
doi = {10.1038/ncomms3692},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {2692},
title = {{Palaeoclimate reconstructions reveal a strong link between El Ni{\~{n}}o–Southern Oscillation and Tropical Pacific mean state}},
url = {https://doi.org/10.1038/ncomms3692},
volume = {4},
year = {2013}
}
@article{Salamalikis2021,
abstract = {This global study analyzes how the total column water vapor (in terms of precipitable water, PW) is related to the attenuation of shortwave solar radiation (SWR) using data from the MERRA-2 reanalysis during 2000–2014 and SWR simulations obtained with the REST2 clear-sky radiation model. The water vapor radiative effect (WVRE) on SWR attenuation is investigated by comparing the clear-sky SWR predictions under humid and ideally dry atmospheres, whereas the quantitative effect of PW on WVRE is determined using the concept of precipitable water efficiency (PWE). At global scale, WVRE exhibits a distinct seasonal pattern ranging from –80.2 to 0 W m-2, with lower values in humid regions where PW is typically high ({\textgreater}4 cm), making the water vapor contribution relatively small. This is attributed to the saturation effect in water vapor absorption. Over arid regions, the solar irradiance attenuation is mainly controlled by the high aerosol loads, and less negative WVRE values are found. Over high-altitude regions, the low PW reduces the atmospheric absorption, resulting in low absolute WVRE magnitudes. PWE is found to extend globally between –133.7 and 0 W m-2 cm-1 on a monthly scale. This range is smaller on a long-term mean monthly or annual basis. On a long-term basis, the monthly PWE results are mainly concentrated between −20 and 0 W m−2 cm−1, generating leptokurtic and left-skewed distributions peaking between −10 and −8 W m−2 cm−1, depending on month. PWE is inversely related to PW on a long-term annual scale, indicating that PWE tends to zero under very humid conditions. A general nonlinear model is proposed to evaluate the hourly PWE at global scale on a monthly basis, separately for the two hemispheres. A PW trend analysis reveals that the Middle East, equatorial regions, central Europe, and Australia exhibit significant temporal trends, further inducing significant trends in WVRE. For those areas, WVRE trends are calculated between −3.3 and 1.5 W m−2 over the entire 15-year period. In addition, the global WVRE over landmasses is classified in terms of the K{\"{o}}ppen-Geiger (KG) climate classification system. The most pronounced radiative effects are found over the equatorial regions, with an average WVRE of −63 W m−2. The Arid KG class provides a complex WVRE pattern ranging from −66 to −24 W m−2. Further segregation of this class shows strongly variable WVRE, induced by local climate differentiation. Over Warm Temperate climates, WVRE is found to vary widely according to the various KG subclasses. For the Cold climate class, PW is mainly concentrated around 1 cm and WVRE is low. The Polar regions include high mountains where WVRE is low, with a median close to −28 W m−2.},
author = {Salamalikis, Vasileios and Vamvakas, Ioannis and Gueymard, Christian A. and Kazantzidis, Andreas},
doi = {10.1016/j.atmosres.2020.105418},
issn = {01698095},
journal = {Atmospheric Research},
keywords = {Atmospheric water vapor,Global shortwave irradiance,K{\"{o}}ppen-Geiger climate classification,Water vapor efficiency,Water vapor radiative effects},
number = {September 2020},
pages = {105418},
publisher = {Elsevier B.V.},
title = {{Atmospheric water vapor radiative effects on shortwave radiation under clear skies: A global spatiotemporal analysis}},
url = {https://doi.org/10.1016/j.atmosres.2020.105418},
volume = {251},
year = {2021}
}
@article{Salt2015,
author = {Salt, L A and van Heuven, S M A C and Claus, M E and Jones, E M and de Baar, H J W},
doi = {10.5194/bg-12-1387-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {5},
pages = {1387--1401},
publisher = {Copernicus Publications},
title = {{Rapid acidification of mode and intermediate waters in the southwestern Atlantic Ocean}},
url = {https://bg.copernicus.org/articles/12/1387/2015/ https://bg.copernicus.org/articles/12/1387/2015/bg-12-1387-2015.pdf},
volume = {12},
year = {2015}
}
@article{Salzmann2008,
abstract = {Aim To produce a robust, comprehensive global biome reconstruction for the Middle Pliocene (c. 3.6–2.6 Ma), which is based on an internally consistent palaeobotanical data set and a state-of-the-art coupled climate–vegetation model. The reconstruction gives a more rigorous picture of climate and environmental change during the Middle Pliocene and provides a new boundary condition for future general circulation model (GCM) studies.$\backslash$r$\backslash$n$\backslash$r$\backslash$nLocation Global.$\backslash$r$\backslash$n$\backslash$r$\backslash$nMethods Compilation of Middle Pliocene vegetation data from 202 marine and terrestrial sites into the comprehensive GIS data base TEVIS (Tertiary Environmental Information System). Translation into an internally consistent classification scheme using 28 biomes. Comparison and synthesis of vegetation reconstruction from palaeodata with the outputs of the mechanistically based BIOME4 model forced by climatology derived from the HadAM3 GCM.$\backslash$r$\backslash$n$\backslash$r$\backslash$nResults The model results compare favourably with available palaeodata and highlight the importance of employing vegetation–climate feedbacks and the anomaly method in biome models. Both the vegetation reconstruction from palaeobotanical data and the BIOME4 prediction indicate a general warmer and moister climate for the Middle Pliocene. Evergreen taiga as well as temperate forest and grassland shifted northward, resulting in much reduced tundra vegetation. Warm-temperate forests (with subtropical taxa) spread in mid and eastern Europe and tropical savannas and woodland expanded in Africa and Australia at the expense of deserts. Discrepancies which occurred between data reconstruction and model simulation can be related to: (1) poor spatial model resolution and data coverage; (2) uncertainties in delimiting biomes using climate parameters; or (3) uncertainties in model physics and/or geological boundary conditions.$\backslash$r$\backslash$n$\backslash$r$\backslash$nMain conclusions The new global biome reconstruction combines vegetation reconstruction from palaeobotanical proxies with model simulations. It is an important contribution to the further understanding of climate and vegetation changes during the Middle Pliocene warm interval and will enhance our knowledge about how vegetation may change in the future.},
author = {Salzmann, U. and Haywood, A. M. and Lunt, D. J. and Valdes, P. J. and Hill, D. J.},
doi = {10.1111/j.1466-8238.2008.00381.x},
issn = {1466822X},
journal = {Global Ecology and Biogeography},
keywords = {BIOME4,Biome,Climate change,General circulation model,Palaeobotany,Palynology,Pliocene,TRIFFID,Tertiary,Vegetation},
number = {3},
pages = {432--447},
title = {{A new global biome reconstruction and data-model comparison for the Middle Pliocene}},
volume = {17},
year = {2008}
}
@article{Salzmann2013,
abstract = {Comparing simulations of key warm periods in Earth history with contemporaneous geological proxy data is a useful approach for evaluating the ability of climate models to simulate warm, high-CO2 climates that are unprecedented in the more recent past1–3. Here we use a global data set of confidence-assessed, proxy-based temperature estimates and biome reconstructions to assess the ability of eight models to simulate warm terrestrial climates of the Pliocene epoch. The Late Pliocene, 3.6–2.6 million years ago, is an accessi- ble geological interval to understand climate processes of a warmer world4. We show that model-predicted surface air temperatures reveal a substantial cold bias in the Northern Hemisphere. Particularly strong data–model mismatches in mean annual temperatures (up to 18 ◦C) exist in northern Rus- sia. Our model sensitivity tests identify insufficient temporal constraints hampering the accurate configuration of model boundary conditions as an important factor impacting on data– model discrepancies.We conclude that to allow a more robust evaluation of the ability of present climate models to predict warm climates, future Pliocene data–model comparison studies should focus on orbitally defined time slices5.},
author = {Salzmann, Ulrich and Dolan, Aisling M. and Haywood, Alan M. and Chan, Wing Le and Voss, Jochen and Hill, Daniel J. and Abe-Ouchi, Ayako and Otto-Bliesner, Bette and Bragg, Frances J. and Chandler, Mark A. and Contoux, Camille and Dowsett, Harry J. and Jost, Anne and Kamae, Youichi and Lohmann, Gerrit and Lunt, Daniel J. and Pickering, Steven J. and Pound, Matthew J. and Ramstein, Gilles and Rosenbloom, Nan A. and Sohl, Linda and Stepanek, Christian and Ueda, Hiroaki and Zhang, Zhongshi},
doi = {10.1038/nclimate2008},
isbn = {1758-678X},
issn = {1758678X},
journal = {Nature Climate Change},
pages = {969--974},
title = {{Challenges in quantifying Pliocene terrestrial warming revealed by data-model discord}},
volume = {3},
year = {2013}
}
@article{Samset2019,
abstract = {The climate of South and East Asia is affected by anthropogenic aerosols, but the magnitude of the aerosol imprint is not well known. As regional emissions are rapidly changing, potential related climate risks must be quantified.},
author = {Samset, Bj{\o}rn H and Lund, Marianne T and Bollasina, Massimo and Myhre, Gunnar and Wilcox, Laura},
doi = {10.1038/s41561-019-0424-5},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {8},
pages = {582--584},
title = {{Emerging Asian aerosol patterns}},
url = {https://doi.org/10.1038/s41561-019-0424-5},
volume = {12},
year = {2019}
}
@article{SANBORN201760,
abstract = {Fossil coral reefs are valuable recorders of glacio-eustatic sea-level changes, as they provide key temporal information on deglacial meltwater pulses (MWPs). The timing, rate, magnitude, and meltwater source of these sea-level episodes remain controversial, despite their importance for understanding ocean-ice sheet dynamics during periods of abrupt climatic change. This study revisits the west coast of the Big Island of Hawaii to investigate the timing of the −150 m H1d terrace drowning off Kawaihae in response to MWP-1A. We present eight new calibrated 14C-AMS ages, which constrain the timing of terrace drowning to at or after 14.75 + 0.33/-0.42 kyr BP, coeval with the age of reef drowning at Kealakekua Bay (U-Th age 14.72 ± 0.10 kyr BP), 70 kms south along the west coast. Integrating the chronology with high-resolution bathymetry and backscatter data, detailed sedimentological analysis, and paleoenvironmental interpretation, we conclude the H1d terrace drowned at the same time along the west coast of Hawaii in response to MWP-1A. The timing of H1d reef drowning is within the reported uncertainty of the timing of MWP-1A interpreted from the IODP Expedition 310 Tahitian reef record.},
author = {Sanborn, Kelsey L and Webster, Jody M and Yokoyama, Yusuke and Dutton, Andrea and Braga, Juan C and Clague, David A and Paduan, Jennifer B and Wagner, Daniel and Rooney, John J and Hansen, John R},
doi = {10.1016/j.quascirev.2017.08.022},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Coastal,Coral reef drowning,Deglaciation,Geomorphology,Hawaii,Late pleistocene,Meltwater Pulse-1A,Sea-level changes,Submerged terraces},
pages = {60--72},
title = {{New evidence of Hawaiian coral reef drowning in response to meltwater pulse-1A}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379117306728},
volume = {175},
year = {2017}
}
@article{doi:10.1002/joc.1756,
abstract = {Abstract A recent report of the U.S. Climate Change Science Program (CCSP) identified a ‘potentially serious inconsistency' between modelled and observed trends in tropical lapse rates (Karl et al., 2006). Early versions of satellite and radiosonde datasets suggested that the tropical surface had warmed more than the troposphere, while climate models consistently showed tropospheric amplification of surface warming in response to human-caused increases in well-mixed greenhouse gases (GHGs). We revisit such comparisons here using new observational estimates of surface and tropospheric temperature changes. We find that there is no longer a serious discrepancy between modelled and observed trends in tropical lapse rates. This emerging reconciliation of models and observations has two primary explanations. First, because of changes in the treatment of buoy and satellite information, new surface temperature datasets yield slightly reduced tropical warming relative to earlier versions. Second, recently developed satellite and radiosonde datasets show larger warming of the tropical lower troposphere. In the case of a new satellite dataset from Remote Sensing Systems (RSS), enhanced warming is due to an improved procedure of adjusting for inter-satellite biases. When the RSS-derived tropospheric temperature trend is compared with four different observed estimates of surface temperature change, the surface warming is invariably amplified in the tropical troposphere, consistent with model results. Even if we use data from a second satellite dataset with smaller tropospheric warming than in RSS, observed tropical lapse rate trends are not significantly different from those in all other model simulations. Our results contradict a recent claim that all simulated temperature trends in the tropical troposphere and in tropical lapse rates are inconsistent with observations. This claim was based on use of older radiosonde and satellite datasets, and on two methodological errors: the neglect of observational trend uncertainties introduced by interannual climate variability, and application of an inappropriate statistical ‘consistency test'. Copyright {\textcopyright} 2008 Royal Meteorological Society},
author = {Santer, B D and Thorne, P W and Haimberger, L and Taylor, K E and Wigley, T M L and Lanzante, J R and Solomon, S and Free, M and Gleckler, P J and Jones, P D and Karl, T R and Klein, S A and Mears, C and Nychka, D and Schmidt, G A and Sherwood, S C and Wentz, F J},
doi = {10.1002/joc.1756},
journal = {International Journal of Climatology},
keywords = {climate model evaluation,differential warming of surface and temperature,statistical significance of trend differences,tropical lapse rates,tropospheric temperature changes},
number = {13},
pages = {1703--1722},
title = {{Consistency of modelled and observed temperature trends in the tropical troposphere}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.1756},
volume = {28},
year = {2008}
}
@incollection{SanterB.D.T.M.L.WigleyT.P.Barnett1996,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {Santer, B.D. and Wigley, T.M.L. and Barnett, T.P. and Anyamba, E.},
booktitle = {Climate Change 1995: The Science of Climate Change. Contribution of Working Group I to the Second Assessment Report of the Intergovernmental Panel on Climate Change},
doi = {https://www.ipcc.ch/report/ar2/wg1},
editor = {Houghton, J.T. and Filho, L.G. Meira and Callander, B.A. and Harris, N. and Kattenberg, A. and Maskell, K.},
isbn = {0521564336},
pages = {407--444},
publisher = {Cambridge University Press},
title = {{Detection of climate change and attribution of causes}},
url = {https://www.ipcc.ch/report/ar2/wg1},
year = {1996}
}
@article{Sapart2012,
abstract = {Nature 490, 85 (2012). doi:10.1038/nature11461},
author = {Sapart, C. J. and Monteil, G. and Prokopiou, M. and {Van De Wal}, R. S.W. and Kaplan, J. O. and Sperlich, P. and Krumhardt, K. M. and {Van Der Veen}, C. and Houweling, S. and Krol, M. C. and Blunier, T. and Sowers, T. and Martinerie, P. and Witrant, E. and Dahl-Jensen, D. and R{\"{o}}ckmann, T.},
doi = {10.1038/nature11461},
isbn = {0028-0836},
issn = {00280836},
journal = {Nature},
pages = {85--88},
pmid = {23038470},
title = {{Natural and anthropogenic variations in methane sources during the past two millennia}},
volume = {490},
year = {2012}
}
@article{Sapiano2012,
abstract = {The timing or phenology of the annual cycle of phytoplankton biomass can be monitored to better understand the underpinnings of the marine ecosystem and assess its response to environmental change. Ten-year, global maps of the mean date of bloom onset, peak concentration and termination of bloom duration were constructed by extracting these phenological metrics from Generalized Linear Models (GLM) fit to time series of 1° ? 1° daily estimates of SeaWiFS chlorophyll concentrations dating from September 1997 to December 2007 as well as to MODIS chlorophyll concentrations from July 2002 to July 2010. The fitted models quantitatively define the annual cycle of phytoplankton throughout the global ocean and from which a baseline of phenological characteristics was extracted. The analysis revealed regionally consistent patterns in the shape and timing of the annual cycle of chlorophyll concentration that are broadly consistent with other published studies. The results showed that a single bloom predominates over the global ocean with secondary, autumn blooms being limited in both location and spatial extent. Bloom duration tended to be zonally consistent, but meridionally complex and did not become progressively shorter with increasing latitude as is sometimes depicted. Both the shape of the annual cycle and the phenological climatologies can be used in future studies to detect significant departures over time.},
annote = {doi: 10.1029/2012JC007958},
author = {Sapiano, M R P and Brown, C W and {Schollaert Uz}, S and Vargas, M},
doi = {10.1029/2012JC007958},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Oceans},
keywords = {MODIS,SeaWiFS,generalized linear model,global,phenology,phytoplankton},
month = {aug},
number = {C8},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Establishing a global climatology of marine phytoplankton phenological characteristics}},
url = {https://doi.org/10.1029/2012JC007958},
volume = {117},
year = {2012}
}
@article{Sasgen2020,
author = {Sasgen, Ingo and Wouters, Bert and Gardner, Alex S. and King, Michalea D. and Tedesco, Marco and Landerer, Felix W. and Dahle, Christoph and Save, Himanshu and Fettweis, Xavier},
doi = {10.1038/s43247-020-0010-1},
issn = {2662-4435},
journal = {Communications Earth {\&} Environment},
month = {dec},
number = {1},
pages = {8},
title = {{Return to rapid ice loss in Greenland and record loss in 2019 detected by the GRACE-FO satellites}},
url = {http://www.nature.com/articles/s43247-020-0010-1},
volume = {1},
year = {2020}
}
@article{Sathyendranath:20,
abstract = {Primary production and photoacclimation models are two important classes of physiological models that find applications in remote sensing of pools and fluxes of carbon associated with phytoplankton in the ocean. They are also key components of ecosystem models designed to study biogeochemical cycles in the ocean. So far, these two classes of models have evolved in parallel, somewhat independently of each other. Here we examine how they are coupled to each other through the intermediary of the photosynthesis--irradiance parameters. We extend the photoacclimation model to accommodate the spectral effects of light penetration in the ocean and the spectral sensitivity of the initial slope of the photosynthesis--irradiance curve, making the photoacclimation model fully compatible with spectrally resolved models of photosynthesis in the ocean. The photoacclimation model contains a parameter {\$}\theta{\$}m, which is the maximum chlorophyll-to-carbon ratio that phytoplankton can attain when available light tends to zero. We explore how size-class-dependent values of {\$}\theta{\$}m could be inferred from field data on chlorophyll and carbon content in phytoplankton, and show that the results are generally consistent with lower bounds estimated from satellite-based primary production calculations. This was accomplished using empirical models linking phytoplankton carbon and chlorophyll concentration, and the range of values obtained in culture measurements. We study the equivalence between different classes of primary production models at the functional level, and show that the availability of a chlorophyll-to-carbon ratio facilitates the translation between these classes. We discuss the importance of the better assignment of parameters in primary production models as an important avenue to reduce model uncertainties and to improve the usefulness of satellite-based primary production calculations in climate research.},
author = {Sathyendranath, Shubha and Platt, Trevor and Kova{\v{c}}, {\v{Z}}arko and Dingle, James and Jackson, Thomas and Brewin, Robert J W and Franks, Peter and Mara{\~{n}}{\'{o}}n, Emilio and Kulk, Gemma and Bouman, Heather A},
doi = {10.1364/AO.386252},
journal = {Applied Optics},
keywords = {Fundamental processes,Light fields,Ocean color},
month = {apr},
number = {10},
pages = {C100--C114},
publisher = {OSA},
title = {{Reconciling models of primary production and photoacclimation}},
url = {http://ao.osa.org/abstract.cfm?URI=ao-59-10-C100},
volume = {59},
year = {2020}
}
@article{s19194285,
abstract = {Ocean colour is recognised as an Essential Climate Variable (ECV) by the Global Climate Observing System (GCOS); and spectrally-resolved water-leaving radiances (or remote-sensing reflectances) in the visible domain, and chlorophyll-a concentration are identified as required ECV products. Time series of the products at the global scale and at high spatial resolution, derived from ocean-colour data, are key to studying the dynamics of phytoplankton at seasonal and inter-annual scales; their role in marine biogeochemistry; the global carbon cycle; the modulation of how phytoplankton distribute solar-induced heat in the upper layers of the ocean; and the response of the marine ecosystem to climate variability and change. However, generating a long time series of these products from ocean-colour data is not a trivial task: algorithms that are best suited for climate studies have to be selected from a number that are available for atmospheric correction of the satellite signal and for retrieval of chlorophyll-a concentration; since satellites have a finite life span, data from multiple sensors have to be merged to create a single time series, and any uncorrected inter-sensor biases could introduce artefacts in the series, e.g., different sensors monitor radiances at different wavebands such that producing a consistent time series of reflectances is not straightforward. Another requirement is that the products have to be validated against in situ observations. Furthermore, the uncertainties in the products have to be quantified, ideally on a pixel-by-pixel basis, to facilitate applications and interpretations that are consistent with the quality of the data. This paper outlines an approach that was adopted for generating an ocean-colour time series for climate studies, using data from the MERIS (MEdium spectral Resolution Imaging Spectrometer) sensor of the European Space Agency; the SeaWiFS (Sea-viewing Wide-Field-of-view Sensor) and MODIS-Aqua (Moderate-resolution Imaging Spectroradiometer-Aqua) sensors from the National Aeronautics and Space Administration (USA); and VIIRS (Visible and Infrared Imaging Radiometer Suite) from the National Oceanic and Atmospheric Administration (USA). The time series now covers the period from late 1997 to end of 2018. To ensure that the products meet, as well as possible, the requirements of the user community, marine-ecosystem modellers, and remote-sensing scientists were consulted at the outset on their immediate and longer-term requirements as well as on their expectations of ocean-colour data for use in climate research. Taking the user requirements into account, a series of objective criteria were established, against which available algorithms for processing ocean-colour data were evaluated and ranked. The algorithms that performed best with respect to the climate user requirements were selected to process data from the satellite sensors. Remote-sensing reflectance data from MODIS-Aqua, MERIS, and VIIRS were band-shifted to match the wavebands of SeaWiFS. Overlapping data were used to correct for mean biases between sensors at every pixel. The remote-sensing reflectance data derived from the sensors were merged, and the selected in-water algorithm was applied to the merged data to generate maps of chlorophyll concentration, inherent optical properties at SeaWiFS wavelengths, and the diffuse attenuation coefficient at 490 nm. The merged products were validated against in situ observations. The uncertainties established on the basis of comparisons with in situ data were combined with an optical classification of the remote-sensing reflectance data using a fuzzy-logic approach, and were used to generate uncertainties (root mean square difference and bias) for each product at each pixel.},
author = {Sathyendranath, Shubha and Brewin, Robert J W and Brockmann, Carsten and Brotas, Vanda and Calton, Ben and Chuprin, Andrei and Cipollini, Paolo and Couto, Andr{\'{e}} B and Dingle, James and Doerffer, Roland and Donlon, Craig and Dowell, Mark and Farman, Alex and Grant, Mike and Groom, Steve and Horseman, Andrew and Jackson, Thomas and Krasemann, Hajo and Lavender, Samantha and Martinez-Vicente, Victor and Mazeran, Constant and M{\'{e}}lin, Fr{\'{e}}d{\'{e}}ric and Moore, Timothy S and M{\"{u}}ller, Dagmar and Regner, Peter and Roy, Shovonlal and Steele, Chris J and Steinmetz, Fran{\c{c}}ois and Swinton, John and Taberner, Malcolm and Thompson, Adam and Valente, Andr{\'{e}} and Z{\"{u}}hlke, Marco and Brando, Vittorio E and Feng, Hui and Feldman, Gene and Franz, Bryan A and Frouin, Robert and Gould, Richard W and Hooker, Stanford B and Kahru, Mati and Kratzer, Susanne and Mitchell, B Greg and Muller-Karger, Frank E and Sosik, Heidi M and Voss, Kenneth J and Werdell, Jeremy and Platt, Trevor},
doi = {10.3390/s19194285},
issn = {1424-8220},
journal = {Sensors},
number = {19},
pages = {4285},
title = {{An Ocean-Colour Time Series for Use in Climate Studies: The Experience of the Ocean-Colour Climate Change Initiative (OC-CCI)}},
url = {https://www.mdpi.com/1424-8220/19/19/4285},
volume = {19},
year = {2019}
}
@article{Schupbach2018,
author = {Sch{\"{u}}pbach, S. and Fischer, H. and Bigler, M. and Erhardt, T. and Gfeller, G. and Leuenberger, D. and Mini, O. and Mulvaney, R. and Abram, N. J. and Fleet, L. and Frey, M. M. and Thomas, E. and Svensson, A. and Dahl-Jensen, D. and Kettner, E. and Kjaer, H. and Seierstad, I. and Steffensen, J. P. and Rasmussen, S. O. and Vallelonga, P. and Winstrup, M. and Wegner, A. and Twarloh, B. and Wolff, K. and Schmidt, K. and Goto-Azuma, K. and Kuramoto, T. and Hirabayashi, M. and Uetake, J. and Zheng, J. and Bourgeois, J. and Fisher, D. and Zhiheng, D. and Xiao, C. and Legrand, M. and Spolaor, A. and Gabrieli, J. and Barbante, C. and Kang, J.-H. and Hur, S. D. and Hong, S. B. and Hwang, H. J. and Hong, S. and Hansson, M. and Iizuka, Y. and Oyabu, I. and Muscheler, R. and Adolphi, F. and Maselli, O. and McConnell, J. and Wolff, E. W.},
doi = {10.1038/s41467-018-03924-3},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1476},
title = {{Greenland records of aerosol source and atmospheric lifetime changes from the Eemian to the Holocene}},
url = {http://www.nature.com/articles/s41467-018-03924-3},
volume = {9},
year = {2018}
}
@article{Schaefer2016a,
abstract = {Measurements of cosmic-ray-produced 10Be and 26Al in a bedrock core from beneath the summit of the Greenland Ice Sheet show that Greenland was nearly ice-free for extended periods under Pleistocene climate forcing.},
author = {Schaefer, Joerg M and Finkel, Robert C and Balco, Greg and Alley, Richard B and Caffee, Marc W and Briner, Jason P and Young, Nicolas E and Gow, Anthony J and Schwartz, Roseanne},
doi = {10.1038/nature20146},
issn = {1476-4687},
journal = {Nature},
number = {7632},
pages = {252--255},
title = {{Greenland was nearly ice-free for extended periods during the Pleistocene}},
url = {https://doi.org/10.1038/nature20146},
volume = {540},
year = {2016}
}
@article{esd-11-925-2020,
author = {Scheen, J and Stocker, T F},
doi = {10.5194/esd-11-925-2020},
journal = {Earth System Dynamics},
number = {4},
pages = {925--951},
title = {{Effect of changing ocean circulation on deep ocean temperature in the last millennium}},
url = {https://esd.copernicus.org/articles/11/925/2020/},
volume = {11},
year = {2020}
}
@article{Scheff2017,
author = {Scheff, Jacob and Seager, Richard and Liu, Haibo},
doi = {10.1175/JCLI-D-16-0854.1},
journal = {Journal of Climate},
pages = {6593--6609},
title = {{Are Glacials Dry? Consequences for Paleoclimatology and for Greenhouse Warming}},
volume = {30},
year = {2017}
}
@article{Scheffers2016,
abstract = {Anthropogenic climate change is now in full swing, our global average temperature already having increased by 1°C from preindustrial levels. Many studies have documented individual impacts of the changing climate that are particular to species or regions, but individual impacts are accumulating and being amplified more broadly. Scheffers et al. review the set of impacts that have been observed across genes, species, and ecosystems to reveal a world already undergoing substantial change. Understanding the causes, consequences, and potential mitigation of these changes will be essential as we move forward into a warming world.Science, this issue p. 10.1126/science.aaf7671 BACKGROUNDClimate change impacts have now been documented across every ecosystem on Earth, despite an average warming of only {\~{}}1°C so far. Here, we describe the full range and scale of climate change effects on global biodiversity that have been observed in natural systems. To do this, we identify a set of core ecological processes (32 in terrestrial and 31 each in marine and freshwater ecosystems) that underpin ecosystem functioning and support services to people. Of the 94 processes considered, 82{\%} show evidence of impact from climate change in the peer-reviewed literature. Examples of observed impacts from meta-analyses and case studies go beyond well-established shifts in species ranges and changes to phenology and population dynamics to include disruptions that scale from the gene to the ecosystem.ADVANCESSpecies are undergoing evolutionary adaptation to temperature extremes, and climate change has substantial impacts on species physiology that include changes in tolerances to high temperatures, shifts in sex ratios in species with temperature-dependent sex determination, and increased metabolic costs of living in a warmer world. These physiological adjustments have observable impacts on morphology, with many species in both aquatic and terrestrial systems shrinking in body size because large surface-to-volume ratios are generally favored under warmer conditions. Other morphological changes include reductions in melanism to improve thermoregulation, and altered wing and bill length in birds.Broader-scale responses to climate change include changes in the phenology, abundance, and distribution of species. Temperate plants are budding and flowering earlier in spring and later in autumn. Comparable adjustments have been observed in marine and freshwater fish spawning events and in the timing of seasonal migrations of animals worldwide. Changes in the abundance and age structure of populations have also been observed, with widespread evidence of range expansion in warm-adapted species and range contraction in cold-adapted species. As a by-product of species redistributions, novel community interactions have emerged. Tropical and boreal species are increasingly incorporated into temperate and polar communities, respectively, and when possible, lowland species are increasingly assimilating into mountain communities. Multiplicative impacts from gene to community levels scale up to produce ecological regime shifts, in which one ecosystem state shifts to an alternative state.OUTLOOKThe many observed impacts of climate change at different levels of biological organization point toward an increasingly unpredictable future for humans. Reduced genetic diversity in crops, inconsistent crop yields, decreased productivity in fisheries from reduced body size, and decreased fruit yields from fewer winter chill events threaten food security. Changes in the distribution of disease vectors alongside the emergence of novel pathogens and pests are a direct threat to human health as well as to crops, timber, and livestock resources. Humanity depends on intact, functioning ecosystems for a range of goods and services. Enhanced understanding of the observed impacts of climate change on core ecological processes is an essential first step to adapting to them and mitigating their influence on biodiversity and ecosystem service provision.Climate change impacts on ecological processes in marine, freshwater, and terrestrial ecosystems.Impacts can be measured on multiple processes at different levels of biological organization within ecosystems. In total, 82{\%} of 94 ecological processes show evidence of being affected by climate change. Within levels of organization, the percentage of processes impacted varies from 60{\%} for genetics to 100{\%} for species distribution.Most ecological processes now show responses to anthropogenic climate change. In terrestrial, freshwater, and marine ecosystems, species are changing genetically, physiologically, morphologically, and phenologically and are shifting their distributions, which affects food webs and results in new interactions. Disruptions scale from the gene to the ecosystem and have documented consequences for people, including unpredictable fisheries and crop yields, loss of genetic diversity in wild crop varieties, and increasing impacts of pests and diseases. In addition to the more easily observed changes, such as shifts in flowering phenology, we argue that many hidden dynamics, such as genetic changes, are also taking place. Understanding shifts in ecological processes can guide human adaptation strategies. In addition to reducing greenhouse gases, climate action and policy must therefore focus equally on strategies that safeguard biodiversity and ecosystems.},
author = {Scheffers, Brett R. and {De Meester}, Luc and Bridge, Tom C.L. and Hoffmann, Ary A. and Pandolfi, John M. and Corlett, Richard T. and Butchart, Stuart H.M. and Pearce-Kelly, Paul and Kovacs, Kit M. and Dudgeon, David and Pacifici, Michela and Rondinini, Carlo and Foden, Wendy B. and Martin, Tara G. and Mora, Camilo and Bickford, David and Watson, James E.M.},
doi = {10.1126/science.aaf7671},
issn = {10959203},
journal = {Science},
number = {6313},
pages = {aaf7671},
title = {{The broad footprint of climate change from genes to biomes to people}},
volume = {354},
year = {2016}
}
@article{Schefuß2011,
abstract = {Intense debate persists about the climatic mechanisms governing hydrologic changes in tropical and subtropical southeast Africa since the Last Glacial Maximum, about 20,000 years ago. In particular, the relative importance of atmospheric and oceanic processes is not firmly established. Southward shifts of the intertropical convergence zone (ITCZ) driven by high-latitude climate changes have been suggested as a primary forcing, whereas other studies infer a predominant influence of Indian Ocean sea surface temperatures on regional rainfall changes. To address this question, a continuous record representing an integrated signal of regional climate variability is required, but has until now been missing. Here we show that remote atmospheric forcing by cold events in the northern high latitudes appears to have been the main driver of hydro-climatology in southeast Africa during rapid climate changes over the past 17,000 years. Our results are based on a reconstruction of precipitation and river discharge changes, as recorded in a marine sediment core off the mouth of the Zambezi River, near the southern boundary of the modern seasonal ITCZ migration. Indian Ocean sea surface temperatures did not exert a primary control over southeast African hydrologic variability. Instead, phases of high precipitation and terrestrial discharge occurred when the ITCZ was forced southwards during Northern Hemisphere cold events, such as Heinrich stadial 1 (around 16,000 years ago) and the Younger Dryas (around 12,000 years ago), or when local summer insolation was high in the late Holocene, that is, during the past 4,000 years. {\textcopyright} 2011 Macmillan Publishers Limited. All rights reserved.},
author = {Schefu{\ss}, Enno and Kuhlmann, Holger and Mollenhauer, Gesine and Prange, Matthias and P{\"{a}}tzold, J{\"{u}}rgen},
doi = {10.1038/nature10685},
issn = {00280836},
journal = {Nature},
number = {7378},
pages = {509--512},
pmid = {22193106},
title = {{Forcing of wet phases in southeast Africa over the past 17,000 years}},
volume = {480},
year = {2011}
}
@article{Schemm2018,
author = {Schemm, S},
doi = {10.1029/2018GL079109},
journal = {Geophysical Research Letters},
pages = {7165--7175},
title = {{Regional trends in weather systems help explain Antarctic sea ice trends}},
volume = {45},
year = {2018}
}
@article{doi:10.1029/2012GL053071,
abstract = {The vertical and spatial structure of the atmospheric El Ni{\~{n}}o-Southern Oscillation (ENSO) signal is investigated using radio occultation (RO) data from August 2006 to December 2010. Due to their high vertical resolution and global coverage, RO data are well suited to describe the full 3-dimensional ENSO structure in the troposphere and lower stratosphere. We find that interannual temperature anomalies in the equatorial region show a natural decomposition into zonal-mean and eddy (deviations from the zonal-mean) components that are both related to ENSO. Consistent with previous studies, we find that during the warm phase of ENSO, zonal-mean temperatures increase in the tropical troposphere and decrease in the tropical stratosphere. Maximum warming occurs above 8 km, and the transition between warming and cooling occurs near the tropopause. This zonal-mean response lags sea surface temperature anomalies in the eastern equatorial Pacific by 3 months. The atmospheric eddy component, in contrast, responds rapidly (within 1 month) to ENSO forcing. This signal features a low-latitude dipole between the Indian and Pacific Oceans, with off-equatorial maxima centered around 20° to 30° latitude in both hemispheres. The eddy response pattern attains maximum amplitude in the upper troposphere near 11 km and (with opposite polarity) in a shallow layer near the tropopause at approximately 17 km. The eddy ENSO signal tends to be out-of-phase between low and middle latitudes in both the troposphere and lower stratosphere.},
author = {Scherllin-Pirscher, B and Deser, C and Ho, S.-P. and Chou, C and Randel, W and Kuo, Y.-H.},
doi = {10.1029/2012GL053071},
journal = {Geophysical Research Letters},
keywords = {ENSO,radio occultation data,upper troposphere and lower stratosphere},
number = {20},
pages = {L20801},
title = {{The vertical and spatial structure of ENSO in the upper troposphere and lower stratosphere from GPS radio occultation measurements}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2012GL053071},
volume = {39},
year = {2012}
}
@article{amt-4-2019-2011,
author = {Scherllin-Pirscher, B and Kirchengast, G and Steiner, A K and Kuo, Y.-H. and Foelsche, U},
doi = {10.5194/amt-4-2019-2011},
journal = {Atmospheric Measurement Techniques},
number = {9},
pages = {2019--2034},
title = {{Quantifying uncertainty in climatological fields from GPS radio occultation: an empirical-analytical error model}},
url = {https://www.atmos-meas-tech.net/4/2019/2011/},
volume = {4},
year = {2011}
}
@article{Scherllin-PirscherB.A.K.SteinerR.A.AnthesS.AlexanderR.BiondiT.BirnerJ.KimW.J.RandelS-W.SonT.Tsuda2020,
author = {Scherllin-Pirscher, B. and Steiner, A. K. and Anthes, R. A. and Alexander, M. J. and Alexander, S. P. and Biondi, R. and Birner, T. and Kim, J. and Randel, W. J. and Son, S. and Tsuda, T. and Zeng, Z.},
doi = {10.1175/JCLI-D-20-0385.1},
journal = {Journal of Climate},
number = {8},
pages = {2813--2838},
title = {{Tropical Temperature Variability in the UTLS: New Insights from GPS Radio Occultation Observations}},
volume = {34},
year = {2021}
}
@article{Schilt2010b,
abstract = {We present records of atmospheric nitrous oxide obtained from the ice cores of the European Project for Ice Coring in Antarctica (EPICA) Dome C and Dronning Maud Land sites shedding light on the concentration of this greenhouse gas on glacial–interglacial and millennial time scales. The extended EPICA Dome C record covers now all interglacials of the last 800,000 years and reveals nitrous oxide variations in concert with climate. Highest mean interglacial nitrous oxide concentrations of 280 parts per billion by volume are observed during the interglacial corresponding to Marine Isotope Stage 11 around 400,000 years before present, at the same time when carbon dioxide and methane reach maximum mean interglacial concentrations. The temperature reconstruction at Dome C indicates colder interglacials between 800,000 and 440,000 years before present compared to the interglacials of the last 440,000 years. In contrast to carbon dioxide and methane, which both respond with lower concentrations at lower temperatures, nitrous oxide shows mean interglacial concentrations of 4–19 parts per billion by volume higher than the preindustrial Holocene value during the interglacials corresponding to Marine Isotope Stage 9–19. At the end of most interglacials, nitrous oxide remains substantially longer on interglacial levels than methane. Nevertheless, nitrous oxide shows millennial-scale variations at the same time as methane throughout the last 800,000 years. We suggest that these millennial-scale variations have been driven by a similar mechanism as the Dansgaard/Oeschger events known from the last glacial. Our data lead to the hypothesis that emissions from the low latitudes drive past variations of the atmospheric nitrous oxide concentration.},
author = {Schilt, Adrian and Baumgartner, Matthias and Blunier, Thomas and Schwander, Jakob and Spahni, Renato and Fischer, Hubertus and Stocker, Thomas F},
doi = {10.1016/j.quascirev.2009.03.011},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
number = {1},
pages = {182--192},
title = {{Glacial–interglacial and millennial-scale variations in the atmospheric nitrous oxide concentration during the last 800,000 years}},
volume = {29},
year = {2010}
}
@article{Schilt2014,
author = {Schilt, Adrian and Brook, Edward J and Bauska, Thomas K and Baggenstos, Daniel and Fischer, Hubertus and Joos, Fortunat and Petrenko, Vasilii V and Schaefer, Hinrich and Schmitt, Jochen and Severinghaus, Jeffrey P and Spahni, Renato and Stocker, Thomas F},
doi = {10.1038/nature13971},
journal = {Nature},
month = {dec},
pages = {234},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Isotopic constraints on marine and terrestrial N2O emissions during the last deglaciation}},
volume = {516},
year = {2014}
}
@article{Schimpf2011a,
author = {Schimpf, D. and Kilian, R. and Kronz, A. and Simon, K. and Sp{\"{o}}tl, C. and W{\"{o}}rner, G. and Mangini, A.},
doi = {10.1016/j.quascirev.2010.12.006},
journal = {Quaternary Science Reviews},
number = {3-4},
pages = {443--459},
title = {{The significance of chemical, isotopic, and detrital components in three coeval stalagmites from the superhumid southernmost Andes (53°S) as high-resolution palaeo-climate proxies}},
volume = {30},
year = {2011}
}
@article{Schmidt2006,
abstract = {Geochemical and sedimentological evidence suggest that the rapid climate warming oscillations of the last ice age, the Dansgaard-Oeschger cycles, were coupled to fluctuations in North Atlantic meridional overturning circulation through its regulation of poleward heat flux. The balance between cold meltwater from the north and warm, salty subtropical gyre waters from the south influenced the strength and location of North Atlantic overturning circulation during this period of highly variable climate. Here we investigate how rapid reorganizations of the ocean-atmosphere system across these cycles are linked to salinity changes in the subtropical North Atlantic gyre. We combine Mg/Ca palaeothermometry and oxygen isotope ratio measurements on planktonic foraminifera across four Dansgaard-Oeschger cycles (spanning 45.9-59.2 kyr ago) to generate a seawater salinity proxy record from a subtropical gyre deep-sea sediment core. We show that North Atlantic gyre surface salinities oscillated rapidly between saltier stadial conditions and fresher interstadials, covarying with inferred shifts in the Tropical Atlantic hydrologic cycle and North Atlantic overturning circulation. These salinity oscillations suggest a reduction in precipitation into the North Atlantic and/or reduced export of deep salty thermohaline waters during stadials. We hypothesize that increased stadial salinities preconditioned the North Atlantic Ocean for a rapid return to deep overturning circulation and high-latitude warming by contributing to increased North Atlantic surface-water density on interstadial transitions. {\textcopyright}2006 Nature Publishing Group.},
author = {Schmidt, Matthew W and Vautravers, Maryline J and Spero, Howard J},
doi = {10.1038/nature05121},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7111},
pages = {561--564},
pmid = {17024090},
title = {{Rapid subtropical North Atlantic salinity oscillations across Dansgaard-Oeschger cycles}},
volume = {443},
year = {2006}
}
@article{doi:10.1029/2018JD028776,
abstract = {Abstract Using volcanic sulfur dioxide emissions in an aerosol-climate model, we derive a time series of global-mean volcanic effective radiative forcing (ERF) from 1979 to 2015. For 2005–2015, we calculate a global multiannual mean volcanic ERF of −0.08 W/m2 relative to the volcanically quiescent 1999–2002 period, due to a high frequency of small-to-moderate-magnitude explosive eruptions after 2004. For eruptions of large magnitude such as 1991 Mt. Pinatubo, our model-simulated volcanic ERF, which accounts for rapid adjustments including aerosol perturbations of clouds, is less negative than that reported in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) that only accounted for stratospheric temperature adjustments. We find that, when rapid adjustments are considered, the relation between volcanic forcing and volcanic stratospheric optical depth (SAOD) is 13–21{\%} weaker than reported in IPCC AR5 for large-magnitude eruptions. Further, our analysis of the recurrence frequency of eruptions reveals that sulfur-rich small-to-moderate-magnitude eruptions with column heights ≥10 km occur frequently, with periods of volcanic quiescence being statistically rare. Small-to-moderate-magnitude eruptions should therefore be included in climate model simulations, given the {\textgreater}50{\%} chance of one or two eruptions to occur in any given year. Not all of these eruptions affect the stratospheric aerosol budget, but those that do increase the nonvolcanic background SAOD by {\~{}}0.004 on average, contributing {\~{}}50{\%} to the total SAOD in the absence of large-magnitude eruptions. This equates to a volcanic ERF of about −0.10 W/m2, which is about two thirds of the ERF from ozone changes induced by ozone-depleting substances.},
author = {Schmidt, Anja and Mills, Michael J and Ghan, Steven and Gregory, Jonathan M and Allan, Richard P and Andrews, Timothy and Bardeen, Charles G and Conley, Andrew and Forster, Piers M and Gettelman, Andrew and Portmann, Robert W and Solomon, Susan and Toon, Owen B},
doi = {10.1029/2018JD028776},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {aerosol-cloud interactions,climate change,volcanic aerosol,volcanic emissions,volcanic eruptions,volcanic radiative forcing},
month = {nov},
number = {22},
pages = {12491--12508},
title = {{Volcanic Radiative Forcing From 1979 to 2015}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JD028776 https://onlinelibrary.wiley.com/doi/10.1029/2018JD028776},
volume = {123},
year = {2018}
}
@article{Schmidt2004,
abstract = {Variations in the strength of the North Atlantic Ocean thermohaline circulation have been linked to rapid climate changes during the last glacial cycle through oscillations in North Atlantic Deep Water formation and northward oceanic heat flux. The strength of the thermohaline circulation depends on the supply of warm, salty water to the North Atlantic, which, after losing heat to the atmosphere, produces the dense water masses that sink to great depths and circulate back south. Here we analyse two Caribbean Sea sediment cores, combining Mg/Ca palaeothermometry with measurements of oxygen isotopes in foraminiferal calcite in order to reconstruct tropical Atlantic surface salinity during the last glacial cycle. We find that Caribbean salinity oscillated between saltier conditions during the cold oxygen isotope stages 2, 4 and 6, and lower salinities during the warm stages 3 and 5, covarying with the strength of North Atlantic Deep Water formation. At the initiation of the Bolling/Aller{\o}d warm interval, Caribbean surface salinity decreased abruptly, suggesting that the advection of salty tropical waters into the North Atlantic amplified thermohaline circulation and contributed to high-latitude warming.},
author = {Schmidt, Matthew W and Spero, Howard J and Lea, David W},
doi = {10.1038/nature02346},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {6979},
pages = {160--163},
pmid = {15014495},
title = {{Links between salinity variation in the Caribbean and North Atlantic thermohaline circulation}},
volume = {428},
year = {2004}
}
@article{doi:10.1002/2015GL063956,
abstract = {Abstract Annually resolved and millennium-long reconstructions of large-scale temperature variability are primarily composed of tree ring width (TRW) chronologies. Changes in ring width, however, have recently been shown to bias the ratio between low- and high-frequency signals. To overcome limitations in capturing the full spectrum of past temperature variability, we present a network of 15 maximum latewood density (MXD) chronologies distributed across the Northern Hemisphere extratropics. Independent subsets of continental-scale records consistently reveal high MXD before 1580 and after 1910, with below average values between these periods. Reconstructed extratropical summer temperatures reflect not only these long-term trends but also distinct cooling pulses after large volcanic eruptions. In contrast to TRW-dominated reconstructions, this MXD-based record indicates a delayed onset of the Little Ice Age by almost two centuries. The reduced memory inherent in MXD is likely responsible for the rapid recovery from volcanic-induced cooling in the fourteenth century and the continuation of warmer temperatures until {\~{}}1600.},
author = {Schneider, Lea and Smerdon, Jason E and B{\"{u}}ntgen, Ulf and Wilson, Rob J S and Myglan, Vladimir S and Kirdyanov, Alexander V and Esper, Jan},
doi = {10.1002/2015GL063956},
journal = {Geophysical Research Letters},
keywords = {Little Ice Age,beta value,maximum latewood density,millennial reconstruction,tree rings,volcanic cooling},
number = {11},
pages = {4556--4562},
title = {{Revising midlatitude summer temperatures back to A.D. 600 based on a wood density network}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015GL063956},
volume = {42},
year = {2015}
}
@article{Schneider2018a,
abstract = {Enabled by advances in data assimilation and the digitization of historical observations, atmospheric reanalysis products that span the entire twentieth century provide valuable gridded data over the sparsely observed high-latitude Southern Hemisphere. Here austral summer and winter surface pressure trends in three reanalyses are compared to trends in a statistically based pressure reconstruction, trends in atmospheric models without data assimilation, and estimates of uncertainty from the reanalyses. In austral summer during the early twentieth century, the reanalyses underestimate the depth of the circumpolar trough, leading to erroneously high pressure values over the region. Around 1950, a rapid increase in the number of assimilated pressure observations leads to a dramatic reduction in the reanalyses standard error and a spurious drop in the surface pressure. A more likely history of the surface pressure over this region is provided by the reconstruction, which is consistent with the model simulations without data assimilation.},
author = {Schneider, David P. and Fogt, Ryan L.},
doi = {10.1002/2017GL076226},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {Antarctica,Southern Ocean,atmospheric reanalysis,surface pressure},
number = {2},
pages = {964--973},
title = {{Artifacts in Century-Length Atmospheric and Coupled Reanalyses Over Antarctica Due To Historical Data Availability}},
volume = {45},
year = {2018}
}
@article{Schroder2019,
author = {Schr{\"{o}}der, Marc and Lockhoff, Maarit and Shi, Lei and August, Thomas and Bennartz, Ralf and Brogniez, Helene and Calbet, Xavier and Fell, Frank and Forsythe, John and Gambacorta, Antonia},
doi = {10.3390/rs11030251},
journal = {Remote Sensing},
pages = {1--28},
title = {{The GEWEX Water Vapor Assessment: Overview and Introduction to Results and Recommendations}},
volume = {11},
year = {2019}
}
@article{Schroder2018a,
abstract = {Abstract. The Global Energy and Water cycle Exchanges (GEWEX) Data and Assessments Panel (GDAP) initiated the GEWEX Water Vapor Assessment (G-VAP), which has the main objectives to quantify the current state of the art in water vapour products being constructed for climate applications and to support the selection process of suitable water vapour products by GDAP for its production of globally consistent water and energy cycle products. During the construction of the G-VAP data archive, freely available and mature satellite and reanalysis data records with a minimum temporal coverage of 10 years were considered. The archive contains total column water vapour (TCWV) as well as specific humidity and temperature at four pressure levels (1000, 700, 500, 300hPa) from 22 different data records. All data records were remapped to a regular longitude–latitude grid of 2° × 2°. The archive consists of four different folders: 22 TCWV data records covering the period 2003–2008, 11 TCWV data records covering the period 1988–2008, as well as 7 specific humidity and 7 temperature data records covering the period 1988–2009. The G-VAP data archive is referenced under the following digital object identifier (doi): https://doi.org/10.5676/EUM{\_}SAF{\_}CM/GVAP/V001. Within G-VAP, the characterization of water vapour products is, among other ways, achieved through intercomparisons of the considered data records, as a whole and grouped into three classes of predominant retrieval condition: clear-sky, cloudy-sky and all-sky. Associated results are shown using the 22 TCWV data records. The standard deviations among the 22 TCWV data records have been analysed and exhibit distinct maxima over central Africa and the tropical warm pool (in absolute terms) as well as over the poles and mountain regions (in relative terms). The variability in TCWV within each class can be large and prohibits conclusions about systematic differences in TCWV between the classes.},
author = {Schr{\"{o}}der, Marc and Lockhoff, Maarit and Fell, Frank and Forsythe, John and Trent, Tim and Bennartz, Ralf and Borbas, Eva and Bosilovich, Michael G. and Castelli, Elisa and Hersbach, Hans and Kachi, Misako and Kobayashi, Shinya and {Robert Kursinski}, E. and Loyola, DIego and Mears, Carl and Preusker, Rene and Rossow, William B. and Saha, Suranjana},
doi = {10.5194/essd-10-1093-2018},
issn = {18663516},
journal = {Earth System Science Data},
number = {2},
pages = {1093--1117},
title = {{The GEWEX Water Vapor Assessment archive of water vapour products from satellite observations and reanalyses}},
volume = {10},
year = {2018}
}
@article{Schroder2016,
abstract = {The Global Energy and Water Cycle Exchanges project (GEWEX) water vapor assessment's (G-VAP) main objective is to analyze and explain strengths and weaknesses of satellite-based data records of water vapor through intercomparisons and comparisons with ground-based data. G-VAP results from the intercomparison of six total column water vapor (TCWV) data records are presented. Prior to the intercomparison, the data records were regridded to a common regular grid of 2° × 2° longitude–latitude. All data records cover a common period from 1988 to 2008. The intercomparison is complemented by an analysis of trend estimates, which was applied as a tool to identify issues in the data records. It was observed that the trends over global ice-free oceans are generally different among the different data records. Most of these differences are statistically significant. Distinct spatial features are evident in maps of differences in trend estimates, which largely coincide with maxima in standard deviations from the ensemble mean. The penalized maximal F test has been applied to global ice-free ocean and selected land regional anomaly time series, revealing differences in trends to be largely caused by breakpoints in the different data records. The time, magnitude, and number of breakpoints typically differ from region to region and between data records. These breakpoints often coincide with changes in observing systems used for the different data records. The TCWV data records have also been compared with data from a radiosonde archive. For example, at Lindenberg, Germany, and at Yichang, China, such breakpoints are not observed, providing further evidence for the regional imprint of changes in the observing system.},
author = {Schr{\"{o}}der, Marc and Lockhoff, Maarit and Forsythe, John M. and Cronk, Heather Q. and {Vonder Haar}, Thomas H. and Bennartz, Ralf},
doi = {10.1175/JAMC-D-15-0304.1},
issn = {1558-8424},
journal = {Journal of Applied Meteorology and Climatology},
keywords = {Climate records,Climate variability,Climatology,Humidity,Observational techniques and algorithms,Physical Meteorology and Climatology,Satellite observations,Stability},
month = {jul},
number = {7},
pages = {1633--1649},
title = {{The GEWEX Water Vapor Assessment: Results from Intercomparison, Trend, and Homogeneity Analysis of Total Column Water Vapor}},
url = {https://journals.ametsoc.org/view/journals/apme/55/7/jamc-d-15-0304.1.xml},
volume = {55},
year = {2016}
}
@article{Schubert2013,
abstract = {Negative carbon isotope excursions measured in marine and terrestrial substrates indicate large-scale changes in the global carbon cycle, yet terrestrial substrates characteristically record a larger-amplitude carbon isotope excursion than marine substrates for a single event. Here we reconcile this difference by accounting for the fundamental increase in carbon isotope fractionation by land plants in response to increasing atmospheric CO2 concentration (pCO2). We show that for any change in pCO2 concentration ($\Delta$pCO2), terrestrial and marine records can be used together to reconstruct background and maximum pCO2 levels across the carbon isotope excursion. When applied to the carbon isotope excursion at the Palaeocene–Eocene boundary, we calculate pCO2=674–1,034 p.p.m.v. during the Late Palaeocene and 1,384–3,342 p.p.m.v. during the height of the carbon isotope excursion across all sources postulated for the carbon release. This analysis demonstrates the need to account for changing pCO2 concentration when analysing large-scale changes in the carbon isotope composition of terrestrial substrates.},
author = {Schubert, Brian A and Jahren, A Hope},
doi = {10.1038/ncomms2659},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {1653},
title = {{Reconciliation of marine and terrestrial carbon isotope excursions based on changing atmospheric CO2 levels}},
url = {https://doi.org/10.1038/ncomms2659},
volume = {4},
year = {2013}
}
@article{Schulte2007a,
abstract = {Human land use of forested regions has intensified worldwide in recent decades, threatening long-term sustainability. Primary effects include conversion of land cover or reversion to an earlier stage of successional development. Both types of change can have cascading effects through ecosystems; however, the long-term effects where forests are allowed to regrow are poorly understood. We quantify the regional-scale consequences of a century of Euro-American land use in the northern U.S. Great Lakes region using a combination of historical Public Land Survey records and current forest inventory and land cover data. Our analysis shows a distinct and rapid trajectory of vegetation change toward historically unprecedented and simplified conditions. In addition to overall loss of forestland, current forests are marked by lower species diversity, functional diversity, and structural complexity compared to pre-Euro-American forests. Today's forest is marked by dominance of broadleaf deciduous species-all 55 ecoregions that comprise the region exhibit a lower relative dominance of conifers in comparison to the pre-Euro-American period. Aspen (Populus grandidentata and P. tremuloides) and maple (Acer saccharum and A. rubrum) species comprise the primary deciduous species that have replaced conifers. These changes reflect the cumulative effects of local forest alterations over the region and they affect future ecosystem conditions as well as the ecosystem services they provide.},
author = {Schulte, Lisa A. and Mladenoff, David J. and Crow, Thomas R. and Merrick, Laura C. and Cleland, David T.},
doi = {10.1007/s10980-007-9095-5},
issn = {09212973},
journal = {Landscape Ecology},
keywords = {Ecosystem simplification,Land use/land cover change,Pre-Euro-American settlement,Sustainability},
pages = {1089--1103},
title = {{Homogenization of northern U.S. Great Lakes forests due to land use}},
volume = {22},
year = {2007}
}
@article{10.1130/G38114.1,
abstract = {Recent observations indicate that ice-ocean interaction drives much of the recent increase in mass loss from the Greenland Ice Sheet; however, the role of ocean forcing in driving past glacier change is poorly understood. To extend the observational record and our understanding of the ocean-cryosphere link, we used a multi-proxy approach that combines new data from proglacial lake sediments, 14C-dated in situ moss that recently emerged from beneath cold-based ice caps, and 10Be ages to reconstruct centennial-scale records of mountain glacier activity for the past ∼10 k.y. in West Greenland. Proglacial lake sediment records and 14C dating of moss indicate the onset of Neoglaciation in West Greenland at ca. 5 ka with substantial snowline lowering and glacier expansion at ca. 3.7 ka followed by additional ice expansion phases at ca. 2.9, ca. 1.7, and ca. 1.4 ka and during the Little Ice Age. We find that widespread glacier growth at ca. 3.7 ka in West Greenland coincides with marked cooling and reduced strength of the West Greenland Current in Disko Bugt. The transition to cooler ocean conditions at ca. 3.7 ka identified in Disko Bugt is registered by marine proxy data farther afield in East Greenland and on the northwestern Icelandic shelf, implying large-scale paleoceanographic changes across the North Atlantic during this interval. The similarity between glacier change on West Greenland and multiple marine and terrestrial records across the North Atlantic suggests that glaciers are strongly influenced by changes in ocean circulation and consequently implies that the ocean-cryosphere teleconnection is a persistent feature of the Arctic system.},
author = {Schweinsberg, Avriel D and Briner, Jason P and Miller, Gifford H and Bennike, Ole and Thomas, Elizabeth K},
doi = {10.1130/G38114.1},
issn = {0091-7613},
journal = {Geology},
number = {3},
pages = {195--198},
title = {{Local glaciation in West Greenland linked to North Atlantic Ocean circulation during the Holocene}},
url = {https://doi.org/10.1130/G38114.1},
volume = {45},
year = {2017}
}
@article{SCHWEINSBERG2018142,
abstract = {Mountain glaciers and ice caps (GIC) independent of the Greenland Ice Sheet respond rapidly to climate variations and records of their past extent provide information on the natural envelope of climate variability. Here, we use a multi-proxy approach that combines proglacial lake sediment analysis, cosmogenic nuclide surface-exposure dating (in situ 10Be and 14C), and radiocarbon dating of recently ice-entombed moss to generate a centennial-scale record of Holocene GIC fluctuations in southwestern Greenland. Following local deglaciation ∼10-9 ka, sediments from proglacial Crash Lake record a glacier advance at ∼9 ka that is indistinguishable from nearby ice sheet moraines, implying a synchronous response of GIC and the Greenland Ice Sheet to a centennial-scale climate event. Following this local glacier advance, GIC experienced net recession until ∼4.6 ka. Radiocarbon ages of in situ moss (n = 29) and Crash Lake sediments reveal intervals of glacier expansion at ∼1.8, 1.2 and 0.7 ka that are superimposed on an overall trend of net glacier expansion throughout the late Holocene. In situ 14C concentrations from bedrock adjacent to radiocarbon-dated moss samples further constrain the duration of ice cover through the Holocene in this region. We find that our glacier-size proxy records during the past ∼4 ka are broadly consistent with relatively lower temperatures recorded in GISP2 and occur during, or following, intervals of volcanic perturbations. Thus, we speculate that volcanic activity, although less frequent and intense than in the early Holocene and during the Little Ice Age, may have led to centennial-scale variability imprinted on net glacier expansion due to decreasing summer insolation through the late Holocene.},
author = {Schweinsberg, Avriel D and Briner, Jason P and Miller, Gifford H and Lifton, Nathaniel A and Bennike, Ole and Graham, Brandon L},
doi = {10.1016/j.quascirev.2018.06.014},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Cosmogenic C,Glacier fluctuations,Greenland,Holocene,Lake sediment,Neoglaciation},
pages = {142--161},
title = {{Holocene mountain glacier history in the Sukkertoppen Iskappe area, southwest Greenland}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379118302531},
volume = {197},
year = {2018}
}
@article{Screen2013,
abstract = {This study examines observed changes (1979–2011) in atmospheric planetary-wave amplitude over northern mid-latitudes, which have been proposed as a possible mechanism linking Arctic amplification and mid-latitude weather extremes. We use two distinct but equally-valid definitions of planetary-wave amplitude, termed meridional amplitude, a measure of north-south meandering, and zonal amplitude, a measure of the intensity of atmospheric ridges and troughs at 45°N. Statistically significant changes in either metric are limited to few seasons, wavelengths, and longitudinal sectors. However in summer, we identify significant increases in meridional amplitude over Europe, but significant decreases in zonal amplitude hemispherically, and also individually over Europe and Asia. Therefore, we argue that possible connections between Arctic amplification and planetary waves, and implications of these, are sensitive to how waves are conceptualized. The contrasting meridional and zonal amplitude trends have different and complex possible implications for midlatitude weather, and we encourage further work to better understand these.},
author = {Screen, James A. and Simmonds, Ian},
doi = {10.1002/grl.50174},
isbn = {1944-8007},
issn = {00948276},
journal = {Geophysical Research Letters},
number = {5},
pages = {959--964},
title = {{Exploring links between Arctic amplification and mid-latitude weather}},
volume = {40},
year = {2013}
}
@article{Scussolini2019,
abstract = {The last extended time period when climate may have been warmer than today was during the Last Interglacial (LIG; ca. 129 to 120 thousand years ago). However, a global view of LIG precipitation is lacking. Here, seven new LIG climate models are compared to the first global database of proxies for LIG precipitation. In this way, models are assessed in their ability to capture important hydroclimatic processes during a different climate. The models can reproduce the proxy-based positive precipitation anomalies from the preindustrial period over much of the boreal continents. Over the Southern Hemisphere, proxy-model agreement is partial. In models, LIG boreal monsoons have 42{\%} wider area than in the preindustrial and produce 55{\%} more precipitation and 50{\%} more extreme precipitation. Austral monsoons are weaker. The mechanisms behind these changes are consistent with stronger summer radiative forcing over boreal high latitudes and with the associated higher temperatures during the LIG.},
author = {Scussolini, Paolo and Bakker, Pepijn and Guo, Chuncheng and Stepanek, Christian and Zhang, Qiong and Braconnot, Pascale and Cao, Jian and Guarino, Maria Vittoria and Coumou, Dim and Prange, Matthias and Ward, Philip J. and Renssen, Hans and Kageyama, Masa and Otto-Bliesner, Bette and Aerts, Jeroen C.J.H.},
doi = {10.1126/sciadv.aax7047},
issn = {23752548},
journal = {Science Advances},
number = {11},
pages = {1--12},
pmid = {31799394},
title = {{Agreement between reconstructed and modeled boreal precipitation of the last interglacial}},
volume = {5},
year = {2019}
}
@article{doi:10.1029/2006JD007363,
abstract = {This study examines global tropopause variability on synoptic, monthly, seasonal, and multidecadal timescales using 1980–2004 radiosonde data. On synoptic and monthly timescales, tropopause height variations are anticorrelated with stratospheric temperature variations and positively correlated with tropospheric temperature variations. Correlations are stronger in the extratropics than in the tropics, for the upper troposphere (500–300 hPa) than for the lower troposphere, and for the lower stratosphere than for the middle stratosphere. The extratropical tropopause is more sensitive to temperature changes than the tropical tropopause, and in both regions, monthly anomalies of tropopause height are more sensitive to stratospheric temperature change than tropospheric, rising 2–3 km per degree cooling of the lower stratosphere. Tropopause height trends over 1980–2004 are upward at almost all of the (predominantly extratropical) stations analyzed, yielding an estimated global trend of 64 ± 21 m/decade, a corresponding tropopause pressure trend of −1.7 ± 0.6 hPa/decade, and tropopause temperature decrease of 0.41 ± 0.09 K/decade. These tropopause trends are accompanied by significant stratospheric cooling and smaller tropospheric warming. However, the tropopause trends are spatially correlated with stratospheric temperature trends and uncorrelated with tropospheric temperature trends. This association of tropopause height and stratospheric temperature trends, together with the presence of a significant quasi-biennial oscillation signal in tropopause height, suggests that at these lowest frequencies the tropopause is primarily coupled with stratospheric temperatures. Therefore, as an indicator of climate change, long-term changes in the tropopause may carry less information about changes throughout the vertical temperature profile than has been suggested by previous studies using reanalyses and global climate models.},
author = {Seidel, Dian J and Randel, William J},
doi = {10.1029/2006JD007363},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {climate variability and trends,radiosonde,stratospheric temperature,tropopause,tropospheric temperature,vertical temperature profile},
month = {nov},
number = {D21},
pages = {D21101},
title = {{Variability and trends in the global tropopause estimated from radiosonde data}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2006JD007363 http://doi.wiley.com/10.1029/2006JD007363},
volume = {111},
year = {2006}
}
@article{doi:10.1002/2015JD024039,
abstract = {Abstract Satellite-based layer average stratospheric temperature (T) climate data records (CDRs) now span more than three decades and so can elucidate climate variability associated with processes on multiple time scales. We intercompare and analyze available published T CDRs covering at least two decades, with a focus on Stratospheric Sounding Unit (SSU) and Microwave Sounding Unit (MSU) CDRs. Recent research has reduced but not eliminated discrepancies between SSU CDRs developed by NOAA and the UK Meteorological Office. The MSU CDRs from NOAA and Remote Sensing Systems are in closer agreement than the CDR from the University of Alabama in Huntsville. The latter has a previously unreported inhomogeneity in 2005, revealed by an abrupt increase in the magnitude and spatial variability of T anomaly differences between CDRs. Although time-varying biases remain in both SSU and MSU CDRs, multiple linear regression analyses reveal consistent solar, El Ni{\~{n}}o–Southern Oscillation (ENSO), quasi-biennial oscillation, aerosol, and piecewise-linear trend signals. Together, these predictors explain 80 to 90{\%} of the variance in the near-global-average T CDRs. The most important predictor variables (in terms of percent explained variance in near-global-average T) for lower stratospheric T measured by MSU are aerosols, solar variability, and ENSO. Trends explain the largest percentage of variance in observations from all three SSU channels. In MSU and SSU CDRs, piecewise-linear trends, with a 1995 break point, indicate cooling during 1979–1994 but no trend during 1995–2013 for MSU and during 1995–2005 for SSU. These observational findings provide a basis for evaluating climate model simulations of stratospheric temperature during the past 35 years.},
author = {Seidel, Dian J and Li, Jian and Mears, Carl and Moradi, Isaac and Nash, John and Randel, William J and Saunders, Roger and Thompson, David W J and Zou, Cheng-Zhi},
doi = {10.1002/2015JD024039},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {climate data record,satellite observations,solar cycle,stratospheric temperature,trend,volcanic aerosol},
number = {2},
pages = {664--681},
title = {{Stratospheric temperature changes during the satellite era}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015JD024039},
volume = {121},
year = {2016}
}
@article{Seneviratne2018b,
abstract = {The United Nations' Paris Agreement includes the aim of pursuing efforts to limit global warming to only 1.5 °C above pre-industrial levels. However, it is not clear what the resulting climate would look like across the globe and over time. Here we show that trajectories towards a ‘1.5 °C warmer world' may result in vastly different outcomes at regional scales, owing to variations in the pace and location of climate change and their interactions with society's mitigation, adaptation and vulnerabilities to climate change. Pursuing policies that are considered to be consistent with the 1.5 °C aim will not completely remove the risk of global temperatures being much higher or of some regional extremes reaching dangerous levels for ecosystems and societies over the coming decades.},
author = {Seneviratne, Sonia I and Rogelj, Joeri and S{\'{e}}f{\'{e}}rian, Roland and Wartenburger, Richard and Allen, Myles R and Cain, Michelle and Millar, Richard J and Ebi, Kristie L and Ellis, Neville and Hoegh-Guldberg, Ove and Payne, Antony J and Schleussner, Carl-Friedrich and Tschakert, Petra and Warren, Rachel F},
doi = {10.1038/s41586-018-0181-4},
issn = {1476-4687},
journal = {Nature},
number = {7708},
pages = {41--49},
title = {{The many possible climates from the Paris Agreement's aim of 1.5 °C warming}},
url = {https://doi.org/10.1038/s41586-018-0181-4},
volume = {558},
year = {2018}
}
@article{Serno2015,
abstract = {Abstract We present a new record of eolian dust flux to the western Subarctic North Pacific (SNP) covering the past 27,000 years based on a core from the Detroit Seamount. Comparing the SNP dust record to the North Greenland Ice Core Project (NGRIP) ice core record shows significant differences in the amplitude of dust changes to the two regions during the last deglaciation, while the timing of abrupt changes is synchronous. If dust deposition in the SNP faithfully records its mobilization in East Asian source regions, then the difference in the relative amplitude must reflect climate-related changes in atmospheric dust transport to Greenland. Based on the synchronicity in the timing of dust changes in the SNP and Greenland, we tie abrupt deglacial transitions in the 230Th-normalized 4He flux record to corresponding transitions in the well-dated NGRIP dust flux record to provide a new chronostratigraphic technique for marine sediments from the SNP. Results from this technique are complemented by radiocarbon dating, which allows us to independently constrain radiocarbon paleoreservoir ages. We find paleoreservoir ages of 745 ± 140 years at 11,653 year B.P., 680 ± 228 years at 14,630 year B.P., and 790 ± 498 years at 23,290 year B.P. Our reconstructed paleoreservoir ages are consistent with modern surface water reservoir ages in the western SNP. Good temporal synchronicity between eolian dust records from the Subantarctic Atlantic and equatorial Pacific and the ice core record from Antarctica supports the reliability of the proposed dust tuning method to be used more widely in other global ocean regions.},
author = {Serno, Sascha and Winckler, Gisela and Anderson, Robert F and Maier, Edith and Ren, Haojia and Gersonde, Rainer and Haug, Gerald H},
doi = {10.1002/2014PA002748},
journal = {Paleoceanography},
number = {6},
pages = {583--600},
title = {{Comparing dust flux records from the Subarctic North Pacific and Greenland: Implications for atmospheric transport to Greenland and for the application of dust as a chronostratigraphic tool}},
volume = {30},
year = {2015}
}
@article{Servain1999a,
abstract = {The tropical Atlantic Ocean exhibits two primary modes of interannual climate variability: an equatorial mode analogous to, but weaker than, the Pacific El Ni{\~{n}}o phenomenon, and a meridional mode that does not have a Pacific counterpart. The equatorial mode is responsible for warm (and cold) sea surface temperature (SST) events, mainly in the Gulf of Guinea, and is identifiable by abnormal changes in the equatorial thermocline slope resulting from zonal-wind anomalies in the western tropical Atlantic. The meridional mode is characterized by a north-south interhemispheric gradient of SST anomalies. Here it is shown, using observed surface and subsurface oceanic temperatures, that the meridional mode is linked to the equatorial mode, at both decadal and short-interannual (1?2 years) time scales. Both modes involve north-south displacements of the ITCZ, as in the annual response.},
annote = {doi: 10.1029/1999GL900014},
author = {Servain, Jacques and Wainer, Ilana and {McCreary Jr.}, Julian P and Dessier, Alain},
doi = {10.1029/1999GL900014},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {feb},
number = {4},
pages = {485--488},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Relationship between the equatorial and meridional modes of climatic variability in the tropical Atlantic}},
url = {https://doi.org/10.1029/1999GL900014},
volume = {26},
year = {1999}
}
@article{Seth2019,
author = {Seth, Anji and Giannini, Alessandra and Rojas, Maisa and Rauscher, Sara A and Bordoni, Simona and Singh, Deepti and Camargo, Suzana J},
doi = {10.1007/s40641-019-00125-y},
issn = {2198-6061},
journal = {Current Climate Change Reports},
keywords = {Climate changes,Global warming,Monsoons,Paleomonsoons,climate changes,global warming,monsoons,paleomonsoons},
month = {jun},
number = {2},
pages = {63--79},
publisher = {Current Climate Change Reports},
title = {{Monsoon Responses to Climate Changes – Connecting Past, Present and Future}},
url = {http://link.springer.com/10.1007/s40641-019-00125-y},
volume = {5},
year = {2019}
}
@article{Seviour2017,
abstract = {Recent studies have proposed that the Arctic stratospheric polar vortex has weakened and shifted away fromthe North Pole during the past three decades. Some of these studies suggest that this trend has been driven by a decline in Arctic sea ice leading to enhanced zonal wave number 1 waves propagating into the stratosphere and that it has in turn contributed to a recent wintertime surface cooling over North America and some parts of Eurasia. Here trends in several measures of the location and strength of the stratospheric polar vortex from 1980 to 2016 are examined in two reanalysis products. All measures show weakening and equatorward shift trends, but only one measure, the vortex centroid latitude, has a trend which is statistically significant at the 95{\%} level in both reanalyses. By comparing large ensembles of historical simulations with preindustrial control simulations for two coupled climate models, the ensemble mean response of the vortex is found to be small relative to internal variability. There is also no relationship between sea ice decline and trends in either vortex location or strength. Despite this, individual ensemble members are found to have vortex trends similar to those observed, indicating that these trends may be primarily a result of natural internally generated climate variability.},
author = {Seviour, William J.M.},
doi = {10.1002/2017GL073071},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {7},
pages = {3365--3373},
title = {{Weakening and shift of the Arctic stratospheric polar vortex: Internal variability or forced response?}},
volume = {44},
year = {2017}
}
@article{Seviour2018,
abstract = {Climate models predict that the Hadley circulation will expand poleward in a warmer climate, a trend which may cause significant changes in global precipitation patterns. However, recent studies have disagreed as to how strongly changes in the Hadley circulation and changes in the hydrological cycle (specifically the latitude at which precipitation balances evaporation) are related. Here we analyze dynamical and hydrological measures of the Southern Hemisphere edge of the tropics using simulations from the fifth Coupled Model Intercomparison Project (CMIP5) and four reanalysis data sets. In simulations with an abrupt quadrupling of atmospheric CO2 concentrations, all models show a poleward expansion in both metrics. However, there is a large spread among models; the ratio of the hydrological to dynamical expansions varies from 0.6 to 1.4. We show that this model spread can be largely explained by differences in internal variability, which in turn is related to the mean state of models. Differences in mean states among reanalyses are similar to those of models, and so reanalyses do not help constrain uncertainty in model trends.},
author = {Seviour, William J.M. and Davis, Sean M. and Grise, Kevin M. and Waugh, Darryn W.},
doi = {10.1002/2017GL076335},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {CMIP5,Hadley cell,hydrological cycle,reanalyses,tropical expansion},
number = {2},
pages = {1106--1113},
title = {{Large Uncertainty in the Relative Rates of Dynamical and Hydrological Tropical Expansion}},
volume = {45},
year = {2018}
}
@article{Sha2019,
author = {Sha, Lijuan and {Ait Brahim}, Yassine and Wassenburg, Jasper A. and Yin, Jianjun and Peros, Matthew and Cruz, Francisco W. and Cai, Yanjun and Li, Hanying and Du, Wenjing and Zhang, Haiwei and Edwards, R. Lawrence and Cheng, Hai},
doi = {10.1029/2019GL084879},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {dec},
number = {23},
pages = {14093--14102},
title = {{How Far North Did the African Monsoon Fringe Expand During the African Humid Period? Insights From Southwest Moroccan Speleothems}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084879},
volume = {46},
year = {2019}
}
@article{doi:10.1029/2019GL082971,
abstract = {Abstract Noble gases in ice cores enable reconstructions of past mean ocean temperature. A recent result from the clathrate-containing WAIS Divide Ice Core showed tight covariation between ocean and Antarctic temperatures throughout the last deglaciation, except for the Younger Dryas interval. In the beginning of this interval, oceans warmed at 2.5 °C/kyr—three times greater than estimates of modern warming. If valid, this challenges our understanding of the mechanisms controlling ocean heat uptake. Here we reconstruct mean ocean temperature with clathrate-free ice samples from Taylor Glacier to test these findings. The two records agree in net temperature change over the Younger Dryas, but the Taylor Glacier record suggests sustained warming at the more modest rate of 1.1 ± 0.2°C/kyr. We explore mechanisms to explain differences between records and suggest that the noble gas content for the Younger Dryas interval of WAIS Divide may have been altered by a decimeter-scale fractionation during bubble-clathrate transformation.},
author = {Shackleton, S and Bereiter, B and Baggenstos, D and Bauska, T K and Brook, E J and Marcott, S A and Severinghaus, J P},
doi = {10.1029/2019GL082971},
journal = {Geophysical Research Letters},
keywords = {Younger Dryas,bubble-to-clathrate transformation,ice cores,ocean heat uptake,paleoclimate},
number = {11},
pages = {5928--5936},
title = {{Is the Noble Gas-Based Rate of Ocean Warming During the Younger Dryas Overestimated?}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082971},
volume = {46},
year = {2019}
}
@article{SHACKLETON1987183,
abstract = {A careful comparison is made between the most detailed records of sea level over the last glacial cycle, and two high-quality oxygen isotope records. One is a high-resolution benthonic record that contains superb detail but proves to record temperature change as well as ice volume; the other is a planktonic record from the west equatorial Pacific where the temperature effect may be minimal but where high resolution is not available. A combined record is generated which may be a better approximation to ice volume than was previously available. This approach cannot yet be applied to the whole Pleistocene. However, comparison of glacial extremes suggests that glacial extremes of stages 12 and 16 significantly exceeded the last glacial maximum as regards ice volume and hence as regards sea level lowering. Interglacial stages 7, 13, 15, 17 and 19 did not attain Holocene oxygen isotope values; possibly the sea did not reach its present level. It is unlikely that sea level was glacio-eustatically higher than present by more than a few metres during any interglacial of the past 2.5 million years.},
author = {Shackleton, N J},
doi = {10.1016/0277-3791(87)90003-5},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
number = {3},
pages = {183--190},
title = {{Oxygen isotopes, ice volume and sea level}},
url = {http://www.sciencedirect.com/science/article/pii/0277379187900035},
volume = {6},
year = {1987}
}
@article{Shakun2012a,
author = {Shakun, Jeremy D and Clark, Peter U and He, Feng and Marcott, Shaun A and Mix, Alan C and Liu, Zhengyu and Otto-Bliesner, Bette and Schmittner, Andreas and Bard, Edouard},
doi = {10.1038/nature10915},
journal = {Nature},
month = {apr},
pages = {49},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation}},
url = {https://doi.org/10.1038/nature10915 http://10.0.4.14/nature10915 https://www.nature.com/articles/nature10915{\#}supplementary-information},
volume = {484},
year = {2012}
}
@article{SHAKUN201558,
abstract = {The sequence of feedbacks that characterized 100-kyr glacial cycles of the past million years remains uncertain, hampering an understanding of the interconnections between insolation, ice sheets, greenhouse gas forcing, and climate. Critical to addressing this issue is an accurate interpretation of the marine $\delta$18O record, the main template for the Ice Ages. This study uses a global compilation of 49 paired sea surface temperature-planktonic $\delta$18O records to extract the mean $\delta$18O of surface ocean seawater over the past 800 kyr, which we interpret to dominantly reflect global ice volume. The results indicate that global surface temperature, inferred deep ocean temperature, and atmospheric CO2 decrease early during each glacial cycle in close association with one another, whereas major ice sheet growth occurs later in glacial cycles. These relationships suggest that ice volume may have exhibited a threshold response to global cooling, and that global deglaciations do not occur until after the growth of large ice sheets. This phase sequence also suggests that the ice sheets had relatively little feedback on global cooling. Simple modeling shows that the rate of ice volume change through time is largely determined by the combined influence of insolation, temperature, and ice sheet size, with possible implications for the evolution of glacial cycles over the past three million years.},
author = {Shakun, Jeremy D and Lea, David W and Lisiecki, Lorraine E and Raymo, Maureen E},
doi = {10.1016/j.epsl.2015.05.042},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {Pleistocene,glacial cycles,global temperature,ice volume,marine oxygen isotope record},
pages = {58--68},
title = {{An 800-kyr record of global surface ocean $\delta$18O and implications for ice volume-temperature coupling}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X15003404},
volume = {426},
year = {2015}
}
@article{Shakun2018,
abstract = {The East Antarctic Ice Sheet (EAIS) is the largest potential contributor to sea-level rise. However, efforts to predict the future evolution of the EAIS are hindered by uncertainty in how it responded to past warm periods, for example, during the Pliocene epoch (5.3 to 2.6 million years ago), when atmospheric carbon dioxide concentrations were last higher than 400 parts per million. Geological evidence indicates that some marine-based portions of the EAIS and the West Antarctic Ice Sheet retreated during parts of the Pliocene1,2, but it remains unclear whether ice grounded above sea level also experienced retreat. This uncertainty persists because global sea-level estimates for the Pliocene have large uncertainties and cannot be used to rule out substantial terrestrial ice loss3, and also because direct geological evidence bearing on past ice retreat on land is lacking. Here we show that land-based sectors of the EAIS that drain into the Ross Sea have been stable throughout the past eight million years. We base this conclusion on the extremely low concentrations of cosmogenic 10Be and 26Al isotopes found in quartz sand extracted from a land-proximal marine sediment core. This sediment had been eroded from the continent, and its low levels of cosmogenic nuclides indicate that it experienced only minimal exposure to cosmic radiation, suggesting that the sediment source regions were covered in ice. These findings indicate that atmospheric warming during the past eight million years was insufficient to cause widespread or long-lasting meltback of the EAIS margin onto land. We suggest that variations in Antarctic ice volume in response to the range of global temperatures experienced over this period—up to 2–3 degrees Celsius above preindustrial temperatures4, corresponding to future scenarios involving carbon dioxide concentrations of between 400 and 500 parts per million—were instead driven mostly by the retreat of marine ice margins, in agreement with the latest models5,6.},
author = {Shakun, Jeremy D and Corbett, Lee B and Bierman, Paul R and Underwood, Kristen and Rizzo, Donna M and Zimmerman, Susan R and Caffee, Marc W and Naish, Tim and Golledge, Nicholas R and Hay, Carling C},
doi = {10.1038/s41586-018-0155-6},
issn = {1476-4687},
journal = {Nature},
number = {7709},
pages = {284--287},
title = {{Minimal East Antarctic Ice Sheet retreat onto land during the past eight million years}},
url = {https://doi.org/10.1038/s41586-018-0155-6},
volume = {558},
year = {2018}
}
@article{Shanahan2015a,
abstract = {During the African Humid Period about 14,800 to 5,500 years ago, changes in incoming solar radiation during Northern Hemisphere summers led to the large-scale expansion and subsequent collapse of the African monsoon. Hydrologic reconstructions from arid North Africa show an abrupt onset and termination of the African Humid Period. These abrupt transitions have been invoked in arguments that the African monsoon responds rapidly to gradual forcing as a result of nonlinear land surface feedbacks. Here we present a reconstruction of precipitation in humid tropical West Africa for the past 20,000 years using the hydrogen isotope composition of leaf waxes preserved in sediments from Lake Bosumtwi, Ghana. We show that over much of tropical and subtropical Africa the monsoon responded synchronously and predictably to glacial reorganizations of overturning circulation in the Atlantic Ocean, but the response to the relatively weaker radiative forcing during the African Humid Period was more spatially and temporally complex. A synthesis of hydrologic reconstructions from across Africa shows that the termination of the African Humid Period was locally abrupt, but occurred progressively later at lower latitudes. We propose that this time-transgressive termination of the African Humid Period reflects declining rainfall intensity induced directly by decreasing summer insolation as well as the gradual southward migration of the tropical rainbelt that occurred during this interval. A frica's tropical rainbelt supplies a significant ({\textgreater}60–90{\%}) portion of northern and equatorial Africa's annual mois-ture, and as a result, changes in the timing or intensity of the seasonal rainfall influence food and water security for more than 150 million people 1 . Future global climate changes are ex-pected to alter the rainbelt 2 , but these changes are likely to be complicated by soil moisture, vegetation and albedo feedbacks, which can lead to abrupt, nonlinear changes in vegetation and climate 3–7 . The importance of such feedbacks is particularly evident during the African Humid Period (AHP), a period of higher than modern rainfall across much of West and North Africa between 14,800 and 5,500 yr BP (refs 5,8–11), when gradually increasing Northern Hemisphere summer insolation drove the intensifica-tion and northward expansion of the rainbelt 10–12 . Modelling stud-ies demonstrate that this early Holocene intensification is con-sistent with insolation forcing 8,13 , but the magnitude and north-ward extent of reconstructed hydrologic and vegetation changes can be reproduced only when ocean and land surface feedbacks are included 14,15 . Some models indicate that these feedbacks are capable of producing dynamic instabilities and nonlinear changes in the rainbelt 4,7 , a finding supported by proxy data from arid North Africa showing an abrupt onset and termination of the AHP (refs 5,16,17). However, subsequent studies have raised ques-tions about the susceptibility of the tropical rainbelt to nonlin-ear feedbacks 6,7 and the spatial synchrony of AHP-related changes over North Africa 10 , with important consequences for our under-standing of past and future hydrologic changes in northern and tropical Africa. To reassess time–space evolution of the AHP and related changes in moisture over the past 20,000 years, we present a new reconstruction of past hydrologic variations in humid tropical West Africa from the sediments of Lake Bosumtwi, Ghana (Supplementary Figs 1 and 2), We compare this with a synthesis of palaeoclimate records from across northern and tropical Africa, as well as against transient simulations of the African rainbelt from the TraCE-21 experiments (www.cgd.ucar. edu/ccr/TraCE; Supplementary Section 4; ref. 18). The Lake Bosumtwi record provides a unique perspective on climate changes in humid tropical West Africa during the AHP; many of the existing AHP records in this region are either low resolution or discontinuous (see Supplementary Section 1.5 and Fig. 6b) or rely on vegetation reconstructions to infer precipitation, which can be complicated by changes in seasonality 6 , land use changes 19 and non-analogue vegetation assemblages 20 . Here, we reconstruct changes in precipitation from the hydrogen isotope composition ($\delta$D wax) of leaf waxes (long (C 31) straight chain n-alkanes; Supplementary Section 2.3), which has been shown to be a reliable indicator of the hydrogen isotope composition of source precipitation in West Africa 21 . As the hydrogen isotopic composition of precipitation in tropical West Africa is controlled mostly by the 'amount effect' 22 , $\delta$D wax values are interpreted here as indicators of changes in wet season precipitation intensity, following corrections for global ice volume and vegetation type (Supplementary Section 2.3 and Fig. 5). Independent support for the $\delta$D wax record comes from an updated reconstruction of palaeolake-level variations at Lake Bosumtwi (Supplementary Section 2.2; ref. 23).},
author = {Shanahan, Timothy M. and McKay, Nicholas P. and Hughen, Konrad A. and Overpeck, Jonathan T. and Otto-Bliesner, Bette and Heil, Clifford W. and King, John and Scholz, Christopher A. and Peck, John},
doi = {10.1038/ngeo2329},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {140--144},
title = {{The time-transgressive termination of the African Humid Period}},
url = {http://www.nature.com/articles/ngeo2329},
volume = {8},
year = {2015}
}
@article{Shao2019,
abstract = {Abstract Identifying processes within the Earth System that have modulated atmospheric pCO2 during each glacial cycle of the late Pleistocene stands as one of the grand challenges in climate science. The growing array of surface ocean pH estimates from the boron isotope proxy across the last glacial termination may reveal regions of the ocean that influenced the timing and magnitude of pCO2 rise. Here we present two new boron isotope records from the subtropical-subpolar transition zone of the Southwest Pacific that span the last 20 kyr, as well as new radiocarbon data from the same cores. The new data suggest this region was a source of carbon to the atmosphere rather than a moderate sink as it is today. Significantly higher outgassing is observed between {\~{}}16.5 and 14 kyr BP, associated with increasing $\delta$13C and [CO3]2? at depth, suggesting loss of carbon from the intermediate ocean to the atmosphere. We use these new boron isotope records together with existing records to build a composite pH/pCO2 curve for the surface oceans. The pH disequilibrium/CO2 outgassing was widespread throughout the last deglaciation, likely explained by upwelling of CO2 from the deep/intermediate ocean. During the Holocene, a smaller outgassing peak is observed at a time of relatively stable atmospheric CO2, which may be explained by regrowth of the terrestrial biosphere countering ocean CO2 release. Our stack is likely biased toward upwelling/CO2 source regions. Nevertheless, the composite pCO2 curve provides robust evidence that various parts of the ocean were releasing CO2 to the atmosphere over the last 25 kyr.},
annote = {doi: 10.1029/2018PA003498},
author = {Shao, Jun and Stott, Lowell D and Gray, William R and Greenop, Rosanna and Pecher, Ingo and Neil, Helen L and Coffin, Richard B and Davy, Bryan and Rae, James W B},
doi = {10.1029/2018PA003498},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
month = {oct},
number = {10},
pages = {1650--1670},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Atmosphere-Ocean CO2 Exchange Across the Last Deglaciation From the Boron Isotope Proxy}},
url = {https://doi.org/10.1029/2018PA003498},
volume = {34},
year = {2019}
}
@article{https://doi.org/10.1029/2020JC016710,
abstract = {Abstract Four global wind wave hindcasts based on the third-generation spectral wave model WAVEWATCH III forced by ERA5, ERA-Interim, National Centers of Environmental Prediction and Climate Forecast System Reanalysis (CFSR) and MERRA2 reanalyzes for 1980–2019 are presented. Absolute magnitudes of both 10-m wind speeds and significant wave heights are the largest in the CFSR and CFSR-based hindcast respectively, particularly in the extratropical regions. The differences in annual extremes between CFSR and ERA5 (and corresponding hindcasts) amount to 2.4 ms−1 for wind speeds and 1.2 m for wave heights. CFSR and CFSR-based hindcast also stand out with respect to remaining datasets, showing mostly negative trends in both mean and extreme characteristics. ERA5-, ERA-Interim-, and MERRA2-based hindcasts show annual positive trends in wave heights in 1980–2019, in particular in the Southern Ocean (up to 0.15 m decade-1 for extreme wave heights in MERRA2-based hindcast) as well as in the central Pacific, equatorial and tropical Atlantic, and Indian Oceans. All four hindcasts agree on the positive linear trends in the North Atlantic midlatitudes and subtropics, western South Atlantic midlatitudes and the tropical South Pacific, and the negative trends in the eastern North Pacific midlatitudes. Areas with significant linear trends in wave heights generally coincide with those for wind speeds, however, they have larger spatial coverage. The interannual variability in significant wave heights is the most consistent across different hindcasts in the eastern midlatitudes of both hemispheres. The performed hindcasts provide a useful background for studies on both present and future wave climates.},
annote = {e2020JC016710 2020JC016710},
author = {Sharmar, V D and Markina, M Yu. and Gulev, S K},
doi = {10.1029/2020JC016710},
journal = {Journal of Geophysical Research: Oceans},
keywords = {CFSR,ERA Interim,ERA5,MERRA2,WAVEWATCH,wind wave climate},
number = {1},
pages = {e2020JC016710},
title = {{Global Ocean Wind-Wave Model Hindcasts Forced by Different Reanalyzes: A Comparative Assessment}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JC016710},
volume = {126},
year = {2021}
}
@article{Shen2014,
abstract = {This paper provides a multivariate regression method to estimate the sampling errors of the annual quasi-global (75°S–75°N) precipitation reconstructed by an empirical orthogonal function (EOF) expansion. The Global Precipitation Climatology Project (GPCP) precipitation data from 1979 to 2008 are used to calculate the EOFs. The Global Historical Climatology Network (GHCN) gridded data (1900–2011) are used to calculate the regression coefficients for reconstructions. The sampling errors of the reconstruction are analyzed in detail for different EOF modes. The reconstructed time series of the global-average annual precipitation shows a 0.024 mm day−1 (100 yr)−1 trend, which is very close to the trend derived from the mean of 25 models of phase 5 of the Coupled Model Intercomparison Project. Reconstruction examples of 1983 El Ni{\~{n}}o precipitation and 1917 La Ni{\~{n}}a precipitation demonstrate that the El Ni{\~{n}}o and La Ni{\~{n}}a precipitation patterns are well reflected in the first two EOFs. Although the validation in the GPCP period shows remarkable skill at predicting oceanic precipitation from land stations, the error pattern analysis through comparison between reconstruction and GHCN suggests the critical importance of improving oceanic measurement of precipitation.},
author = {Shen, Samuel S. P. and Tafolla, Nancy and Smith, Thomas M. and Arkin, Phillip A.},
doi = {10.1175/JAS-D-13-0301.1},
issn = {0022-4928},
journal = {Journal of the Atmospheric Sciences},
month = {sep},
number = {9},
pages = {3250--3268},
title = {{Multivariate Regression Reconstruction and Its Sampling Error for the Quasi-Global Annual Precipitation from 1900 to 2011}},
url = {https://journals.ametsoc.org/doi/10.1175/JAS-D-13-0301.1},
volume = {71},
year = {2014}
}
@article{Shen2020,
author = {Shen, Xiaocen and Wang, Lin and Osprey, Scott},
doi = {10.1016/j.scib.2020.06.028},
issn = {20959281},
journal = {Science Bulletin},
number = {21},
pages = {1800--1802},
publisher = {Science China Press},
title = {{The Southern Hemisphere sudden stratospheric warming of September 2019}},
url = {https://doi.org/10.1016/j.scib.2020.06.028},
volume = {65},
year = {2020}
}
@article{Shepherd2014,
abstract = {The observed depletion of the ozone layer from the 1980s onwards is attributed to halogen source gases emitted by human activities. However, the precision of this attribution is complicated by year-to-year variations in meteorology, that is, dynamical variability, and by changes in tropospheric ozone concentrations. As such, key aspects of the total-column ozone record, which combines changes in both tropospheric and stratospheric ozone, remain unexplained, such as the apparent absence of a decline in total-column ozone levels before 1980, and of any long-term decline in total-column ozone levels in the tropics. Here we use a chemistry-climate model to estimate changes in halogen-induced ozone loss between 1960 and 2010; the model is constrained by observed meteorology to remove the effects of dynamical variability, and driven by emissions of tropospheric ozone precursors to separate out changes in tropospheric ozone. We show that halogen-induced ozone loss closely followed stratospheric halogen loading over the studied period. Pronounced enhancements in ozone loss were apparent in both hemispheres following the volcanic eruptions of El Chichon and, in particular, Mount Pinatubo, which significantly enhanced stratospheric aerosol loads. We further show that approximately 40{\%} of the long-term non-volcanic ozone loss occurred before 1980, and that long-term ozone loss also occurred in the tropical stratosphere. Finally, we show that halogen-induced ozone loss has declined by over 10{\%} since stratospheric halogen loading peaked in the late 1990s, indicating that the recovery of the ozone layer is well underway.},
author = {Shepherd, T. G. and Plummer, D. A. and Scinocca, J. F. and Hegglin, M. I. and Fioletov, V. E. and Reader, M. C. and Remsberg, E. and {Von Clarmann}, T. and Wang, H. J.},
doi = {10.1038/ngeo2155},
issn = {17520908},
journal = {Nature Geoscience},
pages = {443--449},
title = {{Reconciliation of halogen-induced ozone loss with the total-column ozone record}},
volume = {7},
year = {2014}
}
@article{Shi2018,
abstract = {The secular change of the Asian monsoon (AM)-El Ni{\~{n}}o--Southern Oscillation (ENSO) relationship has been recognized as a specter for seasonal forecast. The causes of such changes have not been well understood. How the monsoon-ENSO relationship underwent secular changes beyond instrumental period has rarely been discussed. Here we explore the multidecadal to centennial changes of the AM-ENSO relationship with the recently compiled Reconstructed Asian summer Precipitation (RAP) dataset (1470--2013) and multiple ENSO proxy indices. During the past five centuries, two leading modes of interannual variability of RAP are found to be associated with the ENSO developing and decaying phases, respectively. The mechanisms behind the modern monsoon-ENSO relationship can reasonably well explain the past monsoon behavior. In response to a developing ENSO, precipitation anomalies from the Maritime Continent (MC) via India to northern China are in phase, and this ``chain reaction'' tends to be largely steady since around 1620 AD when the Indian summer monsoon abruptly strengthened. Further, the strengthening of the link between developing-ENSO and Indian-northern China rainfall since 1620 AD concurred with a phase reversal of the Pacific Decadal Oscillation. During the decaying phase, however, the summer rainfall-ENSO relationship over the Yangtze River Valley-southern East China (YRV-SEC), the MC and central Asia, has gone through large multidecadal to centennial changes over the past five centuries. A remarkable reversal of sign in the AM-decaying ENSO relationship occurred roughly from 1740 to 1760 over the YRV-SEC and MC, which may be associated with the long-term strengthening of ENSO intensity. Future research should continue focusing on revealing the possible causes of the low-frequency changes in the monsoon-ENSO relationship using general circulation models and paleoclimate proxy reconstructions.},
author = {Shi, Hui and Wang, Bin},
doi = {10.1007/s00382-018-4392-z},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {aug},
pages = {4583--4598},
title = {{How does the Asian summer precipitation-ENSO relationship change over the past 544 years?}},
url = {https://doi.org/10.1007/s00382-018-4392-z},
volume = {52},
year = {2018}
}
@article{Shi2018b,
author = {Shi, Lei and Schreck, Carl J. and Schr{\"{o}}der, Marc},
doi = {10.3390/rs10081188},
journal = {Remote Sensing},
number = {1188},
pages = {1--15},
title = {{Assessing the Pattern Differences between Satellite-Observed Upper Tropospheric Humidity and Total Column Water Vapor during Major El Ni{\~{n}}o Events}},
volume = {10},
year = {2018}
}
@article{Shi2015,
abstract = {To investigate climate variability in Asia during the last millennium, the spatial and temporal evolution of summer (June--July--August; JJA) temperature in eastern and south-central Asia is reconstructed using multi-proxy records and the regularized expectation maximization (RegEM) algorithm with truncated total least squares (TTLS), under a point-by-point regression (PPR) framework. The temperature index reconstructions show that the late 20th century was the warmest period in Asia over the past millennium. The temperature field reconstructions illustrate that temperatures in central, eastern, and southern China during the 11th and 13th centuries, and in western Asia during the 12th century, were significantly higher than those in other regions, and comparable to levels in the 20th century. Except for the most recent warming, all identified warm events showed distinct regional expressions and none were uniform over the entire reconstruction area. The main finding of the study is that spatial temperature patterns have, on centennial time-scales, varied greatly over the last millennium. Moreover, seven climate model simulations, from the Coupled Model Intercomparison Project Phase 5 (CMIP5), over the same region of Asia, are all consistent with the temperature index reconstruction at the 99 {\%} confidence level. Only spatial temperature patterns extracted as the first empirical orthogonal function (EOF) from the GISS-E2-R and MPI-ESM-P model simulations are significant and consistent with the temperature field reconstruction over the past millennium in Asia at the 90 {\%} confidence level. This indicates that both the reconstruction and the simulations depict the temporal climate variability well over the past millennium. However, the spatial simulation or reconstruction capability of climate variability over the past millennium could be still limited. For reconstruction, some grid points do not pass validation tests and reveal the need for more proxies with high temporal resolution, accurate dating, and sensitive temperature signals, especially in central Asia and before AD 1400.},
author = {Shi, Feng and Ge, Quansheng and Yang, Bao and Li, Jianping and Yang, Fengmei and Ljungqvist, Fredrik Charpentier and Solomina, Olga and Nakatsuka, Takeshi and Wang, Ninglian and Zhao, Sen and Xu, Chenxi and Fang, Keyan and Sano, Masaki and Chu, Guoqiang and Fan, Zexin and Gaire, Narayan P and Zafar, Muhammad Usama},
doi = {10.1007/s10584-015-1413-3},
issn = {1573-1480},
journal = {Climatic Change},
month = {aug},
number = {4},
pages = {663--676},
title = {{A multi-proxy reconstruction of spatial and temporal variations in Asian summer temperatures over the last millennium}},
url = {https://doi.org/10.1007/s10584-015-1413-3},
volume = {131},
year = {2015}
}
@article{Shi2019,
abstract = {Under the influence of global climate change, the discharges of major global rivers directed into the ocean have undergone significant changes. To study the trends and causes in discharge variation, we selected 40 large rivers and analyzed their annual discharges near their estuaries from 1960 to 2010. The method of runoff variation attribution analysis based on the Budyko hypothesis for large-scale basins was developed, in which influencing factors of human activities and glacial melting factors were added to the formula. The contribution rate of climate factors and human activities to changes in discharge were quantitatively identified. Climatic factors include precipitation, evapotranspiration and glacial melting. Human activity factors include underlying surface and artificial water transfer. The contribution rate is determined by the elastic coefficient, which is obtained by the ratio of change rate of each factor and the change rate of runoff. The results indicated that the discharges predominantly showed downward trends with a few upward trends. Rivers in North America and Africa showed downward trends, and those in Europe principally showed upward trends. Climate was the main influencing factor of discharges changes, and only approximately 25{\%} of river discharges were greatly affected by human activities. River discharges in 75{\%} of the basins which mainly contains subtropical monsoon humid climate and savanna climate zones showed upward trends. In the four basins which are mainly contains tropical rainforest climate and tropical monsoon climate, they all showed downward trends. The trend of discharges in the temperate monsoon climate, temperate continental climate, and temperate maritime climate cannot be accurately judged because of irregular variation. The discharges in the mid-high latitudinal zones predominantly showed upward trends, while those in the mid-low latitudinal zones with the influence of human activities showed downward trends.},
author = {Shi, Xiaoqing and Qin, Tianling and Nie, Hanjiang and Weng, Baisha and He, Shan},
doi = {10.3390/ijerph16081469},
issn = {1660-4601},
journal = {International Journal of Environmental Research and Public Health},
keywords = {Climate change,Human activities,River discharges,Spatial distribution,Trend},
month = {apr},
number = {8},
pages = {1469},
pmid = {31027227},
title = {{Changes in Major Global River Discharges Directed into the Ocean}},
url = {https://www.mdpi.com/1660-4601/16/8/1469},
volume = {16},
year = {2019}
}
@article{Shi2019a,
abstract = {Historical temperature records are often partially biased by the urban heat island (UHI) effect. However, the exact magnitude of these biases is an ongoing, controversial scientific question, especially in regions like China where urbanization has greatly increased in recent decades. Previous studies have mainly used statistical information and selected static population targets, or urban areas in a particular year, to classify urban-rural stations and estimate the influence of urbanization on observed warming trends. However, there is a lack of consideration for the dynamic processes of urbanization. The Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD) are three major urban agglomerations in China which were selected to investigate the spatiotemporal heterogeneity of urban expansion effects on observed warming trends in this study. Based on remote sensing (RS) data, urban area expansion processes were taken into consideration and the relationship between urban expansion rates and warming trends was investigated using data from 975 meteorological stations throughout China. Although urban areas constitute less than 1{\%} of land in China, more than 90{\%} of the meteorological stations experienced urban land use change and the average urban expansion rate was 0.33{\%}/a. There was also a significant positive relationship between observed warming trends and urban expansion rates. Background warming, without the influence of urbanization and extra warming induced by urbanization processes, was estimated using a linear regression model based on observed warming trends and urban expansion rates. On average, urbanization led to an additional annual warming of 0.034 ± 0.005 °C/10a. This urbanization warming effect was 0.050 ± 0.007 °C/10a for minimum temperatures and 0.008 ± 0.004 °C/10a for maximum temperatures. Moreover, it appeared that urbanization induced greater warming on the minimum temperature during the cold season and maximum temperature during the warm season.},
author = {Shi, Zitong and Jia, Gensuo and Hu, Yonghong and Zhou, Yuyu},
doi = {10.1007/s00704-019-02892-y},
issn = {1434-4483},
journal = {Theoretical and Applied Climatology},
number = {1},
pages = {1125--1137},
title = {{The contribution of intensified urbanization effects on surface warming trends in China}},
url = {https://doi.org/10.1007/s00704-019-02892-y},
volume = {138},
year = {2019}
}
@article{Shuman2018,
abstract = {Abstract. A synthesis of 93 hydrologic records from across North and Central America, and adjacent tropical and Arctic islands, reveals centennial to millennial trends in the regional hydroclimates of the Common Era (CE; past 2000 years). The hydrological records derive from materials stored in lakes, bogs, caves, and ice from extant glaciers, which have the continuity through time to preserve low-frequency ( {\textgreater} 100 year) climate signals that may extend deeper into the Holocene. The most common pattern, represented in 46 (49 {\%}) of the records, indicates that the centuries before 1000 CE were drier than the centuries since that time. Principal component analysis indicates that millennial-scale trends represent the dominant pattern of variance in the southwestern US, northeastern US, mid-continent, Pacific Northwest, Arctic, and tropics, although not all records within a region show the same direction of change. The Pacific Northwest and the southernmost tier of the tropical sites tended to dry toward present, as many other areas became wetter than before. In 22 records (24 {\%}), the Medieval Climate Anomaly period (800–1300 CE) was drier than the Little Ice Age (1400–1900 CE), but in many cases the difference was part of the longer millennial-scale trend, and, in 25 records (27 {\%}), the Medieval Climate Anomaly period represented a pluvial (wet) phase. Where quantitative records permitted a comparison, we found that centennial-scale fluctuations over the Common Era represented changes of 3–7 {\%} in the modern interannual range of variability in precipitation, but the accumulation of these long-term trends over the entirety of the Holocene caused recent centuries to be significantly wetter, on average, than most of the past 11 000 years.},
author = {Shuman, Bryan N and Routson, Cody and McKay, Nicholas and Fritz, Sherilyn and Kaufman, Darrell and Kirby, Matthew E and Nolan, Connor and Pederson, Gregory T and St-Jacques, Jeannine-Marie},
doi = {10.5194/cp-14-665-2018},
issn = {1814-9332},
journal = {Climate of the Past},
month = {may},
number = {5},
pages = {665--686},
title = {{Placing the Common Era in a Holocene context: millennial to centennial patterns and trends in the hydroclimate of North America over the past 2000 years}},
url = {https://cp.copernicus.org/articles/14/665/2018/},
volume = {14},
year = {2018}
}
@article{Shuman2019,
abstract = {Climate variations in the North Atlantic region can substantially impact surrounding continents. Notably, the Younger Dryas chronozone was named for the ecosystem effects of abrupt changes in the region at circa (ca.) 12.9-11.7 ka (millennia before 1950 AD). Holocene variations since then, however, have been hard to diagnose, and the responsiveness of terrestrial ecosystems continues to be debated. Here, we show that Holocene climate variations had spatial patterns consistent with changes in Atlantic overturning and repeatedly steepened the temperature gradient between Nova Scotia and Greenland since {\textgreater}8 ka. The multicentury changes correlated with hydrologic and vegetation changes in the northeast United States, including when an enhanced temperature gradient coincided with subregional droughts indicated by waterlevel changes at multiple coastal lakes at 4.9-4.6, 4.2-3.9, 2.8-2.1, and 1.3-1.2 ka. We assessed the variability and its effects by replicating signals across sites, using converging evidence from multiple methods, and applying forward models of the systems involved. We evaluated forest responses in the northeast United States and found that they tracked the regional climate shifts including the smallestmagnitude (∼5{\%} or 50 mm) changes in effective precipitation. Although a long-term increase in effective precipitation of {\textgreater}45{\%} ({\textgreater}400 mm) could have prevented ecological communities from equilibrating to the continuously changing conditions, our comparisons confirm stable vegetation-climate relationships and support the use of fossil pollen records for quantitative paleoclimate reconstruction. Overall, the network of records indicates that centennial climate variability has repeatedly affected the North Atlantic region with predictable consequences.},
author = {Shuman, Bryan N. and Marsicek, Jeremiah and Oswald, W. Wyatt and Foster, David R.},
doi = {10.1073/pnas.1814307116},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Climate,Drought,Holocene,North Atlantic,Vegetation},
number = {13},
pages = {5985--5990},
title = {{Predictable hydrological and ecological responses to Holocene North Atlantic variability}},
volume = {116},
year = {2019}
}
@article{Shuman2016,
author = {Shuman, Bryan N and Marsicek, Jeremiah},
doi = {10.1016/j.quascirev.2016.03.009},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {38--51},
publisher = {Elsevier Ltd},
title = {{The structure of Holocene climate change in mid-latitude North America}},
url = {http://dx.doi.org/10.1016/j.quascirev.2016.03.009},
volume = {141},
year = {2016}
}
@article{Siegenthaler2005b,
abstract = {ABSTRACT The most direct method of investigating past variations of the atmospheric CO2 concentration before 1958, when continuous direct atmospheric CO2 measurements started, is the analysis of air extracted from suitable ice cores. Here we present a new detailed CO2 record from the Dronning Maud Land (DML) ice core, drilled in the framework of the European Project for Ice Coring in Antarctica (EPICA) and some new measurements on a previously drilled ice core from the South Pole. The DML CO2 record shows an increase from about 278 to 282 parts per million by volume (ppmv) between ad 1000 and ad 1200 and a fairly continuous decrease to a mean value of about 277 ppmv around ad 1700. While the new South Pole measurements agree well with DML at the minimum at ad 1700 they are on average about 2 ppmv lower during the period ad 1000–1500. Published measurements from the coastal high-accumulation site Law Dome are considered as very reliable because of the reproducibility of the measurements, high temporal resolution and an accurate time scale. Other Antarctic ice cores could not, or only partly, reproduce the pre-industrial measurements from Law Dome. A comparison of the trends of DML and Law Dome shows a general agreement. However we should be able to rule out co-variations caused by the same artefact. Two possible effects are discussed, first production of CO2 by chemical reactions and second diffusion of dissolved air through the ice matrix into the bubbles. While the first effect cannot be totally excluded, comparison of the Law Dome and DML record shows that dissolved air diffusing to bubbles cannot be responsible for the pre-industrial variation. Therefore, the new record is not a proof of the Law Dome results but the first very strong support from an ice core of the Antarctic plateau.},
author = {Siegenthaler, Urs and Monnin, Eric and Kawamura, Kenji and Spahni, Renato and Schwander, Jakob and Stauffer, Bernhard and Stocker, Thomas F. and Barnola, Jean-Marc and Fischer, Hubertus},
doi = {10.1111/j.1600-0889.2005.00131.x},
issn = {0280-6509},
journal = {Tellus B: Chemical and Physical Meteorology},
month = {feb},
number = {1},
pages = {51--57},
title = {{Supporting evidence from the EPICA Dronning Maud Land ice core for atmospheric CO2 changes during the past millennium}},
volume = {57},
year = {2005}
}
@article{Sigl2015,
abstract = {Volcanic eruptions contribute to climate variability, but quantifying these contributions has been limited by inconsistencies in the timing of atmospheric volcanic aerosol loading determined from ice cores and subsequent cooling from climate proxies such as tree rings. Here we resolve these inconsistencies and show that large eruptions in the tropics and high latitudes were primary drivers of interannual-to-decadal temperature variability in the Northern Hemisphere during the past 2,500 years. Our results are based on new records of atmospheric aerosol loading developed from high-resolution, multi-parameter measurements from an array of Greenland and Antarctic ice cores as well as distinctive age markers to constrain chronologies. Overall, cooling was proportional to the magnitude of volcanic forcing and persisted for up to ten years after some of the largest eruptive episodes. Our revised timescale more firmly implicates volcanic eruptions as catalysts in the major sixth-century pandemics, famines, and socioeconomic disruptions in Eurasia and Mesoamerica while allowing multi-millennium quantification of climate response to volcanic forcing.},
author = {Sigl, M. and Winstrup, M. and McConnell, J. R. and Welten, K. C. and Plunkett, G. and Ludlow, F. and B{\"{u}}ntgen, U. and Caffee, M. and Chellman, N. and Dahl-Jensen, D. and Fischer, H. and Kipfstuhl, S. and Kostick, C. and Maselli, O. J. and Mekhaldi, F. and Mulvaney, R. and Muscheler, R. and Pasteris, D. R. and Pilcher, J. R. and Salzer, M. and Sch{\"{u}}pbach, S. and Steffensen, J. P. and Vinther, B. M. and Woodruff, T. E.},
doi = {10.1038/nature14565},
issn = {0028-0836},
journal = {Nature},
month = {jul},
number = {7562},
pages = {543--549},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
shorttitle = {Nature},
title = {{Timing and climate forcing of volcanic eruptions for the past 2,500 years}},
url = {http://www.nature.com/articles/nature14565},
volume = {523},
year = {2015}
}
@article{Siler2019,
abstract = {Climate models simulate an increase in global precipitation at a rate of approximately 1–3{\%} per Kelvin of global surface warming. This change is often interpreted through the lens of the atmospheric energy budget, in which the increase in global precipitation is mostly offset by an increase in net radiative cooling. Other studies have provided different interpretations from the perspective of the surface, where evaporation represents the turbulent transfer of latent heat to the atmosphere. Expanding on this surface perspective, here we derive a version of the Penman–Monteith equation that allows the change in ocean evaporation to be partitioned into a thermodynamic response to surface warming, and additional diagnostic contributions from changes in surface radiation, ocean heat uptake, and boundary-layer dynamics/relative humidity. In this framework, temperature is found to be the primary control on the rate of increase in global precipitation within model simulations of greenhouse gas warming, while the contributions from changes in surface radiation and ocean heat uptake are found to be secondary. The temperature contribution also dominates the spatial pattern of global evaporation change, leading to the largest fractional increases at high latitudes. In the surface energy budget, the thermodynamic increase in evaporation comes at the expense of the sensible heat flux, while radiative changes cause the sensible heat flux to increase. These tendencies on the sensible heat flux partly offset each other, resulting in a relatively small change in the global mean, and contributing to an impression that global precipitation is radiatively constrained.},
author = {Siler, Nicholas and Roe, Gerard H and Armour, Kyle C and Feldl, Nicole},
doi = {10.1007/s00382-018-4359-0},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {7},
pages = {3983--3995},
title = {{Revisiting the surface-energy-flux perspective on the sensitivity of global precipitation to climate change}},
url = {https://doi.org/10.1007/s00382-018-4359-0},
volume = {52},
year = {2019}
}
@article{acp-20-7271-2020,
author = {Simmonds, P G and Rigby, M and Manning, A J and Park, S and Stanley, K M and McCulloch, A and Henne, S and Graziosi, F and Maione, M and Arduini, J and Reimann, S and Vollmer, M K and M{\"{u}}hle, J and O'Doherty, S and Young, D and Krummel, P B and Fraser, P J and Weiss, R F and Salameh, P K and Harth, C M and Park, M.-K. and Park, H and Arnold, T and Rennick, C and Steele, L P and Mitrevski, B and Wang, R H J and Prinn, R G},
doi = {10.5194/acp-20-7271-2020},
journal = {Atmospheric Chemistry and Physics},
number = {12},
pages = {7271--7290},
title = {{The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF6)}},
url = {https://acp.copernicus.org/articles/20/7271/2020/},
volume = {20},
year = {2020}
}
@article{Simmons2010,
author = {Simmons, A J and Willett, K M and Jones, P D and Thorne, P W and Dee, D P},
doi = {10.1029/2009JD012442},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {doi:10.102,http://dx.doi.org/10.1029/2009JD012442},
month = {jan},
number = {D1},
pages = {D01110},
title = {{Low-frequency variations in surface atmospheric humidity, temperature, and precipitation: Inferences from reanalyses and monthly gridded observational data sets}},
url = {http://doi.wiley.com/10.1029/2009JD012442},
volume = {115},
year = {2010}
}
@article{doi:10.1002/qj.2949,
abstract = {The ERA-Interim and JRA-55 reanalyses of synoptic data and several conventional analyses of monthly climatological data provide similar estimates of global-mean surface warming since 1979. They broadly agree on the character of interannual variability and the extremity of the 2015/2016 warm spell to which a strong El Ni{\~{n}}o and low Arctic sea-ice cover contribute. Nevertheless global and regional averages differ on various time-scales due to differences in data coverage and sea-surface temperature analyses; averages from those conventional datasets that infill where they lack direct observations agree better with the averages from the reanalyses. The latest warm event is less extreme when viewed in terms of atmospheric energy, which gives more weight to variability in the Tropics, where the thermal signal has greater vertical penetration and latent energy is a larger factor. Surface warming from 1998 to 2012 is larger than indicated by earlier versions of the conventional datasets used to characterize what the Fifth Assessment Report of the Intergovernmental Panel on Climate Change termed a hiatus in global warming. None of the datasets exhibit net warming over the Antarctic since 1979. Centennial trends from the conventional datasets, HadCRUT4 on the one hand and GISTEMP and NOAAGlobalTemp on the other, differ mainly because sea-surface temperatures differ. Infilling of values where direct observations are lacking is more questionable for the data-sparse earlier decades. Change since the eighteenth century is inevitably more uncertain than change over and after a modern baseline period. The latter is arguably best estimated separately for taking stock of actions to limit climate change, exploiting reanalyses and using satellite data to refine the conventional approach. Nevertheless, early in 2016 the global temperature appears to have first touched or briefly breached a level 1.5 °C above that early in the Industrial Revolution, having touched the 1.0 °C level in 1998 during a previous El Ni{\~{n}}o.},
author = {Simmons, A J and Berrisford, P and Dee, D P and Hersbach, H and Hirahara, S and Th{\'{e}}paut, J.-N.},
doi = {10.1002/qj.2949},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {Arctic warming,El Ni{\~{n}}o,atmospheric energy,reanalysis,temperature trends},
number = {702},
pages = {101--119},
title = {{A reassessment of temperature variations and trends from global reanalyses and monthly surface climatological datasets}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.2949},
volume = {143},
year = {2017}
}
@article{SIMPSON20091631,
abstract = {We constrain a three-dimensional thermomechanical model of Greenland ice sheet (GrIS) evolution from the Last Glacial Maximum (LGM, 21ka BP) to the present-day using, primarily, observations of relative sea level (RSL) as well as field data on past ice extent. Our new model (Huy2) fits a majority of the observations and is characterised by a number of key features: (i) the ice sheet had an excess volume (relative to present) of 4.1m ice-equivalent sea level at the LGM, which increased to reach a maximum value of 4.6m at 16.5ka BP; (ii) retreat from the continental shelf was not continuous around the entire margin, as there was a Younger Dryas readvance in some areas. The final episode of marine retreat was rapid and relatively late (c. 12ka BP), leaving the ice sheet land based by 10ka BP; (iii) in response to the Holocene Thermal Maximum (HTM) the ice margin retreated behind its present-day position by up to 80km in the southwest, 20km in the south and 80km in a small area of the northeast. As a result of this retreat the modelled ice sheet reaches a minimum extent between 5 and 4ka BP, which corresponds to a deficit volume (relative to present) of 0.17m ice-equivalent sea level. Our results suggest that remaining discrepancies between the model and the observations are likely associated with non-Greenland ice load, differences between modelled and observed present-day ice elevation around the margin, lateral variations in Earth structure and/or the pattern of ice margin retreat.},
annote = {Quaternary Ice Sheet-Ocean Interactions and Landscape Responses},
author = {Simpson, Matthew J R and Milne, Glenn A and Huybrechts, Philippe and Long, Antony J},
doi = {10.1016/j.quascirev.2009.03.004},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
number = {17},
pages = {1631--1657},
title = {{Calibrating a glaciological model of the Greenland ice sheet from the Last Glacial Maximum to present-day using field observations of relative sea level and ice extent}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379109000997},
volume = {28},
year = {2009}
}
@article{Simpson2012,
abstract = {After methane, ethane is the most abundant hydrocarbon in the remote atmosphere. It is a precursor to tropospheric ozone and it influences the atmosphere/'s oxidative capacity through its reaction with the hydroxyl radical, ethane/'s primary atmospheric sink. Here we present the longest continuous record of global atmospheric ethane levels. We show that global ethane emission rates decreased from 14.3 to 11.3 teragrams per year, or by 21 per cent, from 1984 to 2010. We attribute this to decreasing fugitive emissions from ethane/'s fossil fuel source—most probably decreased venting and flaring of natural gas in oil fields—rather than a decline in its other major sources, biofuel use and biomass burning. Ethane/'s major emission sources are shared with methane, and recent studies have disagreed on whether reduced fossil fuel or microbial emissions have caused methane/'s atmospheric growth rate to slow. Our findings suggest that reduced fugitive fossil fuel emissions account for at least 10-21 teragrams per year (30-70 per cent) of the decrease in methane/'s global emissions, significantly contributing to methane/'s slowing atmospheric growth rate since the mid-1980s.},
author = {Simpson, Isobel J. and Andersen, Mads P.Sulbaek and Meinardi, Simone and Bruhwiler, Lori and Blake, Nicola J. and Helmig, Detlev and {Sherwood Rowland}, F. and Blake, Donald R.},
doi = {10.1038/nature11342},
issn = {00280836},
journal = {Nature},
pages = {490--494},
pmid = {22914166},
title = {{Long-term decline of global atmospheric ethane concentrations and implications for methane}},
volume = {488},
year = {2012}
}
@article{Sinclair2016,
abstract = {The last deglaciation is the most recent interval of large-scale climate change that drove the Greenland ice sheet from continental shelf to within its present extent. Here, we use a database of 645 published10Be ages from Greenland to document the spatial and temporal patterns of retreat of the Greenland ice sheet during the last deglaciation. Following initial retreat of its marine margins, most land-based deglaciation occurred in Greenland following the end of the Younger Dryas cold period (12.9-11.7 ka). However, deglaciation in east Greenland peaked significantly earlier (13.0-11.5 ka) than that in south Greenland (11.0-10 ka) or west Greenland (10.5-7.0 ka). The terrestrial deglaciation of east and south Greenland coincide with adjacent ocean warming.14C ages and a recent ice-sheet model reconstruction do not capture this progression of terrestrial deglacial ages from east to west Greenland, showing deglaciation occurring later than observed in10Be ages. This model-data misfit likely reflects the absence of realistic ice-ocean interactions. We suggest that oceanic changes may have played an important role in driving the spatial-temporal ice-retreat pattern evident in the10Be data.},
author = {Sinclair, G. and Carlson, A. E. and Mix, A. C. and Lecavalier, B. S. and Milne, G. and Mathias, A. and Buizert, C. and DeConto, R.},
doi = {10.1016/j.quascirev.2016.05.040},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Deglaciation,Greenland ice sheet,Holocene,Ice-sheet models,Model-data comparison,Radiocarbon dating,Surface exposure dating},
pages = {243--258},
title = {{Diachronous retreat of the Greenland ice sheet during the last deglaciation}},
volume = {145},
year = {2016}
}
@article{doi:10.1002/2014GL059821,
abstract = {AbstractWe present the first proxy record of sea-ice area (SIA) in the Ross Sea, Antarctica, from a 130 year coastal ice-core record. High-resolution deuterium excess data show prevailing stable SIA from the 1880s until the 1950s, a 2–5{\%} reduction from the mid-1950s to the early-1990s, and a 5{\%} increase after 1993. Additional support for this reconstruction is derived from ice-core methanesulphonic acid concentrations and whaling records. While SIA has continued to decline around much of the West Antarctic coastline since the 1950s, concurrent with increasing air and ocean temperatures, the underlying trend is masked in the Ross Sea by a switch to positive SIA anomalies since the early-1990s. This increase is associated with a strengthening of southerly winds and the enhanced northward advection of sea ice.},
author = {Sinclair, Kate E and Bertler, Nancy A N and Bowen, Melissa M and Arrigo, Kevin R},
doi = {10.1002/2014GL059821},
journal = {Geophysical Research Letters},
keywords = {Antarctica,Climate,Geochemistry,Ice core,Sea ice},
number = {10},
pages = {3510--3516},
title = {{Twentieth century sea-ice trends in the Ross Sea from a high-resolution, coastal ice-core record}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014GL059821},
volume = {41},
year = {2014}
}
@article{Singh2018,
author = {Singh, H K A and Hakim, G J and Tardif, R and Emile-Geay, J and Noone, D C},
doi = {10.5194/cp-14-157-2018},
issn = {1814-9332},
journal = {Climate of the Past},
month = {feb},
number = {2},
pages = {157--174},
publisher = {Copernicus Publications},
title = {{Insights into Atlantic multidecadal variability using the Last Millennium Reanalysis framework}},
url = {https://www.clim-past.net/14/157/2018/ https://www.clim-past.net/14/157/2018/cp-14-157-2018.pdf},
volume = {14},
year = {2018}
}
@article{Sjolte2018,
author = {Sjolte, Jesper and Sturm, Christophe and Adolphi, Florian and Vinther, Bo M and Werner, Martin and Lohmann, Gerrit and Muscheler, Raimund},
doi = {10.5194/cp-14-1179-2018},
issn = {1814-9332},
journal = {Climate of the Past},
month = {aug},
number = {8},
pages = {1179--1194},
title = {{Solar and volcanic forcing of North Atlantic climate inferred from a process-based reconstruction}},
url = {https://cp.copernicus.org/articles/14/1179/2018/},
volume = {14},
year = {2018}
}
@article{Skeie2020,
abstract = {Radiative forcing (RF) time series for total ozone from 1850 up to the present day are calculated based on historical simulations of ozone from 10 climate models contributing to the Coupled Model Intercomparison Project Phase 6 (CMIP6). In addition, RF is calculated for ozone fields prepared as an input for CMIP6 models without chemistry schemes and from a chemical transport model simulation. A radiative kernel for ozone is constructed and used to derive the RF. The ozone RF in 2010 (2005–2014) relative to 1850 is 0.35 W m−2 [0.08–0.61] (5–95{\%} uncertainty range) based on models with both tropospheric and stratospheric chemistry. One of these models has a negative present-day total ozone RF. Excluding this model, the present-day ozone RF increases to 0.39 W m−2 [0.27–0.51] (5–95{\%} uncertainty range). The rest of the models have RF close to or stronger than the RF time series assessed by the Intergovernmental Panel on Climate Change in the fifth assessment report with the primary driver likely being the new precursor emissions used in CMIP6. The rapid adjustments beyond stratospheric temperature are estimated to be weak and thus the RF is a good measure of effective radiative forcing.},
author = {Skeie, Ragnhild Bieltvedt and Myhre, Gunnar and Hodnebrog, {\O}ivind and Cameron-Smith, Philip J and Deushi, Makoto and Hegglin, Michaela I and Horowitz, Larry W and Kramer, Ryan J and Michou, Martine and Mills, Michael J and Olivi{\'{e}}, Dirk J L and Connor, Fiona M O' and Paynter, David and Samset, Bj{\o}rn H and Sellar, Alistair and Shindell, Drew and Takemura, Toshihiko and Tilmes, Simone and Wu, Tongwen},
doi = {10.1038/s41612-020-00131-0},
issn = {2397-3722},
journal = {npj Climate and Atmospheric Science},
number = {1},
pages = {32},
title = {{Historical total ozone radiative forcing derived from CMIP6 simulations}},
url = {https://doi.org/10.1038/s41612-020-00131-0},
volume = {3},
year = {2020}
}
@article{Skliris2014a,
author = {Skliris, Nikolaos and Marsh, Robert and Josey, Simon A and Good, Simon A and Liu, Chunlei and Allan, Richard P},
doi = {10.1007/s00382-014-2131-7},
isbn = {0038201421317},
journal = {Climate Dynamics},
keywords = {precipitation {\'{a}} hydrological cycle,salinity {\'{a}} freshwater flux,{\'{a}} evaporation {\'{a}}},
number = {3-4},
pages = {709--736},
title = {{Salinity changes in the World Ocean since 1950 in relation to changing surface freshwater fluxes}},
volume = {43},
year = {2014}
}
@article{Skliris2016,
author = {Skliris, Nikolaos and Zika, Jan D and Nurser, George and Josey, Simon A and Marsh, Robert},
doi = {10.1038/srep38752},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {38752},
publisher = {Nature Publishing Group},
title = {{Global water cycle amplifying at less than the Clausius-Clapeyron rate}},
url = {http://dx.doi.org/10.1038/srep38752 http://www.nature.com/articles/srep38752},
volume = {6},
year = {2016}
}
@article{Sloyan2015,
abstract = {In this study we compare optimally interpolated monthly time-series Tasman Sea XBT data and a comprehensive set of ocean data assimilation models forced by atmospheric reanalysis to investigate the stability of the Tasman Sea thermocline and the transport variability of the East Australian Current (EAC), the Tasman Front and EAC-extension. We find that anomalously weaker EAC transport at 25S corresponds to an anomalously weaker Tasman Front and anomalously stronger EAC-extension. We further show that, post about 1980 and relative to the previous 30 years, the anomalously weaker EAC transport at 25S is associated with large-scale changes in the Tasman Sea; specifically stronger stratification above the thermocline, larger thermocline temperature gradients and enhanced energy conversion. Significant correlations are found between the Maria Island station Sea Surface Temperature (SST) variability and stratification, thermocline temperature gradient and baroclinic energy conversion suggesting that non-linear dynamical responses to variability in the basin-scale wind stress curl are important drivers of decadal varibility in the Tasman Sea. We further show that the stability of the EAC is linked, via the South Caledonian Jet, to the stability of the pan-basin subtropical South Pacific Ocean ”storm track”. This article is protected by copyright. All rights reserved.},
author = {Sloyan, Bernadette M. and O'Kane, Terence J.},
doi = {10.1002/2014JC010550},
isbn = {2169-9291},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
number = {5},
pages = {3193--3210},
title = {{Drivers of decadal variability in the Tasman Sea}},
volume = {120},
year = {2015}
}
@article{Smeed2014,
abstract = {Abstract. The Atlantic meridional overturning circulation (AMOC) has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable-based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. From April 2008 to March 2012, the AMOC was an average of 2.7 Sv (1 Sv = 106 m3 s−1) weaker than in the first four years of observation (95{\%} confidence that the reduction is 0.3 Sv or more). Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv) is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the southward flow above the thermocline. The increased southward flow of warm waters is balanced by a decrease in the southward flow of lower North Atlantic deep water below 3000 m. The transport of lower North Atlantic deep water slowed by 7{\%} per year (95{\%} confidence that the rate of slowing is greater than 2.5{\%} per year).},
author = {Smeed, D A and McCarthy, G D and Cunningham, S A and Frajka-Williams, E and Rayner, D and Johns, W E and Meinen, C S and Baringer, M O and Moat, B I and Duchez, A and Bryden, H. L.},
doi = {10.5194/os-10-29-2014},
issn = {1812-0792},
journal = {Ocean Science},
month = {feb},
number = {1},
pages = {29--38},
publisher = {Copernicus GmbH},
title = {{Observed decline of the Atlantic meridional overturning circulation 2004–2012}},
url = {https://os.copernicus.org/articles/10/29/2014/},
volume = {10},
year = {2014}
}
@article{Smeed2018,
author = {Smeed, D A and Josey, S A and Beaulieu, C and Johns, W E and Moat, B I and Frajka-Williams, E and Rayner, D and Meinen, C S and Baringer, M O and Bryden, H L and Others},
doi = {10.1002/2017GL076350},
journal = {Geophysical Research Letters},
number = {3},
pages = {1527--1533},
publisher = {Wiley Online Library},
title = {{The North Atlantic Ocean is in a state of reduced overturning}},
volume = {45},
year = {2018}
}
@article{doi:10.1002/wcc.418,
abstract = {The last quarter century spans the publication of the first assessment report of the Intergovernmental Panel on Climate Change in 1990 and the latest report published in 2013–2014. The five assessment reports appearing over that interval reveal a marked increase in the number of paleoclimate studies addressing the climate of the last 2000 years (the Common Era). An important focus of this work has been on reconstruction of hemispheric and global temperatures. Several early studies in this area generated considerable scientific and public interest, and were followed by high-profile and sometimes vitriolic debates about the magnitude of temperature changes over all or part of the Common Era and their comparison to 20th- and 21st-century global temperature increases due to increasing levels of atmospheric greenhouse gases. Behind the more public debates, however, several consistent themes of scientific inquiry have developed to better characterize climate variability and change over the Common Era. These include attempts to collect more climate proxy archives and understand the signals they contain, improve the statistical methods used to estimate past temperature variability from proxies and their associated uncertainties, and to compare reconstructed temperature variability and change with climate model simulations. All of these efforts are driving a new age of research on the climate of the Common Era that is developing more cohesive and collaborative investigations into the dynamics of climate on time scales of decades to centuries, and an understanding of the implications for modeled climate projections of the future. WIREs Clim Change 2016, 7:746–771. doi: 10.1002/wcc.418 This article is categorized under: Paleoclimates and Current Trends {\textgreater} Paleoclimate},
author = {Smerdon, Jason E and Pollack, Henry N},
doi = {10.1002/wcc.418},
journal = {WIREs Climate Change},
number = {5},
pages = {746--771},
title = {{Reconstructing Earth's surface temperature over the past 2000 years: the science behind the headlines}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/wcc.418},
volume = {7},
year = {2016}
}
@article{Smith2015,
abstract = {AbstractThe amount of water vapor in the atmosphere, total precipitable water (TPW), is an important part of the global water cycle, and a clearer understanding of ocean-area TPW is critical for understanding climate variations. This study uses satellite-period statistics and historical data to analyze monthly oceanic TPW beginning in the nineteenth century. Input data for analyzing the historical TPW includes outputs from an extended dynamic reanalysis and estimates of TPW based on historical sea surface temperature (SST). Methods are developed to optimally use the various inputs to produce an improved analysis. Cross-validation testing is used to guide analysis development. Some evaluation of the resulting analysis indicates several strong climate modes. A global mode indicates multidecadal increases in TPW since the nineteenth century, with strongest increases in the tropics and adjacent to land monsoon regions. Strongest multidecadal changes in the global mode are 1910?40 and since 1980. An ENSO mode for the extended period indicates a trend since the 1980s, opposite to the tendency in the global mode. There is no apparent multidecadal variation in the ENSO mode before 1980, suggesting that its multidecadal relationship with the global mode can change. Analysis of SST over the same period shows climate modes consistent with the TPW modes, and for the satellite period there are consistent variations in the satellite data, showing the strong link between SST and oceanic TPW.},
author = {Smith, Thomas M. and Arkin, Phillip A.},
doi = {10.1175/JCLI-D-14-00601.1},
issn = {08948755},
journal = {Journal of Climate},
number = {8},
pages = {3099--3121},
title = {{Improved historical analysis of oceanic total precipitable water}},
volume = {28},
year = {2015}
}
@article{Smith2020,
abstract = {The effective radiative forcing, which includes the instantaneous forcing plus adjustments from the atmosphere and surface, has emerged as the key metric of evaluating human and natural influence on the climate. We evaluate effective radiative forcing and adjustments in 17 contemporary climate models that are participating in the Coupled Model Intercomparison Project (CMIP6) and have contributed to the Radiative Forcing Model Intercomparison Project (RFMIP). Present-day (2014) global-mean anthropogenic forcing relative to pre-industrial (1850) levels from climate models stands at 2.00 (0:23) Wm2, comprised of 1.81 (0:09) Wm2 from CO2, 1.08 ( 0.21) Wm2 from other well-mixed greenhouse gases, 1:01 ( 0.23) Wm2 from aerosols and 0:09 (0:13) Wm2 from land use change. Quoted uncertainties are 1 standard deviation across model best estimates, and 90 confidence in the reported forcings, due to internal variability, is typically within 0.1 Wm2. The majority of the remaining 0:21Wm2 is likely to be from ozone. In most cases, the largest contributors to the spread in effective radiative forcing (ERF) is from the instantaneous radiative forcing (IRF) and from cloud responses, particularly aerosol-cloud interactions to aerosol forcing. As determined in previous studies, cancellation of tropospheric and surface adjustments means that the stratospherically adjusted radiative forcing is approximately equal to ERF for greenhouse gas forcing but not for aerosols, and consequentially, not for the anthropogenic total. The spread of aerosol forcing ranges from 0:63 to 1:37Wm2, exhibiting a less negative mean and narrower range compared to 10 CMIP5 models. The spread in 4CO2 forcing has also narrowed in CMIP6 compared to 13 CMIP5 models. Aerosol forcing is uncorrelated with climate sensitivity. Therefore, there is no evidence to suggest that the increasing spread in climate sensitivity in CMIP6 models, particularly related to high-sensitivity models, is a consequence of a stronger negative present-day aerosol forcing and little evidence that modelling groups are systematically tuning climate sensitivity or aerosol forcing to recreate observed historical warming.},
author = {Smith, Christopher J and Kramer, Ryan J and Myhre, Gunnar and Alterskjr, Kari and Collins, William and Sima, Adriana and Boucher, Olivier and Dufresne, Jean Louis and Nabat, Pierre and Michou, Martine and Yukimoto, Seiji and Cole, Jason and Paynter, David and Shiogama, Hideo and {M. O'Connor}, Fiona and Robertson, Eddy and Wiltshire, Andy and Andrews, Timothy and Hannay, Cecile and Miller, Ron and Nazarenko, Larissa and Kirkevg, Alf and Olivi, Dirk and Fiedler, Stephanie and Lewinschal, Anna and MacKallah, Chloe and Dix, Martin and Pincus, Robert and {M. Forster}, Piers},
doi = {10.5194/acp-20-9591-2020},
issn = {16807324},
journal = {Atmospheric Chemistry and Physics},
number = {16},
pages = {9591--9618},
title = {{Effective radiative forcing and adjustments in CMIP6 models}},
volume = {20},
year = {2020}
}
@article{Smith1239,
abstract = {Earth{\{}$\backslash$textquoteright{\}}s ice sheets are melting and sea levels are rising, so it behooves us to understand better which climate processes are responsible for how much of the mass loss. Smith et al. estimated grounded and floating ice mass change for the Greenland and Antarctic ice sheets from 2003 to 2019 using satellite laser altimetry data from NASA{\{}$\backslash$textquoteright{\}}s ICESat and ICESat-2 satellites. They show how changing ice flow, melting, and precipitation affect different regions of ice and estimate that grounded-ice loss averaged close to 320 gigatons per year over that period and contributed 14 millimeters to sea level rise.Science, this issue p. 1239Quantifying changes in Earth{\{}$\backslash$textquoteright{\}}s ice sheets and identifying the climate drivers are central to improving sea level projections. We provide unified estimates of grounded and floating ice mass change from 2003 to 2019 using NASA{\{}$\backslash$textquoteright{\}}s Ice, Cloud and land Elevation Satellite (ICESat) and ICESat-2 satellite laser altimetry. Our data reveal patterns likely linked to competing climate processes: Ice loss from coastal Greenland (increased surface melt), Antarctic ice shelves (increased ocean melting), and Greenland and Antarctic outlet glaciers (dynamic response to ocean melting) was partially compensated by mass gains over ice sheet interiors (increased snow accumulation). Losses outpaced gains, with grounded-ice loss from Greenland (200 billion tonnes per year) and Antarctica (118 billion tonnes per year) contributing 14 millimeters to sea level. Mass lost from West Antarctica{\{}$\backslash$textquoteright{\}}s ice shelves accounted for more than 30{\%} of that region{\{}$\backslash$textquoteright{\}}s total.},
author = {Smith, Ben and Fricker, Helen A and Gardner, Alex S and Medley, Brooke and Nilsson, Johan and Paolo, Fernando S and Holschuh, Nicholas and Adusumilli, Susheel and Brunt, Kelly and Csatho, Bea and Harbeck, Kaitlin and Markus, Thorsten and Neumann, Thomas and Siegfried, Matthew R and Zwally, H Jay},
doi = {10.1126/science.aaz5845},
issn = {0036-8075},
journal = {Science},
number = {6496},
pages = {1239--1242},
publisher = {American Association for the Advancement of Science},
title = {{Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes}},
url = {https://science.sciencemag.org/content/368/6496/1239},
volume = {368},
year = {2020}
}
@article{Sniderman2019,
author = {Sniderman, J M K and Hellstrom, J and Woodhead, J D and Drysdale, R N and Bajo, P and Archer, M and Hatcher, L},
doi = {10.1029/2018GL080832},
journal = {Geophysical Research Letters},
number = {3},
pages = {1709--1720},
title = {{Vegetation and Climate Change in Southwestern Australia During the Last Glacial Maximum}},
volume = {46},
year = {2019}
}
@article{Sniderman2016,
abstract = {The Pliocene epoch (5.3–2.6 Ma) represents the most recent geological interval in which global temperatures were several degrees warmer than today and is therefore considered our best analog for a future anthropogenic greenhouse world. However, our understanding of Pliocene climates is limited by poor age control on existing terrestrial climate archives, especially in the Southern Hemisphere, and by persistent disagreement between paleo-data and models concerning the magnitude of regional warming and/or wetting that occurred in response to increased greenhouse forcing. To address these problems, here we document the evolution of Southern Hemisphere hydroclimate from the latest Miocene to the middle Pliocene using radiometrically-dated fossil pollen records preserved in speleothems from semiarid southern Australia. These data reveal an abrupt onset of warm and wet climates early within the Pliocene, driving complete biome turnover. Pliocene warmth thus clearly represents a discrete interval which reversed a long-term trend of late Neogene cooling and aridification, rather than being simply the most recent period of greater-than-modern warmth within a continuously cooling trajectory. These findings demonstrate the importance of high-resolution chronologies to accompany paleoclimate data and also highlight the question of what initiated the sustained interval of Pliocene warmth.},
author = {Sniderman, J. M. Kale and Woodhead, Jon D. and Hellstrom, John and Jordan, Gregory J. and Drysdale, Russell N. and Tyler, Jonathan J. and Porch, Nicholas},
doi = {10.1073/pnas.1520188113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {feb},
number = {8},
pages = {1999--2004},
title = {{Pliocene reversal of late Neogene aridification}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1520188113},
volume = {113},
year = {2016}
}
@article{Snyder2016,
author = {Snyder, Carolyn W},
doi = {10.1038/nature19798},
journal = {Nature},
month = {sep},
pages = {226},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Evolution of global temperature over the past two million years}},
url = {http://dx.doi.org/10.1038/nature19798 http://10.0.4.14/nature19798 https://www.nature.com/articles/nature19798{\#}supplementary-information},
volume = {538},
year = {2016}
}
@article{acp-18-11389-2018,
author = {Sogacheva, Larisa and de Leeuw, Gerrit and Rodriguez, Edith and Kolmonen, Pekka and Georgoulias, Aristeidis K and Alexandri, Georgia and Kourtidis, Konstantinos and Proestakis, Emmanouil and Marinou, Eleni and Amiridis, Vassilis and Xue, Yong and van der A, Ronald J},
doi = {10.5194/acp-18-11389-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {aug},
number = {15},
pages = {11389--11407},
title = {{Spatial and seasonal variations of aerosols over China from two decades of multi-satellite observations – Part 1: ATSR (1995–2011) and MODIS C6.1 (2000–2017)}},
url = {https://acp.copernicus.org/articles/18/11389/2018/},
volume = {18},
year = {2018}
}
@article{Sohn2016,
abstract = {There is an uncertainty in how the Pacific Walker circulation (PWC) will change in response to increased greenhouse gas (GHG) warming. On average, climate models predict that the PWC will weaken. Observational evidence is mixed, with some evidence supporting the models while others do not. In this study, insight into the PWC trend is provided by examining the tropical dry static stability, a quantity that is inversely proportional to the strength of the PWC. For the 1979-2012 period, the static stability increased markedly in all phase 5 of the Coupled Model Intercomparison Project (CMIP5) models, far more so than in the satellite and global reanalysis data, which show a strengthening of the PWC. The stabilization is greater for a subset of models that simulate a significant weakening of the PWC.With the observed sea surface temperature as the lower boundary condition, over the western tropical Pacific, atmospheric models that belong to the weakening-PWC-CMIP5 group produce greater stabilization than those that belong to the strengthening-PWC-CMIP5 group. Compared with the latter group, the former group of atmospheric models simulates weaker trade winds over the western and central tropical Pacific and, consistent with the Bjerknes mechanism, the corresponding CMIP5 models produce a weaker west-east gradient in tropical SST. Given that the models' convective parameterizations overstabilize the atmosphere compared with an explicit convection, the findings here suggest that the models' representations of tropical convection and stability contribute to the models' tendency to simulate a weakening of the PWC and an El Nino-like SST.},
author = {Sohn, Byung Ju and Lee, Sukyoung and Chung, Eui Seok and Song, Hwan Jin},
doi = {10.1175/JCLI-D-15-0374.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Circulation/ dynamics,Convection,Dynamics,ENSO,Walker circulation},
number = {8},
pages = {2765--2779},
title = {{The role of the dry static stability for the recent change in the Pacific Walker circulation}},
volume = {29},
year = {2016}
}
@article{Solomina2015,
abstract = {A global overview of glacier advances and retreats (grouped by regions and by millennia) for the Holocene is compiled from previous studies. The reconstructions of glacier fluctuations are based on 1) mapping and dating moraines defined by14C, TCN, OSL, lichenometry and tree rings (discontinuous records/time series), and 2) sediments from proglacial lakes and speleothems (continuous records/time series). Using 189 continuous and discontinuous time series, the long-term trends and centennial fluctuations of glaciers were compared to trends in the recession of Northern and mountain tree lines, and with orbital, solar and volcanic studies to examine the likely forcing factors that drove the changes recorded. A general trend of increasing glacier size from the early-mid Holocene, to the late Holocene in the extra-tropical areas of the Northern Hemisphere (NH) is related to overall summer temperature, forced by orbitally-controlled insolation. The glaciers in New Zealand and in the tropical Andes also appear to follow the orbital trend, i.e., they were decreasing from the early Holocene to the present. In contrast, glacier fluctuations in some monsoonal areas of Asia and southern South America generally did not follow the orbital trends, but fluctuated at a higher frequency possibly triggered by distinct teleconnections patterns. During the Neoglacial, advances clustered at 4.4-4.2ka, 3.8-3.4ka, 3.3-2.8ka, 2.6ka, 2.3-2.1ka, 1.5-1.4ka, 1.2-1.0ka, 0.7-0.5ka, corresponding to general cooling periods in the North Atlantic. Some of these episodes coincide with multidecadal periods of low solar activity, but it is unclear what mechanism might link small changes in irradiance to widespread glacier fluctuations. Explosive volcanism may have played a role in some periods of glacier advances, such as around 1.7-1.6ka (coinciding with the Taupo volcanic eruption at 232{\"{i}}¿½5CE) but the record of explosive volcanism is poorly known through the Holocene. The compilation of ages suggests that there is no single mechanism driving glacier fluctuations on a global scale. Multidecadal variations of solar and volcanic activity supported by positive feedbacks in the climate system may have played a critical role in Holocene glaciation, but further research on such linkages is needed. The rate and the global character of glacier retreat in the 20th through early 21st centuries appears unusual in the context of Holocene glaciation, though the retreating glaciers in most parts of the Northern Hemisphere are still larger today than they were in the early and/or mid-Holocene. The current retreat, however, is occurring during an interval of orbital forcing that is favorable for glacier growth and is therefore caused by a combination of factors other than orbital forcing, primarily strong anthropogenic effects. Glacier retreat will continue into future decades due to the delayed response of glaciers to climate change.},
author = {Solomina, Olga N. and Bradley, Raymond S. and Hodgson, Dominic A. and Ivy-Ochs, Susan and Jomelli, Vincent and Mackintosh, Andrew N. and Nesje, Atle and Owen, Lewis A. and Wanner, Heinz and Wiles, Gregory C. and Young, Nicolas E.},
doi = {10.1016/j.quascirev.2014.11.018},
isbn = {02773791},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Glacier variations,Global warming,Holocene,Holocene thermal maximum,Modern glacier retreat,Neoglacial,Orbital forcings,Solar activity,Volcanic forcings},
pages = {9--34},
title = {{Holocene glacier fluctuations}},
volume = {111},
year = {2015}
}
@article{Solomina2016,
abstract = {A global compilation of glacier advances and retreats for the past two millennia grouped by 17 regions (excluding Antarctica) highlights the nature of glacier fluctuations during the late Holocene. The dataset includes 275 time series of glacier fluctuations based on historical, tree ring, lake sediment, radiocarbon and terrestrial cosmogenic nuclide data. The most detailed and reliable series for individual glaciers and regional compilations are compared with summer temperature and, when available, winter precipitation reconstructions, the most important parameters for glacier mass balance. In many cases major glacier advances correlate with multi-decadal periods of decreased summer temperature. In a few cases, such as in Arctic Alaska and western Canada, some glacier advances occurred during relatively warm wet times. The timing and scale of glacier fluctuations over the past two millennia varies greatly from region to region. However, the number of glacier advances shows a clear pattern for the high, mid and low latitudes and, hence, points to common forcing factors acting at the global scale. Globally, during the first millennium CE glaciers were smaller than between the advances in 13th to early 20th centuries CE. The precise extent of glacier retreat in the first millennium is not well defined; however, the most conservative estimates indicate that during the 1st and 2nd centuries in some regions glaciers were smaller than at the end of 20th/early 21st centuries. Other periods of glacier retreat are identified regionally during the 5th and 8th centuries in the European Alps, in the 3rd–6th and 9th centuries in Norway, during the 10th–13th centuries in southern Alaska, and in the 18th century in Spitsbergen. However, no single period of common global glacier retreat of centennial duration, except for the past century, has yet been identified. In contrast, the view that the Little Ice Age was a period of global glacier expansion beginning in the 13th century (or earlier) and reaching a maximum in 17th–19th centuries is supported by our data. The pattern of glacier variations in the past two millennia corresponds with cooling in reconstructed temperature records at the continental and hemispheric scales. The number of glacier advances also broadly matches periods showing high volcanic activity and low solar irradiance over the past two millennia, although the resolution of most glacier chronologies is not enough for robust statistical correlations. Glacier retreat in the past 100–150 years corresponds to the anthropogenic global temperature increase. Many questions concerning the relative strength of forcing factors that drove glacier variations in the past 2 ka still remain.},
author = {Solomina, Olga N. and Bradley, Raymond S. and Jomelli, Vincent and Geirsdottir, Aslaug and Kaufman, Darrell S. and Koch, Johannes and McKay, Nicholas P. and Masiokas, Mariano and Miller, Gifford and Nesje, Atle and Nicolussi, Kurt and Owen, Lewis A. and Putnam, Aaron E. and Wanner, Heinz and Wiles, Gregory and Yang, Bao},
doi = {10.1016/j.quascirev.2016.04.008},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Glacier variations,Late Holocene,Little Ice Age,Modern glacier retreat,Neoglacial,Solar and volcanic activity,Temperature change},
month = {oct},
pages = {61--90},
title = {{Glacier fluctuations during the past 2000 years}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379116301196},
volume = {149},
year = {2016}
}
@article{Son2015,
abstract = {When a humid region is affected by arid climate, significant changes in drought characteristics occur due to imbalance of water budget. In this study, change in drought characteristics according to shift of different climates i.e. tropical, warm temperate, cold and polar to Arid Climate (SAC) was analyzed over the Asia monsoon region. Climate zones and the SAC regions were identified by applying the K{\"{o}}ppen climate classification on hydro-meteorological data for the period of 1963-2006. The analysis of hydro-meteorological parameters revealed that the annual precipitation and runoff in the SAC regions appeared to decrease about 12.1{\%} and 27.3{\%}, respectively, while annual average temperature increased about 0.5. °C. Standardized runoff index (SRI) was calculated using model-driven runoff data. The trend and change point analyses of SRI were performed to evaluate the changes in drought characteristics (frequency, duration, severity) before and after shifting of the different climates to arid climate. The results revealed strong decreasing trend of SRI and hence intensified drought conditions for the SAC regions. A change point year of drought occurred about 3-5. years earlier than the shifting time of the SAC region. Frequency and duration of droughts in the SAC regions were observed to increase about 9.2 and 1.5. months, respectively, and drought severity index intensified to about -0.15. It can be concluded that analysis of shifting to arid climate zones should be considered together with changes in drought characteristics, because the drought characteristics and changing arid climate zones are closely related to each other.},
author = {Son, Kyung-Hwan and Bae, Deg-Hyo},
doi = {10.1016/j.jhydrol.2015.09.010},
issn = {00221694},
journal = {Journal of Hydrology},
month = {oct},
pages = {1021--1029},
title = {{Drought analysis according to shifting of climate zones to arid climate zone over Asia monsoon region}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0022169415006939},
volume = {529},
year = {2015}
}
@article{Song2018,
abstract = {Land change is a cause and consequence of global environmental change1,2. Changes in land use and land cover considerably alter the Earth's energy balance and biogeochemical cycles, which contributes to climate change and—in turn—affects land surface properties and the provision of ecosystem services1–4. However, quantification of global land change is lacking. Here we analyse 35 years' worth of satellite data and provide a comprehensive record of global land-change dynamics during the period 1982–2016. We show that—contrary to the prevailing view that forest area has declined globally5—tree cover has increased by 2.24 million km2 (+7.1{\%} relative to the 1982 level). This overall net gain is the result of a net loss in the tropics being outweighed by a net gain in the extratropics. Global bare ground cover has decreased by 1.16 million km2 (−3.1{\%}), most notably in agricultural regions in Asia. Of all land changes, 60{\%} are associated with direct human activities and 40{\%} with indirect drivers such as climate change. Land-use change exhibits regional dominance, including tropical deforestation and agricultural expansion, temperate reforestation or afforestation, cropland intensification and urbanization. Consistently across all climate domains, montane systems have gained tree cover and many arid and semi-arid ecosystems have lost vegetation cover. The mapped land changes and the driver attributions reflect a human-dominated Earth system. The dataset we developed may be used to improve the modelling of land-use changes, biogeochemical cycles and vegetation–climate interactions to advance our understanding of global environmental change1–4,6.},
author = {Song, Xiao-Peng and Hansen, Matthew C. and Stehman, Stephen V. and Potapov, Peter V. and Tyukavina, Alexandra and Vermote, Eric F. and Townshend, John R.},
doi = {10.1038/s41586-018-0411-9},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7720},
pages = {639--643},
title = {{Global land change from 1982 to 2016}},
url = {http://www.nature.com/articles/s41586-018-0411-9},
volume = {560},
year = {2018}
}
@article{Sosdian2018a,
abstract = {Over the course of the Neogene, the Earth underwent profound climatic shifts from the sustained warmth of the middle Miocene to the development of Plio-Pleistocene glacial–interglacial cycles. Major perturbations in the global carbon cycle have occurred alongside these shifts, however the lack of long-term carbonate system reconstructions currently limits our understanding of the link between changes in CO2, carbon cycling, and climate over this time interval. Here we reconstruct continuous surface ocean pH, CO2, and surface ocean aragonite saturation state using boron isotopes from the planktonic foraminifer Trilobatus trilobus and we perform a sensitivity analysis of the key variables in our calculations (e.g. $\delta$11Bsw, [Ca]sw, CCD). We show that the choice of $\delta$11Bsw influences both seawater pH and CO2 while [Ca]sw reconstructed dissolved inorganic carbon exerts a significant influence only on CO2. Over the last 22 Myr, the lowest pH levels occurred in the Middle Miocene Climate Optimum (MMCO; 17–14 Myr ago) reaching ∼7.6±0.1 units in all our scenarios. The extended warmth of the MMCO corresponds to mean CO2 and aragonite saturation state levels of 470–630 ppm and 2.7–3.5, respectively. Despite a general correspondence between our CO2 record and climate, all CO2 scenarios show a peak at ∼9 Ma not matched by corresponding changes in climate reconstructions. This may suggest decoupling (i.e. significant CO2 change without a discernible climate response) for a limited interval in the Late Miocene (11.6–8.5 Ma), although further refinement of our understanding of the temporal evolution of the boron isotopic composition of seawater is necessary to fully evaluate the nature of the relationship between CO2 and climate. Nonetheless, from our long-term view it is clear that low-latitude open ocean marine ecosystems are unlikely to have experienced sustained surface pH and saturation levels below 7.7 and 1.7, respectively, during the past 14 million years (66{\%} CI).},
author = {Sosdian, S. M. and Greenop, R. and Hain, M. P. and Foster, G. L. and Pearson, P. N. and Lear, C. H.},
doi = {10.1016/j.epsl.2018.06.017},
isbn = {0012-821X},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
pages = {362--376},
title = {{Constraining the evolution of Neogene ocean carbonate chemistry using the boron isotope pH proxy (2018a)}},
volume = {248},
year = {2018}
}
@article{Sowers2001b,
abstract = {Nitrous oxide (N2O) is an important atmospheric trace gas whose concentration is determined by numerous sources and sinks. Over the past 200 years, N2O has increased by 17±3{\%} due primarily to increased anthropogenic emissions. Over the last glacial/interglacial transition, data from ice cores show that N2O increased by 35{\%}. This increase may be related to increased terrestrial N2O emissions resulting from a global climate amelioration. Here I describe a new dry extraction technique for measuring the elemental and isotopic composition of N2O in ice core samples. Results from a shallow GISP II ice core spanning the last 200 years provide an estimate for the preanthropogenic N2O concentration of 266±4 ppb. In addition, 11 ice samples from the last interglacial period show fairly uniform N2O values (269±9 ppb). During the penultimate glacial period (131–160 ka), N2O concentrations of air trapped in the glacier fluctuated between 190 ppb and 320 ppb, while CO2 and CH4 concentrations were relatively low and stable. Two local N2O maxima were observed during the penultimate glacial period that actually exceeded “normal” interglacial N2O values (∼265 ppb). The maxima were located in portions of the core which exhibit both elevated dust concentrations and elevated bacterial counts. The $\delta$15N and $\delta$18O of N2O in this portion of the Vostok core were 15‰ higher and 12‰ lower than during the warm Eemian period, respectively. The isotopic data and coincidence between the elevated N2O concentrations and the high bacterial counts may be related to in situ N2O production by bacteria. The lower $\delta$18O values are consistent with the isotopic composition of N2O produced by in-situ nitrification.},
author = {Sowers, Todd},
doi = {10.1029/2000JD900707},
journal = {Journal of Geophysical Research: Atmospheres},
number = {D23},
pages = {31903--31914},
title = {{N2O record spanning the penultimate deglaciation from the Vostok ice core}},
volume = {106},
year = {2001}
}
@techreport{SPARC2013,
author = {SPARC},
doi = {https://www.sparc-climate.org/publications/sparc-reports/sparc-report-no-6/},
editor = {Ko, M.K.W. and Newman, P.A. and Reimann, S. and Strahan, S.E.},
pages = {255},
series = {SPARC Report No. 6, WCRP-15/2013},
title = {{SPARC Report on the Lifetimes of Stratospheric Ozone-Depleting Substances, Their Replacements, and Related Species}},
url = {https://www.sparc-climate.org/publications/sparc-reports/sparc-report-no-6/},
year = {2013}
}
@techreport{Petropavlovskikh2019,
author = {SPARC/IO3C/GAW},
doi = {10.17874/f899e57a20b},
editor = {Petropavlovskikh, I. and Godin-Beekmann, S. and Hubert, D. and Damadeo, R. and Hassler, B. and Sofieva, V.},
pages = {78},
publisher = {SPARC Report No. 9, GAW Report No. 241, WCRP-17/2018},
title = {{SPARC/IO3C/GAW Report on Long-term Ozone Trends and Uncertainties in the Stratosphere}},
url = {https://www.sparc-climate.org/publications/sparc-reports/sparc-report-no-9/},
year = {2019}
}
@article{Spector2017a,
abstract = {Deglaciation of the Ross Sea following the last ice age provides an important opportunity to examine the stability of marine ice sheets and their susceptibility to changing environmental conditions. Insufficient chronology for Ross Sea deglaciation has helped sustain (i) the theory that this region contributed significantly to Meltwater Pulse 1A (MWP-1A) and (ii) the idea that Ross Sea grounding-line retreat occurred in a "swinging gate" pattern hinged north of Roosevelt Island. We present deglaciation records from southern Transantarctic Mountain glaciers, which delivered ice to the central Ross Sea. Abrupt thinning of these glaciers 9--8 kyr B.P. coincided with deglaciation of the Scott Coast, ∼800 km to the north, and ended with the Ross Sea grounding line near Shackleton Glacier. This deglaciation removed grounded ice from most of the central and western Ross Sea in less than 2 kyr. The Ross Sea Sector neither contributed nor responded significantly to MWP-1A.},
author = {Spector, Perry and Stone, John and Cowdery, Seth G. and Hall, Brenda and Conway, Howard and Bromley, Gordon},
doi = {10.1002/2017GL074216},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {aug},
number = {15},
pages = {7817--7825},
title = {{Rapid early-Holocene deglaciation in the Ross Sea, Antarctica}},
url = {http://doi.wiley.com/10.1002/2017GL074216},
volume = {44},
year = {2017}
}
@article{Spencer2017,
author = {Spencer, Roy W and Christy, John R and Braswell, William D},
doi = {10.1007/s13143-017-0010-y},
journal = {Asia-Pacific Journal of Atmospheric Science},
number = {1},
pages = {121--130},
title = {{UAH Version 6 Global Satellite Temperature Products: Methodology and Results}},
volume = {53},
year = {2017}
}
@article{Spielhagen450,
author = {Spielhagen, Robert F and Werner, Kirstin and S{\o}rensen, Steffen Aagaard and Zamelczyk, Katarzyna and Kandiano, Evguenia and Budeus, Gereon and Husum, Katrine and Marchitto, Thomas M and Hald, Morten},
doi = {10.1126/science.1197397},
issn = {0036-8075},
journal = {Science},
number = {6016},
pages = {450--453},
publisher = {American Association for the Advancement of Science},
title = {{Enhanced Modern Heat Transfer to the Arctic by Warm Atlantic Water}},
url = {https://science.sciencemag.org/content/331/6016/450},
volume = {331},
year = {2011}
}
@article{Spinoni2015,
abstract = {Over the past decades, a continuous rise in global air temperatures resulted in significant changes in the global hydrological cycle. Regionally increased frequencies of extreme weather events and changes in the regional extent of drylands resulted in new areas at risk of desertification, a complex process driven by socio-economic and climate-related factors. Although desertification is not confined to drylands, they are the most vulnerable to land degradation processes. To investigate possible changes in climate patterns over the past 60years, we couple the information obtained from the K{\"{o}}ppen-Geiger (KG) climate classification and the FAO aridity index (AI), providing an overview of the most evident global changes in climate regimes from 1951-1980 to 1981-2010 and focussing on the modifications of the extent of drylands. KG and AI indicators have been computed on a 0.5°×0.5° global grid using precipitation data from the Full Data Reanalysis (v6.0) of the Global Precipitation Climatology Centre, and mean temperature and potential evapotranspiration data from the Climate Research Unit of the University of East Anglia (CRUTSv3.20). Both KG and AI show that the arid areas globally increased between 1951-1980 and 1981-2010, but decreased on average in the Americas. North-Eastern Brazil, Southern Argentina, the Sahel, Zambia and Zimbabwe, the Mediterranean area, North-Eastern China and Sub-Himalayan India have been identified as areas with a significant increase of drylands extent. An analysis of the scientific literature gives evidence that most of the areas identified are effectively undergoing desertification, thus confirming the validity of AI and KG to highlight the areas under risk of desertification. We also discuss the global decrease of cold areas, the progressive change from continental to temperate climate in Central Europe, the shift from tundra to continental climate in Alaska, Canada and North-Eastern Russia and the widening of the tropical belt.},
author = {Spinoni, Jonathan and Vogt, J{\"{u}}rgen and Naumann, Gustavo and Carrao, Hugo and Barbosa, Paulo},
doi = {10.1002/joc.4124},
issn = {08998418},
journal = {International Journal of Climatology},
month = {jul},
number = {9},
pages = {2210--2222},
title = {{Towards identifying areas at climatological risk of desertification using the K{\"{o}}ppen-Geiger classification and FAO aridity index}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.4124},
volume = {35},
year = {2015}
}
@article{Spolaor2016,
abstract = {Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called “bromine explosions” and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3 °C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2 °C global average warming target of the recent COP21 Paris climate agreement.},
author = {Spolaor, Andrea and Vallelonga, Paul and Turetta, Clara and Maffezzoli, Niccol{\`{o}} and Cozzi, Giulio and Gabrieli, Jacopo and Barbante, Carlo and Goto-Azuma, Kumiko and Saiz-Lopez, Alfonso and Cuevas, Carlos A and Dahl-Jensen, Dorthe},
doi = {10.1038/srep33925},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {33925},
title = {{Canadian Arctic sea ice reconstructed from bromine in the Greenland NEEM ice core}},
url = {https://doi.org/10.1038/srep33925},
volume = {6},
year = {2016}
}
@article{Spratt2016,
abstract = {Late Pleistocene sea level has been reconstructed from ocean sediment core data using a wide variety of proxies and models. However, the accuracy of individual reconstructions is limited by measurement error, local variations in salinity and temperature, and assumptions particular to each technique. Here we present a sea level stack (average) which increases the signal-to-noise ratio of individual reconstructions. Specifically, we perform principal component analysis (PCA) on seven records from 0 to 430 ka and five records from 0 to 798 ka. The first principal component, which we use as the stack, describes ∼80{\%} of the variance in the data and is similar using either five or seven records. After scaling the stack based on Holocene and Last Glacial Maximum (LGM) sea level estimates, the stack agrees to within 5 m with isostatically adjusted coral sea level estimates for Marine Isotope Stages 5e and 11 (125 and 400 ka, respectively). Bootstrapping and random sampling yield mean uncertainty estimates of 9-12 m (1{\$}\sigma{\$}) for the scaled stack. Sea level change accounts for about 45{\%} of the total orbital-band variance in benthic {\$}\delta{\$}18O, compared to a 65{\%} contribution during the LGM-to-Holocene transition. Additionally, the second and third principal components of our analyses reflect differences between proxy records associated with spatial variations in the {\$}\delta{\$}18O of seawater.},
author = {Spratt, Rachel M and Lisiecki, Lorraine E},
doi = {10.5194/cp-12-1079-2016},
issn = {18149332},
journal = {Climate of the Past},
number = {4},
pages = {1079--1092},
title = {{A Late Pleistocene sea level stack}},
volume = {12},
year = {2016}
}
@article{doi:10.1029/2011GL048970,
abstract = {We examine the spatial trends in Arctic sea ice drift speed from satellite data and the role of wind forcing for the winter months of October through May. Between 1992 and 2009, the spatially averaged trend in drift speed within the Arctic Basin is 10.6{\%} ± 0.9{\%}/decade, and ranges between −4{\%} and 16{\%}/decade depending on the location. The mean trend is dominated by the second half of the period. In fact, for the five years after a clear break point in March 2004, the average trend increased to 46{\%} ± 5{\%}/decade. Over the 1992–2009 period, averaged trends of wind speed from four atmospheric reanalyses are only 1{\%} to 2{\%}/decade. Regionally, positive trends in wind speed (of up to 9{\%}/decade) are seen over a large fraction of the Central Arctic, where the trends in drift speeds are highest. Spatial correlations between the basin-wide trends in wind and drift speeds are moderate (between 0.40 and 0.52). Our results suggest that changes in wind speed explain a fraction of the observed increase in drift speeds in the Central Arctic but not over the entire basin. In other regions thinning of the ice cover is a more likely cause of the increase in ice drift speed.},
author = {Spreen, Gunnar and Kwok, Ron and Menemenlis, Dimitris},
doi = {10.1029/2011GL048970},
journal = {Geophysical Research Letters},
keywords = {Arctic,drift,reanalysis,sea ice,trends,wind},
number = {19},
pages = {L19501},
title = {{Trends in Arctic sea ice drift and role of wind forcing: 1992–2009}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011GL048970},
volume = {38},
year = {2011}
}
@article{Spreen2020,
abstract = {The Fram Strait sea ice volume export 1992–2014 is derived by combining sea ice thickness from upward looking sonars (ULS) with satellite observations of sea ice drift and area. Fram Strait is the main gate for sea ice export from the Arctic. The average yearly sea ice export is 2,400 ± 640 km3. The mean and modal ULS ice thickness in Fram Strait decreased by 15{\%} and 21{\%} per decade, respectively, during 1990–2014. Combined with sea ice drift and area this leads to a decrease of the Arctic sea ice volume export of 27 ± 2{\%} per decade between 1992 and 2014. Thus, for the given time period, changes in sea ice export do not drive the sea ice volume decrease in the Arctic Basin. However, for individual years like 2007 and 2012 the ice export likely has contributed to the loss of summer sea ice. Combined with PIOMAS model simulation we estimate that 14{\%} of the total Arctic sea ice volume is exported every year through Fram Strait. This fraction of the total sea ice volume exported per year does not show a trend because the Arctic Basin ice volume is decreasing at a similar rate as the Fram Strait ice volume export. Compared to ice velocities from Acoustic Doppler Current Profiler (ADCP) the satellite ice drift shows good correspondence in variability but a negative bias. Ice volume transport estimates presented here thus should be considered a conservative estimate. We show, however, that the transport estimates are not sensitive to the exact flux gate location.},
author = {Spreen, Gunnar and de Steur, Laura and Divine, Dmitry and Gerland, Sebastian and Hansen, Edmond and Kwok, Ron},
doi = {10.1029/2019JC016039},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
number = {6},
pages = {e2019JC016039},
title = {{Arctic Sea Ice Volume Export Through Fram Strait From 1992 to 2014}},
volume = {125},
year = {2020}
}
@article{Sprintall2019,
abstract = {The Indonesian seas play a fundamental role in the coupled ocean and climate system with the Indonesian Throughflow (ITF) providing the only tropical pathway connecting the global oceans. Pacific warm pool waters passing through the Indonesian seas are cooled and freshened by strong air-sea fluxes and mixing from internal tides to form a unique water mass that can be tracked across the Indian Ocean basin and beyond. The Indonesian seas lie at the climatological center of the atmospheric deep convection associated with the ascending branch of the Walker Circulation. Regional SST variations cause changes in the surface winds that can shift the center of atmospheric deep convection, subsequently altering the precipitation and ocean circulation patterns within the entire Indo-Pacific region. Recent multi-decadal changes in the wind and buoyancy forcing over the tropical Indo-Pacific have directly affected the vertical profile, strength, and the heat and freshwater transports of the ITF. These changes influence the large-scale sea level, SST, precipitation and wind patterns. Observing long-term changes in mass, heat and freshwater within the Indonesian seas is central to understanding the variability and predictability of the global coupled climate system. Although substantial progress has been made over the past decade in measuring and modeling the physical and biogeochemical variability within the Indonesian seas, large uncertainties remain. A comprehensive strategy is needed for measuring the temporal and spatial scales of variability that govern the various water mass transport streams of the ITF, its connection with the circulation and heat and freshwater inventories and associated air-sea fluxes of the regional and global oceans. This white paper puts forward the design of an observational array using multi-platforms combined with high-resolution models aimed at increasing our quantitative understanding of water mass transformation rates and advection within the Indonesian seas and their impacts on the air-sea climate system.},
author = {Sprintall, Janet and Gordon, Arnold L and Wijffels, Susan E and Feng, Ming and Hu, Shijian and Koch-Larrouy, Ariane and Phillips, Helen and Nugroho, Dwiyoga and Napitu, Asmi and Pujiana, Kandaga and Susanto, R Dwi and Sloyan, Bernadette and Pe{\~{n}}a-Molino, Beatriz and Yuan, Dongliang and Riama, Nelly Florida and Siswanto, Siswanto and Kuswardani, Anastasia and Arifin, Zainal and Wahyudi, A'an J and Zhou, Hui and Nagai, Taira and Ansong, Joseph K and Bourdalle-Badi{\'{e}}, Romain and Chanut, Jerome and Lyard, Florent and Arbic, Brian K and Ramdhani, Andri and Setiawan, Agus},
doi = {10.3389/fmars.2019.00257},
isbn = {2296-7745},
journal = {Frontiers in Marine Science},
pages = {257},
title = {{Detecting Change in the Indonesian Seas}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00257},
volume = {6},
year = {2019}
}
@article{Sprintall2014a,
abstract = {The Indonesian seas provide the only connection between ocean basins in the tropics. A review of observational data and model results concludes that vertical mixing determines the physical properties of water in the Indonesian throughflow.},
author = {Sprintall, Janet and Gordon, Arnold L and Koch-Larrouy, Ariane and Lee, Tong and Potemra, James T and Pujiana, Kandaga and Wijffels, Susan E},
doi = {10.1038/ngeo2188},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {7},
pages = {487--492},
title = {{The Indonesian seas and their role in the coupled ocean–climate system}},
url = {https://doi.org/10.1038/ngeo2188},
volume = {7},
year = {2014}
}
@article{Staehelin2018,
abstract = {In 1926 the stratospheric ozone measurements of the Light Climatic Observatory (LKO) of Arosa (Switzerland) started, marking the start of the world's longest total (or column) ozone measurements. These measurements were driven by the recognition of the importance of atmospheric ozone for human health as well as by scientific curiosity in this by then not well characterized atmospheric trace gas. Since the mid-1970s ground-based measurements of stratospheric ozone have also been justified to society by the need to document the effects of anthropogenic Ozone Depleting Substances (ODSs), which cause stratospheric ozone depletion. Levels of ODSs peaked around the mid-1990s as a result of a global environmental policy to protect the ozone layer implemented by the 1987 Montreal Protocol and its subsequent amendments and adjustments. Consequently, chemical ozone depletion caused by ODSs stopped worsening around the mid-1990s. This renders justification for continued ozone measurements more difficult, and is likely to do so even more in future, when stratospheric ozone recovery is expected. Tendencies of increased cost savings in ozone measurements seem perceptible worldwide, also in Arosa. However, the large natural variability in ozone on diurnal, seasonal and interannual scales complicates to demonstrate the success of the Montreal Protocol. Moreover, chemistry-climate models predict a “super-recovery” of the ozone layer in the second half of this century, i.e. an increase of ozone concentrations beyond pre-1970 levels, as a consequence of ongoing climate change. This paper presents the evolution of the ozone layer and the history of international ozone research and discusses the justification of these measurements for past, present and future.},
author = {Staehelin, Johannes and Viatte, Pierre and St{\"{u}}bi, Rene and Tummon, Fiona and Peter, Thomas},
doi = {10.5194/acp-18-6567-2018},
issn = {16807324},
journal = {Atmospheric Chemistry and Physics},
number = {9},
pages = {6567--6584},
title = {{Stratospheric ozone measurements at Arosa (Switzerland): History and scientific relevance}},
volume = {18},
year = {2018}
}
@article{Stahle2016,
author = {Stahle, David W and Cook, Edward R and Burnette, Dorian J and Villanueva, Jose and Cerano, Julian and Burns, Jordan N and Grif, Daniel and Cook, Benjamin I and Acu, Rodolfo and Torbenson, Max C A and Szejner, Paul and Howard, Ian M},
doi = {10.1016/j.quascirev.2016.06.018},
journal = {Quaternary Science Reviews},
pages = {34--60},
title = {{The Mexican Drought Atlas: Tree-ring reconstructions of the soil moisture balance during the late pre-Hispanic, colonial, and modern eras}},
volume = {149},
year = {2016}
}
@article{Stammerjohn2012,
abstract = {This bi-polar analysis resolves ice edge changes on space/time scales relevant for investigating seasonal ice-ocean feedbacks and focuses on spatio-temporal changes in the timing of annual sea ice retreat and advance over 1979/80 to 2010/11. Where Arctic sea ice decrease is fastest, the sea ice retreat is now nearly 2 months earlier and subsequent advance more than 1 month later (compared to 1979/80), resulting in a 3-month longer summer ice-free season. In the Antarctic Peninsula and Bellingshausen Sea region, sea ice retreat is more than 1 month earlier and advance 2 months later, resulting in a more than 3-month longer summer ice-free season. In contrast, in the western Ross Sea (Antarctica) region, sea ice retreat and advance are more than 1 month later and earlier respectively, resulting in a more than 2 month shorter summer ice-free season. Regardless of trend magnitude or direction, and at latitudes mostly poleward of 70° (N/S), there is strong correspondence between anomalies in the timings of sea ice retreat and subsequent advance, but little correspondence between advance and subsequent retreat. These results support a strong ocean thermal feedback in autumn in response to changes in spring sea ice retreat. Further, model calculations suggest different net ocean heat changes in the Arctic versus Antarctic where autumn sea ice advance is 1 versus 2 months later. Ocean-atmosphere changes, particularly in boreal spring and austral autumn (i.e., during ∼March-May), are discussed and compared, as well as possible inter-hemispheric climate connections.},
author = {Stammerjohn, Sharon and Massom, Robert and Rind, David and Martinson, Douglas},
doi = {10.1029/2012GL050874},
isbn = {0094-8276},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {mar},
number = {6},
pages = {L06501},
title = {{Regions of rapid sea ice change: An inter-hemispheric seasonal comparison}},
url = {http://doi.wiley.com/10.1029/2012GL050874},
volume = {39},
year = {2012}
}
@article{Staten2018,
abstract = {Observations reveal a poleward expansion of the tropics in recent decades, implying a potential role of human activity. However, although theory and modelling suggest increasing GHG concentrations should widen the tropics, previous observational-based studies depict disparate rates of expansion, including many that are far higher than those simulated by climate models. Here, we review the rates and possible causes of observed and projected tropical widening. By accounting for methodological differences, the tropics are found to have widened about 0.5° of latitude per decade since 1979. However, it is too early to detect robust anthropogenically induced widening imprints due to large internal variability. Future work should target the seasonal and regional signatures of forced widening, as well as the associated dynamical mechanisms.},
author = {Staten, Paul W. and Lu, Jian and Grise, Kevin M. and Davis, Sean M. and Birner, Thomas},
doi = {10.1038/s41558-018-0246-2},
isbn = {4155801802462},
issn = {17586798},
journal = {Nature Climate Change},
number = {9},
pages = {768--775},
publisher = {Springer US},
title = {{Re-examining tropical expansion}},
volume = {8},
year = {2018}
}
@article{Staten2020a,
abstract = {Over the past 15 years, numerous studies have suggested that the sinking branches of Earth's Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.},
author = {Staten, Paul W. and Grise, Kevin M. and Davis, Sean M. and Karnauskas, Kristopher B. and Waugh, Darryn W. and Maycock, Amanda C. and Fu, Qiang and Cook, Kerry and Adam, Ori and Simpson, Isla R. and Allen, Robert J and Rosenlof, Karen and Chen, Gang and Ummenhofer, Caroline C. and Quan, Xiao-Wei and Kossin, James P. and Davis, Nicholas A. and Son, Seok-Woo},
doi = {10.1175/bams-d-19-0047.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
number = {6},
pages = {E897--E904},
title = {{Tropical Widening: From Global Variations to Regional Impacts}},
volume = {101},
year = {2020}
}
@article{Steiger2018a,
author = {Steiger, Nathan J and Smerdon, Jason E and Cook, Edward R and Cook, Benjamin I},
doi = {10.1038/sdata.2018.86},
journal = {Scientific Data},
pages = {1--15},
title = {{A reconstruction of global hydroclimate and dynamical variables over the Common Era}},
volume = {5},
year = {2018}
}
@article{Stein2017,
abstract = {Coinciding with global warming, Arctic sea ice has rapidly decreased during the last four decades and climate scenarios suggest that sea ice may completely disappear during summer within the next about 50–100 years. Here we produce Arctic sea ice biomarker proxy records for the penultimate glacial (Marine Isotope Stage 6) and the subsequent last interglacial (Marine Isotope Stage 5e). The latter is a time interval when the high latitudes were significantly warmer than today. We document that even under such warmer climate conditions, sea ice existed in the central Arctic Ocean during summer, whereas sea ice was significantly reduced along the Barents Sea continental margin influenced by Atlantic Water inflow. Our proxy reconstruction of the last interglacial sea ice cover is supported by climate simulations, although some proxy data/model inconsistencies still exist. During late Marine Isotope Stage 6, polynya-type conditions occurred off the major ice sheets along the northern Barents and East Siberian continental margins, contradicting a giant Marine Isotope Stage 6 ice shelf that covered the entire Arctic Ocean.},
author = {Stein, Ruediger and Fahl, Kirsten and Gierz, Paul and Niessen, Frank and Lohmann, Gerrit},
doi = {10.1038/s41467-017-00552-1},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {373},
title = {{Arctic Ocean sea ice cover during the penultimate glacial and the last interglacial}},
url = {https://doi.org/10.1038/s41467-017-00552-1},
volume = {8},
year = {2017}
}
@article{amt-2019-358,
author = {Steiner, A K and Ladst{\"{a}}dter, F and Ao, C O and Gleisner, H and Ho, S.-P. and Hunt, D and Schmidt, T and Foelsche, U and Kirchengast, G and Kuo, Y.-H. and Lauritsen, K B and Mannucci, A J and Nielsen, J K and Schreiner, W and Schw{\"{a}}rz, M and Sokolovskiy, S and Syndergaard, S and Wickert, J},
doi = {10.5194/amt-13-2547-2020},
journal = {Atmospheric Measurement Techniques},
number = {5},
pages = {2547--2575},
title = {{Consistency and structural uncertainty of multi-mission GPS radio occultation records}},
url = {https://www.atmos-meas-tech-discuss.net/amt-2019-358/},
volume = {13},
year = {2020}
}
@article{Steiner2020,
abstract = {Temperature observations of the upper-air atmosphere are now available for more than 40 years from both ground- and satellite-based observing systems. Recent years have seen substantial improvements in reducing long-standing discrepancies among datasets through major reprocessing efforts. The advent of radio occultation (RO) observations in 2001 has led to further improvements in vertically resolved temperature measurements, enabling a detailed analysis of upper-troposphere/lower-stratosphere trends. This paper presents the current state of atmospheric temperature trends from the latest available observational records. We analyze observations from merged operational satellite measurements, radiosondes, lidars, and RO, spanning a vertical range from the lower troposphere to the upper stratosphere. The focus is on assessing climate trends and on identifying the degree of consistency among the observational systems. The results show a robust cooling of the stratosphere of about 1–3 K, and a robust warming of the troposphere of about 0.6–0.8 K over the last four decades (1979–2018). Consistent results are found between the satellite-based layer-average temperatures and vertically resolved radiosonde records. The overall latitude–altitude trend patterns are consistent between RO and radiosonde records. Significant warming of the troposphere is evident in the RO measurements available after 2001, with trends of 0.25–0.35 K per decade. Amplified warming in the tropical upper-troposphere compared to surface trends for 2002–18 is found based on RO and radiosonde records, in approximate agreement with moist adiabatic lapse rate theory. The consistency of trend results from the latest upper-air datasets will help to improve understanding of climate changes and their drivers.},
author = {Steiner, Andrea K. and Ladst{\"{a}}dter, F. and Randel, W. J. and Maycock, A. C. and Fu, Q. and Claud, C. and Gleisner, H. and Haimberger, L. and Ho, S.-P. and Keckhut, P. and Leblanc, T. and Mears, C. and Polvani, L. M. and Santer, B. D. and Schmidt, T. and Sofieva, V. and Wing, R. and Zou, C.-Z.},
doi = {10.1175/JCLI-D-19-0998.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {oct},
number = {19},
pages = {8165--8194},
title = {{Observed Temperature Changes in the Troposphere and Stratosphere from 1979 to 2018}},
url = {https://journals.ametsoc.org/doi/10.1175/JCLI-D-19-0998.1},
volume = {33},
year = {2020}
}
@article{Steiner2013,
author = {Steiner, A K and Hunt, D and Ho, S.-P. and Kirchengast, G and Mannucci, A J and Scherllin-Pirscher, B and Gleisner, H and von Engeln, A and Schmidt, T and Ao, C and Leroy, S S and Kursinski, E R and Foelsche, U and Gorbunov, M and Heise, S and Kuo, Y.-H. and Lauritsen, K B and Marquardt, C and Rocken, C and Schreiner, W and Sokolovskiy, S and Syndergaard, S and Wickert, J},
doi = {10.5194/acp-13-1469-2013},
journal = {Atmospheric Chemistry and Physics},
number = {3},
pages = {1469--1484},
title = {{Quantification of structural uncertainty in climate data records from GPS radio occultation}},
volume = {13},
year = {2013}
}
@article{Steinman2014a,
author = {Steinman, B. A. and Abbott, M. B. and Mann, M. E. and Ortiz, J. D. and Feng, S. and Pompeani, D. P. and Bird, B. W.},
doi = {10.1002/2014GL059499},
journal = {Geophysical Research Letters},
number = {7},
pages = {2553--2560},
title = {{Ocean-atmosphere forcing of centennial hydroclimate variability in the Pacific Northwest}},
volume = {41},
year = {2014}
}
@article{https://doi.org/10.1029/2020PA004037,
annote = {e2020PA004037 2020PA004037},
author = {Steinthorsdottir, M and Coxall, H K and de Boer, A M and Huber, M and Barbolini, N and Bradshaw, C D and Burls, N J and Feakins, S J and Gasson, E and Henderiks, J and Holbourn, A. E. and Kiel, S and Kohn, M J and Knorr, G and K{\"{u}}rschner, W M and Lear, C H and Liebrand, D and Lunt, D J and M{\"{o}}rs, T and Pearson, P N and Pound, M J and Stoll, H and Str{\"{o}}mberg, C A E},
doi = {10.1029/2020PA004037},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Climate modelling,Paleo-biota,Paleo-climate,Paleo-environments,Review,The Miocene},
month = {apr},
number = {4},
pages = {e2020PA004037},
title = {{The Miocene: The Future of the Past}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020PA004037 https://onlinelibrary.wiley.com/doi/10.1029/2020PA004037},
volume = {36},
year = {2021}
}
@article{Stenni2017,
abstract = {Abstract. Climate trends in the Antarctic region remain poorly characterized, owing to the brevity and scarcity of direct climate observations and the large magnitude of interannual to decadal-scale climate variability. Here, within the framework of the PAGES Antarctica2k working group, we build an enlarged database of ice core water stable isotope records from Antarctica, consisting of 112 records. We produce both unweighted and weighted isotopic ($\delta$18O) composites and temperature reconstructions since 0CE, binned at 5- and 10-year resolution, for seven climatically distinct regions covering the Antarctic continent. Following earlier work of the Antarctica2k working group, we also produce composites and reconstructions for the broader regions of East Antarctica, West Antarctica and the whole continent. We use three methods for our temperature reconstructions: (i) a temperature scaling based on the $\delta$18O–temperature relationship output from an ECHAM5-wiso model simulation nudged to ERA-Interim atmospheric reanalyses from 1979 to 2013, and adjusted for the West Antarctic Ice Sheet region to borehole temperature data, (ii) a temperature scaling of the isotopic normalized anomalies to the variance of the regional reanalysis temperature and (iii) a composite-plus-scaling approach used in a previous continent-scale reconstruction of Antarctic temperature since 1CE but applied to the new Antarctic ice core database. Our new reconstructions confirm a significant cooling trend from 0 to 1900CE across all Antarctic regions where records extend back into the 1st millennium, with the exception of the Wilkes Land coast and Weddell Sea coast regions. Within this long-term cooling trend from 0 to 1900CE, we find that the warmest period occurs between 300 and 1000CE, and the coldest interval occurs from 1200 to 1900CE. Since 1900CE, significant warming trends are identified for the West Antarctic Ice Sheet, the Dronning Maud Land coast and the Antarctic Peninsula regions, and these trends are robust across the distribution of records that contribute to the unweighted isotopic composites and also significant in the weighted temperature reconstructions. Only for the Antarctic Peninsula is this most recent century-scale trend unusual in the context of natural variability over the last 2000 years. However, projected warming of the Antarctic continent during the 21st century may soon see significant and unusual warming develop across other parts of the Antarctic continent. The extended Antarctica2k ice core isotope database developed by this working group opens up many avenues for developing a deeper understanding of the response of Antarctic climate to natural and anthropogenic climate forcings. The first long-term quantification of regional climate in Antarctica presented herein is a basis for data–model comparison and assessments of past, present and future driving factors of Antarctic climate.},
author = {Stenni, Barbara and Curran, Mark A. J. and Abram, Nerilie J. and Orsi, Anais and Goursaud, Sentia and Masson-Delmotte, Valerie and Neukom, Raphael and Goosse, Hugues and Divine, Dmitry and van Ommen, Tas and Steig, Eric J. and Dixon, Daniel A. and Thomas, Elizabeth R. and Bertler, Nancy A. N. and Isaksson, Elisabeth and Ekaykin, Alexey and Werner, Martin and Frezzotti, Massimo},
doi = {10.5194/cp-13-1609-2017},
issn = {1814-9332},
journal = {Climate of the Past},
month = {nov},
number = {11},
pages = {1609--1634},
title = {{Antarctic climate variability on regional and continental scales over the last 2000 years}},
url = {https://www.clim-past.net/13/1609/2017/},
volume = {13},
year = {2017}
}
@article{Stephens2019,
abstract = {Environmentally transformative human use of land accelerated with the emergence of agriculture, but the extent, trajectory, and implications of these early changes are not well understood. An empirical global assessment of land use from 10,000 years before the present (yr B.P.) to 1850 CE reveals a planet largely transformed by hunter-gatherers, farmers, and pastoralists by 3000 years ago, considerably earlier than the dates in the land-use reconstructions commonly used by Earth scientists. Synthesis of knowledge contributed by more than 250 archaeologists highlighted gaps in archaeological expertise and data quality, which peaked for 2000 yr B.P. and in traditionally studied and wealthier regions. Archaeological reconstruction of global land-use history illuminates the deep roots of Earth's transformation and challenges the emerging Anthropocene paradigm that large-scale anthropogenic global environmental change is mostly a recent phenomenon.},
author = {Stephens, Lucas and Fuller, Dorian and Boivin, Nicole and Rick, Torben and Gauthier, Nicolas and Kay, Andrea and Marwick, Ben and Armstrong, Chelsey Geralda and Barton, C. Michael and Denham, Tim and Douglass, Kristina and Driver, Jonathan and Janz, Lisa and Roberts, Patrick and Rogers, J. Daniel and Thakar, Heather and Altaweel, Mark and Johnson, Amber L. and {Sampietro Vattuone}, Maria Marta and Aldenderfer, Mark and Archila, Sonia and Artioli, Gilberto and Bale, Martin T. and Beach, Timothy and Borrell, Ferran and Braje, Todd and Buckland, Philip I. and {Jim{\'{e}}nez Cano}, Nayeli Guadalupe and Capriles, Jos{\'{e}} M. and {Diez Castillo}, Agust{\'{i}}n and {\c{C}}ilingiroğlu, {\c{C}}iler and {Negus Cleary}, Michelle and Conolly, James and Coutros, Peter R. and Covey, R. Alan and Cremaschi, Mauro and Crowther, Alison and Der, Lindsay and di Lernia, Savino and Doershuk, John F. and Doolittle, William E. and Edwards, Kevin J. and Erlandson, Jon M. and Evans, Damian and Fairbairn, Andrew and Faulkner, Patrick and Feinman, Gary and Fernandes, Ricardo and Fitzpatrick, Scott M. and Fyfe, Ralph and Garcea, Elena and Goldstein, Steve and Goodman, Reed Charles and {Dalpoim Guedes}, Jade and Herrmann, Jason and Hiscock, Peter and Hommel, Peter and Horsburgh, K. Ann and Hritz, Carrie and Ives, John W. and Junno, Aripekka and Kahn, Jennifer G. and Kaufman, Brett and Kearns, Catherine and Kidder, Tristram R. and Lano{\"{e}}, Fran{\c{c}}ois and Lawrence, Dan and Lee, Gyoung-Ah and Levin, Maureece J. and Lindskoug, Henrik B. and L{\'{o}}pez-S{\'{a}}ez, Jos{\'{e}} Antonio and Macrae, Scott and Marchant, Rob and Marston, John M. and McClure, Sarah and McCoy, Mark D. and Miller, Alicia Ventresca and Morrison, Michael and {Motuzaite Matuzeviciute}, Giedre and M{\"{u}}ller, Johannes and Nayak, Ayushi and Noerwidi, Sofwan and Peres, Tanya M. and Peterson, Christian E. and Proctor, Lucas and Randall, Asa R. and Renette, Steve and {Robbins Schug}, Gwen and Ryzewski, Krysta and Saini, Rakesh and Scheinsohn, Vivian and Schmidt, Peter and Sebillaud, Pauline and Seitsonen, Oula and Simpson, Ian A. and So{\l}tysiak, Arkadiusz and Speakman, Robert J. and Spengler, Robert N. and Steffen, Martina L. and Storozum, Michael J. and Strickland, Keir M. and Thompson, Jessica and Thurston, T. L. and Ulm, Sean and Ustunkaya, M. Cemre and Welker, Martin H. and West, Catherine and Williams, Patrick Ryan and Wright, David K. and Wright, Nathan and Zahir, Muhammad and Zerboni, Andrea and Beaudoin, Ella and {Munevar Garcia}, Santiago and Powell, Jeremy and Thornton, Alexa and Kaplan, Jed O. and Gaillard, Marie-Jos{\'{e}} and {Klein Goldewijk}, Kees and Ellis, Erle},
doi = {10.1126/science.aax1192},
issn = {0036-8075},
journal = {Science},
month = {aug},
number = {6456},
pages = {897--902},
title = {{Archaeological assessment reveals Earth's early transformation through land use}},
url = {https://www.science.org/doi/10.1126/science.aax1192},
volume = {365},
year = {2019}
}
@article{STEPHENSON201961,
abstract = {Global inventories of stable sea-level markers for the peak of the last interglacial period, Marine Isotopic Stage (MIS) 5e, play a pivotal role in determining sea-level changes and in testing models of glacial isostatic adjustment. Here, we present surveying and radiometric dating results for emergent terraces from northern Madagascar, which is generally regarded as a stable equatorial site. Fossil coral specimens were dated using conventional and open-system corrected uranium series methods. Elevation of the upper (undated) terrace decreases from 33.8 m to 29.5 m over a distance of 35 km. An intermediate terrace has an average radiometric age of 130.7±13.2 ka (i.e. MIS 5e). Its elevation decreases from 9.3 m to 2.8 m over a distance of 80 km. The record of the lowest terrace is fragmentary and consists of beach rock containing rare corals with ages of 1.6–3.8 ka. The spatial gradient of the MIS 5e marker is inconsistent with glacio-isostatic adjustment calculations. Instead, we propose that variable elevations of this marker around Madagascar, and possibly throughout the Indian Ocean, at least partly reflect spatial patterns of dynamic topography generated by sub-plate mantle convection.},
author = {Stephenson, Simon N and White, Nicky J and Li, Tao and Robinson, Laura F},
doi = {10.1016/j.epsl.2019.04.029},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {MIS 5e,dynamic topography,geodynamics,glacial isostatic adjustment,last interglacial period,sea level},
pages = {61--69},
title = {{Disentangling interglacial sea level and global dynamic topography: Analysis of Madagascar}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X1930233X},
volume = {519},
year = {2019}
}
@article{Stevens2018,
abstract = {The International Commission on Stratigraphy (ICS) utilises benchmark chronostratigraphies to divide geologic time. The reliability of these records is fundamental to understand past global change. Here we use the most detailed luminescence dating age model yet published to show that the ICS chronology for the Quaternary terrestrial type section at Jingbian, desert marginal Chinese Loess Plateau, is inaccurate. There are large hiatuses and depositional changes expressed across a dynamic gully landform at the site, which demonstrates rapid environmental shifts at the East Asian desert margin. We propose a new independent age model and reconstruct monsoon climate and desert expansion/contraction for the last {\~{}}250 ka. Our record demonstrates the dominant influence of ice volume on desert expansion, dust dynamics and sediment preservation, and further shows that East Asian Summer Monsoon (EASM) variation closely matches that of ice volume, but lags insolation by {\~{}}5 ka. These observations show that the EASM at the monsoon margin does not respond directly to precessional forcing.},
author = {Stevens, T. and Buylaert, J.-P. and Thiel, C. and {\'{U}}jv{\'{a}}ri, G. and Yi, S. and Murray, A. S. and Frechen, M. and Lu, H.},
doi = {10.1038/s41467-018-03329-2},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {983},
title = {{Ice-volume-forced erosion of the Chinese Loess Plateau global Quaternary stratotype site}},
url = {http://www.nature.com/articles/s41467-018-03329-2},
volume = {9},
year = {2018}
}
@article{StevensTBuylaertJ-PLuHThielCMurrayAFrechenM2016,
author = {Stevens, Thomas and Buylaert, Jan-Pieter and Lu, Huayu and Thiel, Christine and Murray, Andrew and Frechen, Manfred and Yi, Shuangwen and Zeng, Lin and et al {Stevens T, Buylaert J-P, Lu H, Thiel C, Murray A, Frechen M} and Stevens, Thomas and Buylaert, Jan-Pieter and Lu, Huayu and Thiel, Christine and Murray, Andrew and Frechen, Manfred and Yi, Shuangwen and Zeng, Lin},
doi = {10.1002/jqs.2848},
journal = {Journal of Quaternary Science},
number = {4},
pages = {391--405},
title = {{Mass accumulation rate and monsoon records from Xifeng, Chinese Loess Plateau, based on a luminescence age model}},
volume = {31},
year = {2016}
}
@article{Stjern2011,
author = {Stjern, Camilla W. and Stohl, Andreas and Kristj{\'{a}}nsson, J{\'{o}}n Egill},
doi = {10.1029/2010JD014603},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jan},
number = {D2},
pages = {D02212},
title = {{Have aerosols affected trends in visibility and precipitation in Europe?}},
url = {http://doi.wiley.com/10.1029/2010JD014603},
volume = {116},
year = {2011}
}
@article{doi:10.1029/2019GL084396,
abstract = {Abstract Small volcanic eruptions and their effects have recently come into research focus. While large eruptions are known to strongly affect stratospheric temperature, the impacts of smaller eruptions are hard to quantify because their signals are masked by natural variability. Here, we quantify the temperature signals from small volcanic eruptions between 2002 and 2016 using new vertically resolved aerosol data and precise temperature observations from radio occultation. We find characteristic space-time signals that can be associated with specific eruptions. In the lower stratosphere, robust warming signals are observed, while in the midstratosphere also cooling signals of some eruptions appear. We find that the volcanic contribution to the temperature trend is up to 20{\%}, depending on latitude and altitude. We conclude that detailed knowledge of the vertical structure of volcanic temperature impacts is crucial for comprehensive trend analysis in order to separate natural from anthropogenic temperature changes.},
author = {Stocker, Matthias and Ladst{\"{a}}dter, Florian and Wilhelmsen, Hallgeir and Steiner, Andrea K},
doi = {10.1029/2019GL084396},
journal = {Geophysical Research Letters},
keywords = {satellite observations,stratospheric temperature,temperature trends,volcanic signals},
number = {21},
pages = {12486--12494},
title = {{Quantifying Stratospheric Temperature Signals and Climate Imprints From Post-2000 Volcanic Eruptions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084396},
volume = {46},
year = {2019}
}
@article{Stokes2015,
author = {Stokes, Chris R. and Tarasov, Lev and Blomdin, Robin and Cronin, Thomas M. and Fisher, Timothy G. and Gyllencreutz, Richard and H{\"{a}}ttestrand, Clas and Heyman, Jakob and Hindmarsh, Richard C.A. and Hughes, Anna L.C. and Jakobsson, Martin and Kirchner, Nina and Livingstone, Stephen J. and Margold, Martin and Murton, Julian B. and Noormets, Riko and Peltier, W. Richard and Peteet, Dorothy M. and Piper, David J.W. and Preusser, Frank and Renssen, Hans and Roberts, David H. and Roche, Didier M. and Saint-Ange, Francky and Stroeven, Arjen P. and Teller, James T.},
doi = {10.1016/j.quascirev.2015.07.016},
issn = {02773791},
journal = {Quaternary Science Reviews},
month = {oct},
pages = {15--49},
title = {{On the reconstruction of palaeo-ice sheets: Recent advances and future challenges}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S027737911530055X},
volume = {125},
year = {2015}
}
@article{STOLL20191,
abstract = {Published alkenone $\epsilon$p records spanning known glacial pCO2 cycles show considerably less variability than predicted by the diffusive model for cellular carbon acquisition and isotope fractionation. We suggest this pattern is consistent with a systematic cellular enhancement of the carbon supply to photosynthesis via carbon concentrating mechanisms under the case of carbon limitation during low pCO2 glacial time periods, an effect also manifest under carbon limitation in experimental cultures of coccolithophores as well as diatoms. While the low-amplitude $\epsilon$p signal over glacial pCO2 cycles has led some to question the reliability of $\epsilon$p for reconstructing long-term pCO2, the [CO2]aq in the tropical oceans during glacial pCO2 minima represents the most extreme low CO2 conditions likely experienced by phytoplankton in the Cenozoic, and the strongest upregulation of carbon concentrating mechanisms. Using a statistical multilinear regression model, we quantitatively parse out the factors (namely light, growth rate, and [CO2]aq), that contribute to variation in $\epsilon$p in alkenone-producing algae, which confirms a much smaller dependence of $\epsilon$p on [CO2]aq in the low [CO2]aq range, than inferred from the hyperbolic form of the diffusive model. Application of the new statistical model to two published tropical $\epsilon$p records spanning the late Neogene produces much more dynamic pCO2 estimates than the conventional diffusive model and reveals a significant pCO2 decline over the last 15 Ma, which is broadly consistent with recent results from boron isotopes of foraminifera. The stable isotopic fractionation between coccolith calcite and seawater dissolved inorganic carbon (here $\Delta$coccolith-DIC) also shows systematic variations over glacial-interglacial cycles which may, following future experimental constraints, help estimate the degree of upregulation of parts of the algal carbon concentrating mechanism over glacial cycles.},
author = {Stoll, Heather M and Guitian, Jose and Hernandez-Almeida, Ivan and Mejia, Luz Maria and Phelps, Samuel and Polissar, Pratigya and Rosenthal, Yair and Zhang, Hongrui and Ziveri, Patrizia},
doi = {10.1016/j.quascirev.2019.01.012},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {1--20},
title = {{Upregulation of phytoplankton carbon concentrating mechanisms during low CO2 glacial periods and implications for the phytoplankton pCO2 proxy}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379118305377},
volume = {208},
year = {2019}
}
@article{Stone2013a,
author = {Stone, E J and Lunt, D J and Annan, J D and Hargreaves, J C},
doi = {10.5194/cp-9-621-2013},
issn = {1814-9332},
journal = {Climate of the Past},
month = {mar},
number = {2},
pages = {621--639},
publisher = {Copernicus Publications},
title = {{Quantification of the Greenland ice sheet contribution to Last Interglacial sea level rise}},
url = {https://www.clim-past.net/9/621/2013/ https://www.clim-past.net/9/621/2013/cp-9-621-2013.pdf},
volume = {9},
year = {2013}
}
@article{Storto2017,
abstract = {Quantifying the effect of the seawater density changes on sea level variability is of crucial importance for climate change studies, as the sea level cumulative rise can be regarded as both an important climate change indicator and a possible danger for human activities in coastal areas. In this work, as part of the Ocean Reanalysis Intercomparison Project, the global and regional steric sea level changes are estimated and compared from an ensemble of 16 ocean reanalyses and 4 objective analyses. These estimates are initially compared with a satellite-derived (altimetry minus gravimetry) dataset for a short period (2003–2010). The ensemble mean exhibits a significant high correlation at both global and regional scale, and the ensemble of ocean reanalyses outperforms that of objective analyses, in particular in the Southern Ocean. The reanalysis ensemble mean thus represents a valuable tool for further analyses, although large uncertainties remain for the inter-annual trends. Within the extended intercomparison period that spans the altimetry era (1993–2010), we find that the ensemble of reanalyses and objective analyses are in good agreement, and both detect a trend of the global steric sea level of 1.0 and 1.1 ± 0.05 mm/year, respectively. However, the spread among the products of the halosteric component trend exceeds the mean trend itself, questioning the reliability of its estimate. This is related to the scarcity of salinity observations before the Argo era. Furthermore, the impact of deep ocean layers is non-negligible on the steric sea level variability (22 and 12 {\%} for the layers below 700 and 1500 m of depth, respectively), although the small deep ocean trends are not significant with respect to the products spread.},
author = {Storto, Andrea and Masina, Simona and Balmaseda, Magdalena and Guinehut, St{\'{e}}phanie and Xue, Yan and Szekely, Tanguy and Fukumori, Ichiro and Forget, Gael and Chang, You-Soon and Good, Simon A and K{\"{o}}hl, Armin and Vernieres, Guillaume and Ferry, Nicolas and Peterson, K Andrew and Behringer, David and Ishii, Masayoshi and Masuda, Shuhei and Fujii, Yosuke and Toyoda, Takahiro and Yin, Yonghong and Valdivieso, Maria and Barnier, Bernard and Boyer, Tim and Lee, Tony and Gourrion, J{\'{e}}rome and Wang, Ou and Heimback, Patrick and Rosati, Anthony and Kovach, Robin and Hernandez, Fabrice and Martin, Matthew J and Kamachi, Masafumi and Kuragano, Tsurane and Mogensen, Kristian and Alves, Oscar and Haines, Keith and Wang, Xiaochun},
doi = {10.1007/s00382-015-2554-9},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {3},
pages = {709--729},
title = {{Steric sea level variability (1993–2010) in an ensemble of ocean reanalyses and objective analyses}},
url = {https://doi.org/10.1007/s00382-015-2554-9},
volume = {49},
year = {2017}
}
@article{Stothers1997,
author = {Stothers, Richard B.},
doi = {10.1029/96JD03985},
issn = {01480227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {mar},
number = {D5},
pages = {6143--6151},
title = {{Stratospheric aerosol clouds due to very large volcanic eruptions of the early twentieth century: Effective particle sizes and conversion from pyrheliometric to visual optical depth}},
url = {http://doi.wiley.com/10.1029/96JD03985},
volume = {102},
year = {1997}
}
@article{Strikis2018,
abstract = {Heinrich Stadials significantly affected tropical precipitation through changes in the interhemispheric temperature gradient as a result of abrupt cooling in the North Atlantic. Here, we focus on changes in South American monsoon precipitation during Heinrich Stadials using a suite of speleothem records covering the last 85 ky B.P. from eastern South America. We document the response of South American monsoon precipitation to episodes of extensive iceberg discharge, which is distinct from the response to the cooling episodes that precede the main phase of ice-rafted detritus deposition. Our results demonstrate that iceberg discharge in the western subtropical North Atlantic led to an abrupt increase in monsoon precipitation over eastern South America. Our findings of an enhanced Southern Hemisphere monsoon, coeval with the iceberg discharge into the North Atlantic, are consistent with the observed abrupt increase in atmospheric methane concentrations during Heinrich Stadials.},
author = {Str{\'{i}}kis, Nicol{\'{a}}s M. and Cruz, Francisco W. and Barreto, Eline A.S. and Naughton, Filipa and Vuille, Mathias and Cheng, Hai and Voelker, Antje H.L. and Zhang, Haiwei and Karmann, Ivo and {Lawrence Edwards}, R. and Auler, Augusto S. and Santos, Roberto Ventura and Sales, Hamilton Reis},
doi = {10.1073/pnas.1717784115},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Heinrich Stadial,Ice-rafted detritus,South American monsoon,Speleothem},
number = {15},
pages = {3788--3793},
pmid = {29581293},
title = {{South American monsoon response to iceberg discharge in the North Atlantic}},
volume = {115},
year = {2018}
}
@article{bg-17-813-2020,
author = {Stramma, L and Schmidtko, S and Bograd, S J and Ono, T and Ross, T and Sasano, D and Whitney, F A},
doi = {10.5194/bg-17-813-2020},
journal = {Biogeosciences},
number = {3},
pages = {813--831},
title = {{Trends and decadal oscillations of oxygen and nutrients at 50 to 300m depth in the equatorial and North Pacific}},
url = {https://bg.copernicus.org/articles/17/813/2020/},
volume = {17},
year = {2020}
}
@article{Streletskiy2015,
abstract = {Spatial variability and temporal trends of the shallow ground thermal regime and permafrost active-layer thickness (ALT) were estimated over 1963-2013 using daily soil temperature data available from stations of the Russian Hydrometeorological Service. Correlation analysis was used to evaluate the role of changing climatic conditions on the ground thermal regime. ALT data collected by the Circumpolar Active Layer Monitoring program in Russia were used to expand the geography of ALT observations over 1999-2013, and to identify 'hot spots' of soil temperature and ALT change. Results indicate that a substantially higher rate of change in the thermal regime of permafrost-affected soils prevailed during 1999-2013, relative to the last fifty years. Results indicate that the thermal regime of the upper permafrost in western Russia is strongly associated with air temperature, with much weaker relationships in central and eastern Russia. The thermal regime of permafrost-affected soils shows stronger dependence on climatic conditions over the last fifteen years relative to the historical 50-year period. Geostatistical analysis revealed that the cities of Norilsk and Susuman are hot spots of permafrost degradation. Of six settlements selected for detailed analysis in various parts of the permafrost regions, all but one (Chukotka), show substantial changes in the shallow ground thermal regime. Northern locations in the continuous permafrost region show thickening of the active layer, while those farther south experienced development of residual thaw layers above the permafrost and decreases in the duration of the freezing period.},
author = {Streletskiy, Dmitry A. and Sherstiukov, Artem B. and Frauenfeld, Oliver W. and Nelson, Frederick E.},
doi = {10.1088/1748-9326/10/12/125005},
isbn = {1748-9326},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {Arctic,active layer,climate change,monitorin,permafrost,soil temperature},
number = {12},
pages = {125005},
title = {{Changes in the 1963–2013 shallow ground thermal regime in Russian permafrost regions}},
volume = {10},
year = {2015}
}
@article{Streletskiy2017,
author = {Streletskiy, Dmitry A. and Shiklomanov, Nikolay I. and Little, Jonathon D. and Nelson, Frederick E. and Brown, Jerry and Nyland, Kelsey E. and Klene, Anna E.},
doi = {10.1002/ppp.1918},
issn = {10456740},
journal = {Permafrost and Periglacial Processes},
month = {jul},
number = {3},
pages = {566--572},
title = {{Thaw Subsidence in Undisturbed Tundra Landscapes, Barrow, Alaska, 1962–2015}},
url = {http://doi.wiley.com/10.1002/ppp.1918},
volume = {28},
year = {2017}
}
@article{Studholme2018,
abstract = {Poleward trends in seasonal-mean latitudes of tropical cyclones (TCs) have been identified in direct observations from 1980 to the present. Paleoclimate reconstructions also indicate poleward–equatorward migrations over centennial–millennial time scales. Hadley circulation (HC) is often both implicitly and explicitly invoked to provide dynamical linkages to these shifts, although no direct analysis of concurrent changes in the recent period has been presented. Here, the observational TC record (1981–2016) and ERA-Interim, JRA-55, and MERRA-2 are studied to examine potential relationships between the two. A zonally asymmetric HC is defined by employing Helmholtz theory for vector decomposition, and this permits the derivation of novel HC diagnostics local to TC basins.},
author = {Studholme, Joshua and Gulev, Sergey},
doi = {10.1175/JCLI-D-17-0852.1},
issn = {0894-8755},
journal = {Journal of Climate},
keywords = {Atmosphere,Hadley circulation,Tropical cyclones},
month = {jun},
number = {11},
pages = {4367--4389},
title = {{Concurrent Changes to Hadley Circulation and the Meridional Distribution of Tropical Cyclones}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0852.1},
volume = {31},
year = {2018}
}
@article{Su2018,
abstract = {Continental flow plays a significant role in the global ecosystem. With increased global warming and a booming economy exacerbating water scarcity, global analyses of continental discharge are of great relevance to water management. In this paper, the Mann-Kendall (MK) test, with variations accounting for lag-1 autocorrelation, full autocorrelation, and long-term persistence, was used to detect the long-term flow trends in 916 of the world's largest ocean-reaching rivers over the period 1948–2004. Field significance was evaluated using Walker's test. Globally, the results revealed more decreases in streamflow than increases. With the traditional MK test, 503 rivers had decreased streamflow, with 120 showing significant decreases, whereas 408 rivers had increased streamflow, with 51 showing significant increases. Regionally, positive streamflow trends mainly occurred in high-latitude areas and negative streamflow trends mainly occurred in low-latitude areas, a pattern that can be attributed to uneven precipitation and the effects of global warming. When the full autocorrelation structure and long-term persistence behavior were taken into account in the trend analysis, there was a large reduction in the number of rivers with significant changes in streamflow. Negligible departures from the traditional MK results were observed when only the lag-1 autocorrelation was taken into consideration. For the Americas and Europe, annual integrated river flow showed a slight upward trend; for other continents, there was a slight downward trend. For all oceans except the Arctic Ocean, integrated river flow had a downward trend. We investigated the causal relationships between streamflow and ocean signals using the Granger causality test. El Ni{\~{n}}o–Southern Oscillation (ENSO) signals were significantly causal for river flow in over 36{\%} of global rivers tested. The influence of the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO) was significant in more than a quarter of rivers studied. The Pacific Decadal Oscillation (PDO) was responsible for the variation in streamflow for over a quarter of rivers studied. Streamflow was affected by the interactions between ocean signals as well as by anthropogenic activities.},
author = {Su, Lu and Miao, Chiyuan and Kong, Dongxian and Duan, Qingyun and Lei, Xiaohui and Hou, Qianqian and Li, Hu},
doi = {10.1016/j.jhydrol.2018.06.058},
isbn = {8610588041},
issn = {00221694},
journal = {Journal of Hydrology},
keywords = {Global river,Granger causality test,Long-term trend,Ocean signals},
number = {March},
pages = {818--833},
title = {{Long-term trends in global river flow and the causal relationships between river flow and ocean signals}},
volume = {563},
year = {2018}
}
@article{Su2020,
abstract = {{\textless}p{\textgreater}Retrieving information concerning the interior of the ocean using satellite remote sensing data has a major impact on studies of ocean dynamic and climate changes; however, the lack of information within the ocean limits such studies about the global ocean. In this paper, an artificial neural network, combined with satellite data and gridded Argo product, is used to estimate the ocean heat content (OHC) anomalies over four different depths down to 2000 m covering the near-global ocean, excluding the polar regions. Our method allows for the temporal hindcast of the OHC to other periods beyond the 2005–2018 training period. By applying an ensemble technique, the hindcasting uncertainty could also be estimated by using different 9-year periods for training and then calculating the standard deviation across six ensemble members. This new OHC product is called the Ocean Projection and Extension neural Network (OPEN) product. The accuracy of the product is accessed using the coefficient of determination (R2) and the relative root-mean-square error (RRMSE). The feature combinations and network architecture are optimized via a series of experiments. Overall, intercomparison with several routinely analyzed OHC products shows that the OPEN OHC has an R2 larger than 0.95 and an RRMSE of {\textless}0.20 and presents notably accurate trends and variabilities. The OPEN product can therefore provide a valuable complement for studies of global climate changes.{\textless}/p{\textgreater}},
author = {Su, Hua and Zhang, Haojie and Geng, Xupu and Qin, Tian and Lu, Wenfang and Yan, Xiao-Hai},
doi = {10.3390/rs12142294},
issn = {2072-4292},
journal = {Remote Sensing},
keywords = {artificial neural network,deep ocean remote sensing,ocean heat content,remote sensing retrieval},
month = {jul},
number = {14},
pages = {2294},
publisher = {Multidisciplinary Digital Publishing Institute},
title = {{OPEN: A New Estimation of Global Ocean Heat Content for Upper 2000 Meters from Remote Sensing Data}},
url = {https://www.mdpi.com/2072-4292/12/14/2294},
volume = {12},
year = {2020}
}
@article{Sun2018,
abstract = {Previous observational analyses show that the land-surface diurnal temperature range (DTR) has decreased in the past 6 decades worldwide. Based on a newly developed China Meteorological Administration--Land Surface Air Temperature (CMA-LSAT) dataset, we analyzed the DTR changes between 1901 and 2014. Results indicate that the global land surface DTR significantly decreased at a rate of −{\{}$\backslash$thinspace{\}}0.036 {\{}$\backslash$textdegree{\}}C decade−{\{}$\backslash$thinspace{\}}1 over the 1901--2014 period, mainly due to the large decrease in DTR from 1951 to 2014. For the first half of the twentieth century, most grid boxes (spatial resolution 5{\{}$\backslash$textdegree{\}}{\{}$\backslash$thinspace{\}}{\{}$\backslash$texttimes{\}}{\{}$\backslash$thinspace{\}}5{\{}$\backslash$textdegree{\}}) show a positive DTR trend, with the positive trends of 32.4{\%} grid boxes being statistically significant, leading to a large and significant increase of 0.048 {\{}$\backslash$textdegree{\}}C decade−{\{}$\backslash$thinspace{\}}1 in DTR. However, a dramatic reversal in DTR change occurred in early 1950s, with most parts of global lands exhibiting a shift from increasing to decreasing trends. The global land average DTR decrease during 1951--2014 was −{\{}$\backslash$thinspace{\}}0.054 {\{}$\backslash$textdegree{\}}C decade−{\{}$\backslash$thinspace{\}}1, with 45.0{\%} grid boxes showing significant negative trends. The reverse phenomenon is more obvious in the Northern Hemisphere than that in the Southern Hemisphere. For the periods 1979--2014 and 1998--2014, the decreasing trends in DTR mainly occur in the Northern Hemisphere. The DTR in the Southern Hemisphere experienced much larger increases during the two recent periods than during the period 1951--2014. Asia, Eastern North America, and Australia exhibited widespread decreases in DTR, although the trend pattern for global DTR is generally mixed during 1979--2014 and 1998--2014. There is a good negative correlation between DTR and precipitation in the Northern Hemisphere from 1901 to 2014, with a correlation coefficient of −{\{}$\backslash$thinspace{\}}0.61. The change in precipitation and number of volcanic eruptions, and the ``early brightening'' of Europe (Stockholm) all benefit the increase of DTR at global and regional scales in the first half of the twentieth century.},
author = {Sun, Xiubao and Ren, Guoyu and You, Qinglong and Ren, Yuyu and Xu, Wenhui and Xue, Xiaoying and Zhan, Yunjian and Zhang, Siqi and Zhang, Panfeng},
doi = {10.1007/s00382-018-4329-6},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {jun},
pages = {3343--3356},
title = {{Global diurnal temperature range (DTR) changes since 1901}},
url = {https://doi.org/10.1007/s00382-018-4329-6},
volume = {52},
year = {2018}
}
@article{Sun2015,
abstract = {AbstractAlthough the Indian Ocean dipole (IOD) and ENSO are significantly correlated, there are indeed some IODs independent of ENSO. In this research, the characteristics of independent IOD are investigated and a new triggering mechanism is proposed based on case study and statistical analysis. Results show that the independent IODs peak in an earlier season and have a weaker intensity compared with the IODs associated with ENSO. The wind anomaly associated with the independent IOD is very unique and shows a monsoonlike pattern, in addition to the equatorial easterly wind anomaly (EEWA) common to all IODs. The evolution of the EEWA associated with the independent IOD is well captured by the second EOF mode of the equatorial zonal wind interannual variability, suggesting that the independent IOD is an important climate mode inherent to the tropical Indian Ocean. The EEWA associated with the independent IOD is tightly linked to Indian summer monsoon activities in spring, and the convection anomalies associated with early summer monsoon onset in the Bay of Bengal plays a key role in inducing the EEWA. The EEWA can persist through spring and summer and causes a series of processes similar to those related to the IODs associated with ENSO. The correlation between the independent IOD and Indian summer monsoon activities increases dramatically after the 1980s, which is probably due to the mean state change in the tropical Indian Ocean climate system.},
annote = {doi: 10.1175/JCLI-D-14-00580.1},
author = {Sun, Shuangwen and Lan, Jian and Fang, Yue and Tana and Gao, Xiaoqian},
doi = {10.1175/JCLI-D-14-00580.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jan},
number = {13},
pages = {5063--5076},
publisher = {American Meteorological Society},
title = {{A Triggering Mechanism for the Indian Ocean Dipoles Independent of ENSO}},
url = {https://doi.org/10.1175/JCLI-D-14-00580.1},
volume = {28},
year = {2015}
}
@article{Sun2018,
abstract = {In this paper, we present a comprehensive review of the data sources and estimation methods of 30 currently available global precipitation datasets, including gauge-based, satellite-related, and reanalysis datasets. We analyzed the discrepancies between the datasets at daily to annual timescales and found large differences in both the magnitude and the variability of precipitation estimates. The magnitude of annual precipitation estimates over global land deviated by as much as 300 mm/yr among the products. Reanalysis datasets had a larger degree of variability than the other types of datasets. The degree of variability in precipitation estimates also varied by region. Large differences in annual and seasonal estimates were found in tropical oceans, complex mountain areas, northern Africa, and some high-latitude regions. Overall, the variability associated with extreme precipitation estimates was slightly greater at lower latitudes than at higher latitudes. The reliability of precipitation datasets is mainly limited by the number and spatial coverage of surface stations, the satellite algorithms, and the data assimilation models. The inconsistencies described limit the capability of the products for climate monitoring, attribution, and model validation.},
author = {Sun, Qiaohong and Miao, Chiyuan and Duan, Qingyun and Ashouri, Hamed and Sorooshian, Soroosh and Hsu, Kuo Lin},
doi = {10.1002/2017RG000574},
isbn = {8610588041},
issn = {19449208},
journal = {Reviews of Geophysics},
keywords = {development,gauge-based,global precipitation,reanalysis,satellite-based,uncertainty},
number = {1},
pages = {79--107},
title = {{A Review of Global Precipitation Data Sets: Data Sources, Estimation, and Intercomparisons}},
volume = {56},
year = {2018}
}
@article{Sun2021,
abstract = {Based on C-LSAT2.0, using high- and low-frequency components reconstruction methods, combined with observation constraint masking, a reconstructed C-LSAT2.0 with 756 ensemble members from the 1850s to 2018 has been developed. These ensemble versions have been merged with the ERSSTv5 ensemble dataset, and an upgraded version of the CMST-Interim dataset with 5° × 5° resolution has been developed. The CMST-Interim dataset has significantly improved the coverage rate of global surface temperature data. After reconstruction, the data coverage before 1950 increased from 78{\%}–81{\%} of the original CMST to 81{\%}–89{\%}. The total coverage after 1955 reached about 93{\%}, including more than 98{\%} in the Northern Hemisphere and 81{\%}–89{\%} in the Southern Hemisphere. Through the reconstruction ensemble experiments with different parameters, a good basis is provided for more systematic uncertainty assessment of C-LSAT2.0 and CMST-Interim. In comparison with the original CMST, the global mean surface temperatures are estimated to be cooler in the second half of 19th century and warmer during the 21st century, which shows that the global warming trend is further amplified. The global warming trends are updated from 0.085 ± 0.004°C (10 yr) −1 and 0.128 ± 0.006°C (10 yr) −1 to 0.089 ± 0.004°C (10 yr) −1 and 0.137 ± 0.007°C (10 yr) −1 , respectively, since the start and the second half of 20th century.},
author = {Sun, Wenbin and Li, Qingxiang and Huang, Boyin and Cheng, Jiayi and Song, Zhaoyang and Li, Haiyan and Dong, Wenjie and Zhai, Panmao and Jones, Phil},
doi = {10.1007/s00376-021-1012-3},
issn = {0256-1530},
journal = {Advances in Atmospheric Sciences},
month = {may},
number = {5},
pages = {875--888},
title = {{The Assessment of Global Surface Temperature Change from 1850s: The C-LSAT2.0 Ensemble and the CMST-Interim Datasets}},
url = {https://doi.org/10.1007/s00376-021-1012-3 https://link.springer.com/10.1007/s00376-021-1012-3},
volume = {38},
year = {2021}
}
@article{Susanto2015,
abstract = {Abstract The Indonesian throughflow (ITF) from the Pacific to the Indian Ocean plays an important role in global ocean circulation and climate. Yet, continuous ITF measurement is difficult and expensive. The longest time series of in situ measurements of the ITF to date were taken in the Makassar Strait, the main pathway of the ITF. Here we have demonstrated a plausible approach to derive the ITF transport proxy using satellite altimetry sea surface height (SSH), gravimetry ocean bottom pressure (OBP) data, in situ measurements from the Makassar Strait from 1996 to 1998 and 2004 to 2011, and a theoretical formulation. We first identified the optimal locations of the correlation between the observed ITF transport through the Makassar Strait and the pressure gradients, represented by the SSH and OBP differences between the Pacific and Indian Oceans at a 1° ? 1° horizontal resolution. The optimal locations were found centered at 162°E and 11°N in the Pacific Ocean and 80°E and 0° in the Indian Ocean, then were used in the theoretical formulation to estimate the throughflow. The proxy time series follow the observation time series quite well, with the 1993?2011 mean proxy transport of 11.6?±?3.2 Sv southward, varying from 5.6 Sv during the strong 1997 El Ni{\~{n}}o to 16.9 Sv during the 2007 La Nina period, which are consistent with previous estimates. The observed Makassar mean transport is 13.0?±?3.8 Sv southward over 2004?2011, while the SSH proxy (for the same period) gives an ITF mean transport of 13.9?±?4.1 Sv and the SSH?+?OBP proxy (for 2004?2010) is 15.8?±?3.2 Sv.},
annote = {doi: 10.1002/2014JC010382},
author = {Susanto, R Dwi and Song, Y Tony},
doi = {10.1002/2014JC010382},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Indonesian throughflow,Makassar transport,ocean bottom pressure,sea level,throughflow proxy},
month = {apr},
number = {4},
pages = {2844--2855},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Indonesian throughflow proxy from satellite altimeters and gravimeters}},
url = {https://doi.org/10.1002/2014JC010382},
volume = {120},
year = {2015}
}
@article{Susskind,
author = {Susskind, J and Schmidt, G A and Lee, J N and Iredell, L},
doi = {10.1088/1748-9326/aafd4e},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {apr},
number = {4},
pages = {044030},
title = {{Recent global warming as confirmed by AIRS}},
url = {http://stacks.iop.org/1748-9326/14/i=4/a=044030?key=crossref.8a80e2fa8d397a7780e1aae037ad603a},
volume = {14},
year = {2019}
}
@article{Suzuki2018,
abstract = {{\textcopyright} 2017 The Author(s) A dataset of historical river discharge into oceans was created using the CaMa-Flood global river routing model and adjusted runoff from the land component of JRA-55. The major rivers were well resolved with a 0.25° horizontal resolution. The total runoff on each drainage basin exhibits a distinctive bias on decadal time scales. The input runoff data were modified using 5-year low-pass-filtered multiplicative factors to fit the annual mean climatology and decadal variations in the reference dataset. The model incorporated data from 1958 to 2016. The yearly and seasonal variations of the major rivers are well represented by the model.},
author = {Suzuki, Tatsuo and Yamazaki, Dai and Tsujino, Hiroyuki and Komuro, Yoshiki and Nakano, Hideyuki and Urakawa, Shogo},
doi = {10.1007/s10872-017-0458-5},
isbn = {1087201704585},
issn = {1573868X},
journal = {Journal of Oceanography},
keywords = {Freshwater budget,Historical dataset,JRA-55,Ocean model,River discharge},
number = {4},
pages = {421--429},
publisher = {Springer Japan},
title = {{A dataset of continental river discharge based on JRA-55 for use in a global ocean circulation model}},
url = {https://doi.org/10.1007/s10872-017-0458-5},
volume = {74},
year = {2018}
}
@article{Svendsen2014,
abstract = {Observations indicate that since the 1970s Equatorial Atlantic sea surface temperature (SST) variations in boreal summer tend to modulate El Ni{\~{n}}o in the following seasons, indicating that the Atlantic Ocean can have importance for predicting the El Ni{\~{n}}o–Southern Oscillation (ENSO). The cause of the change in the recent decades remains unknown. Here we show that in the Bergen Climate Model (BCM), a freshwater forced weakening of the Atlantic meridional overturning circulation (AMOC) results in a strengthening of the relation between the Atlantic and the Pacific similar to that observed since the 1970s. During the weakening AMOC phase, SST and precipitation increase in the central Equatorial Atlantic, while the mean state of the Pacific does not change significantly. In the Equatorial Atlantic the SST variability has also increased, with a peak in variability in boreal summer. In addition, the characteristic timescales of ENSO variability is shifted towards higher frequencies. TheBCM version used here is flux-adjusted, and hence Atlantic variability is realistic in contrast to in many other models. These results indicate that in the BCM a weakening AMOC can change the mean background state of the Tropical Atlantic surface conditions, enhancing Equatorial Atlantic variability, and resulting in a stronger relationship between the Tropical Atlantic and Pacific Oceans. This in turn alters the variability in the Pacific.},
author = {Svendsen, Lea and Kvamst{\o}, Nils Gunnar and Keenlyside, Noel},
doi = {10.1007/s00382-013-1904-8},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {11},
pages = {2931--2941},
title = {{Weakening AMOC connects Equatorial Atlantic and Pacific interannual variability}},
url = {https://doi.org/10.1007/s00382-013-1904-8},
volume = {43},
year = {2014}
}
@article{doi:10.1002/2013GL059076,
abstract = {Abstract Atlantic multidecadal variability (AMV) is known to impact climate globally, and knowledge about the persistence of AMV is important for understanding past and future climate variability, as well as modeling and assessing climate impacts. The short observational data do not significantly resolve multidecadal variability, but recent paleoproxy reconstructions show multidecadal variability in North Atlantic temperature prior to the instrumental record. However, most of these reconstructions are land-based, not necessarily representing sea surface temperature. Proxy records are also subject to dating errors and microenvironmental effects. We extend the record of AMV 90 years past the instrumental record using principle component analysis of five marine-based proxy records to identify the leading mode of variability. The first principal component is consistent with the observed AMV, and multidecadal variability seems to persist prior to the instrumental record. Thus, we demonstrate that reconstructions of past Atlantic low-frequency variability can be improved by combining marine-based proxies.},
author = {Svendsen, Lea and Hetzinger, Steffen and Keenlyside, Noel and Gao, Yongqi},
doi = {10.1002/2013GL059076},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {AMO,AMV,Multi-decadal variability,coral records,proxy reconstruction},
month = {feb},
number = {4},
pages = {1295--1300},
publisher = {Wiley-Blackwell},
title = {{Marine-based multiproxy reconstruction of Atlantic multidecadal variability}},
url = {https://doi.org/10.1002/2013GL059076 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013GL059076},
volume = {41},
year = {2014}
}
@article{Swart2012a,
abstract = {Changes in the position and strength of the Southern Hemisphere surface westerlies have significant implications for ocean circulation and the global carbon cycle. Here we compare the climatologies, as well as the trends, in the position and strength of the surface westerly wind-stress jet in reanalyses with the Coupled Model Intercomparison Project (CMIP) phase 3 and phase 5 models over the his- torical period from 1979–2010. We show that both the CMIP3 and CMIP5 models exhibit an equatorward biased climatological jet position. The reanalyses and climate models both show significant trends in annual mean jet strength, though the climate models underestimate the strengthening. Neither reanalyses nor models show a robust trend in annual mean jet position over the historical period, though significant trends do occur in the Austral summer position. We also compare the response of the CMIP3 and CMIP5 model wind-stresses to a range of anthropogenic forcing scenarios for the 21st century.},
author = {Swart, N. C. and Fyfe, J. C.},
doi = {10.1029/2012GL052810},
isbn = {0094-8276},
issn = {00948276},
journal = {Geophysical Research Letters},
number = {16},
pages = {6--11},
title = {{Observed and simulated changes in the Southern Hemisphere surface westerly wind-stress}},
volume = {39},
year = {2012}
}
@article{10.3389/fmars.2019.00421,
abstract = {Air-sea and air-sea-ice fluxes in the Southern Ocean play a critical role in global climate through their impact on the overturning circulation and oceanic heat and carbon uptake. The challenging conditions in the Southern Ocean have led to sparse spatial and temporal coverage of observations. This has led to a “knowledge gap” that increases uncertainty in atmosphere and ocean dynamics and boundary-layer thermodynamic processes, impeding improvements in weather and climate models. Improvements will require both process-based research to understand the mechanisms governing air-sea exchange and a significant expansion of the observing system. This will improve flux parameterizations and reduce uncertainty associated with bulk formulae and satellite observations. Improved estimates spanning the full Southern Ocean will need to take advantage of ships, surface moorings, and the growing capabilities of autonomous platforms with robust and miniaturized sensors. A key challenge is to identify observing system sampling requirements. This requires models, Observing System Simulation Experiments (OSSEs), and assessments of the specific spatial-temporal accuracy and resolution required for priority science and assessment of observational uncertainties of the mean state and direct flux measurements. Year-round, high-quality, quasi-continuous in situ flux measurements and observations of extreme events are needed to validate, improve and characterize uncertainties in blended reanalysis products and satellite data as well as to improve parameterizations. Building a robust observing system will require community consensus on observational methodologies, observational priorities, and effective strategies for data management and discovery.},
author = {Swart, Sebastiaan and Gille, Sarah T and Delille, Bruno and Josey, Simon and Mazloff, Matthew and Newman, Louise and Thompson, Andrew F and Thomson, Jim and Ward, Brian and du Plessis, Marcel D and Kent, Elizabeth C and Girton, James and Gregor, Luke and Heil, Petra and Hyder, Patrick and Pezzi, Luciano Ponzi and de Souza, Ronald Buss and Tamsitt, Veronica and Weller, Robert A and Zappa, Christopher J},
doi = {10.3389/fmars.2019.00421},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
pages = {421},
title = {{Constraining Southern Ocean Air-Sea-Ice Fluxes Through Enhanced Observations}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00421},
volume = {6},
year = {2019}
}
@article{Sydeman2015,
abstract = {Climate change impacts on vertebrates have consequences for marine ecosystem structures and services. We review marine fish, mammal, turtle, and seabird responses to climate change and discuss their potential for adaptation. Direct and indirect responses are demonstrated from every ocean. Because of variation in research foci, observed responses differ among taxonomic groups (redistributions for fish, phenology for seabirds). Mechanisms of change are (i) direct physiological responses and (ii) climate-mediated predator-prey interactions. Regional-scale variation in climate-demographic functions makes range-wide population dynamics challenging to predict. The nexus of metabolism relative to ecosystem productivity and food webs appears key to predicting future effects on marine vertebrates. Integration of climate, oceanographic, ecosystem, and population models that incorporate evolutionary processes is needed to prioritize the climate-related conservation needs for these species.},
author = {Sydeman, William J. and Poloczanska, Elvira and Reed, Thomas E. and Thompson, Sarah Ann},
doi = {10.1126/science.aac9874},
issn = {10959203},
journal = {Science},
number = {6262},
pages = {772--777},
title = {{Climate change and marine vertebrates}},
volume = {350},
year = {2015}
}
@article{Tan2020,
abstract = {Changes in precipitation seasonality or redistribution of precipitation could exert significant influences on regional water resources availability and the well-being of the ecosystem. However, due to the nonuniform distribution of precipitation stations and intermittency of precipitation, precise detection of changes in precipitation seasonality on the global scale is absent. This study identifies and inter-compares trends in precipitation seasonality within seven precipitation datasets during the past three decades, including two gauge-based datasets derived from the Climatic Research Unit (CRU) and the Global Precipitation Climatology Centre (GPCC), one remote sensing-retrieval obtained from Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), three reanalysis datasets obtained from National Centers for Environmental Prediction reanalysis II (NCEP2), European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim), and Modern Era Reanalysis for Research and Applications Version 2 (MERRA2), and one precipitation dataset merged from above three types, Multi-Source Weighted Ensemble Precipitation Version 1.2 (MSWEP{\_}V1.2). Values of two indices representing the precipitation seasonality, the normal seasonality index (SI) and the dimensionless seasonality index (DSI), are estimated for each land grid in each precipitation dataset. The results show that DSI is more sensitive to changes in the temporal distribution of precipitation as it considers both annual amount and monthly fluctuations of precipitation, compared to SI that only considers monthly fluctuations of precipitation. There are large differences in precipitation seasonality at annual and climatologic scales between precipitation datasets for both SI and DSI. Within the seven precipitation datasets, PERSIANN-CDR SI and DSI show high precipitation seasonality while CRU SI, and ERA-Interim and MERRA2 DSI show the low precipitation seasonality in all continental regions. During 1988–2013, PERSIANN-CDR, NCEP2 and ERA-Interim show more widespread, statistically significant trends in precipitation seasonality than other four precipitation datasets. PERSIANN-CDR and NCEP2 show statistically significant decreases in SI over Middle East and Central Asia, while ERA-Interim, MERRA2 and MSWEP{\_}V1.2 SI increase over Central and South Africa. Increases in SI over the most of South America are significant. Regions of Canada/Greenland/Iceland, East and South Africa show significant increases in precipitation seasonality, while South Europe/Mediterranean and Central Africa show significant decreases in precipitation seasonality in most datasets. Although time series of seasonality indices values fluctuate correlatively in recent three decades, there are no regions on which all precipitation datasets show a consistent, statistically significant, positive or negative trend in indices of precipitation seasonality. These inconsistent changes in precipitation seasonality within various precipitation datasets imply the importance of choosing dataset when studying changes in regional precipitation seasonality.},
author = {Tan, Xuezhi and Wu, Yi and Liu, Bingjun and Chen, Shiling},
doi = {10.1007/s00382-020-05158-w},
isbn = {0038202005158},
issn = {14320894},
journal = {Climate Dynamics},
keywords = {Climate change,Global regions,Precipitation datasets,Precipitation seasonality,Seasonality indices},
number = {5-6},
pages = {3091--3108},
title = {{Inconsistent changes in global precipitation seasonality in seven precipitation datasets}},
volume = {54},
year = {2020}
}
@article{Tang2017,
abstract = {The variation trends of the cold-point tropopause (CPT) are presented using radiosonde observations from 77 stations over China during 1979–2014. The latitude regions over China from 18°N to 53°N are divided into 7 latitude zones with every 5° intervals, and the spatial areas of 18°N–53°N, 75°E–135°E are divided into 27 lattices with 5°×10° grids. The annual-mean values of height-of-CPT (H-CPT) and temperature-of-CPT (T-CPT) are then calculated by all the available samples within each latitude and longitude bin. By using the least squares regression method, it is found that the H-CPT increases with the rate of 273m/decade, and overall the significant cooling rate of −0.70K/decade for the T-CPT over the whole of China. Then, the trends and latitude distribution of H-CPT and T-CPT for each latitude zone are analyzed. The difference of H-CPT among latitude distribution characteristic is reducing year by year, and the difference of T-CPT is enlarging. The H-CPT displays a rising trend between 28°N–53°N latitude region with the positive change rates, and it has decline trend between 18°N–28°N latitude region with the negative change rates. The change rates of T-CPT are negative values for all latitude zones. At last, the nonuniform latitudinal and longitudinal distribution of long-term trends of H-CPT and T-CPT are first presented for each spatial cell.},
author = {Tang, Chaoli and Li, Xuebin and Li, Jianyu and Dai, Congming and Deng, Luofeng and Wei, Heli},
doi = {10.1016/j.atmosres.2017.04.008},
issn = {0169-8095},
journal = {Atmospheric Research},
pages = {1--9},
title = {{Distribution and trends of the cold-point tropopause over China from 1979 to 2014 based on radiosonde dataset}},
volume = {193},
year = {2017}
}
@article{Tao2015,
author = {Tao, M and Konopka, P and Ploeger, F and Groo{\ss}, J.-U. and M{\"{u}}ller, R and Volk, C M and Walker, K A and Riese, M},
doi = {10.5194/acp-15-8695-2015},
journal = {Atmospheric Chemistry and Physics},
number = {15},
pages = {8695--8715},
title = {{Impact of the 2009 major sudden stratospheric warming on the composition of the stratosphere}},
volume = {15},
year = {2015}
}
@article{Tarasick2019,
abstract = {From the earliest observations of ozone in the lower atmosphere in the 19th century, both measurement methods and the portion of the globe observed have evolved and changed. These methods have different uncertainties and biases, and the data records differ with respect to coverage (space and time), information content, and representativeness. In this study, various ozone measurement methods and ozone datasets are reviewed and selected for inclusion in the historical record of background ozone levels, based on relationship of the measurement technique to the modern UV absorption standard, absence of interfering pollutants, representativeness of the well-mixed boundary layer and expert judgement of their credibility. There are significant uncertainties with the 19th and early 20th-century measurements related to interference of other gases. Spectroscopic methods applied before 1960 have likely underestimated ozone by as much as 11{\%} at the surface and by about 24{\%} in the free troposphere, due to the use of differing ozone absorption coefficients.},
author = {Tarasick, David and Galbally, Ian E. and Cooper, Owen R. and Schultz, Martin G. and Ancellet, Gerard and Leblanc, Thierry and Wallington, Timothy J. and Ziemke, Jerry and Liu, Xiong and Steinbacher, Martin and Staehelin, Johannes and Vigouroux, Corinne and Hannigan, James W. and Garc{\'{i}}a, Omaira and Foret, Gilles and Zanis, Prodromos and Weatherhead, Elizabeth and Petropavlovskikh, Irina and Worden, Helen and Osman, Mohammed and Liu, Jane and Chang, Kai-Lan and Gaudel, Audrey and Lin, Meiyun and Granados-Mu{\~{n}}oz, Maria and Thompson, Anne M. and Oltmans, Samuel J. and Cuesta, Juan and Dufour, Gaelle and Thouret, Valerie and Hassler, Birgit and Trickl, Thomas and Neu, Jessica L.},
doi = {10.1525/elementa.376},
editor = {Helmig, Detlev and Lewis, Alastair},
issn = {2325-1026},
journal = {Elementa: Science of the Anthropocene},
month = {jan},
number = {1},
pages = {39},
title = {{Tropospheric Ozone Assessment Report: Tropospheric ozone from 1877 to 2016, observed levels, trends and uncertainties}},
url = {https://online.ucpress.edu/elementa/article/doi/10.1525/elementa.376/112518/Tropospheric-Ozone-Assessment-Report-Tropospheric},
volume = {7},
year = {2019}
}
@article{Tardif2019,
author = {Tardif, Robert and Hakim, Gregory J and Perkins, Walter A and Horlick, Kaleb A and Erb, Michael P and Emile-Geay, Julien and Anderson, David M and Steig, Eric J and Noone, David},
doi = {10.5194/cp-15-1251-2019},
issn = {18149332},
journal = {Climate of the Past},
number = {4},
pages = {1251--1273},
title = {{Last Millennium Reanalysis with an expanded proxy database and seasonal proxy modeling}},
volume = {15},
year = {2019}
}
@article{https://doi.org/10.1002/2017PA003225,
abstract = {Abstract The late Pliocene is the most recent interval in Earth's history to sustain global temperatures within the range of warming predicted for the 21st century, providing an appealing analog for the changes we might encounter in the coming century. Published global reconstructions and climate models find an average +2° summer sea surface temperature anomaly relative to modern during the 3.3–3.0 Ma interval of the late Pliocene, when atmospheric CO2 concentrations last reached 400 ppm. Here we present a new diatom-based reconstruction of Pliocene interglacial sea surface conditions from IODP Site U1361, on the East Antarctic continental rise. We find that open ocean conditions in the mid-Pliocene became increasingly influenced by sea ice from 3.6–3.2 Ma, prior to the onset of Northern Hemisphere glaciation. This cooling trend was interrupted by a temporary southward migration of the Antarctic Polar Front, bathing U1361 in subantarctic waters during a single interglacial—marine isotope stage KM3 (3.17–3.15 Ma)—after which sea ice returned. Building on the identification of this single outlier interglacial, we have revisited earlier reconstructions to explore the response of the Southern Ocean/cryosphere system to peak late Pliocene warmth. By applying a modern chronostratigraphic framework to those low-resolution reconstructions, we identify the same frontal migration in four other cores in the Pacific sector of the Southern Ocean, documenting a major migration of the polar front during a key interval of warm climate. These new results suggest that KM3 is a crucial interval to test ice sheet stability in the context of anthropogenic warming.},
author = {Taylor-Silva, B I and Riesselman, C R},
doi = {10.1002/2017PA003225},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Antarctic polar front,East Antarctic Ice Sheet,International Ocean Discovery Program,Pliocene,Southern Ocean,diatom micropaleontology},
number = {1},
pages = {76--92},
title = {{Polar Frontal Migration in the Warm Late Pliocene: Diatom Evidence From the Wilkes Land Margin, East Antarctica}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017PA003225},
volume = {33},
year = {2018}
}
@article{TESI2020106299,
abstract = {Time-series analyses of satellite images reveal that sea ice extent in the Ross Sea has experienced significant changes over the last 40 years, likely triggered by large-scale atmospheric anomalies. However, resolving how sea ice in the Ross Sea has changed over longer timeframes has until now remained more elusive. Here we used a laminated sediment piston core (14.6 m) collected from the Edisto inlet (Western Ross Sea) to reconstruct fast ice dynamics over the last 2.6 ka. Our goal was to first understand the climate expression of selected well-defined sediment laminae and then use these characteristics for reconstructing past sea ice behaviour across the whole sedimentary sequence. We used the recently established sea ice diatom biomarker proxy IPSO25 in combination with diatom census counts and bulk analyses. Analyses performed on a suite of discrete laminae revealed statistically significant differences between dark and light laminae reflecting different depositional conditions. Based on their respective biogeochemical fingerprints, we infer that dark laminae accumulated during sea ice thaws in early summer. Under these conditions, laminae contain relatively high concentrations of IPSO25 and display an enriched $\delta$13C composition for the bulk organic matter (OM). While diatom assemblages in dark laminae are relatively homogenous, as the thaw continues later in the summer, Corethron pennatum becomes the dominant diatom species, resulting in the formation of light laminae characterized by low IPSO25 concentrations. Since C. pennatum can migrate vertically through the water column to uptake nutrients and avoid competition in oligotrophic waters, its high concentration likely reflects stratified and ice-free surface waters typical of late summer. Down-core trends show that the correlation between sediment brightness and geochemical fingerprint (i.e., IPSO25 and $\delta$13C) holds throughout the record. Based on the knowledge gained at lamina level, our down-core high-resolution reconstruction shows that the summer fast ice coverage changed dramatically during the late Holocene. Specifically, we conclude that the Edisto inlet experienced regular early summer opening between 2.6 ka, and ca. 0.7 ka, after which, coastal fast ice persisted during summer months and ice-free conditions became less frequent. Comparison with previous regional ice core data suggests that the sudden cooling recorded over the Victoria Land Coast region since 0.7 ka might potentially explain our observation of persistent summer fast ice in the Western Ross Sea. Our study has shown that multi-proxy data derived from laminated sediments can provide hitherto unknown detail regarding past summer sea ice dynamics in coastal Antarctic regions.},
author = {Tesi, T and Belt, S T and Gariboldi, K and Muschitiello, F and Smik, L and Finocchiaro, F and Giglio, F and Colizza, E and Gazzurra, G and Giordano, P and Morigi, C and Capotondi, L and Nogarotto, A and K{\"{o}}seoğlu, D and {Di Roberto}, A and Gallerani, A and Langone, L},
doi = {10.1016/j.quascirev.2020.106299},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Fast ice,IPSO,Laminated sediments,Ross sea,Sea ice},
pages = {106299},
title = {{Resolving sea ice dynamics in the north-western Ross Sea during the last 2.6 ka: From seasonal to millennial timescales}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379120302614},
volume = {237},
year = {2020}
}
@article{doi:10.1175/JCLI-D-16-0341.1,
abstract = { AbstractProjections of twenty-first-century Northern Hemisphere (NH) spring snow cover extent (SCE) from two climate model ensembles are analyzed to characterize their uncertainty. Phase 5 of the Coupled Model Intercomparison Project (CMIP5) multimodel ensemble exhibits variability resulting from both model differences and internal climate variability, whereas spread generated from a Canadian Earth System Model–Large Ensemble (CanESM-LE) experiment is solely a result of internal variability. The analysis shows that simulated 1981–2010 spring SCE trends are slightly weaker than observed (using an ensemble of snow products). Spring SCE is projected to decrease by −3.7{\%} ± 1.1{\%} decade−1 within the CMIP5 ensemble over the twenty-first century. SCE loss is projected to accelerate for all spring months over the twenty-first century, with the exception of June (because most snow in this month has melted by the latter half of the twenty-first century). For 30-yr spring SCE trends over the twenty-first century, internal variability estimated from CanESM-LE is substantial, but smaller than intermodel spread from CMIP5. Additionally, internal variability in NH extratropical land warming trends can affect SCE trends in the near future (R2 = 0.45), while variability in winter precipitation can also have a significant (but lesser) impact on SCE trends. On the other hand, a majority of the intermodel spread is driven by differences in simulated warming (dominant in March–May) and snow cover available for melt (dominant in June). The strong temperature–SCE linkage suggests that model uncertainty in projections of SCE could be potentially reduced through improved simulation of spring season warming over land. },
author = {Thackeray, Chad W and Fletcher, Christopher G and Mudryk, Lawrence R and Derksen, Chris},
doi = {10.1175/JCLI-D-16-0341.1},
journal = {Journal of Climate},
number = {23},
pages = {8647--8663},
title = {{Quantifying the Uncertainty in Historical and Future Simulations of Northern Hemisphere Spring Snow Cover}},
url = {https://doi.org/10.1175/JCLI-D-16-0341.1},
volume = {29},
year = {2016}
}
@article{Thatcher2020,
abstract = {Iberia is predicted under future warming scenarios to be increasingly impacted by drought. While it is known that this region has experienced multiple intervals of enhanced aridity over the Holocene, additional hydroclimate-sensitive records from Iberia are necessary to place current and future drying into a broader perspective. Toward that end, we present a multi-proxy composite record from six well-dated and overlapping speleothems from Buraca Gloriosa (BG) cave, located in western Portugal. The coherence between the six stalagmites in this composite stalagmite record illustrates that climate (not in-cave processes) impacts speleothem isotopic values. This record provides the first high-resolution, precisely dated, terrestrial record of Holocene hydroclimate from west-central Iberia. The BG record reveals that aridity in western Portugal increased secularly from 9.0 ka BP to present, as evidenced by rising values of both carbon ($\delta$13C) and oxygen ($\delta$18O) stable isotope values. This trend tracks the decrease in Northern Hemisphere summer insolation and parallels Iberian margin sea surface temperatures (SST). The increased aridity over the Holocene is consistent with changes in Hadley Circulation and a southward migration of the Intertropical Convergence Zone (ITCZ). Centennial-scale shifts in hydroclimate are coincident with changes in total solar irradiance (TSI) after 4 ka BP. Several major drying events are evident, the most prominent of which was centered around 4.2 ka BP, a feature also noted in other Iberian climate records and coinciding with well-documented regional cultural shifts. Substantially, wetter conditions occurred from 0.8 ka BP to 0.15 ka BP, including much of the ‘Little Ice Age'. This was followed by increasing aridity toward present day. This composite stalagmite proxy record complements oceanic records from coastal Iberia, lacustrine records from inland Iberia, and speleothem records from both northern and southern Spain and depicts the spatial and temporal variability in hydroclimate in Iberia.},
author = {Thatcher, Diana L. and Wanamaker, Alan D. and Denniston, Rhawn F. and Asmerom, Yemane and Polyak, Victor J. and Fullick, Daniel and Ummenhofer, Caroline C. and Gillikin, David P. and Haws, Jonathan A.},
doi = {10.1177/0959683620908648},
issn = {14770911},
journal = {Holocene},
keywords = {Holocene,Iberia,Portugal,drought,hydroclimate,stalagmite},
number = {7},
pages = {966--981},
title = {{Hydroclimate variability from western Iberia (Portugal) during the Holocene: Insights from a composite stalagmite isotope record}},
volume = {30},
year = {2020}
}
@article{Thibodeau2018,
abstract = {Abstract The Atlantic meridional overturning circulation (AMOC) is a key component of the global climate system. Recent studies suggested a twentieth-century weakening of the AMOC of unprecedented amplitude ({\~{}}15{\%}) over the last millennium. Here we present a record of $\delta$18O in benthic foraminifera from sediment cores retrieved from the Laurentian Channel and demonstrate that the $\delta$18O trend is linked to the strength of the AMOC. In this 100-year record, the AMOC signal decreased steadily to reach its minimum value in the late 1970s, where the weakest AMOC signal then remains constant until 2000. We also present a longer $\delta$18O record of 1,500 years and highlight the uniqueness of the last century $\delta$18O trend. Moreover, the Little Ice Age period is characterized by statistically heavier $\delta$18O, suggesting a relatively weak AMOC. Implications for understanding the mechanisms driving the intensity of AMOC under global warming and high-latitude freshwater input are discussed.},
annote = {doi: 10.1029/2018GL080083},
author = {Thibodeau, Benoit and Not, Christelle and Zhu, Jiang and Schmittner, Andreas and Noone, David and Tabor, Clay and Zhang, Jiaxu and Liu, Zhengyu},
doi = {10.1029/2018GL080083},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Atlantic meridional overturning circulation,climate change,global change,ocean model,oceanography,stable isotope},
month = {nov},
number = {22},
pages = {12376--12385},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Last Century Warming Over the Canadian Atlantic Shelves Linked to Weak Atlantic Meridional Overturning Circulation}},
url = {https://doi.org/10.1029/2018GL080083},
volume = {45},
year = {2018}
}
@article{https://doi.org/10.1029/2019PA003669,
abstract = {Abstract Despite minor variations in sea surface temperature (SST) compared to other tropical regions, coupled ocean-atmosphere dynamics in the Indian Ocean cause widespread drought, wildfires, and flooding. It is unclear whether changes in the Indian Ocean mean state can support stronger SST variability and climatic extremes. Here we focus on the Last Glacial Maximum (19,000–21,000 years before present) when background oceanic conditions could have been favorable for stronger variability. Using individual foraminiferal analyses and climate model simulations, we find that seasonal and interannual SST variations in the eastern equatorial Indian Ocean were much larger during this glacial period relative to modern conditions. The increase in year-to-year variance is consistent with the emergence of an equatorial mode of climate variability, which strongly resembles the Pacific El Ni{\~{n}}o and is currently not active in the Indian Ocean.},
author = {Thirumalai, Kaustubh and DiNezio, Pedro N and Tierney, Jessica E and Puy, Martin and Mohtadi, Mahyar},
doi = {10.1029/2019PA003669},
journal = {Paleoceanography and Paleoclimatology},
number = {8},
pages = {1316--1327},
title = {{An El Ni{\~{n}}o Mode in the Glacial Indian Ocean?}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019PA003669},
volume = {34},
year = {2019}
}
@article{doi:10.1002/2016GL068130,
abstract = {Abstract Antarctic sea ice has been increasing in recent decades, but with strong regional differences in the expression of sea ice change. Declining sea ice in the Bellingshausen Sea since 1979 (the satellite era) has been linked to the observed warming on the Antarctic Peninsula, while the Ross Sea sector has seen a marked increase in sea ice during this period. Here we present a 308 year record of methansulphonic acid from coastal West Antarctica, representing sea ice conditions in the Amundsen-Ross Sea. We demonstrate that the recent increase in sea ice in this region is part of a longer trend, with an estimated {\~{}}1° northward expansion in winter sea ice extent (SIE) during the twentieth century and a total expansion of {\~{}}1.3° since 1702. The greatest reconstructed SIE occurred during the mid-1990s, with five of the past 30 years considered exceptional in the context of the past three centuries.},
author = {Thomas, Elizabeth R and Abram, Nerilie J},
doi = {10.1002/2016GL068130},
journal = {Geophysical Research Letters},
keywords = {Antarctica,ice core,sea ice reconstruction},
number = {10},
pages = {5309--5317},
title = {{Ice core reconstruction of sea ice change in the Amundsen-Ross Seas since 1702 A.D.}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GL068130},
volume = {43},
year = {2016}
}
@article{Thomas2017b,
abstract = {Here we review Antarctic snow accumulation variability, at the regional scale, over the past 1000 years. A total of 80 ice core snow accumulation records were gathered, as part of a community led project coordinated by the PAGES Antarctica 2k working group. The ice cores were assigned to seven geographical regions, separating the high accumulation coastal zones below 2000{\&}thinsp;m elevation from the dry central Antarctic Plateau. The regional composites of annual snow accumulation were evaluated against modelled surface mass balance (SMB) from RACMO2.4 and precipitation from ERA-interim reanalysis. With the exception of the Weddell Sea coast, the low-elevation composites capture the regional precipitation and SMB variability. The central Antarctic sites lack coherency and are either not representing regional precipitation or indicate the models inability to capture relevant precipitation processes in the cold, dry central plateau. The drivers of precipitation are reviewed for each region and the temporal variability and trends evaluated over the past 100, 200 and 1000 years. Our study suggests an overall increase in SMB across the grounded Antarctic ice sheet of {\~{}}{\&}thinsp;44{\&}thinsp;GT since 1800{\&}thinsp;AD, with the largest (area-weighted) contribution from the Antarctic Peninsula (AP). Only four ice core records cover the full 1000 years and suggest a decrease in snow accumulation during this period. However, our study emphasizes the importance of low elevation coastal zones (especially AP and DML), which have been underrepresented in previous investigations of temporal snow accumulation.},
author = {Thomas, Elizabeth R. and {Melchior Van Wessem}, J. and Roberts, Jason and Isaksson, Elisabeth and Schlosser, Elisabeth and Fudge, Tyler J. and Vallelonga, Paul and Medley, Brooke and Lenaerts, Jan and Bertler, Nancy and {Van Den Broeke}, Michiel R. and Dixon, Daniel A. and Frezzotti, Massimo and Stenni, Barbara and Curran, Mark and Ekaykin, Alexey A.},
doi = {10.5194/cp-13-1491-2017},
issn = {18149332},
journal = {Climate of the Past},
number = {11},
pages = {1491--1513},
title = {{Regional Antarctic snow accumulation over the past 1000 years}},
volume = {13},
year = {2017}
}
@article{geosciences9120506,
abstract = {Dramatic changes in sea ice have been observed in both poles in recent decades. However, the observational period for sea ice is short, and the climate models tasked with predicting future change in sea ice struggle to capture the current Antarctic trends. Paleoclimate archives, from marine sedimentary records and coastal Antarctic ice cores, provide a means of understanding sea ice variability and its drivers over decadal to centennial timescales. In this study, we collate published records of Antarctic sea ice over the past 2000 years (2 ka). We evaluate the current proxies and explore the potential of combining marine and ice core records to produce multi-archive reconstructions. Despite identifying 92 sea ice reconstructions, the spatial and temporal resolution is only sufficient to reconstruct circum-Antarctic sea ice during the 20th century, not the full 2 ka. Our synthesis reveals a 90 year trend of increasing sea ice in the Ross Sea and declining sea ice in the Bellingshausen, comparable with observed trends since 1979. Reconstructions in the Weddell Sea, the Western Pacific and the Indian Ocean reveal small negative trends in sea ice during the 20th century (1900–1990), in contrast to the observed sea ice expansion in these regions since 1979.},
author = {Thomas, Elizabeth R and Allen, Claire S and Etourneau, Johan and King, Amy C F and Severi, Mirko and Winton, V Holly L and Mueller, Juliane and Crosta, Xavier and Peck, Victoria L},
doi = {10.3390/geosciences9120506},
issn = {2076-3263},
journal = {Geosciences},
month = {dec},
number = {12},
pages = {506},
title = {{Antarctic Sea Ice Proxies from Marine and Ice Core Archives Suitable for Reconstructing Sea Ice over the Past 2000 Years}},
url = {https://www.mdpi.com/2076-3263/9/12/506},
volume = {9},
year = {2019}
}
@article{Thomason2018,
abstract = {We describe the construction of a continuous 38-year record of stratospheric aerosol optical properties. The Global Space-based Stratospheric Aerosol Climatology, or GloSSAC, provided the input data to the construction of the Climate Model Intercomparison Project stratospheric aerosol forcing data set (1979–2014) and we have extended it through 2016 following an identical process. GloSSAC focuses on the Stratospheric Aerosol and Gas Experiment (SAGE) series of instruments through mid-2005, and on the Optical Spectrograph and InfraRed Imager System (OSIRIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data thereafter. We also use data from other space instruments and from ground-based, air, and balloon borne instruments to fill in key gaps in the data set. The end result is a global and gap-free data set focused on aerosol extinction coefficient at 525 and 1020 nm and other parameters on an "as available" basis. For the primary data sets, we developed a new method for filling the post-Pinatubo eruption data gap for 1991–1993 based on data from the Cryogenic Limb Array Etalon Spectrometer. In addition, we developed a new method for populating wintertime high latitudes during the SAGE period employing a latitude-equivalent latitude conversion process that greatly improves the depiction of aerosol at high latitudes compared to earlier similar efforts. We report data in the troposphere only when and where it is available. This is primarily during the SAGE II period except for the most enhanced part of the Pinatubo period. It is likely that the upper troposphere during Pinatubo was greatly enhanced over non-volcanic periods and that domain remains substantially under-characterized. We note that aerosol levels during the OSIRIS/CALIPSO period in the lower stratosphere at mid- and high latitudes is routinely higher than what we observed during the SAGE II period. While this period had nearly continuous low-level volcanic activity, it is possible that the enhancement in part reflects deficiencies in the data set. We also expended substantial effort to quality assess the data set and the product is by far the best we have produced. GloSSAC version 1.0 is available in netCDF format at the NASA Atmospheric Data Center at https://eosweb.larc.nasa.gov/. GloSSAC users should cite this paper and the data set DOI (https://doi.org/10.5067/GloSSAC-L3-V1.0).},
author = {Thomason, Larry W. and Ernest, Nicholas and Mill{\'{a}}n, Luis and Rieger, Landon and Bourassa, Adam and Vernier, Jean-Paul and Manney, Gloria and Luo, Beiping and Arfeuille, Florian and Peter, Thomas},
doi = {10.5194/essd-10-469-2018},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {mar},
number = {1},
pages = {469--492},
title = {{A global space-based stratospheric aerosol climatology: 1979–2016}},
volume = {10},
year = {2018}
}
@article{doi:10.1002/2017PA003089,
abstract = {Abstract Finely laminated sediments within Bainbridge Crater Lake, Gal{\'{a}}pagos, provide a record of El Ni{\~{n}}o–Southern Oscillation (ENSO) events over the Holocene. Despite the importance of this sediment record, hypotheses for how climate variability is preserved in the lake sediments have not been tested. Here we present results of long-term monitoring of the local climate and limnology and a revised interpretation of the sediment record. Brown-green, organic-rich, siliciclastic laminae reflect warm, wet conditions typical of El Ni{\~{n}}o events, whereas carbonate and gypsum precipitate during cool, dry La Ni{\~{n}}a events and persistent dry periods, respectively. Applying this new interpretation, we find that ENSO events of both phases were generally less frequent during the mid-Holocene ({\~{}}6100–4000 calendar years B.P.) relative to the last {\~{}}1500 calendar years. Abundant carbonate laminations between 3500 and 3000 calendar years B.P. imply that conditions in the Gal{\'{a}}pagos region were cool and dry during this period when the tropical Pacific E-W sea surface temperature (SST) gradient likely strengthened. The frequency of El Ni{\~{n}}o and La Ni{\~{n}}a events then intensified dramatically around 1750–2000 calendar years B.P., consistent with a weaker SST gradient and an increased frequency of ENSO events in other regional records. This strong interannual variability persisted until {\~{}}700 calendar years B.P., when ENSO-related variability at the lake decreased as the SST gradient strengthened. Persistent, dry conditions then dominated between 300 and 50 calendar years B.P. (A.D. 1650–1900, ± {\~{}}100 years), whereas wetter conditions and frequent El Ni{\~{n}}o events dominated in the most recent century.},
author = {Thompson, Diane M and Conroy, Jessica L and Collins, Aaron and Hlohowskyj, Stephan R and Overpeck, Jonathan T and Riedinger-Whitmore, Melanie and Cole, Julia E and Bush, Mark B and Whitney, H and Corley, Timothy L and Kannan, Miriam Steinitz},
doi = {10.1002/2017PA003089},
journal = {Paleoceanography},
keywords = {El Ni{\~{n}}o–Southern Oscillation (ENSO),Gal{\'{a}}pagos archipelago,climate variability,mid-Holocene,monitoring,tropical Pacific Ocean},
number = {8},
pages = {903--922},
title = {{Tropical Pacific climate variability over the last 6000 years as recorded in Bainbridge Crater Lake, Gal{\'{a}}pagos}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017PA003089},
volume = {32},
year = {2017}
}
@article{Thompson2013,
abstract = {The northeastern United States is a predominately-forested region that, like most of the eastern U.S., has undergone a 400-year history of intense logging, land clearance for agriculture, and natural reforestation. This setting affords the opportunity to address a major ecological question: How similar are today's forests to those existing prior to European colonization? Working throughout a nine-state region spanning Maine to Pennsylvania, we assembled a comprehensive database of archival land-survey records describing the forests at the time of European colonization. We compared these records to modern forest inventory data and described: (1) the magnitude and attributes of forest compositional change, (2) the geography of change, and (3) the relationships between change and environmental factors and historical land use. We found that with few exceptions, notably the American chestnut, the same taxa that made up the pre-colonial forest still comprise the forest today, despite ample opportunities for species invasion and loss. Nonetheless, there have been dramatic shifts in the relative abundance of forest taxa. The magnitude of change is spatially clustered at local scales ({\textless}125 km) but exhibits little evidence of regional-scale gradients. Compositional change is most strongly associated with the historical extent of agricultural clearing. Throughout the region, there has been a broad ecological shift away from late successional taxa, such as beech and hemlock, in favor of early- and mid-successional taxa, such as red maple and poplar. Additionally, the modern forest composition is more homogeneous and less coupled to local climatic controls.},
author = {Thompson, Jonathan R. and Carpenter, Dunbar N. and Cogbill, Charles V. and Foster, David R.},
doi = {10.1371/journal.pone.0072540},
editor = {Bond-Lamberty, Ben},
isbn = {1932-6203},
issn = {1932-6203},
journal = {PLOS ONE},
month = {sep},
number = {9},
pages = {e72540},
pmid = {24023749},
title = {{Four Centuries of Change in Northeastern United States Forests}},
url = {https://dx.plos.org/10.1371/journal.pone.0072540},
volume = {8},
year = {2013}
}
@article{Thompson2008,
author = {Thompson, David W J and Kennedy, John J and Wallace, John M and Jones, Phil D},
doi = {10.1038/nature06982},
journal = {Nature},
month = {may},
pages = {646},
publisher = {Nature Publishing Group},
title = {{A large discontinuity in the mid-twentieth century in observed global-mean surface temperature}},
url = {http://dx.doi.org/10.1038/nature06982 http://10.0.4.14/nature06982},
volume = {453},
year = {2008}
}
@article{Thornalley2018,
abstract = {The Atlantic meridional overturning circulation (AMOC) is a system of ocean currents that has an essential role in Earth's climate, redistributing heat and influencing the carbon cycle1, 2. The AMOC has been shown to be weakening in recent years 1 ; this decline may reflect decadal-scale variability in convection in the Labrador Sea, but short observational datasets preclude a longer-term perspective on the modern state and variability of Labrador Sea convection and the AMOC1, 3–5. Here we provide several lines of palaeo-oceanographic evidence that Labrador Sea deep convection and the AMOC have been anomalously weak over the past 150 years or so (since the end of the Little Ice Age, LIA, approximately ad 1850) compared with the preceding 1,500 years. Our palaeoclimate reconstructions indicate that the transition occurred either as a predominantly abrupt shift towards the end of the LIA, or as a more gradual, continued decline over the past 150 years; this ambiguity probably arises from non-AMOC influences on the various proxies or from the different sensitivities of these proxies to individual components of the AMOC. We suggest that enhanced freshwater fluxes from the Arctic and Nordic seas towards the end of the LIA—sourced from melting glaciers and thickened sea ice that developed earlier in the LIA—weakened Labrador Sea convection and the AMOC. The lack of a subsequent recovery may have resulted from hysteresis or from twentieth-century melting of the Greenland Ice Sheet 6 . Our results suggest that recent decadal variability in Labrador Sea convection and the AMOC has occurred during an atypical, weak background state. Future work should aim to constrain the roles of internal climate variability and early anthropogenic forcing in the AMOC weakening described here.},
author = {Thornalley, David J.R. and Oppo, Delia W. and Ortega, Pablo and Robson, Jon I. and Brierley, Chris M. and Davis, Renee and Hall, Ian R. and Moffa-Sanchez, Paola and Rose, Neil L. and Spooner, Peter T. and Yashayaev, Igor and Keigwin, Lloyd D.},
doi = {10.1038/s41586-018-0007-4},
isbn = {4158601800},
issn = {14764687},
journal = {Nature},
pages = {227--230},
pmid = {29643484},
title = {{Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years}},
volume = {556},
year = {2018}
}
@article{Thornalley2013,
abstract = {Six Ocean Drilling Program (ODP) sites, in the Northwest Atlantic have been used to investigate kinematic and chemical changes in the ?Western Boundary Undercurrent? (WBUC) during the development of full glacial conditions across the Marine Isotope Stage 5a/4 boundary ({\~{}}70,000?years ago). Sortable silt mean grain size measurements are employed to examine changes in near bottom flow speeds, together with carbon isotopes measured in benthic foraminifera and {\%} planktic foraminiferal fragmentation as proxies for changes in water-mass chemistry. A depth transect of cores, spanning 1.8?4.6?km depth, allows changes in both the strength and depth of the WBUC to be constrained across millennial scale events. measurements reveal that the flow speed structure of the WBUC during warm intervals (?interstadials?) was comparable to modern (Holocene) conditions. However, significant differences are observed during cold intervals, with higher relative flow speeds inferred for the shallow component of the WBUC ({\~{}}2?km depth) during all cold ?stadial? intervals (including Heinrich Stadial 6), and a substantial weakening of the deep component ({\~{}}3?4?km) during full glacial conditions. Our results therefore reveal that the onset of full glacial conditions was associated with a regime shift to a shallower mode of circulation (involving Glacial North Atlantic Intermediate Water) that was quantitatively distinct from preceding cold stadial events. Furthermore, our chemical proxy data show that the physical response of the WBUC during the last glacial inception was probably coupled to basin-wide changes in the water-mass composition of the deep Northwest Atlantic.},
annote = {doi: 10.1002/palo.20025},
author = {Thornalley, David J R and Barker, Stephen and Becker, Julia and Hall, Ian R and Knorr, Gregor},
doi = {10.1002/palo.20025},
issn = {0883-8305},
journal = {Paleoceanography},
keywords = {Abrupt climate change,Glacial,North Atlantic,Ocean circulation,Western Boundary Undercurrent},
month = {jun},
number = {2},
pages = {253--262},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Abrupt changes in deep Atlantic circulation during the transition to full glacial conditions}},
url = {https://doi.org/10.1002/palo.20025},
volume = {28},
year = {2013}
}
@article{Thornalley2011,
abstract = {Paired Mg/Ca-{\$}\delta{\$}18O measurements on multiple species of planktic foraminifera are combined with published benthic isotope records from south of Iceland in order to assess the role North Atlantic freshwater input played in determining the evolution of hydrography and climate during the last deglaciation. We demonstrate that Globigerina bulloides and Globorotalia inflata are restricted to intervals when warm Atlantic waters reached the area south of Iceland, and therefore Mg/Ca-{\$}\delta{\$}18O data from these species monitor changes in the temperature and seawater {\$}\delta{\$}18O signature of the northward inflow of Atlantic water to the area. In contrast, Neogloboquadrina pachyderma (sinistral) calcifies within local subpolar/polar waters and new Mg/Ca-{\$}\delta{\$}18O analyses on this species document changes in this water mass. We observe two major surface ocean events during Heinrich Stadial 1 ({\$}{\~{}}{\$}17-14.7ka): an early freshening of the Atlantic Inflow ({\$}{\~{}}{\$}17-16ka), and a later interval (16-14.7ka) of local surface freshening, sea-ice formation and brine rejection that was associated with a further reduction in deep ocean ventilation. Centennial-scale cold intervals during the B{\o}lling-Aller{\o}d (BA, 14.7-12.9ka) were likely triggered by the rerouting of North American continental run-off during ice-sheet retreat. However, the relative effects of these freshwater events on deep ventilation and climate south of Iceland appear to have been modulated by the background climate deterioration. Two freshwater events occurred during the Younger Dryas cold interval (YD, 12.9-11.7ka), both accompanied by a reduction in deep ventilation south of Iceland: an early YD freshening of the Atlantic Inflow and local subpolar/polar waters, and a late YD ice-rafted detritus event that was possibly related to brine formation south of Iceland. Based on our reconstructions, the strengthening of the Atlantic Meridional Overturning Circulation at the onset of BA and Holocene may have been promoted by the subsurface warming of subpolar/polar water, brine formation that drew warm saline Atlantic water northwards, and the high background salinity of the Atlantic Inflow. {\textcopyright}2010 Elsevier B.V.},
author = {Thornalley, David J R and Elderfield, Harry and McCave, I Nick},
doi = {10.1016/j.gloplacha.2010.06.003},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Climate,Deglaciation,Melt water,North Atlantic,Salinity,Temperature},
month = {dec},
number = {3-4},
pages = {163--175},
title = {{Reconstructing North Atlantic deglacial surface hydrography and its link to the Atlantic overturning circulation}},
volume = {79},
year = {2011}
}
@article{doi:10.1002/2015JD024584,
author = {Thorne, P W and Donat, M G and Dunn, R J H and Williams, C N and Alexander, L V and Caesar, J and Durre, I and Harris, I and Hausfather, Z and Jones, P D and Menne, M J and Rohde, R and Vose, R S and Davy, R and Klein-Tank, A M G and Lawrimore, J H and Peterson, T C and Rennie, J J},
doi = {10.1002/2015JD024584},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {assessment,diurnal temperature range,intercomparison,trends},
number = {10},
pages = {5138--5158},
title = {{Reassessing changes in diurnal temperature range: Intercomparison and evaluation of existing global data set estimates (2016b)}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015JD024584},
volume = {121},
year = {2016}
}
@article{doi:10.1002/2015JD024583,
author = {Thorne, P W and Menne, M J and Williams, C N and Rennie, J J and Lawrimore, J H and Vose, R S and Peterson, T C and Durre, I and Davy, R and Esau, I and Klein-Tank, A M G and Merlone, A},
doi = {10.1002/2015JD024583},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {diurnal temperature range,homogeneity,trends},
number = {10},
pages = {5115--5137},
title = {{Reassessing changes in diurnal temperature range: A new data set and characterization of data biases (2016a)}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015JD024583},
volume = {121},
year = {2016}
}
@article{Tian2017b,
abstract = {AbstractThe cause of the change in amplitude of the El Ni{\~{n}}o–Southern Oscillation (ENSO) during the mid-Holocene was investigated by diagnosing the model simulations that participated in the Paleoclimate Modelling Intercomparison Project Phases 2 and 3. Consistent with paleoclimate records, 20 out of the 28 models reproduced a weaker-than-pre-industrial ENSO amplitude during the mid-Holocene. Two representative models were then selected to explore the underlying mechanisms of air–sea feedback processes. A mixed layer heat budget diagnosis indicated that the weakened ENSO amplitude was primarily attributed to the decrease in the Bjerknes thermocline feedback, while the meridional advective feedback also played a role. During the mid-Holocene, the thermocline response to a unit anomalous zonal wind stress forcing in the equatorial Pacific weakened in both models because of the increased ENSO meridional scale. A further investigation revealed that the greater ENSO meridional width was caused by the strengthening of the Pacific subtropical cell, which was attributed to the enhanced mean trade wind that resulted from the intensified Asian and African monsoon rainfall and associated large-scale east–west circulation in response to the mid-Holocene orbital forcing.},
author = {Tian, Zhiping and Li, Tim and Jiang, Dabang and Chen, Lin},
doi = {10.1175/JCLI-D-16-0899.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Atmosphere-ocean interaction,Climate models,ENSO,Interannual variability,Model evaluation/performance,Pacific Ocean},
number = {17},
pages = {7049--7070},
title = {{Causes of ENSO weakening during the mid-Holocene}},
volume = {30},
year = {2017}
}
@article{TierneyJ.E.ZhuJ.KingJ.MalevichS.B.HakimG.J.Poulsen9999,
author = {Tierney, J.E. and Zhu, J. and King, J. and Malevich, S.B. and Hakim, G.J. and Poulsen, C.J.},
doi = {10.1038/s41586-020-2617-x},
journal = {Nature},
pages = {569--573},
title = {{Glacial cooling and climate sensitivity revisited}},
url = {https://doi.org/10.1038/s41586-020-2617-x},
volume = {584},
year = {2020}
}
@article{Tierney2015,
abstract = {The recent decline in Horn of Africa rainfall during the March–May “long rains” season has fomented drought and famine, threatening food security in an already vulnerable region. Some attribute this decline to anthropogenic forcing, whereas others maintain that it is a feature of internal climate variability. We show that the rate of drying in the Horn of Africa during the 20th century is unusual in the context of the last 2000 years, is synchronous with recent global and regional warming, and therefore may have an anthropogenic component. In contrast to 20th century drying, climate models predict that the Horn of Africa will become wetter as global temperatures rise. The projected increase in rainfall mainly occurs during the September–November “short rains” season, in response to large-scale weakening of the Walker circulation. Most of the models overestimate short rains precipitation while underestimating long rains precipitation, causing the Walker circulation response to unrealistically dominate the annual mean. Our results highlight the need for accurate simulation of the seasonal cycle and an improved understanding of the dynamics of the long rains season to predict future rainfall in the Horn of Africa.},
author = {Tierney, Jessica E. and Ummenhofer, Caroline C. and DeMenocal, Peter B.},
doi = {10.1126/sciadv.1500682},
issn = {2375-2548},
journal = {Science Advances},
month = {oct},
number = {9},
pages = {e1500682},
title = {{Past and future rainfall in the Horn of Africa}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.1500682},
volume = {1},
year = {2015}
}
@article{Tilinina2013a,
author = {Tilinina, N and Gulev, S K and Rudeva, I and Koltermann, P},
doi = {10.1175/JCLI-D-12-00777.1},
journal = {Journal of Climate},
pages = {6419--6438},
title = {{Comparing Cyclone Life Cycle Characteristics and Their Interannual Variability in Different Reanalyses}},
volume = {26},
year = {2013}
}
@article{Timmermann2018,
abstract = {El Ni{\~{n}}o events are characterized by surface warming of the tropical Pacific Ocean and weakening of equatorial trade winds that occur every few years. Such conditions are accompanied by changes in atmospheric and oceanic circulation, affecting global climate, marine and terrestrial ecosystems, fisheries and human activities. The alternation of warm El Ni{\~{n}}o and cold La Ni{\~{n}}a conditions, referred to as the El Ni{\~{n}}o–Southern Oscillation (ENSO), represents the strongest year-to-year fluctuation of the global climate system. Here we provide a synopsis of our current understanding of the spatio-temporal complexity of this important climate mode and its influence on the Earth system.},
author = {Timmermann, Axel and An, Soon-Il and Kug, Jong-Seong and Jin, Fei-Fei and Cai, Wenju and Capotondi, Antonietta and Cobb, Kim and Lengaigne, Matthieu and McPhaden, Michael J and Stuecker, Malte F and Stein, Karl and Wittenberg, Andrew T and Yun, Kyung-Sook and Bayr, Tobias and Chen, Han-Ching and Chikamoto, Yoshimitsu and Dewitte, Boris and Dommenget, Dietmar and Grothe, Pamela and Guilyardi, Eric and Ham, Yoo-Geun and Hayashi, Michiya and Ineson, Sarah and Kang, Daehyun and Kim, Sunyong and Kim, WonMoo and Lee, June-Yi and Li, Tim and Luo, Jing-Jia and McGregor, Shayne and Planton, Yann and Power, Scott and Rashid, Harun and Ren, Hong-Li and Santoso, Agus and Takahashi, Ken and Todd, Alexander and Wang, Guomin and Wang, Guojian and Xie, Ruihuang and Yang, Woo-Hyun and Yeh, Sang-Wook and Yoon, Jinho and Zeller, Elke and Zhang, Xuebin},
doi = {10.1038/s41586-018-0252-6},
issn = {1476-4687},
journal = {Nature},
number = {7715},
pages = {535--545},
title = {{El Ni{\~{n}}o–Southern Oscillation complexity}},
url = {https://doi.org/10.1038/s41586-018-0252-6},
volume = {559},
year = {2018}
}
@article{Tokarska2019a,
abstract = {Recent estimates of the amount of carbon dioxide that can still be emitted while achieving the Paris Agreement temperature goals are larger than previously thought. One potential reason for these larger estimates may be the different temperature metrics used to estimate the observed global mean warming for the historical period, as they affect the size of the remaining carbon budget. Here we explain the reasons behind these remaining carbon budget increases, and discuss how methodological choices of the global mean temperature metric and the reference period influence estimates of the remaining carbon budget. We argue that the choice of the temperature metric should depend on the domain of application. For scientific estimates of total or remaining carbon budgets, globally averaged surface air temperature estimates should be used consistently for the past and the future. However, when used to inform the achievement of the Paris Agreement goal, a temperature metric consistent with the science that was underlying and directly informed the Paris Agreement should be applied. The resulting remaining carbon budgets should be calculated using the appropriate metric or adjusted to reflect these differences among temperature metrics. Transparency and understanding of the implications of such choices are crucial to providing useful information that can bridge the science–policy gap.},
author = {Tokarska, Katarzyna B and Schleussner, Carl-Friedrich and Rogelj, Joeri and Stolpe, Martin B and Matthews, H Damon and Pfleiderer, Peter and Gillett, Nathan P},
doi = {10.1038/s41561-019-0493-5},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {12},
pages = {964--971},
title = {{Recommended temperature metrics for carbon budget estimates, model evaluation and climate policy}},
url = {https://doi.org/10.1038/s41561-019-0493-5},
volume = {12},
year = {2019}
}
@article{Tokinaga2011a,
abstract = {Seasonal and interannual variations of the equatorial cold tongue are defining features of the tropical Atlantic Ocean. An analysis of bias-corrected observations suggests that cold-tongue variability has weakened over the past six decades.},
author = {Tokinaga, Hiroki and Xie, Shang-Ping},
doi = {10.1038/ngeo1078},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {4},
pages = {222--226},
title = {{Weakening of the equatorial Atlantic cold tongue over the past six decades}},
url = {https://doi.org/10.1038/ngeo1078},
volume = {4},
year = {2011}
}
@article{Tomita2019a,
author = {Tomita, Hiroyuki and Hihara, Tsutomu and Kako, Shin'ichiro and Kubota, Masahisa and Kutsuwada, Kunio},
doi = {10.1007/s10872-018-0493-x},
isbn = {0123456789},
issn = {0916-8370},
journal = {Journal of Oceanography},
keywords = {Air-sea interaction,Air–sea flux,Global climate,J-OFURO,Remote sensing,Surface freshwater flux,Surface heat flux,Surface momentum flux,air,air-sea interaction,global climate,j-ofuro,remote sensing,sea flux,surface freshwater flux,surface heat flux,surface momentum flux},
month = {apr},
number = {2},
pages = {171--194},
publisher = {Springer Japan},
title = {{An introduction to J-OFURO3, a third-generation Japanese ocean flux data set using remote-sensing observations}},
url = {https://doi.org/10.1007/s10872-018-0493-x http://link.springer.com/10.1007/s10872-018-0493-x},
volume = {75},
year = {2019}
}
@article{Toohey2017,
abstract = {The injection of sulfur into the stratosphere by explosive volcanic eruptions is the cause of significant climate variability. Based on sulfate records from a suite of ice cores from Greenland and Antarctica, the eVolv2k database includes estimates of the magnitudes and approximate source latitudes of major volcanic stratospheric sulfur injection (VSSI) events from 500 BCE to 1900 CE, constituting an update of prior reconstructions and an extension of the record by 1000 years. The database incorporates improvements to the ice core records (in terms of synchronisation and dating) and refinements to the methods used to estimate VSSI from ice core records, and it includes first estimates of the random uncertainties in VSSI values. VSSI estimates for many of the largest eruptions, including Samalas (1257), Tambora (1815), and Laki (1783), are within 10 {\{}{\%}{\}} of prior estimates. A number of strong events are included in eVolv2k which are largely underestimated or not included in earlier VSSI reconstructions, including events in 540, 574, 682, and 1108 CE. The long-term annual mean VSSI from major volcanic eruptions is estimated to be ∼ 0.5 Tg [S] yr−1, ∼ 50 {\{}{\%}{\}} greater than a prior reconstruction due to the identification of more events and an increase in the magnitude of many intermediate events. A long-term latitudinally and monthly resolved stratospheric aerosol optical depth (SAOD) time series is reconstructed from the eVolv2k VSSI estimates, and the resulting global mean SAOD is found to be similar (within 33 {\{}{\%}{\}}) to a prior reconstruction for most of the largest eruptions. The long-term (500 BCE–1900 CE) average global mean SAOD estimated from the eVolv2k VSSI estimates including a constant background injection of stratospheric sulfur is ∼ 0.014, 30 {\{}{\%}{\}} greater than a prior reconstruction. These new long-term reconstructions of past VSSI and SAOD variability give context to recent volcanic forcing, suggesting that the 20th century was a period of somewhat weaker than average volcanic forcing, with current best estimates of 20th century mean VSSI and SAOD values being 25 and 14 {\{}{\%}{\}} less, respectively, than the mean of the 500 BCE to 1900 CE period. The reconstructed VSSI and SAOD data are available at https://doi.org/10.1594/WDCC/eVolv2k{\{}{\_}{\}}v2.},
author = {Toohey, Matthew and Sigl, Michael},
doi = {10.5194/essd-9-809-2017},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {nov},
number = {2},
pages = {809--831},
title = {{Volcanic stratospheric sulfur injections and aerosol optical depth from 500 BCE to 1900 CE}},
volume = {9},
year = {2017}
}
@article{Toucanne2015,
abstract = {The role of mid-latitude precipitation in the hydrological forcing leading to the deposition of sapropels in the Mediterranean Sea remains unclear. The new GDEC-4-2 borehole, East Corsica margin (northern Tyrrhenian Sea), provides the first precisely dated evidence for enhanced rainfall in the Western Mediterranean during warm intervals of interglacial periods over the last 547 kyr. Comparison of GDEC-4-2 proxy records with pollen sequences and speleothems from the central and eastern Mediterranean reveals that these pluvial events were regional in character and occurred probably in response to the intensification of the Mediterranean storm track along the northern Mediterranean borderlands in autumn/winter. Our dataset suggests that the timing of maxima of the Mediterranean autumn/winter storm track precipitation coincide with that of the North African summer monsoon and sapropel deposition. Besides highlighting a close coupling between mid- and low-latitude hydrological changes, our findings suggest that during warm intervals of interglacial periods the reduced sea-surface water salinities, together with the high flux of nutrient and organic matter, produced by the monsoonal Nile (and wadi-systems) floods, were maintained throughout the winter by the Mediterranean rainfall. This provides an important additional constraint on the hydrological perturbation causing sapropel formation.},
author = {Toucanne, Samuel and {Angue Minto'o}, Charlie Morelle and Fontanier, Christophe and Bassetti, Maria Angela and Jorry, Stephan J. and Jouet, Gwena{\"{e}}l},
doi = {10.1016/j.quascirev.2015.10.016},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Interglacials,Mediterranean,Rainfall,Sapropel},
pages = {178--195},
title = {{Tracking rainfall in the northern Mediterranean borderlands during sapropel deposition}},
volume = {129},
year = {2015}
}
@article{https://doi.org/10.1029/2019PA003773,
abstract = {Abstract The Antarctic Circumpolar Current (ACC) is the world's largest current system connecting all three major basins of the global ocean. Our knowledge of glacial-interglacial changes in ACC dynamics in the southeast Pacific is not well constrained and presently only based on reconstructions covering the last glacial cycle. Here we use a combination of mean sortable silt grain size of the terrigenous sediment fraction (10–63 $\mu$m, ) and X-ray fluorescence scanner-derived Zr/Rb ratios as flow strength proxies to examine ACC variations at the Pacific entrance to the Drake Passage (DP) in the vicinity of the Subantarctic Front. Our results indicate that at the DP entrance, ACC strength varied by {\~{}}6–16{\%} on glacial-interglacial time scales, yielding higher current speeds during interglacial times and reduced current speeds during glacials. We provide evidence that previous observations of a reduction in DP throughflow during the last glacial period are part of a consistent pattern extending for at least the last 1.3 Ma. The orbital-scale cyclicity follows well-known global climate changes from prevailing ca. 41-kyr cycles in the early part of the record (1.3 Ma to 850 ka; marine isotope stage 21) across the mid-Pleistocene transition into the middle and late Pleistocene 100-kyr world. A comparison to a bottom water flow record from the deep western boundary current off New Zealand (Ocean Drilling Program Site 1123) reveals anti-phased changes between the two sites. The enhanced supply of deep water along the DP and into the Atlantic Ocean during interglacials corresponds to a weakened flow of the SW Pacific deep western boundary current.},
annote = {e2019PA003773 2019PA003773},
author = {Toyos, Mar{\'{i}}a H and Lamy, Frank and Lange, Carina B and Lembke-Jene, Lester and Saavedra-Pellitero, Mariem and Esper, Oliver and Arz, Helge W},
doi = {10.1029/2019PA003773},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Antarctic Circumpolar Current,Drake Passage,Zr/Rb,orbital-scale variations,sortable silt},
number = {7},
pages = {e2019PA003773},
title = {{Antarctic Circumpolar Current Dynamics at the Pacific Entrance to the Drake Passage Over the Past 1.3 Million Years}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019PA003773},
volume = {35},
year = {2020}
}
@article{doi:10.1175/JAMC-D-16-0136.1,
author = {Tradowsky, Jordis S and Burrows, Chris P and Healy, Sean B and Eyre, John R},
doi = {10.1175/JAMC-D-16-0136.1},
journal = {Journal of Applied Meteorology and Climatology},
number = {6},
pages = {1643--1661},
title = {{A New Method to Correct Radiosonde Temperature Biases Using Radio Occultation Data}},
url = {https://doi.org/10.1175/JAMC-D-16-0136.1},
volume = {56},
year = {2017}
}
@article{Trammell2015,
author = {Trammell, James H. and Jiang, Xun and Li, Liming and Liang, Maochang and Li, Mao and Zhou, Jing and Fetzer, Eric and Yung, Yuk},
doi = {10.1155/2015/981092},
issn = {16879317},
journal = {Advances in Meteorology},
number = {981092},
pages = {1--9},
title = {{Investigation of Precipitation Variations over Wet and Dry Areas from Observation and Model}},
volume = {2015},
year = {2015}
}
@article{Treat2018,
abstract = {The history of permafrost aggradation and thaw in northern peatlands can serve as an indicator of regional climatic history in regions where records are sparse. We infer regional trends in the timing of permafrost aggradation and thaw in North American and Eurasian peatland ecosystems based on plant macrofossils and peat properties using existing peat core records from more than 250 cores. Results indicate that permafrost was continuously present in peatlands during the last 6000 years in some present-day continuous permafrost zones and formed after 6000 BP in peatlands in the isolated to discontinuous permafrost regions. Rates of permafrost aggradation in peatlands generally increased after 3000 BP and were greatest between 750 and 0 BP, corresponding with neoglacial cooling and the Little Ice Age (LIA), respectively. Peak periods of permafrost thaw occurred after 250 BP, when permafrost aggradation in peatlands reached its maximum extent and as temperatures began warming after the LIA, suggesting that p...},
author = {Treat, Claire C. and Jones, Miriam C.},
doi = {10.1177/0959683617752858},
issn = {14770911},
journal = {Holocene},
keywords = {bog,boreal,fen,macrofossils,peatlands,permafrost,synthesis,taiga,tundra},
number = {6},
pages = {998--1010},
title = {{Near-surface permafrost aggradation in Northern Hemisphere peatlands shows regional and global trends during the past 6000 years}},
volume = {28},
year = {2018}
}
@article{Trenberth2017,
abstract = {{\{}{\textcopyright}{\}}2017. The Authors.The Atlantic Meridional Overturning Circulation plays a major role in moving heat and carbon around in the ocean. A new estimate of ocean heat transports for 2000 through 2013 throughout the Atlantic is derived. Top-of-atmosphere radiation is combined with atmospheric reanalyses to estimate surface heat fluxes and combined with vertically integrated ocean heat content to estimate ocean heat transport divergence as a residual. Atlantic peak northward ocean heat transports average 1.18{\{}$\backslash$textpm{\}}0.13PW (1 sigma) at 15{\{}$\backslash$textdegree{\}}N but vary considerably in latitude and time. Results agree well with observational estimates at 26.5{\{}$\backslash$textdegree{\}}N from the RAPID array, but for 2004-2013 the meridional heat transport is 1.00{\{}$\backslash$textpm{\}}0.11PW versus 1.23{\{}$\backslash$textpm{\}}0.11PW for RAPID. In addition, these results have no hint of a trend, unlike the RAPID results. Strong westerlies north of a meridian drive ocean currents and an ocean heat loss into the atmosphere that is exacerbated by a decrease in ocean heat transport northward.},
author = {Trenberth, Kevin E. and Fasullo, John T.},
doi = {10.1002/2016GL072475},
isbn = {0094-8276},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {4},
pages = {1919--1927},
pmid = {20944749},
title = {{Atlantic meridional heat transports computed from balancing Earth's energy locally}},
volume = {44},
year = {2017}
}
@article{Trouet2018,
author = {Trouet, V and Babst, F and Meko, M},
doi = {10.1038/s41467-017-02699-3},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {180},
title = {{Recent enhanced high-summer North Atlantic Jet variability emerges from three-century context}},
url = {http://www.nature.com/articles/s41467-017-02699-3},
volume = {9},
year = {2018}
}
@article{MK2013,
abstract = {ABSTRACT: Characteristics of the spring and fall phytoplankton blooms in spawning areas on the Scotian Shelf, Canada, were estimated from remote sensing data. These blooms, along with anomalies in the North Atlantic Oscillation, were used to explain variation in the recruitment of 4 populations of cod and haddock. We tested the effects of the timing of the bloom using the chlorophyll a (chl a) signal, the maximum amount of chl a, the timing of the diatom bloom, and the maximum relative dominance of diatoms on the recruitment (to Age 1) of cod and haddock on the Scotian Shelf. Models were run separately for the effects of the spring and fall blooms. Only 3 of 10 models tested (0-lag) explained significant (80 to 92{\%}) variation in recruitment. However, the performance of these models was not consistent across populations or species, suggesting that generalities about how spring and fall phytoplankton blooms affect recruitment cannot yet be made. The differences among models suggest that fish larvae are probably adapted locally to food production and thus indirectly to the characteristics of the phytoplankton bloom, which in turn are influenced by regional (meso-scale) oceanographic conditions.},
annote = {10.3354/meps10451},
author = {Trzcinski, MK and Devred, E and Platt, T and Sathyendranath, S},
doi = {10.3354/meps10451},
issn = {0171-8630},
journal = {Marine Ecology Progress Series},
month = {oct},
pages = {187--197},
title = {{Variation in ocean colour may help predict cod and haddock recruitment}},
url = {http://www.int-res.com/abstracts/meps/v491/p187-197/},
volume = {491},
year = {2013}
}
@article{Tschudi2016,
abstract = {Recent satellite observations yield estimates of the distribution of sea ice thickness across the entire Arctic Ocean. While these sensors were only placed in operation within the last few years, information from other sensors may assist us with estimating the distribution of sea ice thickness in the Arctic beginning in the 1980s. A previous study found that the age of sea ice is correlated to sea ice thickness from 2003 to 2006, but an extension of the temporal analysis is needed to better quantify this relationship and its variability from year to year. Estimates of the ice age/thickness relationship may allow the thickness record to be extended back to 1985, the beginning of our ice age dataset. Comparisons of ice age and thickness estimates derived from both ICESat (2004–2008) and IceBridge (2009–2015) reveal that the relationship between age and thickness differs between these two campaigns, due in part to the difference in area of coverage. Nonetheless, sea ice thickness and age exhibit a direct relationship when compared on pan-Arctic or regional spatial scales.},
author = {Tschudi, Mark A. and Stroeve, Julienne C. and Stewart, J. Scott},
doi = {10.3390/rs8060457},
issn = {20724292},
journal = {Remote Sensing},
keywords = {Cryosphere,Remote sensing,Sea ice},
number = {6},
pages = {457},
title = {{Relating the Age of Arctic Sea Ice to its Thickness, as Measured during NASA's ICESat and IceBridge Campaigns}},
volume = {8},
year = {2016}
}
@article{Tseng2019,
abstract = {Equatorial Rossby waves (ERWs) are manifest as westward-propagating, planetary-scale waves that feature a symmetric pair of pressure and zonal wind fields about the equator. ERWs can modulate tropical convective activity, especially in South Asia and the Maritime Continents, and represent an important mode of intraseasonal variability additional to the Madden-Julian Oscillation. Changes in the frequency and intensity of ERWs during the recent decades were investigated based on observations of tropospheric winds and tropical convection. Spectral analyses indicated that ERWs appear to have intensified especially in the upper troposphere; this is associated with increased convective activity located off the equator. The strengthening and westward shift of the Walker circulation observed in the recent decades acted to increase the tropical vertical westerly shear and, subsequently, may contribute to the increased ERW activity. Further investigation on the dynamical process of the vertical zonal shear enhancement will improve the understanding of the changing ERW characteristics.},
author = {Tseng, Wan Ling and {Simon Wang}, S. Y. and Hsu, Huang-Hsiung and Meyer, Jonathan D.D.},
doi = {10.3319/TAO.2019.01.18.02},
issn = {23117680},
journal = {Terrestrial, Atmospheric and Oceanic Sciences},
keywords = {ERWs,Equatorial Rossby waves,Walker circulation,Wind shear},
number = {4},
pages = {563--574},
title = {{Intensification of the decadal activity in Equatorial Rossby Waves and linkage to changing tropical circulation}},
volume = {30},
year = {2019}
}
@article{Tsubouchi2021,
abstract = {Warm water of subtropical origin flows northward in the Atlantic Ocean and transports heat to high latitudes. This poleward heat transport has been implicated as one possible cause of the declining sea-ice extent and increasing ocean temperatures across the Nordic Seas and the Arctic Ocean, but robust estimates are still lacking. Here, we use a box inverse model and more than 20 years of volume transport measurements to show that the mean ocean heat transport was 305 ± 26 TW for 1993–2016. A significant increase of 21 TW occurred after 2001, which is sufficient to account for the recent accumulation of heat in the northern seas. Ocean heat transport may therefore have been a major contributor to climate change since the late 1990s. This increased heat transport contrasts with the Atlantic Meridional Overturning Circulation (AMOC) slowdown at mid-latitudes and indicates a discontinuity of the overturning circulation measured at different latitudes in the Atlantic Ocean.},
author = {Tsubouchi, Takamasa and V{\aa}ge, Kjetil and Hansen, Bogi and Larsen, Karin Margretha H and {\O}sterhus, Svein and Johnson, Clare and J{\'{o}}nsson, Steingr{\'{i}}mur and Valdimarsson, H{\'{e}}ðinn},
doi = {10.1038/s41558-020-00941-3},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {1},
pages = {21--26},
title = {{Increased ocean heat transport into the Nordic Seas and Arctic Ocean over the period 1993–2016}},
url = {https://doi.org/10.1038/s41558-020-00941-3},
volume = {11},
year = {2021}
}
@misc{Turner2018,
abstract = {The Paleocene-Eocene Thermal Maximum (PETM, approx. 56 Ma) provides a test case for investigating how the Earth system responds to rapid greenhouse gas-driven warming. However, current rates of carbon emissions are approximately 10 Pg C yr-1, whereas those proposed for the PETM span orders of magnitude-from ≪1 Pg C yr-1 to greater than the anthropogenic rate. Emissions rate estimates for the PETM are hampered by uncertainty over the total mass of PETM carbon released as well as the PETM onset duration. Here, I review constraints on the onset duration of the carbon isotope excursion (CIE) that is characteristic of the event with a focus on carbon cycle model-based attempts that forgo the need for a traditional sedimentary age model. I also review and compare existing PETM carbon input scenarios employing the Earth system model cGENIE and suggest another possibility-that abrupt input of an isotopically depleted carbon source combined with elevated volcanic outgassing over a longer interval can together account for key features of the PETM CIE.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.},
author = {Turner, Sandra Kirtland},
booktitle = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
doi = {10.1098/rsta.2017.0082},
issn = {1364503X},
number = {2130},
pages = {20170082},
publisher = {Royal Society Publishing},
title = {{Constraints on the onset duration of the Paleocene-Eocene Thermal Maximum}},
volume = {376},
year = {2018}
}
@article{Turner2015,
abstract = {In contrast to the Arctic, total sea ice extent (SIE) across the Southern Ocean has increased since the late 1970s, with the annual mean increasing at a rate of 186×103 km2 per decade (1.5{\%} per decade; p{\textless}0.01) for 1979–2013. However, this overall increase masks larger regional variations, most notably an increase (decrease) over the Ross (Amundsen–Bellingshausen) Sea. Sea ice variability results from changes in atmospheric and oceanic conditions, although the former is thought to be more significant, since there is a high correlation between anomalies in the ice concentration and the near-surface wind field. The Southern Ocean SIE trend is dominated by the increase in the Ross Sea sector, where the SIE is significantly correlated with the depth of the Amundsen Sea Low (ASL), which has deepened since 1979. The depth of the ASL is influenced by a number of external factors, including tropical sea surface temperatures, but the low also has a large locally driven intrinsic variability, suggesting that SIE in these areas is especially variable. Many of the current generation of coupled climate models have difficulty in simulating sea ice. However, output from the better-performing IPCC CMIP5 models suggests that the recent increase in Antarctic SIE may be within the bounds of intrinsic/internal variability.},
author = {Turner, John and Hosking, J. Scott and Bracegirdle, Thomas J. and Marshall, Gareth J. and Phillips, Tony},
doi = {10.1098/rsta.2014.0163},
issn = {1364503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Climate change,Cryosphere,Sea ice,Southern Ocean},
number = {2045},
pages = {20140163},
title = {{Recent changes in Antarctic Sea Ice}},
volume = {373},
year = {2015}
}
@article{Turney2016,
author = {Turney, Chris S M and McGlone, Matt and Palmer, Jonathan and Fogwill, Christopher and Hogg, Alan and Thomas, Zo{\"{e}} A. and Lipson, Mathew and Wilmshurst, Janet M and Fenwick, Pavla and Jones, Richard T and Hines, Ben and Clark, Graeme F},
doi = {10.1002/jqs.2828},
issn = {02678179},
journal = {Journal of Quaternary Science},
keywords = {southern hemisphere westerlies,southern ocean,subantarctic islands,subfossil trees,tree line},
month = {jan},
number = {1},
pages = {12--19},
title = {{Intensification of Southern Hemisphere westerly winds 2000–1000 years ago: evidence from the subantarctic Campbell and Auckland Islands (52–50°S)}},
url = {http://doi.wiley.com/10.1002/jqs.2828},
volume = {31},
year = {2016}
}
@article{Turney2016b,
author = {Turney, C S M and Jones, R T and Fogwill, C and Hatton, J and Williams, A N and Hogg, A and Thomas, Z A and Palmer, J},
doi = {10.5194/cp-12-189-2016},
journal = {Climate of the Past},
pages = {189--200},
title = {{A 250-year periodicity in Southern Hemisphere westerly winds over the last 2600 years (2016a)}},
volume = {12},
year = {2016}
}
@article{Turney2017a,
author = {Turney, C. S. M. and Wilmshurst, J. M. and Jones, R. T. and Wood, J. R. and Palmer, J. G. and Hogg, A. G. and Thomas, Z.},
doi = {10.1016/j.quascirev.2016.12.017},
journal = {Quaternary Science Reviews},
pages = {77--87},
title = {{Reconstructing atmospheric circulation over southern New Zealand: Establishment of modern westerly airflow 5500 years ago and implications for Southern Hemisphere Holocene climate change}},
volume = {159},
year = {2017}
}
@article{TurneyC.S.M.JonesR.T.McKayN.P.vanSebilleE.ThomasZ.A.HillenbradnC.D.Fogwill,
abstract = {0.8 ± 0.3 ∘C in both hemispheres with an early maximum peak of {\textgreater} 2.1 ± 0.3 ∘C. Using the reconstructed SSTs suggests a mean LIG global thermosteric sea level rise of 0.08 ± 0.1 m and a peak contribution of 0.39 ± 0.1 m, respectively (assuming warming penetrated to 2000 m depth). The data provide an important natural baseline for a warmer world, constraining the contributions of Greenland and Antarctic ice sheets to global sea level during a geographically widespread expression of high sea level, and can be used to test the next inter-comparison of models for projecting future climate change. The dataset described in this paper, including summary temperature and thermosteric sea level reconstructions, is available at https://doi.org/10.1594/PANGAEA.904381 (Turney et al., 2019).]]{\textgreater}},
author = {Turney, Chris S. M. and Jones, Richard T. and McKay, Nicholas P. and van Sebille, Erik and Thomas, Zo{\"{e}} A. and Hillenbrand, Claus-Dieter and Fogwill, Christopher J.},
doi = {10.5194/essd-12-3341-2020},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {dec},
number = {4},
pages = {3341--3356},
title = {{A global mean sea surface temperature dataset for the Last Interglacial (129–116 ka) and contribution of thermal expansion to sea level change}},
url = {https://essd.copernicus.org/articles/12/3341/2020/},
volume = {12},
year = {2020}
}
@article{Tweedy2017a,
abstract = {Abstract. The quasi-biennial oscillation (QBO) is a quasiperiodic alternation between easterly and westerly zonal winds in the tropical stratosphere, propagating downward from the middle stratosphere to the tropopause with a period that varies from 24 to 32 months ( ∼ 28 months on average). The QBO wind oscillations affect the distribution of chemical constituents, such as ozone (O3), water vapor (H2O), nitrous oxide (N2O), and hydrochloric acid (HCl), through the QBO-induced meridional circulation. In the 2015–2016 winter, radiosonde observations revealed an anomaly in the downward propagation of the westerly phase, which was disrupted by the upward displacement of the westerly phase from ∼ 30 hPa up to 15 hPa and the sudden appearance of easterlies at 40 hPa. Such a disruption is unprecedented in the observational record from 1953 to the present. In this study we show the response of trace gases to this QBO disruption using O3, HCl, H2O, and temperature from the Aura Microwave Limb Sounder (MLS) and total ozone measurements from the Solar Backscatter Ultraviolet (SBUV) Merged Ozone Data Set (MOD). Results reveal the development of positive anomalies in stratospheric equatorial O3 and HCl over ∼ 50–30 hPa in May–September of 2016 and a substantial decrease in O3 in the subtropics of both hemispheres. The SBUV observations show near-record low levels of column ozone in the subtropics in 2016, resulting in an increase in the surface UV index during northern summer. Furthermore, cold temperature anomalies near the tropical tropopause result in a global decrease in stratospheric water vapor.},
author = {Tweedy, Olga V and Kramarova, Natalya A and Strahan, Susan E and Newman, Paul A and Coy, Lawrence and Randel, William J and Park, Mijeong and Waugh, Darryn W and Frith, Stacey M},
doi = {10.5194/acp-17-6813-2017},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jun},
number = {11},
pages = {6813--6823},
title = {{Response of trace gases to the disrupted 2015–2016 quasi-biennial oscillation}},
url = {https://acp.copernicus.org/articles/17/6813/2017/},
volume = {17},
year = {2017}
}
@article{Tyrlis2020,
author = {Tyrlis, E and Bader, J and Manzini, E and Ukita, J and Nakamura, H and Matei, D},
doi = {10.1002/qj.3784},
journal = {Quarterly Journal of the Royal Meteorological Society},
pages = {2138--2153},
title = {{On the role of Ural Blocking in driving the Warm Arctic–Cold Siberia pattern}},
volume = {145},
year = {2020}
}
@article{Ummenhofer2016a,
abstract = {AbstractThe Indian Ocean has sustained robust surface warming in recent decades, but the role of multidecadal variability remains unclear. Using ocean model hindcasts, characteristics of low-frequency Indian Ocean temperature variations are explored. Simulated upper-ocean temperature changes across the Indian Ocean in the hindcast are consistent with those recorded in observational products and ocean reanalyses. Indian Ocean temperatures exhibit strong warming trends since the 1950s limited to the surface and south of 30°S, while extensive subsurface cooling occurs over much of the tropical Indian Ocean. Previous work focused on diagnosing causes of these long-term trends in the Indian Ocean over the second half of the twentieth century. Instead, the temporal evolution of Indian Ocean subsurface heat content is shown here to reveal distinct multidecadal variations associated with the Pacific decadal oscillation, and the long-term trends are thus interpreted to result from aliasing of the low-frequency variability. Transmission of the multidecadal signal occurs via an oceanic pathway through the Indonesian Throughflow and is manifest across the Indian Ocean centered along 12°S as westward-propagating Rossby waves modulating thermocline and subsurface heat content variations. Resulting low-frequency changes in the eastern Indian Ocean thermocline depth are associated with decadal variations in the frequency of Indian Ocean dipole (IOD) events, with positive IOD events unusually common in the 1960s and 1990s with a relatively shallow thermocline. In contrast, the deeper thermocline depth in the 1970s and 1980s is associated with frequent negative IOD and rare positive IOD events. Changes in Pacific wind forcing in recent decades and associated rapid increases in Indian Ocean subsurface heat content can thus affect the basin?s leading mode of variability, with implications for regional climate and vulnerable societies in surrounding countries.},
annote = {doi: 10.1175/JCLI-D-16-0200.1},
author = {Ummenhofer, Caroline C and Biastoch, Arne and B{\"{o}}ning, Claus W},
doi = {10.1175/JCLI-D-16-0200.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {nov},
number = {5},
pages = {1739--1751},
publisher = {American Meteorological Society},
title = {{Multidecadal Indian Ocean Variability Linked to the Pacific and Implications for Preconditioning Indian Ocean Dipole Events}},
url = {https://doi.org/10.1175/JCLI-D-16-0200.1},
volume = {30},
year = {2016}
}
@techreport{Unesco1981,
address = {Paris, France},
author = {UNESCO/ICES/SCOR/IAPSO},
pages = {144},
publisher = {UNESCO Technical Papers in Marine Science No. 37. United Nations Educational, Scientific and Cultural Organization (UNESCO)},
title = {{Background papers and supporting data on the Practical Salinity Scale 1978}},
url = {https://www.jodc.go.jp/jodcweb/info/ioc{\_}doc/UNESCO{\_}tech/047932eb.pdf},
year = {1981}
}
@article{refId0,
author = {Usoskin, I. G. and Gallet, Y. and Lopes, F. and Kovaltsov, G. A. and Hulot, G.},
doi = {10.1051/0004-6361/201527295},
journal = {Astronomy {\&} Astrophysics},
pages = {A150},
title = {{Solar activity during the Holocene: the Hallstatt cycle and its consequence for grand minima and maxima}},
url = {https://doi.org/10.1051/0004-6361/201527295},
volume = {587},
year = {2016}
}
@article{ClimatefieldcompletionviaMarkovrandomfieldsApplicationtotheHadCRUT46temperaturedataset,
address = {Boston MA, USA},
author = {Vaccaro, Adam and Emile-Geay, Julien and Guillot, Dominque and Verna, Resherle and Morice, Colin and Kennedy, John and Rajaratnam, Bala},
doi = {10.1175/JCLI-D-19-0814.1},
journal = {Journal of Climate},
pages = {1--66},
publisher = {American Meteorological Society},
title = {{Climate field completion via Markov random fields – Application to the HadCRUT4.6 temperature dataset}},
url = {https://journals.ametsoc.org/view/journals/clim/aop/JCLI-D-19-0814.1/JCLI-D-19-0814.1.xml},
year = {2021}
}
@article{VACCHI2016172,
abstract = {A review of 917 relative sea-level (RSL) data-points has resulted in the first quality-controlled database constraining the Holocene sea-level histories of the western Mediterranean Sea (Spain, France, Italy, Slovenia, Croatia, Malta and Tunisia). We reviewed and standardized the geological RSL data-points using a new multi-proxy methodology based on: (1) modern taxa assemblages in Mediterranean lagoons and marshes; (2) beachrock characteristics (cement fabric and chemistry, sedimentary structures); and (3) the modern distribution of Mediterranean fixed biological indicators. These RSL data-points were coupled with the large number of archaeological RSL indicators available for the western Mediterranean. We assessed the spatial variability of RSL histories for 22 regions and compared these with the ICE-5G (VM2) GIA model. In the western Mediterranean, RSL rose continuously for the whole Holocene with a sudden slowdown at {\~{}}7.5kaBP and a further deceleration during the last {\~{}}4.0kaBP, after which time observed RSL changes are mainly related to variability in isostatic adjustment. The sole exception is southern Tunisia, where data show evidence of a mid-Holocene high-stand compatible with the isostatic impacts of the melting history of the remote Antarctic ice sheet. Our results indicate that late-Holocene sea-level rise was significantly slower than the current one. First estimates of GIA contribution indicate that, at least in the northwestern sector, it accounts at least for the 25–30{\%} of the ongoing sea-level rise recorded by Mediterranean tidal gauges. Such contribution is less constrained at lower latitudes due to the lower quality of the late Holocene index points. Future applications of spatio-temporal statistical techniques are required to better quantify the gradient of the isostatic contribution and to provide improved context for the assessment of 20th century acceleration of Mediterranean sea-level rise.},
author = {Vacchi, Matteo and Marriner, Nick and Morhange, Christophe and Spada, Giorgio and Fontana, Alessandro and Rovere, Alessio},
doi = {10.1016/j.earscirev.2016.02.002},
issn = {0012-8252},
journal = {Earth-Science Reviews},
keywords = {Holocene,Isostatic adjustment,Mediterranean Sea,Sea-level database,Sea-level proxy},
pages = {172--197},
title = {{Multiproxy assessment of Holocene relative sea-level changes in the western Mediterranean: Sea-level variability and improvements in the definition of the isostatic signal}},
url = {http://www.sciencedirect.com/science/article/pii/S0012825216300241},
volume = {155},
year = {2016}
}
@article{Vaks2013,
author = {Vaks, A. and Gutareva, O. S. and Breitenbach, S. F. M. and Avirmed, E. and Mason, A. J. and Thomas, A. L. and Osinzev, A. V. and Kononov, A. M. and Henderson, G. M.},
doi = {10.1126/science.1228729},
issn = {0036-8075},
journal = {Science},
month = {apr},
number = {6129},
pages = {183--186},
title = {{Speleothems Reveal 500,000-Year History of Siberian Permafrost}},
url = {https://www.science.org/doi/10.1126/science.1228729},
volume = {340},
year = {2013}
}
@article{Vaks2020,
author = {Vaks, A. and Mason, A. J. and Breitenbach, S. F. M. and Kononov, A. M. and Osinzev, A. V. and Rosensaft, M. and Borshevsky, A. and Gutareva, O. S. and Henderson, G. M.},
doi = {10.1038/s41586-019-1880-1},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7789},
pages = {221--225},
title = {{Palaeoclimate evidence of vulnerable permafrost during times of low sea ice}},
volume = {577},
year = {2020}
}
@article{VandenBos2018,
author = {van den Bos, Valerie and Rees, Andrew and Newnham, Rewi and Vandergoes, Marcus and Wilmshurst, Janet and Augustinus, Paul},
doi = {10.1016/j.quascirev.2018.10.008},
issn = {02773791},
journal = {Quaternary Science Reviews},
month = {dec},
pages = {77--88},
publisher = {Elsevier Ltd},
title = {{Holocene temperature, humidity and seasonality in northern New Zealand linked to Southern Hemisphere summer insolation}},
url = {https://doi.org/10.1016/j.quascirev.2018.10.008 https://linkinghub.elsevier.com/retrieve/pii/S0277379118306693},
volume = {201},
year = {2018}
}
@article{VandenBroeke2017,
abstract = {Surface processes currently dominate Greenland ice sheet (GrIS) mass loss. We review recent developments in the observation and modeling of GrIS surface mass balance (SMB), published after the July 2012 deadline for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5). Since IPCC AR5, our understanding of GrIS SMB has further improved, but new observational and model studies have also revealed that temporal and spatial variability of many processes are still poorly quantified and understood, e.g., bio-albedo, the formation of ice lenses and their impact on lateral meltwater transport, heterogeneous vertical meltwater transport (‘piping'), the impact of atmospheric-circulation changes and mixed-phase clouds on the surface energy balance, and the magnitude of turbulent heat exchange over rough ice surfaces. As a result, these processes are only schematically or not at all included in models that are currently used to assess and predict future GrIS surface mass loss.},
author = {van den Broeke, Michiel and Box, Jason and Fettweis, Xavier and Hanna, Edward and No{\"{e}}l, Brice and Tedesco, Marco and van As, Dirk and van de Berg, Willem Jan and van Kampenhout, Leo},
doi = {10.1007/s40641-017-0084-8},
issn = {2198-6061},
journal = {Current Climate Change Reports},
pages = {345--356},
title = {{Greenland Ice Sheet Surface Mass Loss: Recent Developments in Observation and Modeling}},
volume = {3},
year = {2017}
}
@article{VanDijk2020,
abstract = {Earth's climate sensitivity, defined as the temperature increase for a doubling of partial pressure of carbon dioxide (pCO2), and the mechanisms responsible for amplification of high-latitude warming remain controversial. The latest Palaeocene/earliest Eocene (LPEE; 57–55 million years ago) is a time when atmospheric CO2 concentrations peaked between 1,400 and 4,000 ppm, which allows us to evaluate the climatic response to high pCO2. Here we present a reconstruction of continental temperatures and oxygen isotope compositions of precipitation (reflective of specific humidity) based on clumped and oxygen isotope analysis of pedogenic siderites. We show that continental mean annual temperatures reached 41 °C in the equatorial tropics, and summer temperatures reached 23 °C in the Arctic. The oxygen isotope compositions of precipitation reveal that compared with the present day the hot LPEE climate was characterized by an increase in specific humidity and the average residence time of atmospheric moisture and by a decrease in the subtropical-to-polar specific humidity gradient. The global increase in specific humidity reflects the fact that atmospheric vapour content is more sensitive to changes in pCO2 than evaporation and precipitation, resulting in an increase in the residence time of moisture in the atmosphere. Pedogenic siderite data from other super-greenhouse periods support the evidence that the spatial patterns of specific humidity and warmth are related, providing a new means to evaluate Earth's climate sensitivity.},
author = {van Dijk, Joep and Fernandez, Alvaro and Bernasconi, Stefano M. and {Caves Rugenstein}, Jeremy K. and Passey, Simon R. and White, Tim},
doi = {10.1038/s41561-020-00648-2},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {nov},
number = {11},
pages = {739--744},
publisher = {Springer US},
title = {{Spatial pattern of super-greenhouse warmth controlled by elevated specific humidity}},
url = {http://dx.doi.org/10.1038/s41561-020-00648-2 http://www.nature.com/articles/s41561-020-00648-2},
volume = {13},
year = {2020}
}
@article{Vandenberghe2014,
author = {Vandenberghe, Jef and French, Hugh M. and Gorbunov, Aldar and Marchenko, Sergei and Velichko, Andrey A. and Jin, Huijun and Cui, Zhijiu and Zhang, Tingjun and Wan, Xudong},
doi = {10.1111/bor.12070},
issn = {03009483},
journal = {Boreas},
month = {jul},
number = {3},
pages = {652--666},
title = {{The Last Permafrost Maximum (LPM) map of the Northern Hemisphere: permafrost extent and mean annual air temperatures, 25–17 ka BP}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/bor.12070},
volume = {43},
year = {2014}
}
@article{Vanderwal2013,
abstract = {Species are largely predicted to shift poleward as global temperatures increase, with this fingerprint of climate change being already observed across a range of taxonomic groups and, mostly temperate, geographic locations(1-5). However, the assumption of uni-directional distribution shifts does not account for complex interactions among temperature, precipitation and species-specific tolerances(6), all of which shape the direction and magnitude of changes in a species' climatic niche. We analysed 60 years of past climate change on the Australian continent, assessing the velocity of changes in temperature and precipitation, as well as changes in climatic niche space for 464 Australian birds. We show large magnitude and rapid rates of change in Australian climate over the past 60 years resulting in high-velocity and multi-directional, including equatorial, shifts in suitable climatic space for birds (ranging from 0.1 to 7.6 km yr(-1), mean 1.27 km yr(-1)). Overall, if measured only in terms of poleward distribution shifts, the fingerprint of climate change is underestimated by an average of 26{\%} in temperate regions of the continent and by an average of 95{\%} in tropical regions. We suggest that the velocity of movement required by Australian species to track their climatic niche may be much faster than previously thought and that the interaction between temperature and precipitation changes will result in multi-directional distribution shifts globally.},
author = {Vanderwal, Jeremy and Murphy, Helen T. and Kutt, Alex S. and Perkins, Genevieve C. and Bateman, Brooke L. and Perry, Justin J. and Reside, April E.},
doi = {10.1038/nclimate1688},
issn = {1758678X},
journal = {Nature Climate Change},
pages = {239--243},
title = {{Focus on poleward shifts in species' distribution underestimates the fingerprint of climate change}},
volume = {3},
year = {2013}
}
@misc{Vasskog2015,
abstract = {During the Last Interglacial (LIG) period, between 130 and 116 thousand years before present (ka BP), the Greenland Ice Sheet (GrIS) was considerably reduced in size, contributing to a global mean sea-level (MSL) rise of 0.5-4.2m relative to the present. This is not sufficient to explain the 6-9m MSL rise estimated for the LIG, which implies that a significant contribution to the LIG highstand came from Antarctica. Following the LIG the GrIS grew and attained its maximum volume of about 12m global sea-level equivalents (SLEs) between 18 and 16ka BP. Since then the GrIS margins have retreated on an order of several hundred km, following a general pattern of lagged response to changes in high-latitude summer insolation and global greenhouse gas concentrations. On shorter timescales and over smaller spatial scales the combination of internal ice-sheet dynamics and external climate dynamics has often resulted in a more complex and asynchronous behaviour of the ice-sheet margin. The GrIS probably reached its minimum Holocene extent around 4ka BP, and modelling studies suggest that it contributed to a rise in global MSL of less than 0.2m relative to the present at this time. A period of steady growth followed the Holocene minimum and in many areas the ice sheet advanced beyond its present limits during the 'Little Ice Age' (i.e. the last few centuries). Currently the GrIS occupies an area of {\~{}}1.7×106km2 and features a volume of {\~{}}2.96×106km3, which amounts to {\~{}}7.4m SLE. Observations show that the rate of mass loss from the GrIS has been accelerating over the past few decades, and ice sheet modelling indicates that we have to go back to the last deglaciation (around 10ka BP) in order to find sustained melt rates that were higher than those experienced over the last decade. The future development of the GrIS will have a profound influence on sea level, both globally and regionally, but there are large uncertainties related to how the GrIS will respond to future global warming. Based on a range of modelling studies employing different emission scenarios, the GrIS is expected to contribute about 0.1-0.3m to global MSL rise by the end of the 21st century. In a longer time perspective, modelling suggests that melting of the GrIS may replace ocean thermal expansion as the most important factor in future sea-level rise, potentially contributing with 0.7-2.6m SLE within the next 500years. Multi-millennial simulations show that the entire ice sheet ({\~{}}7.4m SLE) might disappear completely within less than three thousand years under high-emission scenarios, i.e. with atmospheric CO2 reaching four times preindustrial levels.},
author = {Vasskog, Kristian and Langebroek, Petra M. and Andrews, John T. and Nilsen, Jan Even {\O}. and Nesje, Atle},
booktitle = {Earth-Science Reviews},
doi = {10.1016/j.earscirev.2015.07.006},
issn = {00128252},
keywords = {Deglaciation,Greenland Ice Sheet,Holocene,Last Glacial Maximum,Last Interglacial,Sea level change},
month = {nov},
pages = {45--67},
publisher = {Elsevier},
title = {{The Greenland Ice Sheet during the last glacial cycle: Current ice loss and contribution to sea-level rise from a palaeoclimatic perspective}},
volume = {150},
year = {2015}
}
@article{Vautard2012,
author = {Vautard, R and McVicar, T R and Thepaut, J N and Roderic, M L},
doi = {10.1175/2012BAMSStateoftheClimate.1},
journal = {Bulletin of the American Meteorological Society},
number = {7},
pages = {S36--S38},
title = {{Land surface winds and atmospheric evaporative demand [in “State of the Climate in 2011”]}},
volume = {93},
year = {2012}
}
@article{Vavrus2018,
abstract = {The rapidly warming Arctic climate may affect weather in middle latitudes, but controversies remain as to mechanisms and robustness. Here, I synthesize recent advances in this rapidly changing field and summarize recommendations on paths forward.},
author = {Vavrus, Stephen J},
doi = {10.1007/s40641-018-0105-2},
issn = {2198-6061},
journal = {Current Climate Change Reports},
number = {3},
pages = {238--249},
title = {{The Influence of Arctic Amplification on Mid-latitude Weather and Climate}},
url = {https://doi.org/10.1007/s40641-018-0105-2},
volume = {4},
year = {2018}
}
@article{Velicogna2020,
author = {Velicogna, Isabella and Mohajerani, Yara and A, Geruo and Landerer, Felix and Mouginot, Jeremie and Noel, Brice and Rignot, Eric and Sutterley, Tyler and Broeke, Michiel and Wessem, Melchior and Wiese, David},
doi = {10.1029/2020GL087291},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {apr},
number = {8},
pages = {e2020GL087291},
title = {{Continuity of Ice Sheet Mass Loss in Greenland and Antarctica From the GRACE and GRACE Follow‐On Missions}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020GL087291},
volume = {47},
year = {2020}
}
@article{Venegas1996a,
abstract = {A singular value decomposition (SVD) analysis is used to determine the coupled modes of variability of monthly sea surface temperature (SST) and sea level pressure (SLP) data from the South Atlantic region, for the period 1953?1992. We find that the three leading SVD modes respectively account for 63{\%}, 20{\%} and 6{\%} of the total square covariance. The first mode represents an approximately 15-year period oscillation in the strength of the subtropical anticyclone, accompanied by fluctuations of a north-south dipole structure in the SST. It appears to be linked to the global-scale interdecadal (15-year) joint mode in SST and SLP recently studied by Mann and Park. The second mode is characterized by east-west displacements of the anticyclone center, in association with strong 6 to 7-year period fluctuations of SST off the coast of Africa. The third mode is characterized by north-south displacements of the anticyclone and 4-year period fluctuations in the SST in a broad band across the central South Atlantic. This mode is strongly correlated with ENSO.},
annote = {doi: 10.1029/96GL02373},
author = {Venegas, Silvia A and Mysak, Lawrence A and Straub, David N},
doi = {10.1029/96GL02373},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {sep},
number = {19},
pages = {2673--2676},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Evidence for interannual and interdecadal climate variability in the South Atlantic}},
url = {https://doi.org/10.1029/96GL02373},
volume = {23},
year = {1996}
}
@article{Venter2016,
abstract = {Human pressures on the environment are changing spatially and temporally, with profound implications for the planet's biodiversity and human economies. Here we use recently available data on infrastructure, land cover and human access into natural areas to construct a globally standardized measure of the cumulative human footprint on the terrestrial environment at 1 km 2 resolution from 1993 to 2009. We note that while the human population has increased by 23{\%} and the world economy has grown 153{\%}, the human footprint has increased by just 9{\%}. Still, 75{\%} the planet's land surface is experiencing measurable human pressures. Moreover, pressures are perversely intense, widespread and rapidly intensifying in places with high biodiversity. Encouragingly, we discover decreases in environmental pressures in the wealthiest countries and those with strong control of corruption. Clearly the human footprint on Earth is changing, yet there are still opportunities for conservation gains.},
author = {Venter, Oscar and Sanderson, Eric W. and Magrach, Ainhoa and Allan, James R. and Beher, Jutta and Jones, Kendall R. and Possingham, Hugh P. and Laurance, William F. and Wood, Peter and Fekete, Bal{\'{a}}zs M. and Levy, Marc A. and Watson, James E. M.},
doi = {10.1038/ncomms12558},
issn = {2041-1723},
journal = {Nature Communications},
month = {nov},
number = {1},
pages = {12558},
title = {{Sixteen years of change in the global terrestrial human footprint and implications for biodiversity conservation}},
url = {http://www.nature.com/articles/ncomms12558},
volume = {7},
year = {2016}
}
@article{https://doi.org/10.1029/2020GL088476,
abstract = {Abstract Understanding ice sheet evolution through the geologic past can help constrain ice sheet models that predict future ice dynamics. Existing geological records of grounding line retreat in the Ross Sea, Antarctica, have been confined to ice-free and terrestrial archives, which reflect dynamics from periods of more extensive ice cover. Therefore, our perspective of grounding line retreat since the Last Glacial Maximum remains incomplete. Sediments beneath Ross Ice Shelf and grounded ice offer complementary insight into the southernmost extent of grounding line retreat, yielding a more complete view of ice dynamics during deglaciation. Here we thermochemically separate the youngest organic carbon to estimate ages from sediments extracted near the Whillans Ice Stream grounding line to provide direct evidence for grounding line retreat in that region as recent as the mid-Holocene (7.2 kyr B.P.). Our study demonstrates the utility of accurately dated, grounding-line-proximal sediment deposits for reconstructing past interactions between marine and subglacial environments.},
annote = {e2020GL088476 2020GL088476},
author = {Venturelli, R A and Siegfried, M R and Roush, K A and Li, W and Burnett, J and Zook, R and Fricker, H A and Priscu, J C and Leventer, A and Rosenheim, B E},
doi = {10.1029/2020GL088476},
journal = {Geophysical Research Letters},
number = {15},
pages = {e2020GL088476},
title = {{Mid-Holocene Grounding Line Retreat and Readvance at Whillans Ice Stream, West Antarctica}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL088476},
volume = {47},
year = {2020}
}
@article{Vernier2011,
author = {Vernier, J.-P. and Thomason, L. W. and Pommereau, J.-P. and Bourassa, A. and Pelon, J. and Garnier, A. and Hauchecorne, A. and Blanot, L. and Trepte, C. and Degenstein, Doug and Vargas, F.},
doi = {10.1029/2011GL047563},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jun},
number = {12},
pages = {L12807},
publisher = {Wiley-Blackwell},
title = {{Major influence of tropical volcanic eruptions on the stratospheric aerosol layer during the last decade}},
url = {http://doi.wiley.com/10.1029/2011GL047563},
volume = {38},
year = {2011}
}
@article{Vicente-serrano2018,
author = {Vicente-Serrano, Sergio M. and Nieto, Raquel and Gimeno, Luis and Azorin-Molina, Cesar and Drumond, Anita and {El Kenawy}, Ahmed and Dominguez-Castro, Fernando and Tomas-Burguera, Miquel and Pe{\~{n}}a-Gallardo, Marina},
doi = {10.5194/esd-9-915-2018},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {jun},
number = {2},
pages = {915--937},
title = {{Recent changes of relative humidity: regional connections with land and ocean processes}},
url = {https://esd.copernicus.org/articles/9/915/2018/},
volume = {9},
year = {2018}
}
@article{doi:10.1029/2011GL050118,
abstract = {Inter-annual variations in Arctic sea ice drift speed (Vi) in 1989–2009 were analyzed on the basis of buoy data and atmospheric circulation indices. In the circumpolar and eastern Arctic and the Fram Strait, the annual mean Vi was best explained by the sea level pressure (SLP) difference across the Arctic Ocean along meridians 270°E and 90°E, called as the Central Arctic Index (CAI). In general, Vi was more strongly related to CAI than to the Dipole Anomaly (DA). This was because CAI is calculated across the Transpolar Drift Stream (TDS), whereas the pressure patterns affecting DA sometimes move far from TDS. CAI also has the benefit of being a simple index, insensitive to the calculation method applied, whereas DA, as the second mode of a principal component analysis, is sensitive both to the time period and area of calculations. In summer, the circulation index most important for the circumpolar mean Vi was the SLP gradient across the Fram Strait. In the Canadian Basin in winter, the Arctic Oscillation index was most important. Circulation indices explained 48{\%} of the variance of the annual mean Viin the circumpolar Arctic, 38{\%} in the eastern Arctic, and 25{\%} in the Canadian Basin. The local air-ice momentum flux ($\tau$) was always better than the 10 m wind speed in explaining Vi, but $\tau$ outperformed the circulation indices only in the Fram Strait. Atmospheric forcing did not explain the increasing trend in Vi in the period 1989–2009.},
author = {Vihma, Timo and Tisler, Priit and Uotila, Petteri},
doi = {10.1029/2011GL050118},
journal = {Geophysical Research Letters},
keywords = {Arctic,atmospheric circulation indices,ice drift},
number = {2},
pages = {L02501},
title = {{Atmospheric forcing on the drift of Arctic sea ice in 1989–2009}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011GL050118},
volume = {39},
year = {2012}
}
@article{Villalba2012,
author = {Villalba, Ricardo and Lara, Antonio and Masiokas, Mariano H and Urrutia, Roc{\'{i}}o and Luckman, Brian H and Marshall, Gareth J and Mundo, Ignacio A and Christie, Duncan A and Cook, Edward R and Neukom, Raphael and Allen, Kathryn and Fenwick, Pavla and Boninsegna, Jos{\'{e}} A and Srur, Ana M and Morales, Mariano S and Araneo, Diego and Palmer, Jonathan G and Cuq, Emilio and Aravena, Juan C and Holz, Andr{\'{e}}s and Lequesne, Carlos},
doi = {10.1038/ngeo1613},
journal = {Nature Geoscience},
number = {October},
pages = {793--798},
title = {{Unusual Southern Hemisphere tree growth patterns induced by changes in the Southern Annular Mode}},
volume = {5},
year = {2012}
}
@article{doi:10.1175/JCLI-D-16-0626.1,
abstract = { AbstractUnprecedented changes in Earth's water budget and a recent boom in salinity observations prompted the use of long-term salinity trends to fingerprint the amount of freshwater entering and leaving the oceans (the ocean water cycle). Here changes in the ocean water cycle in the past two decades are examined to evaluate whether the rain-gauge notion can be extended to shorter time scales. Using a novel framework it is demonstrated that there have been persistent changes (defined as significant trends) in both salinity and the ocean water cycle in many ocean regions, including the subtropical gyres in both hemispheres, low latitudes of the tropical Pacific, the North Atlantic Subpolar Gyre, and the Arctic Ocean. On average, the ocean water cycle has amplified by approximately 5{\%} since 1993, but strong regional variations exist (as well as dependency on the surface freshwater flux products chosen). Despite an intensified ocean water cycle in the last two decades, changes in surface salinity do not follow expected patterns of amplified salinity contrasts, challenging the perception that if it rains more the seas always get fresher and if it evaporates more the seas always get saltier. These findings imply a time of emergence of anthropogenic hydrological signals shorter in surface freshwater fluxes than in surface salinity and point to the importance of ocean circulation, salt transports, and natural climate variability in shaping patterns of decadal change in surface salinity. Therefore, the use of salinity measurements in conjunction with ocean salt fluxes can provide a more meaningful way of fingerprinting changes in the global water cycle on decadal time scales. },
author = {Vinogradova, Nadya T and Ponte, Rui M},
doi = {10.1175/JCLI-D-16-0626.1},
journal = {Journal of Climate},
number = {14},
pages = {5513--5528},
title = {{In Search of Fingerprints of the Recent Intensification of the Ocean Water Cycle}},
url = {https://doi.org/10.1175/JCLI-D-16-0626.1},
volume = {30},
year = {2017}
}
@article{Voigt2015,
author = {Voigt, I. and Chiessi, C. M. and Prange, M. and Mulitza, S. and Groeneveld, J. and Varma, V. and Henrich, R.},
doi = {10.1002/2014PA002677},
journal = {Paleoceanography},
number = {2},
pages = {39--51},
title = {{Holocene shifts of the southern westerlies across the South Atlantic}},
volume = {30},
year = {2015}
}
@article{SathyendranathS.S.PardoM.BenincasaV.E.BrandoR.J.W.Brewin2018a,
author = {von Schuckmann, Karina and Traon, Pierre-Yves Le and Smith, Neville and Pascual, Ananda and Brasseur, Pierre and Fennel, Katja and Djavidnia, Samy and Aaboe, Signe and Fanjul, Enrique Alvarez and Autret, Emmanuelle and Axell, Lars and Aznar, Roland and Benincasa, Mario and Bentamy, Abderahim and Boberg, Fredrik and Bourdall{\'{e}}-Badie, Romain and Nardelli, Bruno Buongiorno and Brando, Vittorio E and Bricaud, Cl{\'{e}}ment and Breivik, Lars-Anders and Brewin, Robert J W and Capet, Arthur and Ceschin, Adrien and Ciliberti, Stefania and Cossarini, Gianpiero and de Alfonso, Marta and {de Pascual Collar}, Alvaro and de Kloe, Jos and Deshayes, Julie and Desportes, Charles and Dr{\'{e}}villon, Marie and Drillet, Yann and Droghei, Riccardo and Dubois, Clotilde and Embury, Owen and Etienne, H{\'{e}}l{\`{e}}ne and Fratianni, Claudia and Lafuente, Jes{\'{u}}s Garc{\'{i}}a and Sotillo, Marcos Garcia and Garric, Gilles and Gasparin, Florent and Gerin, Riccardo and Good, Simon and Gourrion, J{\'{e}}rome and Gr{\'{e}}goire, Marilaure and Greiner, Eric and Guinehut, St{\'{e}}phanie and Gutknecht, Elodie and Hernandez, Fabrice and Hernandez, Olga and H{\o}yer, Jacob and Jackson, Laura and Jandt, Simon and Josey, Simon and Juza, M{\'{e}}lanie and Kennedy, John and Kokkini, Zoi and Korres, Gerasimos and K{\~{o}}uts, Mariliis and Lagemaa, Priidik and Lavergne, Thomas and le Cann, Bernard and Legeais, Jean-Fran{\c{c}}ois and Lemieux-Dudon, Benedicte and Levier, Bruno and Lien, Vidar and Maljutenko, Ilja and Manzano, Fernando and Marcos, Marta and Marinova, Veselka and Masina, Simona and Mauri, Elena and Mayer, Michael and Melet, Angelique and M{\'{e}}lin, Fr{\'{e}}d{\'{e}}ric and Meyssignac, Benoit and Monier, Maeva and M{\"{u}}ller, Malte and Mulet, Sandrine and Naranjo, Cristina and Notarstefano, Giulio and Paulmier, Aur{\'{e}}lien and Gomez, Bego{\~{n}}a P{\'{e}}rez and Gonzalez, Irene P{\'{e}}rez and Peneva, Elisaveta and Perruche, Coralie and Peterson, K Andrew and Pinardi, Nadia and Pisano, Andrea and Pardo, Silvia and Poulain, Pierre-Marie and Raj, Roshin P and Raudsepp, Urmas and Ravdas, Michaelis and Reid, Rebecca and Rio, Marie-H{\'{e}}l{\`{e}}ne and Salon, Stefano and Samuelsen, Annette and Sammartino, Michela and Sammartino, Simone and Sand{\o}, Anne Britt and Santoleri, Rosalia and Sathyendranath, Shubha and She, Jun and Simoncelli, Simona and Solidoro, Cosimo and Stoffelen, Ad and Storto, Andrea and Szerkely, Tanguy and Tamm, Susanne and Tietsche, Steffen and Tinker, Jonathan and Tintore, Joaqu{\'{i}}n and Trindade, Ana and van Zanten, Daphne and Vandenbulcke, Luc and Verhoef, Anton and Verbrugge, Nathalie and Viktorsson, Lena and von Schuckmann, Karina and Wakelin, Sarah L and Zacharioudaki, Anna and Zuo, Hao and and {Sathyendranath, S. S. Pardo, M. Benincasa, V.E. Brando, R.J.W. Brewin}, F. M{\'{e}}lin and Santoleri, Rosalia},
doi = {10.1080/1755876X.2018.1489208},
journal = {Journal of Operational Oceanography},
number = {sup1},
pages = {S1--S142},
publisher = {Taylor {\&} Francis},
title = {{Copernicus Marine Service Ocean State Report}},
url = {https://doi.org/10.1080/1755876X.2018.1489208},
volume = {11},
year = {2018}
}
@article{essd-12-2013-2020,
author = {von Schuckmann, K and Cheng, L and Palmer, M D and Hansen, J and Tassone, C and Aich, V and Adusumilli, S and Beltrami, H and Boyer, T and Cuesta-Valero, F J and Desbruy{\`{e}}res, D and Domingues, C and Garcia-Garcia, A and Gentine, P and Gilson, J and Gorfer, M and Haimberger, L and Ishii, M and Johnson, G C and Killick, R and King, B A and Kirchengast, G and Kolodziejczyk, N and Lyman, J and Marzeion, B and Mayer, M and Monier, M and Monselesan, D P and Purkey, S and Roemmich, D and Schweiger, A and Seneviratne, S I and Shepherd, A and Slater, D A and Steiner, A K and Straneo, F and Timmermans, M.-L. and Wijffels, S E},
doi = {10.5194/essd-12-2013-2020},
journal = {Earth System Science Data},
number = {3},
pages = {2013--2041},
title = {{Heat stored in the Earth system: where does the energy go?}},
url = {https://essd.copernicus.org/articles/12/2013/2020/},
volume = {12},
year = {2020}
}
@article{doi:10.1080/1755876X.2019.1633075,
author = {von Schuckmann, Karina and Traon, Pierre-Yves Le and (Chair), Neville Smith and Pascual, Ananda and Djavidnia, Samuel and Gattuso, Jean-Pierre and Gr{\'{e}}goire, Marilaure and Nolan, Glenn and Aaboe, Signe and Aguiar, Eva and Fanjul, Enrique {\'{A}}lvarez and Alvera-Azc{\'{a}}rate, Aida and Aouf, Lotfi and Barciela, Rosa and Behrens, Arno and Rivas, Maria Belmonte and Ismail, Sana Ben and Bentamy, Abderrahim and Borgini, Mireno and Brando, Vittorio E and Bensoussan, Nathaniel and Blauw, Anouk and Bry{\`{e}}re, Philippe and Nardelli, Bruno Buongiorno and Caballero, Ainhoa and Yumruktepe, Veli {\c{C}}ağlar and Cebrian, Emma and Chiggiato, Jacopo and Clementi, Emanuela and Corgnati, Lorenzo and de Alfonso, Marta and {de Pascual Collar}, {\'{A}}lvaro and Deshayes, Julie and Lorenzo, Emanuele Di and Dominici, Jean-Marie and Dupouy, C{\'{e}}cile and Dr{\'{e}}villon, Marie and Echevin, Vincent and Eleveld, Marieke and Enserink, Lisette and Sotillo, Marcos Garc{\'{i}}a and Garnesson, Philippe and Garrabou, Joaquim and Garric, Gilles and Gasparin, Florent and Gayer, Gerhard and Gohin, Francis and Grandi, Alessandro and Griffa, Annalisa and Gourrion, J{\'{e}}r{\^{o}}me and Hendricks, Stefan and Heuz{\'{e}}, C{\'{e}}line and Holland, Elisabeth and Iovino, Doroteaciro and Juza, M{\'{e}}lanie and Kersting, Diego Kurt and Kipson, Silvija and Kizilkaya, Zafer and Korres, Gerasimos and K{\~{o}}uts, Mariliis and Lagemaa, Priidik and Lavergne, Thomas and Lavigne, Heloise and Ledoux, Jean-Baptiste and Legeais, Jean-Fran{\c{c}}ois and Lehodey, Patrick and Linares, Cristina and Liu, Ye and Mader, Julien and Maljutenko, Ilja and Mangin, Antoine and Manso-Narvarte, Ivan and Mantovani, Carlo and Markager, Stiig and Mason, Evan and Mignot, Alexandre and Menna, Milena and Monier, Maeva and Mourre, Baptiste and M{\"{u}}ller, Malte and Nielsen, Jacob Woge and Notarstefano, Giulio and Oca{\~{n}}a, Oscar and Pascual, Ananda and Patti, Bernardo and Payne, Mark R and Peirache, Marion and Pardo, Silvia and G{\'{o}}mez, Bego{\~{n}}a P{\'{e}}rez and Pisano, Andrea and Perruche, Coralie and Peterson, K Andrew and Pujol, Marie-Isabelle and Raudsepp, Urmas and Ravdas, Michalis and Raj, Roshin P and Renshaw, Richard and Reyes, Emma and Ricker, Robert and Rubio, Anna and Sammartino, Michela and Santoleri, Rosalia and Sathyendranath, Shubha and Schroeder, Katrin and She, Jun and Sparnocchia, Stefania and Staneva, Joanna and Stoffelen, Ad and Szekely, Tanguy and Tilstone, Gavin H and Tinker, Jonathan and Tintor{\'{e}}, Joaqu{\'{i}}n and Tranchant, Beno{\^{i}}t and Uiboupin, Rivo and der Zande, Dimitry Van and von Schuckmann, Karina and Wood, Richard and Nielsen, Jacob Woge and Zabala, Mikel and Zacharioudaki, Anna and Zuberer, Fr{\'{e}}d{\'{e}}ric and Zuo, Hao},
doi = {10.1080/1755876X.2019.1633075},
journal = {Journal of Operational Oceanography},
number = {sup1},
pages = {S1--S123},
publisher = {Taylor {\&} Francis},
title = {{Copernicus Marine Service Ocean State Report, Issue 3}},
url = {https://doi.org/10.1080/1755876X.2019.1633075},
volume = {12},
year = {2019}
}
@article{doi:10.1029/2005GL024379,
abstract = {New data acquisitions are used to examine recent global trends in maximum temperature, minimum temperature, and the diurnal temperature range (DTR). On average, the analysis covers the equivalent of 71{\%} of the total global land area, 17{\%} more than in previous studies. Consistent with the IPCC Third Assessment Report, minimum temperature increased more rapidly than maximum temperature (0.204 vs. 0.141°C dec−1) from 1950–2004, resulting in a significant DTR decrease (−0.066°C dec−1). In contrast, there were comparable increases in minimum and maximum temperature (0.295 vs. 0.287°C dec−1) from 1979–2004, muting recent DTR trends (−0.001°C dec−1). Minimum and maximum temperature increased in almost all parts of the globe during both periods, whereas a widespread decrease in the DTR was only evident from 1950–1980.},
author = {Vose, Russell S and Easterling, David R and Gleason, Byron},
doi = {10.1029/2005GL024379},
journal = {Geophysical Research Letters},
number = {23},
pages = {L23822},
title = {{Maximum and minimum temperature trends for the globe: An update through 2004}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2005GL024379},
volume = {32},
year = {2005}
}
@article{https://doi.org/10.1029/2020GL090873,
abstract = {Plain Language Summary NOAA provides a suite of climate services to government, business, academia and the public to support informed decision-making. Among these services is the State of the Climate report, which is a collection of monthly summaries recapping climate-related occurrences across the globe. This report relies heavily upon NOAA's Global Surface Temperature dataset to depict recent monthly conditions and long-term changes. Our research introduces a new edition of this flagship dataset that is based upon additional temperature data and improved scientific methods. The new dataset extends back to 1850 and has complete coverage of all land and ocean areas for the first time. These improvements are particularly important in the Arctic, which has warmed more rapidly than the rest of the planet in recent decades, and the new dataset likewise has larger trends than its predecessor in that part of the world. The introduction of this new dataset is consistent with the NOAA practice of periodically developing improved versions of its foundational datasets, the goal being to ensure the best possible representation of historical conditions across the globe. The results of this paper suggest that the new dataset can substantially contribute to future NOAA monitoring and assessment activities.},
annote = {e2020GL090873 2020GL090873},
author = {Vose, R S and Huang, B and Yin, X and Arndt, D and Easterling, D R and Lawrimore, J H and Menne, M J and Sanchez-Lugo, A and Zhang, H M},
doi = {10.1029/2020GL090873},
journal = {Geophysical Research Letters},
keywords = {arctic,global temperature,trends},
number = {4},
pages = {e2020GL090873},
title = {{Implementing Full Spatial Coverage in NOAA's Global Temperature Analysis}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL090873},
volume = {48},
year = {2021}
}
@article{Vrieling2013,
abstract = {The spatial distribution of crops and farming systems in Africa is determined by the duration of the period during which crop and livestock water requirements are met. The length of growing period (LGP) is normally assessed from weather station data-scarce in large parts of Africa-or coarse-resolution rainfall estimates derived from weather satellites. In this study, we analyzed LGP and its variability based on the 1981-2011 GIMMS NDVI3g dataset. We applied a variable threshold method in combination with a searching algorithm to determine start- and end-of-season. We obtained reliable LGP estimates for arid, semi-arid and sub-humid climates that are consistent in space and time. This approach effectively mapped bimodality for clearly separated wet seasons in the Horn of Africa. Due to cloud contamination, the identified bimodality along the Guinea coast was judged to be less certain. High LGP variability is dominant in arid and semi-arid areas, and is indicative of crop failure risk. Significant negative trends in LGP were found for the northern part of the Sahel, for parts of Tanzania and northern Mozambique, and for the short rains of eastern Kenya. Positive trends occurred across western Africa, in southern Africa, and in eastern Kenya for the long rains. Our LGP analysis provides useful information for the mapping of farming systems, and to study the effects of climate variability and other drivers of change on vegetation and crop suitability.},
author = {Vrieling, Anton and de Leeuw, Jan and Said, Mohammed},
doi = {10.3390/rs5020982},
isbn = {2072-4292},
issn = {2072-4292},
journal = {Remote Sensing},
keywords = {Africa,Avhrr,Farming systems,Length of growing period,Ndvi time series,Ndvi3g,Phenology},
month = {feb},
number = {2},
pages = {982--1000},
title = {{Length of Growing Period over Africa: Variability and Trends from 30 Years of NDVI Time Series}},
url = {http://www.mdpi.com/2072-4292/5/2/982},
volume = {5},
year = {2013}
}
@article{VYVERBERG2018170,
abstract = {We present a detailed taxonomic and lithologic analysis of fossil reefs in the Granitic Seychelles to improve constraints on global mean sea level behavior during the last interglacial sea-level highstand, {\~{}}129,000–116,000 years ago. In particular, we have assessed the coralgal reef outcrops for any sedimentalogic evidence of sub-orbital sea level oscillations that may have occurred during this warm, interglacial period. At the outcrop scale, we observe at least three distinct episodes of reef growth punctuated by two discontinuities that typically manifest as coral rubble layers or extensive lateral encrustations of the hydrozoan coral Millepora exaesa. Hiatuses in reef growth at other sites around the world have been interpreted as relative sea level falls and/or environmental disturbances. We have tested the hypothesis that these discontinuities, that we refer to as disturbance horizons, are related to ephemeral drops in sea level that have been inferred at last interglacial reef sites from other sites around the globe. At two sites, there is sedimentological evidence in the form of extensive dissolution and freshwater cements associated with the disturbance horizons that would require subaerial exposure followed by marine inundation. At the remaining sites, evidence is consistent with, but not necessarily indicative of, an ephemeral drop in sea level. To establish if these disturbance horizons are coeval between the outcrops and if they are local or global features, requires high-precision dating of the disturbance horizons along with a critical analysis of sedimentary and chronological evidence from other sites around the globe. If the disturbance horizons observed in the Seychelles represent transient sea-level falls or still stands during the last interglacial, this would imply a dynamic behavior of the polar ice sheets during this past warm period.},
author = {Vyverberg, Karen and Dechnik, Belinda and Dutton, Andrea and Webster, Jody M and Zwartz, Dan and Portell, Roger W},
doi = {10.1016/j.margeo.2018.02.010},
issn = {0025-3227},
journal = {Marine Geology},
keywords = {Indian Ocean,Last interglacial,Reefs and carbonate mounds,Sea level change},
pages = {170--187},
title = {{Episodic reef growth in the granitic Seychelles during the Last Interglacial: Implications for polar ice sheet dynamics}},
url = {http://www.sciencedirect.com/science/article/pii/S002532271730018X},
volume = {399},
year = {2018}
}
@article{Wachowicz2021,
abstract = {As the Arctic continues to warm, a weakening of upper-tropospheric westerly winds is hypothesized to induce a meandering jet stream and slower propagation of Rossby waves. As such, current hypotheses suggest an increase in Greenland blocking due to increased stationarity of the high amplitude waves. These hypotheses have been supported observationally with the Greenland blocking index (GBI). However, given an expected increase in overall geopotential heights corresponding to increased temperatures in the region, we assess the robustness of trends in Greenland blocking using additional blocking metrics in addition to the GBI, which has largely been the focused blocking metric for this region to date. Our results show sensitivity of the GBI-based increases in blocking to global and zonally averaged 500-hPa geopotential heights, which results in inconsistent increasing trends over the 1979–2018 period when compared with other blocking metrics. Seasonal blocking frequencies of the GBI show a significant increase in blocking for JJA, though no significant trend in JJA blocking occurs for most metrics. Other indices suggest a decrease in blocking frequency in September–November (SON) and December–February (DJF), though these trends are not statistically significant. Yet, when smoothed using a 5-year running mean, these other metrics suggest an increase in both DJF and JJA blocking with a decrease only in SON blocking, which are consistent with findings of significant changes in GBI. We report no best metric for identifying Greenland blocking. Instead, we present some shortcomings of the different metrics used in this study. These results provide insight into selection of Greenland blocking events for future research, as over- or under-estimation of blocking activity can impact estimates of surface mass balance of the ice sheet.},
author = {Wachowicz, Lori J. and Preece, Jonathon R. and Mote, Thomas L. and Barrett, Bradford S. and Henderson, Gina R.},
doi = {10.1002/joc.6923},
issn = {0899-8418},
journal = {International Journal of Climatology},
keywords = {GBI,Greenland,blocking,trends},
month = {jan},
number = {S1},
pages = {joc.6923},
title = {{Historical trends of seasonal Greenland blocking under different blocking metrics}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/joc.6923},
volume = {41},
year = {2021}
}
@article{WAELBROECK2002295,
abstract = {We show that robust regressions can be established between relative sea-level (RSL) data and benthic foraminifera oxygen isotopic ratios from the North Atlantic and Equatorial Pacific Ocean over the last climatic cycle. We then apply these regressions to long benthic isotopic records retrieved at one North Atlantic and one Equatorial Pacific site to build a composite RSL curve, as well as the associated confidence interval, over the last four climatic cycles. Our proposed reconstruction of RSL is in good agreement with the sparse RSL data available prior to the last climatic cycle. We compute bottom water temperature changes at the two sites and at one Southern Indian Ocean site, taking into account potential variations in North Atlantic local deep water $\delta$18O. Our results indicate that a Last Glacial Maximum (LGM) enrichment of the ocean mean oxygen isotopic ratio of 0.95‰ is the lowest value compatible with unfrozen deep waters in the Southern Indian Ocean if local deep water $\delta$18O did not increase during glacials with respect to present. Such a value of the LGM mean ocean isotopic enrichment would impose a maximum decrease in local bottom water $\delta$18O at the North Atlantic site of 0.30‰ during glacials.},
annote = {EPILOG},
author = {Waelbroeck, C and Labeyrie, L and Michel, E and Duplessy, J C and McManus, J F and Lambeck, K and Balbon, E and Labracherie, M},
doi = {10.1016/S0277-3791(01)00101-9},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
number = {1},
pages = {295--305},
title = {{Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379101001019},
volume = {21},
year = {2002}
}
@article{Wagner2019,
abstract = {Mediterranean climates are characterized by strong seasonal contrasts between dry summers and wet winters. Changes in winter rainfall are critical for regional socioeconomic development, but are difficult to simulate accurately1 and reconstruct on Quaternary timescales. This is partly because regional hydroclimate records that cover multiple glacial–interglacial cycles2,3 with different orbital geometries, global ice volume and atmospheric greenhouse gas concentrations are scarce. Moreover, the underlying mechanisms of change and their persistence remain unexplored. Here we show that, over the past 1.36 million years, wet winters in the northcentral Mediterranean tend to occur with high contrasts in local, seasonal insolation and a vigorous African summer monsoon. Our proxy time series from Lake Ohrid on the Balkan Peninsula, together with a 784,000-year transient climate model hindcast, suggest that increased sea surface temperatures amplify local cyclone development and refuel North Atlantic low-pressure systems that enter the Mediterranean during phases of low continental ice volume and high concentrations of atmospheric greenhouse gases. A comparison with modern reanalysis data shows that current drivers of the amount of rainfall in the Mediterranean share some similarities to those that drive the reconstructed increases in precipitation. Our data cover multiple insolation maxima and are therefore an important benchmark for testing climate model performance.},
author = {Wagner, Bernd and Vogel, Hendrik and Francke, Alexander and Friedrich, Tobias and Donders, Timme and Lacey, Jack H and Leng, Melanie J and Regattieri, Eleonora and Sadori, Laura and Wilke, Thomas and Zanchetta, Giovanni and Albrecht, Christian},
doi = {10.1038/s41586-019-1529-0},
journal = {Nature},
pages = {256--260},
title = {{Mediterranean winter rainfall in phase with African monsoons during the past 1.36 million years}},
volume = {573},
year = {2019}
}
@article{Wainer2014a,
abstract = {Climate indices based on sea surface temperature (SST) can synthesize information related to physical processes that describe change and variability in continental precipitation from floods to droughts. The South Atlantic Subtropical Dipole index (SASD) is based on the distribution of SST in the South Atlantic and fits these criteria. It represents the dominant mode of variability of SST in the South Atlantic, which is modulated by changes in the position and intensity of the South Atlantic Subtropical High. Here we reconstructed an index of the South Atlantic Ocean SST (SASD-like) for the past twelve thousand years (the Holocene period) based on proxy-data. This has great scientific implications and important socio-economic ramifications because of its ability to infer variability of precipitation and moisture over South America where past climate data is limited. For the first time a reconstructed index based on proxy data on opposite sides of the SASD-like mode is able to capture, in the South Atlantic, the significant cold events in the Northern Hemisphere at 12.9−11.6 kyr BP and 8.6−8.0 ky BP. These events are related, using a transient model simulation, to precipitation changes over South America.},
author = {Wainer, Ilana and Prado, Luciana Figueiredo and Khodri, Myriam and Otto-Bliesner, Bette},
doi = {10.1038/srep05291},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {5291},
title = {{Reconstruction of the South Atlantic Subtropical Dipole index for the past 12,000 years from surface temperature proxy}},
url = {https://doi.org/10.1038/srep05291},
volume = {4},
year = {2014}
}
@misc{WalshJ.E.W.L.ChapmanF.Fetterer2019,
address = {Boulder, CO, USA},
author = {Walsh, J. E. and Chapman, W. L. and Fetterer, F. and Stewart, J. S.},
doi = {10.7265/jj4s-tq79},
publisher = {National Snow and Ice Data Center (NSIDC)},
title = {{Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward, Version 2}},
url = {https://nsidc.org/data/g10010},
year = {2019}
}
@article{Walsh2017,
abstract = {Arctic sea ice data from a variety of historical sources have been synthesized into a database extending back to 1850 with monthly time-resolution. The synthesis procedure includes interpolation to a uniform grid and an analog-based estimation of ice concentrations in areas of no data. The consolidated database shows that there is no precedent as far back as 1850 for the 21st century's minimum ice extent of sea ice on the pan-Arctic scale. A regional-scale exception to this statement is the Bering Sea. The rate of retreat since the 1990s is also unprecedented and especially large in the Beaufort and Chukchi Seas. Decadal and multidecadal variations have occurred in some regions, but their magnitudes are smaller than that of the recent ice loss. Interannual variability is prominent in all regions and will pose a challenge to sea ice prediction efforts.},
author = {Walsh, John E. and Fetterer, Florence and {Scott Stewart}, J. and Chapman, William L.},
doi = {10.1111/j.1931-0846.2016.12195.x},
issn = {19310846},
journal = {Geographical Review},
keywords = {Arctic,climate change,ice extent,sea ice},
number = {1},
pages = {89--107},
title = {{A database for depicting Arctic sea ice variations back to 1850}},
volume = {107},
year = {2017}
}
@article{Wang2016g,
abstract = {Global warming seems leveling off somewhat during 1993–2013 despite increasing atmospheric greenhouse gases. What has happened to the Kuroshio Current system concurrently? Available independent data sets from 1993 to 2013 point to a single answer. Here we show a systemwide weakened Kuroshio during the period despite enhanced warming along its path. The Pacific warm pool upstream of the Kuroshio is still becoming warmer during the period. It injects more heat into the Current despite the weakened Kuroshio, which is associated with weakened westerlies and cyclonic trends of basin-scale wind stress curl. The weakened Kuroshio will modulate heat and mass exchanges between the tropics and extratropics, impacting the energy balance of climate system. It will also significantly influence mass, heat, salinity, and nutrient exchanges between the Pacific and adjacent marginal seas, which in turn impacts the regional weather, fisheries, and environments.},
author = {Wang, You-Lin and Wu, Chau-Ron and Chao, Shenn-Yu},
doi = {10.1002/2016GL069432},
isbn = {1944-8007},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {sep},
number = {17},
pages = {9200--9207},
title = {{Warming and weakening trends of the Kuroshio during 1993–2013}},
url = {http://doi.wiley.com/10.1002/2016GL069432},
volume = {43},
year = {2016}
}
@article{Wang2018,
abstract = {The Kuroshio transports warm water in the Pacific poleward from the tropics and plays a crucial role in modulating surrounding climate. Based on independent data sets, we demonstrated that the Kuroshio weakened downstream east of Taiwan, but intensified upstream east of Luzon Island during 1993--2013. The surface velocity (volume transport) of the Kuroshio has decreased 12.5{\%} (4{\~{}}5{\%}) off east Taiwan but increased 18{\%} (8{\~{}}18{\%}) off east Luzon. The discordant upstream--downstream trend was attributable to changes in oceanic eddies and basin surface winds: greater (lesser) cyclonic eddies, lesser (greater) anticyclonic eddies, and positive (negative) tendency in the Pacific Basin wind curl contributed to a weakened (intensified) downstream (upstream) Kuroshio. The difference in water mass between the upstream and downstream Kuroshio was balanced by an anomalous eastward flow, the southern branch of the Subtropical Counter Current which was enhanced and evacuated the redundant water eastward into the Pacific.},
author = {Wang, You-Lin and Wu, Chau-Ron},
doi = {10.1038/s41598-018-32843-y},
isbn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {14633},
title = {{Discordant multi-decadal trend in the intensity of the Kuroshio along its path during 1993–2013}},
volume = {8},
year = {2018}
}
@article{Wang2016f,
abstract = {This study inter-compares extratropical cyclone activity in the following nine reanalysis datasets: the ERA-20C Reanalysis (ERA20C), the Twentieth Century Reanalysis, version 2c (20CR), the Japanese 55-year Reanalysis (JRA55), the Modern Era Retrospective-analysis for Research and Applications (MERRA), the NCEP Climate Forecast System Reanalysis (CFSR), the ERA-Interim Reanalysis (ERAint), the ERA40 Reanalysis, the NCEP–NCAR Reanalysis (NCEP1), and the NCEP-DOE Reanalysis (NCEP2). The inter-comparison is based on cyclones identified using an objective cyclone tracking algorithm. In general, reanalyses of higher horizontal resolutions show higher cyclone counts, with MERRA and 20CR showing the highest and lowest mean counts of all-cyclones, respectively. However, MERRA shows the highest mean intensity (i.e., geostrophic winds) of all-cyclones, and CFSR the lowest, although MERRA and CFSR share a similar horizontal resolution. MERRA is most different from the other datasets, showing many more cyclones of shallow-medium core pressures and much higher counts of cyclones of strong intensity than the others, while CFSR shows many more cyclones of moderate intensity than the others. MERRA cyclones tend to have weaker surface winds but stronger geostrophic winds than the corresponding CFSR cyclones. The track-to-track agreement between the datasets is better for moderate-deep cyclones than for shallow ones, better in the NH than in the SH, and better in winter than in summer in both hemispheres. There is more similarity in temporal trends and variability than in specific cyclone counts and intensity, and more similarity in deep-cyclone (core pressure ≤ 980 hPa) statistics than in all-cyclone statistics. In particular, all the four datasets that cover the period from 1958 to 2010 agree well in terms of trend direction and interannual variability in hemispheric counts of deep-cyclones, showing a general increase in both hemispheres over the past half century, although the magnitude of increase varies notably from dataset to dataset. The agreement in trends of deep-cyclone counts is generally better in winter than in summer, and better in the NH than in the SH, with nearly perfect agreement for the counts of NH winter deep-cyclones. However, the nine datasets do not agree well in terms of trend and interannual variability in the mean intensity of deep cyclones, especially in summer and in SH winter. The temporal homogeneity of cyclone statistics in each dataset wa{\ldots}},
author = {Wang, Xiaolan L. and Feng, Yang and Chan, Rodney and Isaac, Victor},
doi = {10.1016/j.atmosres.2016.06.010},
isbn = {0169-8095},
issn = {01698095},
journal = {Atmospheric Research},
pages = {133--153},
publisher = {Elsevier B.V.},
title = {{Inter-comparison of extra-tropical cyclone activity in nine reanalysis datasets}},
volume = {181},
year = {2016}
}
@article{Wang2016e,
abstract = {Oceanic oxygen levels are projected to drop in certain areas due to warming climate, but the net effect to the overall ocean redox state is difficult to predict. Here we measured the “stable” uranium isotope composition (238U/235U) in globally representative hydrogenous ferromanganese crusts in order to reconstruct the redox evolution of the global ocean throughout the Cenozoic. Samples averaging ∼3 Myr intervals have analytically indistinguishable 238U/235U throughout the Cenozoic. Combined with a U isotope mass balance model, we suggest that the overall ocean redox state has remained remarkably stable on million year time scales throughout the Cenozoic, despite large surface temperature fluctuations during this time. This suggests that stabilizing feedbacks (for example, nutrient limitation in low oxygen zones) may have prevented dramatic large-scale shifts in oxygen levels in the ocean. However, the Fe-Mn crust record will be unlikely to reflect rapid perturbations in ocean redox state. To investigate these events, sediment archives with faster accumulation rates and redox proxies with faster response time must be explored.},
author = {Wang, Xiangli and Planavsky, Noah J. and Reinhard, Christopher T. and Hein, James R. and Johnson, Thomas M.},
doi = {10.2475/01.2016.02},
issn = {00029599},
journal = {American Journal of Science},
keywords = {Cenozoic marine redox,Redox proxies,Uranium isotopes},
month = {jan},
number = {11},
pages = {64--83},
publisher = {Yale University},
title = {{A Cenozoic seawater redox record derived from 238U/235U in ferromanganese crusts}},
volume = {315},
year = {2016}
}
@article{Wang2017c,
abstract = {The North Atlantic experiences climate variability on multidecadal scales, which is sometimes referred to as Atlantic multidecadal variability. However, the relative contributions of external forcing such as changes in solar irradiance or volcanic activity and internal dynamics to these variations are unclear. Here we provide evidence for persistent summer Atlantic multidecadal variability from AD 800 to 2010 using a network of annually resolved terrestrial proxy records from the circum-North Atlantic region. We find that large volcanic eruptions and solar irradiance minima induce cool phases of Atlantic multidecadal variability and collectively explain about 30{\%} of the variance in the reconstruction on timescales greater than 30 years. We are then able to isolate the internally generated component of Atlantic multidecadal variability, which we define as the Atlantic multidecadal oscillation. We find that the Atlantic multidecadal oscillation is the largest contributor to Atlantic multidecadal variability over the past 1,200 years. We also identify coherence between the Atlantic multidecadal oscillation and Northern Hemisphere temperature variations, leading us to conclude that the apparent link between Atlantic multidecadal variability and regional to hemispheric climate does not arise solely from a common response to external drivers, and may instead reflect dynamic processes.},
author = {Wang, Jianglin and Yang, Bao and Ljungqvist, Fredrik Charpentier and Luterbacher, J{\"{u}}rg and Osborn, Timothy J. and Briffa, Keith R and Zorita, Eduardo},
doi = {10.1038/ngeo2962},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {7},
pages = {512--517},
title = {{Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 years}},
url = {https://doi.org/10.1038/ngeo2962},
volume = {10},
year = {2017}
}
@article{Wang2013f,
author = {Wang, Bin and Liu, Jian and Kim, H.-J. and Webster, Peter J and Yim, S.-Y. and Xiang, Baoqiang},
doi = {10.1073/pnas.1219405110},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {apr},
number = {14},
pages = {5347--5352},
title = {{Northern Hemisphere summer monsoon intensified by mega-El Ni{\~{n}}o/southern oscillation and Atlantic multidecadal oscillation}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1219405110},
volume = {110},
year = {2013}
}
@article{WangY.BrandtM.ZhaoM.TongX.XingK.XueF.KangM.WangL.JiangY.Fensholt2018,
abstract = {The Loess Plateau in China is prone to widespread land degradation (soil erosion, deforestation, and water loss), and therefore, ecological restoration programmes aiming to re‐establish the ecosystem by revegetation have been implemented during recent decades. Consequently, a widespread increase in vegetation cover has been reported, but the state and dynamics of forests remain largely unknown. Here, we used field and satellite data to produce annual forest probability scores at 250 × 250 m between 2001 and 2016. We classified the forest dynamics into three types: net gain, net loss, and fluctuation. Assuming that an increasing probability score reflects forest growth, we categorised the annual forest areas into different growing stages indicating the transition between planting and mature forest. In total, the area of forest increase was 48,786 km2, and the percentage of forested areas of the region changed from 8.19{\%} to 15.82{\%} within 16 years. In areas of forest net gain, there was a clear transition from low‐ to high‐probability forest areas, providing evidence that a general forest transition is occurring on the Loess Plateau. The method developed for continuous monitoring of forest probability scores offers a benchmarking for further decision making on ecological restoration of the region and for mapping of afforestation projects elsewhere. The findings on major forest increases demonstrate that land degradation is in fact reversible, with implications for many ecosystem services (e.g., carbon storage and provisioning of forest products).},
author = {Wang, Yuhang and Brandt, Martin and Zhao, Mingfei and Tong, Xiaowei and Xing, Kaixiong and Xue, Feng and Kang, Muyi and Wang, Lanhui and Jiang, Yuan and Fensholt, Rasmus},
doi = {10.1002/ldr.3174},
journal = {Land Degradation and Development},
number = {11},
pages = {4080--4091},
title = {{Major forest increase on the Loess Plateau, China (2001–2016)}},
volume = {29},
year = {2018}
}
@article{Wang2020,
author = {Wang, Chenggong and Hu, Yongyun and Wen, Xinyu and Zhou, Chen and Liu, Jiping},
doi = {10.1007/s00382-020-05414-z},
isbn = {0123456789},
issn = {0930-7575},
journal = {Climate Dynamics},
keywords = {AOGCMs,Climate,Cold tongue,Double ITCZ,The Hadley circulation,aogcms,climate,cold tongue,double itcz,the hadley circulation},
month = {nov},
number = {9-10},
pages = {2823--2834},
publisher = {Springer Berlin Heidelberg},
title = {{Inter-model spread of the climatological annual mean Hadley circulation and its relationship with the double ITCZ bias in CMIP5}},
url = {https://doi.org/10.1007/s00382-020-05414-z https://link.springer.com/10.1007/s00382-020-05414-z},
volume = {55},
year = {2020}
}
@article{Wang2018g,
abstract = {Predictions of changes of the land monsoon rainfall (LMR) in the coming decades are of vital importance for successful sustainable economic development. Current dynamic models, though, have shown little skill in the decadal prediction of the Northern Hemisphere (NH) LMR (NHLMR). The physical basis and predictability for such predictions remain largely unexplored. Decadal change of the NHLMR reflects changes in the total NH continental precipitation, tropical general circulation, and regional land monsoon rainfall over northern Africa, India, East Asia, and North America. Using observations from 1901 to 2014 and numerical experiments, it is shown that the decadal variability of the NHLMR is rooted primarily in (i) the north-south hemispheric thermal contrast in the Atlantic-Indian Ocean sector measured by the North Atlantic-south Indian Ocean dipole (NAID) sea surface temperature (SST) index and (ii) an east-west thermal contrast in the Pacific measured by an extended El Ni{\~{n}}o-Southern Oscillation (XEN) index. Results from a 500-yr preindustrial control experiment demonstrate that the leading mode of decadal NHLMR and the associated NAID and XEN SST anomalies may be largely an internal mode of Earth's climate system, although possibly modified by natural and anthropogenic external forcing. A 51-yr, independent forward-rolling decadal hindcast was made with a hybrid dynamic conceptual model and using the NAID index predicted by a multiclimate model ensemble. The results demonstrate that the decadal changes in the NHLMR can be predicted approximately a decade in advance with significant skills, opening a promising way forward for decadal predictions of regional land monsoon rainfall worldwide.},
author = {Wang, Bin and Li, Juan and Cane, Mark A. and Liu, Jian and Webster, Peter J. and Xiang, Baoqiang and Kim, Hye Mi and Cao, Jian and Ha, Kyung Ja},
doi = {10.1175/JCLI-D-17-0521.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Atmosphere-ocean interaction,Climate prediction,Decadal variability,Monsoons},
number = {7},
pages = {2699--2714},
title = {{Toward predicting changes in the land monsoon rainfall a decade in advance}},
volume = {31},
year = {2018}
}
@article{Wang2016,
abstract = {AbstractThis study analyzes trends in precipitable water (PW) over land and ocean from 1988 to 2011, the PW–surface temperature Ts relationship, and their diurnal asymmetry using homogenized radiosonde data, microwave satellite observations, and ground-based global positioning system (GPS) measurements. It is found that positive PW trends predominate over the globe, with larger magnitudes over ocean than over land. The PW trend is correlated with surface warming spatially over ocean with a pattern correlation coefficient of 0.51. The PW percentage increase rate normalized by Ts expressed as is larger and closer to the rate implied by the Clausius–Clapeyron (C–C) equation over ocean than over land. The 2-hourly GPS PW data show that the PW trend from 1995 to 2011 is larger at night than during daytime. Nighttime PW monthly anomalies correlate positively and significantly with nighttime minimum temperature Tmin at all stations, but this is not true for daytime PW and maximum temperature Tmax. The ratio of r...},
author = {Wang, Junhong and Dai, Aiguo and Mears, Carl},
doi = {10.1175/JCLI-D-15-0485.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Climate change,Diurnal effects,Observational techniques and algorithms,Physical meteorology and climatology,Radiosonde observations,Satellite observations,Trends,Variability,Water vapor},
number = {14},
pages = {5205--5222},
title = {{Global water vapor trend from 1988 to 2011 and its diurnal asymmetry based on GPS, radiosonde, and microwave satellite measurements}},
volume = {29},
year = {2016}
}
@article{Wang2020e,
abstract = {This paper reviews the current knowledge on detection, attribution and projection of global and regional monsoons (South Asian, East Asian, Australian, South American, North American, and African) under climate change.},
author = {Wang, Bin and Biasutti, Michela and Byrne, Michael P. and Castro, Christopher and Chang, Chih-Pei and Cook, Kerry and Fu, Rong and Grimm, Alice M. and Ha, Kyung-Ja and Hendon, Harry and Kitoh, Akio and Krishnan, R. and Lee, June-Yi and Li, Jianping and Liu, Jian and Moise, Aurel and Pascale, Salvatore and Roxy, M. K. and Seth, Anji and Sui, Chung-Hsiung and Turner, Andrew and Yang, Song and Yun, Kyung-Sook and Zhang, Lixia and Zhou, Tianjun},
doi = {10.1175/bams-d-19-0335.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
number = {1},
pages = {E1--E19},
title = {{Monsoons Climate Change Assessment}},
volume = {102},
year = {2021}
}
@article{Wang2014,
abstract = {Monsoon has earned increasing attention from the climate community since the last century, yet only recently have regional monsoons been recognized as a global system. It remains a debated issue, however, as to what extent and at which timescales the global monsoon can be viewed as a major mode of climate variability. For this purpose, a PAGES (Past Global Changes) working group (WG) was set up to investigate the concept of the global monsoon and its future research directions. The WG's synthesis is presented here. On the basis of observation and proxy data, the WG found that the regional monsoons can vary coherently, although not perfectly, at various timescales, varying between interannual, interdecadal, centennial, millennial, orbital and tectonic timescales, conforming to the global monsoon concept across timescales. Within the global monsoon system, each subsystem has its own features, depending on its geographic and topographic conditions. Discrimination between global and regional components in the monsoon system is a key to revealing the driving factors in monsoon variations; hence, the global monsoon concept helps to enhance our understanding and to improve future projections of the regional monsoons. This paper starts with a historical review of the global monsoon concept in both modern and paleo-climatology, and an assessment of monsoon proxies used in regional and global scales. The main body of the paper is devoted to a summary of observation data at various timescales, providing evidence of the coherent global monsoon system. The paper concludes with a projection of future monsoon shifts in a warming world. The synthesis will be followed by a companion paper addressing driving mechanisms and outstanding issues in global monsoon studies.},
author = {Wang, P. X. and Wang, B. and Cheng, H. and Fasullo, J. and Guo, Z. T. and Kiefer, T. and Liu, Z. Y.},
doi = {10.5194/cp-10-2007-2014},
isbn = {1814-9324},
issn = {18149332},
journal = {Climate of the Past},
number = {6},
pages = {2007--2052},
title = {{The global monsoon across timescales: Coherent variability of regional monsoons}},
volume = {10},
year = {2014}
}
@article{Wang2017,
abstract = {The present paper addresses driving mechanisms of global monsoon (GM) variability and outstanding issues in GM science. This is the second synthesis of the PAGES GM Working Group following the first synthesis “The Global Monsoon across Time Scales: coherent variability of regional monsoons” published in 2014 (Climate of the Past, 10, 2007–2052). Here we introduce the GM as a planetary scale circulation system and give a brief accounting of why it exhibits regional structure. The primary driver of the GM is solar insolation, and the specific features in the underlying surface, such as land-sea distribution, topography, and oceanic circulations, are mainly responsible for the differences among regional monsoon systems. We then analyze the monsoon formation mechanisms, together with the major processes that drive monsoon variations at various timescales, including external forcings and internal feedbacks. On long time scales, external forcings often induce variability on a global scale, whereas short-term variability in regional monsoon systems is usually caused by internal feedbacks within the climate system. Finally, a number of debatable issues are discussed, with an emphasis on time scales beyond the instrumental record. These include the dual nature of the monsoon as wind and rain, the meaning of oxygen isotope in hydrological cycle, in particular of speleothem $\delta$18O, the role of ice-sheet in monsoon variations, etc. In general, the GM as a system comprises a hierarchy of regional and local monsoons with various degrees of similarity, though all show coherent variability driven by a common solar forcing. The goal of the GM concept, therefore, is by no means to replace or diminish research on the regional monsoons, but to help dissect the mechanisms and controlling factors of monsoon variability at various temporal-spatial scales.},
author = {Wang, Pin Xian and Wang, Bin and Cheng, Hai and Fasullo, John and Guo, ZhengTang and Kiefer, Thorsten and Liu, ZhengYu},
doi = {10.1016/j.earscirev.2017.07.006},
isbn = {0012-8252},
issn = {00128252},
journal = {Earth-Science Reviews},
keywords = {Climate variability,Hydrological cycle,Monsoon,Monsoon mechanism,Precipitation,Solar insolation},
month = {nov},
number = {July 2016},
pages = {84--121},
publisher = {Elsevier},
title = {{The global monsoon across time scales: Mechanisms and outstanding issues}},
url = {http://dx.doi.org/10.1016/j.earscirev.2017.07.006 https://linkinghub.elsevier.com/retrieve/pii/S0012825216302070},
volume = {174},
year = {2017}
}
@article{Wang2014a,
author = {Wang, Shanshan and Huang, Jianping and He, Yongli and Guan, Yuping},
doi = {10.1038/srep06651},
issn = {2045-2322},
journal = {Scientific Reports},
month = {may},
number = {1},
pages = {6651},
publisher = {The Author(s)},
title = {{Combined effects of the Pacific Decadal Oscillation and El Ni{\~{n}}o-Southern Oscillation on Global Land Dry–Wet Changes}},
url = {http://www.nature.com/articles/srep06651},
volume = {4},
year = {2014}
}
@article{Wang2016d,
abstract = {Satellite-derived vegetation phenology has been recognized as a key indicator for detecting changes in the terrestrial biosphere in response to global climate change. However, multi-decadal changes and spatial variation of vegetation phenology over the Northern Hemisphere and their relationship to climate change have not yet been fully investigated. In this article, we investigated the spatial variability and temporal trends of vegetation phenology over the Northern Hemisphere by calibrating and analyzing time series of the satellite-derived normalized difference vegetation index (NDVI) during 1982–2012, and then further examine how vegetation phenology responds to climate change within different ecological zones. We found that during the period from 1982 to 2012 most of the high latitude areas experienced an increase in growing period largely due to an earlier beginning of vegetation growing season (BGS), but there was no significant trend in the vegetation growing peaks. The spatial pattern of phenology within different eco-zones also experienced a large variation over the past three decades. Comparing the periods of 1982–1992, 1992–2002 with 2002–2012, the spatial pattern of change rate of phenology shift (RPS) shows a more significant trend in advancing of BGS, delaying of EGS (end of growing season) and prolonging of LGS (length of growing season) during 2002–2012, overall shows a trend of accelerating change. Temperature is a major determinant of phenological shifts, and the response of vegetation phenology to temperature varied across different eco-zones.},
author = {Wang, Siyuan and Yang, Bojuan and Yang, Qichun and Lu, Linlin and Wang, Xiaoyue and Peng, Yaoyao},
doi = {10.1371/journal.pone.0157134},
issn = {19326203},
journal = {PLOS ONE},
number = {6},
pages = {e0157134},
pmid = {27276082},
title = {{Temporal trends and spatial variability of vegetation phenology over the Northern Hemisphere during 1982–2012}},
volume = {11},
year = {2016}
}
@article{doi:10.1175/JTECH-D-13-00134.1,
abstract = {AbstractThe Advanced Microwave Sounding Unit-A (AMSU-A, 1998–present) not only continues but surpasses the Microwave Sounding Unit's (MSU, 1978–2006) capability in atmospheric temperature observation. It provides valuable satellite measurements for higher vertical resolution and long-term climate change research and trend monitoring. This study presented methodologies for generating 11 channels of AMSU-A-only atmospheric temperature data records from the lower troposphere to the top of the stratosphere. The recalibrated AMSU-A level 1c radiances recently developed by the Center for Satellite Applications and Research group were used. The recalibrated radiances were adjusted to a consistent sensor incidence angle (nadir), channel frequencies (prelaunch-specified central frequencies), and observation time (local solar noon time). Radiative transfer simulations were used to correct the sensor incidence angle effect and the National Oceanic and Atmospheric Administration-15 (NOAA-15) channel 6 frequency shift. Multiyear averaged diurnal/semidiurnal anomaly climatologies from climate reanalysis as well as climate model simulations were used to adjust satellite observations to local solar noon time. Adjusted AMSU-A measurements from six satellites were carefully quality controlled and merged to generate 13+ years (1998–2011) of a monthly 2.5° × 2.5° gridded atmospheric temperature data record. Major trend features in the AMSU-A-only atmospheric temperature time series, including global mean temperature trends and spatial trend patterns, were summarized.},
author = {Wang, Wenhui and Zou, Cheng-Zhi},
doi = {10.1175/JTECH-D-13-00134.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {4},
pages = {808--825},
title = {{AMSU-A-Only Atmospheric Temperature Data Records from the Lower Troposphere to the Top of the Stratosphere}},
url = {https://doi.org/10.1175/JTECH-D-13-00134.1},
volume = {31},
year = {2014}
}
@article{Wang2016,
abstract = {Tropopause temperatures (TPTs) control the amount of stratospheric water vapour, which influences chemistry, radiation and circulation in the stratosphere, and is also an important driver of surface climate. Decadal variability and long-term trends in tropical TPTs as well as stratospheric water vapour are largely unknown. Here, we present for the first time evidence, from reanalysis and state-of-the-art climate model simulations, of a link between decadal variability in tropical TPTs and the Pacific Decadal Oscillation (PDO). The negative phase of the PDO is associated with anomalously cold sea surface temperatures (SSTs) in the tropical east and central Pacific, which enhance the zonal SST gradient across the equatorial Pacific. The latter drives a stronger Walker Circulation and a weaker Hadley Circulation, which leads to less convection and subsequently a warmer tropopause over the central equatorial Pacific. Over the North Pacific, positive sea level pressure anomalies occur, which damp vertical wave propagation into the stratosphere. This in turn slows the Brewer-Dobson circulation, and hence warms the tropical tropopause, enabling more water vapour to enter the stratosphere. The reverse chain of events holds for the positive phase of the PDO. Such ocean-troposphere-stratosphere interactions may provide an important feedback on the Earth's global surface temperature.},
author = {Wang, Wuke and Matthes, Katja and Omrani, Nour Eddine and Latif, Mojib},
doi = {10.1038/srep29537},
issn = {20452322},
journal = {Scientific Reports},
pages = {29537},
title = {{Decadal variability of tropical tropopause temperature and its relationship to the Pacific Decadal Oscillation}},
volume = {6},
year = {2016}
}
@article{Wang2020f,
abstract = {Atmospheric water vapor plays a key role in the global water and energy cycles. Accurate estimation of water vapor and consistent representation of its spatial-temporal variation are critical to climate analysis and model validation. This study used ground observational data from global radiosonde and sunphotometer networks to evaluate MODIS (MODerate-resolution Imaging Spectroradiometer) precipitable water vapor (PWV) products for 2000–2017. The products included the thermal-infrared (TIR) (Collection 6, C006) and its updated version (Collection 061, C061), and near-infrared (NIR) products (C061). Our results demonstrated that compared to its earlier version subject to sensor crosstalk problem, the C061{\_}TIR data showed improved accuracy in terms of bias, standard deviation, mean absolute error, root mean square error, and coefficient of determination, regression slope and intercept. Among the PWV products, C061{\_}NIR data achieved the best overall performance in accuracy evaluation. The C061{\_}NIR revealed the PWV had a multi-year average of 2.50 ± 0.08 cm for the globe, 2.03 ± 0.06 cm for continents, and 2.70 ± 0.09 cm for oceans in 2000–2017. The PWV values yielded an increasing rate of 0.015 cm/year for the globe, 0.010 cm/year for continents, and 0.017 cm/year for oceans. Nearly 98.95{\%} of the globe showed an increasing trend, 80.74{\%} of statistical significance, mainly distributed within and around the tropical zones. The findings should be valuable for understanding of global water and energy cycles.},
author = {Wang, Ruonan and Liu, Yuanbo},
doi = {10.1016/j.rse.2020.111896},
issn = {00344257},
journal = {Remote Sensing of Environment},
keywords = {Climate change,Global precipitable water vapor,MODIS,Radiosonde,Sunphotometer},
number = {May},
pages = {111896},
publisher = {Elsevier},
title = {{Recent declines in global water vapor from MODIS products: Artifact or real trend?}},
url = {https://doi.org/10.1016/j.rse.2020.111896},
volume = {247},
year = {2020}
}
@article{ResponseofSouthernChinaWinterRainfalltoElNioDiversityandItsRelevancetoProjectedSouthernChinaRainfallChange,
address = {Boston MA, USA},
author = {Wang, Qiang and Cai, Wenju and Zhong, Wenxiu and Zeng, Lili and Wu, Lixin and Wang, Dongxiao},
doi = {10.1175/JCLI-D-18-0571.1},
journal = {Journal of Climate},
number = {11},
pages = {3343--3356},
publisher = {American Meteorological Society},
title = {{Response of Southern China Winter Rainfall to El Ni{\~{n}}o Diversity and Its Relevance to Projected Southern China Rainfall Change}},
url = {https://journals.ametsoc.org/view/journals/clim/32/11/jcli-d-18-0571.1.xml},
volume = {32},
year = {2019}
}
@article{Wang2017b,
abstract = {An interdecadal weakening in the North Atlantic storm track (NAST) and a poleward shift of the North Pacific storm track (NPST) are found during October–March for the period 1979–2015. A significant warming of surface air temperature (Ts) over northeastern North America and a La Ni{\~{n}}a–like change in the North Pacific under the background of Arctic amplification are found to be the contributors to the observed changes in the NAST and the NPST, respectively, via modulation of local baroclinicity. The interdecadal change in baroclinic energy conversion is consistent with changes in storm tracks with an energy loss from eddies to mean flow over the North Atlantic and an energy gain over the North Pacific. The analysis of simulations from the Community Earth System Model Large Ensemble project, although with some biases in storm-track and Ts simulations, supports the observed relationship between the NAST and Ts over northeastern North America, as well as the link between the NPST and El Ni{\~{n}}o–Southern Oscillation. The near-future projections of Ts and storm tracks are characterized by a warmer planet under the influence of increasing greenhouse gases and a significant weakening of both the NAST and the NPST. The potential role of the NAST in redistributing changes in Ts over the surrounding regions is also examined. The anomalous equatorward moisture flux associated with the weakening trend of the NAST would enhance the warming over its upstream region and hinder the warming over its downstream region via modulation of the downward infrared radiation.},
author = {Wang, Jiabao and Kim, Hye-Mi and Chang, Edmund K. M.},
doi = {10.1175/JCLI-D-16-0650.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {may},
number = {10},
pages = {3705--3724},
title = {{Changes in Northern Hemisphere Winter Storm Tracks under the Background of Arctic Amplification}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0650.1},
volume = {30},
year = {2017}
}
@article{Ward2015,
abstract = {Identifying and quantifying the sources of climate impacts from land use and land cover change (LULCC) is necessary to optimize policies regarding LULCC for climate change mitigation. These climate impacts are typically defined relative to emissions of CO2, or sometimes emissions of other long-lived greenhouse gases. Here we use previously published estimates of the radiative forcing (RF) of LULCC that include the short-lived forcing agents O3 and aerosols, in addition to long-lived greenhouse gases and land albedo change, for six projections of LULCC as a metric for quantifying climate impacts. The LULCC RF is attributed to three categories of LULCC activities: direct modifications to land cover, agriculture, and wildfire response, and sources of the forcing are ascribed to individual grid points for each sector. Results for the year 2010 show substantial positive forcings from the direct modifications and agriculture sectors, particularly from India, China, and southeast Asia, and a smaller magnitude negative forcing response from wildfires. The RF from direct modifications, mainly deforestation activities, exhibits a large range in future outcomes for the standard future scenarios implying that these activities, and not agricultural emissions (which lead to more consistent RFs between scenarios), will drive the LULCC RF in the future. We show that future forest area change can be used as a predictor of the future RF from direct modification activities, especially in the tropics, suggesting that deforestation-prevention policies that 20 value land based on its C-content may be particularly effective at mitigating climate forcing originating in the tropics from this sector. Although, the response of wildfire RF to tropical land cover changes is not as easily scalable and yet imposes a non-trivial feedback onto the total LULCC RF. [ABSTRACT FROM AUTHOR]},
author = {Ward, D. S. and Mahowald, N. M.},
doi = {10.5194/esd-6-175-2015},
issn = {21904987},
journal = {Earth System Dynamics},
number = {1},
pages = {175--194},
title = {{Local sources of global climate forcing from different categories of land use activities}},
volume = {6},
year = {2015}
}
@article{Ward2014,
abstract = {Pressure on land resources is expected to increase as global population continues to climb and the world becomes more affluent, swelling the demand for food. Changing climate may exert additional pressures on natural lands as present-day productive regions may shift, or soil quality may degrade, and the recent rise in demand for biofuels increases competition with edible crops for arable land. Given these projected trends there is a need to understand the global climate impacts of land use and land cover change (LULCC). Here we quantify the climate impacts of global LULCC in terms of modifications to the balance between incoming and outgoing radiation at the top of the atmosphere (radiative forcing, RF) that are caused by changes in long-lived and short-lived greenhouse gas concentrations, aerosol effects, and land surface albedo. We attribute historical changes in terrestrial carbon storage, global fire emissions, secondary organic aerosol emissions, and surface albedo to LULCC using simulations with the Community Land Model version 3.5. These LULCC emissions are combined with estimates of agricultural emissions of important trace gases and mineral dust in two sets of Community Atmosphere Model simulations to calculate the RF of changes in atmospheric chemistry and aerosol concentrations attributed to LULCC. With all forcing agents considered together, we show that 40{\%} (±16{\%}) of the present-day anthropogenic RF can be attributed to LULCC. Changes in the emission of non-CO2 greenhouse gases and aerosols from LULCC enhance the total LULCC RF by a factor of 2 to 3 with respect to the LULCC RF from CO2 alone. This enhancement factor also applies to projected LULCC RF, which we compute for four future scenarios associated with the Representative Concentration Pathways. We attribute total RFs between 0.9 and 1.9 W m−2 to LULCC for the year 2100 (relative to a pre-industrial state). To place an upper bound on the potential of LULCC to alter the global radiation budget, we include a fifth scenario in which all arable land is cultivated by 2100. This theoretical extreme case leads to a LULCC RF of 3.9 W m−2 (±0.9 W m−2), suggesting that not only energy policy but also land policy is necessary to minimize future increases in RF and associated climate changes.},
author = {Ward, D. S. and Mahowald, N. M. and Kloster, S.},
doi = {10.5194/acp-14-12701-2014},
isbn = {1412701201},
issn = {16807324},
journal = {Atmospheric Chemistry and Physics},
number = {23},
pages = {12701--12724},
title = {{Potential climate forcing of land use and land cover change}},
volume = {14},
year = {2014}
}
@article{Warren1999,
abstract = {Abstract Snow depth and density were measured at Soviet drifting stations on multiyear Arctic sea ice. Measurements were made daily at fixed stakes at the weather station and once- or thrice-monthly at 10-m intervals on a line beginning about 500 m from the station buildings and extending outward an additional 500 or 1000 m. There were 31 stations, with lifetimes of 1–7 yr. Analyses are performed here for the 37 years 1954–91, during which time at least one station was always reporting. Snow depth at the stakes was sometimes higher than on the lines, and sometimes lower, but no systematic trend of snow depth was detected as a function of distance from the station along the 1000-m lines that would indicate an influence of the station. To determine the seasonal progression of snow depth for each year at each station, priority was given to snow lines if available; otherwise the fixed stakes were used, with an offset applied if necessary. The ice is mostly free of snow during August. Snow accumulates rapidly ...},
author = {Warren, Stephen G. and Rigor, Ignatius G. and Untersteiner, Norbert and Radionov, Vladimir F. and Bryazgin, Nikolay N. and Aleksandrov, Yevgeniy I. and Colony, Roger},
doi = {10.1175/1520-0442(1999)012<1814:SDOASI>2.0.CO;2},
isbn = {0894-8755},
issn = {08948755},
journal = {Journal of Climate},
number = {6},
pages = {1814--1829},
title = {{Snow depth on Arctic sea ice}},
volume = {12},
year = {1999}
}
@article{Watanabe2011,
author = {Watanabe, Tsuyoshi and Suzuki, Atsushi and Minobe, Shoshiro and Kawashima, Tatsunori and Kameo, Koji and Minoshima, Kayo and Aguilar, Yolanda M and Wani, Ryoji and Kawahata, Hodaka and Sowa, Kohki and Nagai, Takaya and Kase, Tomoki},
doi = {10.1038/nature09777},
journal = {Nature},
month = {mar},
pages = {209--211},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Permanent El Ni{\~{n}}o during the Pliocene warm period not supported by coral evidence}},
url = {https://doi.org/10.1038/nature09777 http://10.0.4.14/nature09777 https://www.nature.com/articles/nature09777{\#}supplementary-information},
volume = {471},
year = {2011}
}
@article{Watson2015,
abstract = {The rate of global mean sea-level (GMSL) rise has been suggested to be lower for the past decade compared with the preceding decade as a result of natural variability, with an average rate of rise since 1993 of +3.2 ± 0.4 mm yr {\^{a}} '1 (refs,). However, satellite-based GMSL estimates do not include an allowance for potential instrumental drifts (bias drift). Here, we report improved bias drift estimates for individual altimeter missions from a refined estimation approach that incorporates new Global Positioning System (GPS) estimates of vertical land movement (VLM). In contrast to previous results (for example, refs,), we identify significant non-zero systematic drifts that are satellite-specific, most notably affecting the first 6 years of the GMSL record. Applying the bias drift corrections has two implications. First, the GMSL rate (1993 to mid-2014) is systematically reduced to between +2.6 ± 0.4 mm yr {\^{a}} '1 and +2.9 ± 0.4 mm yr {\^{a}} '1, depending on the choice of VLM applied. These rates are in closer agreement with the rate derived from the sum of the observed contributions, GMSL estimated from a comprehensive network of tide gauges with GPS-based VLM applied (updated from ref.) and reprocessed ERS-2/Envisat altimetry. Second, in contrast to the previously reported slowing in the rate during the past two decades, our corrected GMSL data set indicates an acceleration in sea-level rise (independent of the VLM used), which is of opposite sign to previous estimates and comparable to the accelerated loss of ice from Greenland and to recent projections, and larger than the twentieth-century acceleration.},
author = {Watson, Christopher S and White, Neil J and Church, John A and King, Matt A and Burgette, Reed J and Legresy, Benoit},
doi = {10.1038/nclimate2635},
issn = {17586798},
journal = {Nature Climate Change},
number = {6},
pages = {565--568},
title = {{Unabated global mean sea-level rise over the satellite altimeter era}},
volume = {5},
year = {2015}
}
@article{Waugh2017,
abstract = {AbstractThe term polar vortex has become part of the everyday vocabulary, but there is some confusion in the media, general public, and science community regarding what polar vortices are and how they are related to various weather events. Here, we clarify what is meant by polar vortices in the atmospheric science literature. It is important to recognize the existence of two separate planetary-scale circumpolar vortices: one in the stratosphere and the other in the troposphere. These vortices have different structures, seasonality, dynamics, and impacts on extreme weather. The tropospheric vortex is much larger than its stratospheric counterpart and exists year-round, whereas the stratospheric polar vortex forms in fall but disappears in the spring of each year. Both vortices can, in some circumstances, play a role in extreme weather events at the surface, such as cold-air outbreaks, but these events are not the consequence of either the existence or gross properties of these two vortices. Rather, cold-air outbreaks are most directly related to transient, localized displacements of the edge of the tropospheric polar vortex that may, in some circumstances, be related to the stratospheric polar vortex, but there is no known one-to-one connection between these phenomena.},
author = {Waugh, Darryn W. and Sobel, Adam H. and Polvani, Lorenzo M.},
doi = {10.1175/BAMS-D-15-00212.1},
issn = {00030007},
journal = {Bulletin of the American Meteorological Society},
number = {1},
pages = {37--44},
title = {{What is the polar vortex and how does it influence weather?}},
volume = {98},
year = {2017}
}
@article{WCRPGlobalSeaLevelBudgetGroup2018,
abstract = {Abstract. Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g., acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or poorly known contributions, such as the unsurveyed deep ocean or the still uncertain land water component. In the context of the World Climate Research Programme Grand Challenge entitled Regional Sea Level and Coastal Impacts, an international effort involving the sea-level community worldwide has been recently initiated with the objective of assessing the various datasets used to estimate components of the sea-level budget during the altimetry era (1993 to present). These datasets are based on the combination of a broad range of space-based and in situ observations, model estimates, and algorithms. Evaluating their quality, quantifying uncertainties and identifying sources of discrepancies between component estimates is extremely useful for various applications in climate research. This effort involves several tens of scientists from about 50 research teams/institutions worldwide (www.wcrp-climate.org/grand-challenges/gc-sea-level, last access: 22 August 2018). The results presented in this paper are a synthesis of the first assessment performed during 2017–2018. We present estimates of the altimetry-based global mean sea level (average rate of 3.1±0.3mmyr−1 and acceleration of 0.1mmyr−2 over 1993–present), as well as of the different components of the sea-level budget (http://doi.org/10.17882/54854, last access: 22 August 2018). We further examine closure of the sea-level budget, comparing the observed global mean sea level with the sum of components. Ocean thermal expansion, glaciers, Greenland and Antarctica contribute 42{\%}, 21{\%}, 15{\%} and 8{\%} to the global mean sea level over the 1993–present period. We also study the sea-level budget over 2005–present, using GRACE-based ocean mass estimates instead of the sum of individual mass components. Our results demonstrate that the global mean sea level can be closed to within 0.3mmyr−1 (1$\sigma$). Substantial uncertainty remains for the land water storage component, as shown when examining individual mass contributions to sea level.},
author = {{WCRP Global Sea Level Budget Group}},
doi = {10.5194/essd-10-1551-2018},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {aug},
number = {3},
pages = {1551--1590},
title = {{Global sea-level budget 1993–present}},
volume = {10},
year = {2018}
}
@article{https://doi.org/10.1029/2018JF004988,
abstract = {Ice rises are regions of grounded ice embedded within floating ice shelves. The deformation of ice past them increases the back stress generated by the ice shelf, slowing the flow of the ice sheet. We present ground-based ice-penetrating radar data from Henry Ice Rise in the Ronne Ice Shelf, West Antarctica, that indicates regrounding during the Holocene. Relic crevasses and melt synclines are observed upstream of the present-day grounding line. We conclude that these features formed during a previous flow configuration, from which the grounding line has since advanced to its current position. In agreement with previous work, our observations can be explained if initial grounding of the ice shelf occurred on a bathymetric high, forming an ice rumple that migrated upstream and temporarily ungrounded over the topographic high. The grounding line then advanced, preserving relic basal crevasses in the newly grounded ice. Using a simple ice-flow model, we simulate the burial of these crevasses. While accounting for uncertainty in accumulation, firn density, radar-derived depth, ice-thickening history, initial crevasse height, and glacial isostatic adjustment, we estimate a burial time of 6 ± 2 kyr before present for the oldest relic crevasses, indicating that the ice rise formed at approximately this time. This potentially increased the buttressing generated by the Ronne Ice Shelf, causing thickening and advance of the ice sheet. By dating the formation and providing details of ice-rise formation, these new results can provide useful constraints on both large-scale ice-sheet models and models of ice-rumple and ice-rise formation.},
author = {Wearing, Martin G and Kingslake, Jonathan},
doi = {10.1029/2018JF004988},
journal = {Journal of Geophysical Research: Earth Surface},
keywords = {Antarctica,grounding line,ice flow,ice rise,ice sheet,ice sheet history},
number = {8},
pages = {2224--2240},
title = {{Holocene Formation of Henry Ice Rise, West Antarctica, Inferred From Ice-Penetrating Radar}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JF004988},
volume = {124},
year = {2019}
}
@article{Webster2018,
abstract = {Snow is the most reflective, and also the most insulative, natural material on Earth. Consequently, it is an integral part of the sea-ice and climate systems. However, the spatial and temporal heterogeneities of snow pose challenges for observing, understanding and modelling those systems under anthropogenic warming. Here, we survey the snow–ice system, then provide recommendations for overcoming present challenges. These include: collecting process-oriented observations for model diagnostics and understanding snow–ice feedbacks, and improving our remote sensing capabilities of snow for monitoring large-scale changes in snow on sea ice. These efforts could be achieved through stronger coordination between the observational, remote sensing and modelling communities, and would pay dividends through distinct improvements in predictions of polar environments.},
author = {Webster, Melinda and Gerland, Sebastian and Holland, Marika and Hunke, Elizabeth and Kwok, Ron and Lecomte, Olivier and Massom, Robert and Perovich, Don and Sturm, Matthew},
doi = {10.1038/s41558-018-0286-7},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {nov},
number = {11},
pages = {946--953},
title = {{Snow in the changing sea-ice systems}},
url = {http://www.nature.com/articles/s41558-018-0286-7},
volume = {8},
year = {2018}
}
@article{Wei2019,
author = {Wei, Jing and Peng, Yiran and Mahmood, Rashed and Sun, Lin and Guo, Jianping},
doi = {10.5194/acp-19-7183-2019},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {may},
number = {10},
pages = {7183--7207},
title = {{Intercomparison in spatial distributions and temporal trends derived from multi-source satellite aerosol products}},
url = {https://www.atmos-chem-phys.net/19/7183/2019/},
volume = {19},
year = {2019}
}
@article{Wei2020,
abstract = {Predicting river discharge and inundation is crucial for water resources management and flood hazard reduction; however, it is still unclear to what extent their variabilities can be captured on global scale. This study evaluates uncertainty sources in the quasi-global river discharge and inundation simulations using the Variable Infiltration Capacity (VIC) macroscale hydrologic model and the Catchment-based Macroscale Floodplain (CaMa-Flood) hydrodynamic model, forced with five high-resolution satellite precipitation datasets. The simulated discharge is first evaluated against more than 2852 sites selected from the Global Streamflow Indices and Metadata Archive (GSIM) dataset, and then the simulated inundation is compared with complementary multiple satellite observations. Globally, about 38{\%} – 43{\%} of the stations produce reasonable discharge simulations with positive Kling-Gupta Efficiency (KGE) on monthly time scale. The simulations show good agreement for flood fractions with mean correlations ranging from 0.47 to 0.62 for satellite detected events. The potential uncertainties sources of discharge and inundation simulation related to physics setting and forcing datasets, such as precipitation, land surface model, routing model, and observation from site and satellite are discussed, as well as future directions for improving large-scale model applications. By using default model settings, we hope our study can offer valuable insights into the applicability of flood simulations and provide guides for model development.},
author = {Wei, Zhongwang and He, Xiaogang and Zhang, Yonggen and Pan, Ming and Sheffield, Justin and Peng, Liqing and Yamazaki, Dai and Moiz, Abdul and Liu, Yaping and Ikeuchi, Koji},
doi = {10.1016/j.jhydrol.2020.125180},
issn = {00221694},
journal = {Journal of Hydrology},
keywords = {Floodplain hydrodynamic model,Inundation simulations,Land surface model,River discharge,Uncertainty sources},
pages = {125180},
title = {{Identification of uncertainty sources in quasi-global discharge and inundation simulations using satellite-based precipitation products}},
volume = {589},
year = {2020}
}
@article{Wen2014,
abstract = {Pacific Decadal Oscillation (PDO) index is an important indicator of climate variability. However, large discrepancies are found among real-time PDO monitoring indices maintained by several operational centers, with larger uncertainty exhibiting prior to 1950s and after late 1990s on seasonal to decadal time scales. Two historical sea surface temperature (SST) data sets are used to investigate causes for the uncertainty: the Extended Reconstructed Sea Surface Temperature version 3b (ERSST 3b) and the Hadley Center Sea Ice and SST data set (HadISST) version 1. It is found that choices of spatial structure of Empirical Orthogonal Function (EOF) vector and SST data set are important sources of uncertainty on seasonal to decadal time scales, while choice of climatological base period only contributes to uncertainty on seasonal time scale. Decadal variation of differences in PDO indices from ERSST and HadISST is associated with systematic differences between the two data sets in the central and the north-eastern Pacific.},
author = {Wen, Caihong and Kumar, Arun and Xue, Yan},
doi = {10.1002/2014GL061992},
isbn = {0094-8276},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {PDO,SST,uncertainty},
number = {22},
pages = {7980--7986},
title = {{Factors contributing to uncertainty in Pacific Decadal Oscillation index}},
volume = {41},
year = {2014}
}
@article{Wendt2019,
author = {Wendt, Kathleen A and H{\"{a}}uselmann, Anamaria D and Fleitmann, Dominik and Berry, Akemi E and Wang, Xianfeng and Auler, Augusto S and Cheng, Hai and Edwards, R Lawrence},
doi = {10.1016/j.epsl.2018.12.025},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
pages = {94--102},
publisher = {Elsevier B.V.},
title = {{Three-phased Heinrich Stadial 4 recorded in NE Brazil stalagmites}},
url = {https://doi.org/10.1016/j.epsl.2018.12.025},
volume = {510},
year = {2019}
}
@article{cp-14-527-2018,
author = {Werner, J P and Divine, D V and {Charpentier Ljungqvist}, F and Nilsen, T and Francus, P},
doi = {10.5194/cp-14-527-2018},
journal = {Climate of the Past},
number = {4},
pages = {527--557},
title = {{Spatio-temporal variability of Arctic summer temperatures over the past 2 millennia}},
url = {https://www.clim-past.net/14/527/2018/},
volume = {14},
year = {2018}
}
@article{West2020,
abstract = {Early Eocene climates were globally warm, with ice-free conditions at both poles. Early Eocene polar landmasses supported extensive forest ecosystems of a primarily temperate biota but also with abundant thermophilic elements, such as crocodilians, and mesothermic taxodioid conifers and angiosperms. The globally warm early Eocene was punctuated by geologically brief hyperthermals such as the Paleocene-Eocene Thermal Maximum (PETM), culminating in the Early Eocene Climatic Optimum (EECO), during which the range of thermophilic plants such as palms extended into the Arctic. Climate models have struggled to reproduce early Eocene Arctic warm winters and high precipitation, with models invoking a variety of mechanisms, from atmospheric classCombining double low CO2 levels that are unsupported by proxy evidence to the role of an enhanced hydrological cycle, to reproduce winters that experienced no direct solar energy input yet remained wet and above freezing. Here, we provide new estimates of climate and compile existing paleobotanical proxy data for upland and lowland midlatitude sites in British Columbia, Canada, and northern Washington, USA, and from high-latitude lowland sites in Alaska and the Canadian Arctic to compare climatic regimes between the middle and high latitudes of the early Eocene - spanning the PETM to the EECO - in the northern half of North America. In addition, these data are used to reevaluate the latitudinal temperature gradient in North America during the early Eocene and to provide refined biome interpretations of these ancient forests based on climate and physiognomic data.},
author = {West, Christopher K. and Greenwood, David R. and Reichgelt, Tammo and Lowe, Alexander J. and Vachon, Janelle M. and Basinger, James F.},
doi = {10.5194/cp-16-1387-2020},
issn = {18149332},
journal = {Climate of the Past},
number = {4},
pages = {1387--1410},
title = {{Paleobotanical proxies for early Eocene climates and ecosystems in northern North America from middle to high latitudes}},
volume = {16},
year = {2020}
}
@article{Westerhold1383,
abstract = {Deep-sea benthic foraminifera preserve an essential record of Earth{\{}$\backslash$textquoteright{\}}s past climate in their oxygen- and carbon-isotope compositions. However, this record lacks sufficient temporal resolution and/or age control in some places to determine which climate forcing and feedback mechanisms were most important. Westerhold et al. present a highly resolved and well-dated record of benthic carbon and oxygen isotopes for the past 66 million years. Their reconstruction and analysis show that Earth{\{}$\backslash$textquoteright{\}}s climate can be grouped into discrete states separated by transitions related to changing greenhouse gas levels and the growth of polar ice sheets. Each climate state is paced by orbital cycles but responds to variations in radiative forcing in a state-dependent manner.Science, this issue p. 1383Much of our understanding of Earth{\{}$\backslash$textquoteright{\}}s past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a new, highly resolved, astronomically dated, continuous composite of benthic foraminifer isotope records developed in our laboratories. Four climate states{\{}$\backslash$textemdash{\}}Hothouse, Warmhouse, Coolhouse, Icehouse{\{}$\backslash$textemdash{\}}are identified on the basis of their distinctive response to astronomical forcing depending on greenhouse gas concentrations and polar ice sheet volume. Statistical analysis of the nonlinear behavior encoded in our record reveals the key role that polar ice volume plays in the predictability of Cenozoic climate dynamics.},
author = {Westerhold, Thomas and Marwan, Norbert and Drury, Anna Joy and Liebrand, Diederik and Agnini, Claudia and Anagnostou, Eleni and Barnet, James S K and Bohaty, Steven M and {De Vleeschouwer}, David and Florindo, Fabio and Frederichs, Thomas and Hodell, David A and Holbourn, Ann E and Kroon, Dick and Lauretano, Vittoria and Littler, Kate and Lourens, Lucas J and Lyle, Mitchell and P{\"{a}}like, Heiko and R{\"{o}}hl, Ursula and Tian, Jun and Wilkens, Roy H and Wilson, Paul A and Zachos, James C},
doi = {10.1126/science.aba6853},
issn = {0036-8075},
journal = {Science},
number = {6509},
pages = {1383--1387},
publisher = {American Association for the Advancement of Science},
title = {{An astronomically dated record of Earth's climate and its predictability over the last 66 million years}},
url = {https://science.sciencemag.org/content/369/6509/1383},
volume = {369},
year = {2020}
}
@article{doi:10.1002/2017GL075433,
abstract = {Abstract El Ni{\~{n}}o–Southern Oscillation (ENSO) dominates interannual climate variability; thus, understanding its response to climate forcing is critical. ENSO's sensitivity to changing insolation is poorly understood, due to contrasting interpretations of Holocene proxy records. Some records show dampened ENSO during the early to mid-Holocene, consistent with insolation forcing of ENSO amplitude, but other records emphasize decadal-centennial fluctuations in ENSO strength, with no clear trend. To clarify Holocene ENSO behavior, we collected proxy data spanning the last {\~{}}12 kyr and find relatively low El Ni{\~{n}}o amplitude during the early to mid-Holocene. Our data, together with published work, indicate both a long-term trend in ENSO strength due to June insolation forcing and high-amplitude decadal-centennial fluctuations; both behaviors are shown in models. The best supported mechanism for insolation-driven dampening of ENSO is weakening of the upwelling feedback by insolation-forced warming/deepening of thermocline source waters. Elucidating the thermocline's role will help predict future ENSO change.},
author = {White, Sarah M and Ravelo, A Christina and Polissar, Pratigya J},
doi = {10.1002/2017GL075433},
journal = {Geophysical Research Letters},
keywords = {ENSO,foraminifera,insolation,paleoceanography,paleoclimate,tropical Pacific},
number = {1},
pages = {316--326},
title = {{Dampened El Ni{\~{n}}o in the Early and Mid-Holocene Due To Insolation-Forced Warming/Deepening of the Thermocline}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL075433},
volume = {45},
year = {2018}
}
@article{amt-11-1333-2018,
author = {Wilhelmsen, H and Ladst{\"{a}}dter, F and Scherllin-Pirscher, B and Steiner, A K},
doi = {10.5194/amt-11-1333-2018},
journal = {Atmospheric Measurement Techniques},
number = {3},
pages = {1333--1346},
title = {{Atmospheric QBO and ENSO indices with high vertical resolution from GNSS radio occultation temperature measurements}},
url = {https://www.atmos-meas-tech.net/11/1333/2018/},
volume = {11},
year = {2018}
}
@article{Willett2019,
author = {Willett, Kate M. and Dunn, Robert J. H. and Kennedy, John J. and Berry, David I.},
doi = {10.5194/essd-12-2853-2020},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {nov},
number = {4},
pages = {2853--2880},
publisher = {Copernicus Publications},
title = {{Development of the HadISDH.marine humidity climate monitoring dataset}},
url = {https://essd.copernicus.org/articles/12/2853/2020/},
volume = {12},
year = {2020}
}
@article{Willett2014,
author = {Willett, K M and Dunn, R J H and Thorne, P W and Bell, S and Podesta, M De and Parker, D E and Jones, P D and Jr, C N Williams},
doi = {10.5194/cp-10-1983-2014},
journal = {Climate of the Past},
pages = {1983--2006},
title = {{HadISDH land surface multi-variable humidity and temperature record for climate monitoring}},
volume = {10},
year = {2014}
}
@article{doi:10.1029/2011JD016761,
abstract = {Changes in the circumstances behind in situ temperature measurements often lead to biases in individual station records that, collectively, can also bias regional temperature trends. Since these biases are comparable in magnitude to climate change signals, homogeneity “corrections” are necessary to make the records suitable for climate analysis. To quantify the effectiveness of U.S. surface temperature homogenization, a randomized perturbed ensemble of the USHCN pairwise homogenization algorithm was run against a suite of benchmark analogs to real monthly temperature data. Results indicate that all randomized versions of the algorithm consistently produce homogenized data closer to the true climate signal in the presence of widespread systematic errors. When applied to the real-world observations, the randomized ensemble reinforces previous understanding that the two dominant sources of bias in the U.S. temperature records are caused by changes to time of observation (spurious cooling in minimum and maximum) and conversion to electronic resistance thermometers (spurious cooling in maximum and warming in minimum). Error bounds defined by the ensemble output indicate that maximum temperature trends are positive for the past 30, 50 and 100 years, and that these maximums contain pervasive negative biases that cause the unhomogenized (raw) trends to fall below the lower limits of uncertainty. Moreover, because residual bias in the homogenized analogs is one-tailed under biased errors, it is likely that maximum temperature trends have been underestimated in the USHCN. Trends for minimum temperature are also positive over the three periods, but the ensemble error bounds encompass trends from the unhomogenized data.},
author = {Williams, Claude N and Menne, Matthew J and Thorne, Peter W},
doi = {10.1029/2011JD016761},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {benchmarking,temperature trends,uncertainty},
number = {D5},
pages = {D05116},
title = {{Benchmarking the performance of pairwise homogenization of surface temperatures in the United States}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011JD016761},
volume = {117},
year = {2012}
}
@article{Williams2011a,
abstract = {Accurate land cover reconstructions are essential to understanding the past and present biogeochemical and biogeophysical interactions between the land surface and atmosphere and the impacts of these interactions on climate. Here we quantitatively reconstruct late Quaternary shifts in woody cover across the Northern Hemisphere forest-tundra ecotone, based on a synthesis of Northern Hemisphere pollen records and contemporary observations of woody cover from the advanced very high resolution radiometer sensor. Our reconstructions document the expansion of Northern Hemisphere forests following deglaciation and reveal significant hemispheric asymmetries in the Holocene position, steepness, and history of the forest-tundra ecotone. In western Canada, for example, forest expansion and infilling continued through the Holocene, while in much of northern Asia, forests reached their maximal expansion during the early Holocene, then retreated. The woody cover reconstructions are generally consistent with macrofossil-based reconstructions of northern tree line dynamics and complement them by extending study of the northern forest-tundra ecotone from the tree line limit (well mapped by macrofossils) to the entire ecotone. Using the Lund-Potsdam-Jena dynamic vegetation model, we estimate that changes in northern forest density resulted in at least a 47.7 Gt C increase in aboveground carbon sequestration between 21 and 9 ka, a 13.9 Gt C increase between 9 and 6 ka, and a 3.5 Gt C loss of aboveground carbon from northern forests after 6 ka. This trajectory is consistent with atmospheric carbon isotopic measurements for the Holocene, which suggest carbon uptake by the terrestrial biosphere until 6 ka and small carbon releases from the terrestrial biosphere afterward.},
author = {Williams, John W. and Tarasov, Pavel and Brewer, Simon and Notaro, Michael},
doi = {10.1029/2010JG001458},
issn = {01480227},
journal = {Journal of Geophysical Research: Biogeosciences},
number = {G1},
pages = {G01017},
title = {{Late Quaternary variations in tree cover at the northern forest-tundra ecotone}},
volume = {116},
year = {2011}
}
@article{Williams2017d,
author = {Williams, B. and Halfar, J. and Delong, K. L. and Smith, E. and Steneck, R. and Lebednik, P. A. and Jacob, D. E. and Fietzke, J. and Moore, G. W.K.},
doi = {10.1002/2017GL073138},
journal = {Geophysical Research Letters},
pages = {3761--3769},
title = {{North Pacific twentieth century decadal-scale variability is unique for the past 342 years}},
volume = {44},
year = {2017}
}
@article{Wilson2018,
abstract = {Understanding ice sheet behaviour in the geological past is essential for evaluating the role of the cryosphere in the climate system and for projecting rates and magnitudes of sea level rise in future warming scenarios1–4. Although both geological data5–7 and ice sheet models3,8 indicate that marine-based sectors of the East Antarctic Ice Sheet were unstable during Pliocene warm intervals, the ice sheet dynamics during late Pleistocene interglacial intervals are highly uncertain3,9,10. Here we provide evidence from marine sedimentological and geochemical records for ice margin retreat or thinning in the vicinity of the Wilkes Subglacial Basin of East Antarctica during warm late Pleistocene interglacial intervals. The most extreme changes in sediment provenance, recording changes in the locus of glacial erosion, occurred during marine isotope stages 5, 9, and 11, when Antarctic air temperatures11 were at least two degrees Celsius warmer than pre-industrial temperatures for 2,500 years or more. Hence, our study indicates a close link between extended Antarctic warmth and ice loss from the Wilkes Subglacial Basin, providing ice-proximal data to support a contribution to sea level from a reduced East Antarctic Ice Sheet during warm interglacial intervals. While the behaviour of other regions of the East Antarctic Ice Sheet remains to be assessed, it appears that modest future warming may be sufficient to cause ice loss from the Wilkes Subglacial Basin.},
author = {Wilson, David J and Bertram, Rachel A and Needham, Emma F and van de Flierdt, Tina and Welsh, Kevin J and McKay, Robert M and Mazumder, Anannya and Riesselman, Christina R and Jimenez-Espejo, Francisco J and Escutia, Carlota},
doi = {10.1038/s41586-018-0501-8},
issn = {1476-4687},
journal = {Nature},
number = {7723},
pages = {383--386},
title = {{Ice loss from the East Antarctic Ice Sheet during late Pleistocene interglacials}},
url = {https://doi.org/10.1038/s41586-018-0501-8},
volume = {561},
year = {2018}
}
@article{Windler2019,
abstract = {The Indo-Pacific Warm Pool is the largest source of heat and rainfall on Earth, but the mechanisms driving long-term climate variability in this region remain uncertain. Some studies suggest that precessional variations in insolation exert a primary role; alternatively, sea level change may be more important, with exposure of the Sunda and Sahul shelves leading to weakened Walker circulation across the Indian Ocean during glacial periods. The limited number of paleoclimate records from the warm pool that extend beyond the Last Glacial Maximum makes it difficult to test these competing hypotheses. Here, we present a 450,000-year long reconstruction of sea surface temperatures, sub-surface temperatures, and regional vegetation from southern Sumatra. We show that the dominant signal in each record is the 100 ky glacial cycle. We find that both surface and sub-surface temperatures cool during glacial periods, but the sub-surface cools more, reflecting a shoaling of the thermocline. Southern Sumatra and western Java consistently exhibit increased C 4 grass coverage and an enhanced dry season during glacial periods. The observed changes in the thermocline and rainfall seasonality are consistent with the shelf exposure mechanism, suggesting that sea level changes exert a prominent role in warm pool climate over glacial-interglacial timescales.},
author = {Windler, Grace and Tierney, Jessica E. and DiNezio, Pedro N. and Gibson, Kelly and Thunell, Robert},
doi = {10.1016/j.epsl.2019.03.038},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {GDGT,Indo-Pacific Warm Pool,Pleistocene paleoclimate,alkenone,leaf wax,shelf exposure},
pages = {66--76},
publisher = {Elsevier B.V.},
title = {{Shelf exposure influence on Indo-Pacific Warm Pool climate for the last 450,000 years}},
url = {https://doi.org/10.1016/j.epsl.2019.03.038},
volume = {516},
year = {2019}
}
@article{Winguth2012,
abstract = {The prominent global warming event at the Paleocene-Eocene boundary (55 Ma), referred to as the Paleocene-Eocene Thermal Maximum (PETM), was characterized by rapid temperature increase and changes in the global carbon cycle in {\textless}10,000 yr, and a major extinction of benthic foraminifera. We explore potential causes of this extinction in response to environmental changes linked to a mas- sive carbon injection by comparing sedimentary records with results from a comprehensive climate–carbon cycle model, and infer that an increase in oceanic vertical temperature gradients and stratifi ca- tion led to decreased productivity and oxygen depletion in the deep sea. Globally, productivity diminished particularly in the equatorial zone by weakening of the trades and hence upwelling, leading to a decline in food supply for benthic organisms. In contrast, near the Ross Sea, export of organic matter into the deep sea was enhanced due to increased near-surface mixing related to a positive salinity anomaly caused by a rise in wind-driven vertical mixing, contribut- ing to the depletion of the deep-sea oxygen concentration, combined with a sluggish deep-sea circulation. The extinction of deep-sea ben- thic foraminifera at the PETM thus was probably caused by multiple environmental changes, including decreased carbonate saturation and ocean acidifi cation, lowered oxygen levels, and a globally reduced food supply, all related to a massive carbon injection.},
author = {Winguth, Arne M.E. and Thomas, Ellen and Winguth, Cornelia},
doi = {10.1130/G32529.1},
issn = {00917613},
journal = {Geology},
month = {mar},
number = {3},
pages = {263--266},
title = {{Global decline in ocean ventilation, oxygenation, and productivity during the Paleocene-Eocene Thermal Maximum: Implications for the benthic extinction}},
volume = {40},
year = {2012}
}
@article{Winnick2015,
abstract = {We use a one-dimensional reactive transport model of isotopes in precipitation ($\delta$18O) to investigate the physical mechanisms controlling global meridional isotope profiles under early Eocene hothouse conditions. Simulations of early Eocene precipitation isotopes display reduced meridional gradients relative to the modern climate with the largest increases in $\delta$18O occurring at high latitudes, matching proxy data. These reduced gradients are controlled primarily by polar amplification that increases high-latitude length scales of specific humidity and match our compilation of proxy-based reconstructions. Comparing Eocene general circulation model simulations run with pCO2 of 2240 and 4480 ppm, we find that meridional isotopic profiles are insensitive to the associated 5°C change in global temperatures due to the relative lack of polar amplification. Finally, we hypothesize that observed negative $\delta$D anomalies in precipitation during peak warming of early Eocene hyperthermal events are the result of a theorized reduction in the strength of midlatitude transient eddies. Key Points Data-model comparison of latitudinal gradients of early Eocene precipitation isotopes Gradients in hothouse climates controlled by degree of polar amplification and transport Gradients are insensitive to warming/cooling within hothouse climates},
author = {Winnick, Matthew J. and Caves, Jeremy K. and Chamberlain, C. Page},
doi = {10.1002/2015GL064829},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Eocene climate,isotope gradients,oxygen isotopes,precipitation},
month = {oct},
number = {19},
pages = {8216--8224},
title = {{A mechanistic analysis of early Eocene latitudinal gradients of isotopes in precipitation}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015GL064829},
volume = {42},
year = {2015}
}
@article{Winski2017,
abstract = {Future precipitation changes in a warming climate depend regionally upon the response of natural climate modes to anthropogenic forcing. North Pacific hydroclimate is dominated by the Aleutian Low, a semi-permanent wintertime feature characterized by frequent low-pressure conditions that is influenced by tropical Pacific Ocean temperatures through the Pacific-North American (PNA) teleconnection pattern. Instrumental records show a recent increase in coastal Alaskan precipitation and Aleutian Low intensification, but are of insufficient length to accurately assess low frequency trends and forcing mechanisms. Here we present a 1200-year seasonally- to annually-resolved ice core record of snow accumulation from Mt. Hunter in the Alaska Range developed using annual layer counting and four ice-flow thinning models. Under a wide range of glacier flow conditions and layer counting uncertainty, our record shows a doubling of precipitation since ∼1840 CE, with recent values exceeding the variability observed over the past millennium. The precipitation increase is nearly synchronous with the warming of western tropical Pacific and Indian Ocean sea surface temperatures. While regional 20th Century warming may account for a portion of the observed precipitation increase on Mt. Hunter, the magnitude and seasonality of the precipitation change indicate a long-term strengthening of the Aleutian Low.},
author = {Winski, Dominic and Osterberg, Erich and Ferris, David and Kreutz, Karl and Wake, Cameron and Campbell, Seth and Hawley, Robert and Roy, Samuel and Birkel, Sean and Introne, Douglas and Handley, Michael},
doi = {10.1038/s41598-017-18022-5},
issn = {20452322},
journal = {Scientific Reports},
number = {1},
pages = {1--12},
publisher = {Springer US},
title = {{Industrial-age doubling of snow accumulation in the Alaska Range linked to tropical ocean warming}},
url = {http://dx.doi.org/10.1038/s41598-017-18022-5},
volume = {7},
year = {2017}
}
@article{Wirth2013,
author = {Wirth, S. B. and Glur, L. and Gilli, A. and Anselmetti, F. S.},
doi = {10.1016/j.quascirev.2013.09.002},
journal = {Quaternary Science Reviews},
pages = {112--128},
title = {{Holocene flood frequency across the Central Alps – solar forcing and evidence for variations in North Atlantic atmospheric circulation}},
volume = {80},
year = {2013}
}
@article{Witkowski2018,
abstract = {Past changes in the atmospheric concentration of carbon dioxide ( P co 2 ) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past P co 2 remains a prevalent challenge in paleoclimate studies. The current long-term P co 2 reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic P co 2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛ p ) that increases as P co 2 increases. This concept has been widely applied to alkenones, but here, we expand this concept both spatially and temporally by applying it to all marine phytoplankton via a diagenetic product of chlorophyll, phytane. We obtained data from 306 marine sediments and oils, which showed that Ɛ p ranges from 11 to 24‰, agreeing with the observed range of maximum fractionation of Rubisco (i.e., 25 to 28‰). The observed secular P co 2 trend derived from phytane-based Ɛ p mirrors the available compilations of P co 2 over the past 420 Ma, except for two periods in which our higher estimates agree with the warm climate during those time periods. Our record currently provides the longest secular trend in P co 2 based on a single marine proxy, covering the past 500 Ma of Earth history.},
author = {Witkowski, Caitlyn R. and Weijers, Johan W.H. and Blais, Brian and Schouten, Stefan and {Sinninghe Damst{\'{e}}}, Jaap S.},
doi = {10.1126/sciadv.aat4556},
issn = {23752548},
journal = {Science Advances},
number = {11},
pages = {eaat4556},
title = {{Molecular fossils from phytoplankton reveal secular PCO2 trend over the phanerozoic}},
volume = {4},
year = {2018}
}
@techreport{WMO2018a,
author = {WMO},
doi = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
pages = {588},
publisher = {World Meteorological Organization (WMO)},
series = {Global Ozone Research and Monitoring Project – Report No. 58},
title = {{Scientific Assessment of Ozone Depletion: 2018}},
url = {https://csl.noaa.gov/assessments/ozone/2018/downloads/},
year = {2018}
}
@article{Woodborne2015,
abstract = {A proxy rainfall record for northeastern South Africa based on carbon isotope analysis of four baobab (Adansonia digitata L.) trees shows centennial and decadal scale variability over the last 1,000 years. The record is in good agreement with a 200-year tree ring record from Zimbabwe, and it indicates the existence of a rainfall dipole between the summer and winter rainfall areas of South Africa. The wettest period was c. AD 1075 in the Medieval Warm Period, and the driest periods were c. AD 1635, c. AD 1695 and c. AD1805 during the Little Ice Age. Decadal-scale variability suggests that the rainfall forcing mechanisms are a complex interaction between proximal and distal factors. Periods of higher rainfall are significantly associated with lower sea-surface temperatures in the Agulhas Current core region and a negative Dipole Moment Index in the Indian Ocean. The correlation between rainfall and the El Ni{\~{n}}o/Southern Oscillation Index is non-static. Wetter conditions are associated with predominantly El Ni{\~{n}}o conditions over most of the record, but since about AD 1970 this relationship inverted and wet conditions are currently associated with la Nina conditions. The effect of both proximal and distal oceanic influences are insufficient to explain the rainfall regime shift between the Medieval Warm Period and the Little Ice Age, and the evidence suggests that this was the result of a northward shift of the subtropical westerlies rather than a southward shift of the Intertropical Convergence Zone.},
author = {Woodborne, Stephan and Hall, Grant and Robertson, Iain and Patrut, Adrian and Rouault, Mathieu and Loader, Neil J. and Hofmeyr, Michele},
doi = {10.1371/journal.pone.0124202},
issn = {19326203},
journal = {PLOS ONE},
number = {5},
pages = {e0124202},
pmid = {25970402},
title = {{A 1000-year carbon isotope rainfall proxy record from South African baobab trees (Adansonia digitata L.)}},
volume = {10},
year = {2015}
}
@article{Woodgate2018,
abstract = {Year-round in situ Bering Strait mooring data (1990–2015) document a long-term increase (∼0.01 Sv/yr) in the annual mean transport of Pacific waters into the Arctic. Between 2002 and 2015, all annual mean transports (except 2005 and 2012) are greater than the previously accepted climatology (∼0.8 Sv). The record-length maximum (2014: 1.2 ± 0.1 Sv) is 70{\%} higher than the record-length minimum (2001: 0.7 ± 0.1 Sv), corresponding to a reduction in the flushing time of the Chukchi Sea (to ∼4.5 months from ∼7.5 months). The transport increase results from stronger northward flows (not fewer southward flow events), yielding a 150{\%} increase in kinetic energy, presumably with impacts on bottom suspension, mixing, and erosion. Curiously, we find no significant trends in annual mean flow in the Alaskan Coastal Current (ACC), although note that these data are only available 2002–2015. Record-length trends in annually integrated heat and freshwater fluxes (primarily driven by volume flux trends) are large (0.06 ± 0.05 × 1020 J/yr; 30 ± 20 km3/yr; relative to −1.9 °C and 34.8 psu), with heat flux lows in 2001 and 2012 (∼3 × 1020 J) and highs in 2007 and 2015 (∼5.5 × 1020 J), and a freshwater range of ∼2300 km3 (2001) to ∼3500 km3 (2014). High-flow year 2015 (volume transport ∼1.1 Sv) has the highest annual mean temperature recorded, ∼0.7 °C, astoundingly warmer than the record-length mean of 0.0 ± 0.2 °C, while low-flow year 2012 (∼0.8 Sv) is also remarkably cold (∼−0.6 °C), likely due to anomalously weak northward flow in January–March, partly driven by anomalously strong southward winds in March. A seasonal decomposition of properties of the main flow shows significant freshening in winter (∼0.03 psu/yr, January–March) likely due to sea-ice changes, but no trend (or perhaps salinization) in the rest of the year. A seasonal warming trend in the strait proper in May and June (∼0.04 °C/yr) is reflected in a trend to earlier arrival (0.9 ± 0.8 days/yr) of waters warmer than 0 °C. Contrastingly, no significant trend is found in the time of cooling of the strait. The strait's seasonal increasing transport trends (∼0.02 Sv/yr) are largest from May–November, likely due to the large wind-driven variability masking the signal in other months. We show that Ekman set-up of waters along the coast in the strait can explain the strong correlation of the water velocity with along-strait winds (as opposed to across-strait winds). We highlight the strong seasonality of this relationship (r ∼ 0.8 in winter, but only ∼0.4 in summer), which reflects the weak influence of the (seasonally weak) winds in summer. By separating the flow into portions driven by (a) the local wind and (b) a far-field (Pacific-Arctic “pressure-head”) forcing, we find the increase in the Bering Strait throughflow is primarily due to a strong increase in the far-field forcing, not changes in the wind. We propose a higher annual mean transport for the strait for the 2000s, (1.0 ± 0.05 Sv) based on recent flow increases, and present estimated seasonal climatologies for properties and fluxes for the strait and for the ACC. Heat and freshwater seasonalities are strongly influenced by the ACC and stratification. Finally we conclude that year-round in situ mooring are still the only currently viable way of obtaining accurate quantifications of the properties of the Pacific input to the Arctic.},
author = {Woodgate, Rebecca A},
doi = {10.1016/j.pocean.2017.12.007},
issn = {0079-6611},
journal = {Progress in Oceanography},
keywords = {Annual variations,Arctic Ocean,Arctic freshwater,Arctic heat,Bering Sea,Bering Strait,Chukchi Sea,Pacific Ocean,Seasonal variations,Water currents,Water properties},
pages = {124--154},
title = {{Increases in the Pacific inflow to the Arctic from 1990 to 2015, and insights into seasonal trends and driving mechanisms from year-round Bering Strait mooring data}},
url = {http://www.sciencedirect.com/science/article/pii/S0079661117302215},
volume = {160},
year = {2018}
}
@article{doi:10.1002/joc.2103,
abstract = {Abstract Release 2.5 of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a major update (covering 1662–2007) of the world's most extensive surface marine meteorological data collection. Building on extensive national and international partnerships, many new and improved contributing datasets have been processed into a uniform format and combined with the previous Release 2.4. The new data range from early non-instrumental ship observations to measurements initiated in the twentieth century from buoys and other automated platform types. Improvements to existing data include replacing preliminary Global Telecommunication System (GTS) receipts with more reliable, delayed mode reports for post-1997 data, and in the processing and quality control (QC) of humidity observations. Over the entire period of record, spatial and temporal coverage has been enriched and data and metadata quality has been improved. Along with the observations, now updated monthly in near real time, Release 2.5 includes quality-controlled monthly summary products for 2° latitude × 2° longitude (since 1800) and 1° × 1° boxes (since 1960), together with multiple options for access to the data and products. The measured and estimated data in Release 2.5 are subject to many technical changes, multiple archive sources, and historical events throughout the more than three-century record. Some of these data characteristics are highlighted, including known unresolved errors and inhomogeneities, which may impact climate and other research applications. Anticipated future directions for ICOADS aim to continue adding scientific value to the observations, products, and metadata, as well as strengthen the cooperative enterprise through expanded linkages to international initiatives and organisations. Copyright {\textcopyright} 2010 Royal Meteorological Society},
author = {Woodruff, Scott D and Worley, Steven J and Lubker, Sandra J and Ji, Zaihua and {Eric Freeman}, J and Berry, David I and Brohan, Philip and Kent, Elizabeth C and Reynolds, Richard W and Smith, Shawn R and Wilkinson, Clive},
doi = {10.1002/joc.2103},
journal = {International Journal of Climatology},
keywords = {buoy data,data rescue,humidity,marine meteorological data,metadata,sea level pressure,sea surface temperature,ship data},
number = {7},
pages = {951--967},
title = {{ICOADS Release 2.5: extensions and enhancements to the surface marine meteorological archive}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.2103},
volume = {31},
year = {2011}
}
@article{Woodworth2014,
abstract = {The variability in mean sea level (MSL) during 1950--2009 along the northeast American Atlantic coast north of Cape Hatteras has been studied, using data from tide gauges and satellite altimetry and information from the Liverpool/Hadley Centre (LHC) ocean model, thereby providing new insights into the spatial and temporal scales of the variability. Although a relationship between sea level and the overturning circulation can be identified (an increase of approximately 1.5 cm in MSL for a decrease of 1 Sv in overturning transport), it is the effect of the nearshore wind forcing on the shelf that is found to dominate the interannual sea-level variability. In particular, winds are found to be capable of producing low-frequency changes in MSL (``accelerations'') in a narrow coastal band, comparable to those observed by the tide gauges. Evidence is presented supporting the idea of a ``'common mode''of spatially coherent low-frequency MSL variability, both to the north and south of Cape Hatteras and throughout the northwest Atlantic, which is associated with large spatial-scale density changes from year to year.},
author = {Woodworth, Philip L. and Maqueda, Miguel {\'{A}}.Morales and Roussenov, Vassil M. and Williams, Richard G. and Hughes, Chris W.},
doi = {10.1002/2014JC010520},
isbn = {2169-9291},
issn = {21699291},
journal = {Journal of Geophysical Research: Oceans},
number = {12},
pages = {8916--8935},
title = {{Mean sea-level variability along the northeast American Atlantic coast and the roles of the wind and the overturning circulation}},
volume = {119},
year = {2014}
}
@article{Woollings2018a,
author = {Woollings, Tim and Barnes, Elizabeth A. and Hoskins, Brian and Kwon, Young-Oh and Lee, Robert W. and Li, Camille and Madonna, Erica and McGraw, Marie and Parker, Tess and Rodrigues, Regina and Spensberger, Clemens and Williams, Keith},
doi = {10.1175/JCLI-D-17-0286.1},
journal = {Journal of Climate},
pages = {1297--1314},
title = {{Daily to Decadal Modulation of Jet Variability (2018a)}},
volume = {31},
year = {2018}
}
@article{Woollings2018,
author = {Woollings, T and Barriopedro, D and Methven, J and Son, S-W and Martius, O and Harvey, B and Sillmann, J and Lupo, A R and Seneviratne, S},
doi = {10.1007/s40641-018-},
journal = {Current Climate Change Reports},
number = {3},
pages = {287--300},
title = {{Blocking and its Response to Climate Change (2018b)}},
volume = {4},
year = {2018}
}
@article{Woollings2014,
abstract = {Long records of the latitude and speed of the North Atlantic eddy-driven jet stream since 1871 are presented from the newly available Twentieth Century Reanalysis. These jet variations underlie the variability associated with patterns such as the North Atlantic Oscillation (NAO) and have considerable societal impact through variations in the prevailing westerly winds. While the NAO combines variations in the latitude and speed of the jet, these two characteristics are shown to have quite different seasonal cycles and interannual variability, suggesting that they may have different dynamical influences. In general, the features exhibited in shorter records are shown to be robust, for example the strong skewness of the NAO distribution. Related to this is a clear multimodality of the jet latitude distribution, which suggests the existence of preferred positions of the jet. Decadal variations in jet latitude are shown to correspond to changes in the occurrence of these preferred positions. However, it is the speed rather than the latitude of the jet that exhibits the strongest decadal variability, and in most seasons this is clearly distinct from a white-noise representation of the seasonal means. When viewed in this longer term context, the variations of recent decades do not appear unusual and recent values of jet latitude and speed are not unprecedented in the historical record.},
author = {Woollings, Tim and Czuchnicki, Camelia and Franzke, Christian},
doi = {10.1002/qj.2197},
issn = {1477870X},
journal = {Quarterly Journal of the Royal Meteorological Society},
number = {680},
pages = {783--791},
title = {{Twentieth century North Atlantic jet variability}},
volume = {140},
year = {2014}
}
@article{Woosley2016a,
abstract = {Abstract The extended multilinear regression method is used to determine the uptake and storage of anthropogenic carbon in the Atlantic Ocean based on repeat occupations of four cruises from 1989 to 2014 (A16, A20, A22, and A10), with an emphasis on the 2003?2014 period. The results show a significant increase in basin-wide anthropogenic carbon storage in the North Atlantic, which absorbed 4.4?±?0.9?Pg?C?decade?1 from 2003 to 2014 compared to 1.9?±?0.4?Pg?C?decade?1 for the 1989?2003 period. This decadal variability is attributed to changing ventilation patterns associated with the North Atlantic Oscillation and increasing release of anthropogenic carbon into the atmosphere. There are small changes in the uptake rate of CO2 in the South Atlantic for these time periods (3.7?±?0.8?Pg?C?decade?1 versus 3.2?±?0.7?Pg?C?decade?1). Several eddies are identified containing {\~{}}20{\%} more anthropogenic carbon than the surrounding waters in the South Atlantic demonstrating the importance of eddies in transporting anthropogenic carbon. The uptake of carbon results in a decrease in pH of {\~{}}0.0021?±?0.0007?year?1 for surface waters during the last 10?years, in line with the atmospheric increase in CO2.},
annote = {doi: 10.1002/2015GB005248},
author = {Woosley, Ryan J and Millero, Frank J and Wanninkhof, Rik},
doi = {10.1002/2015GB005248},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {Atlantic Ocean,anthropogenic carbon,ocean acidification},
month = {jan},
number = {1},
pages = {70--90},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Rapid anthropogenic changes in CO2 and pH in the Atlantic Ocean: 2003–2014}},
url = {https://doi.org/10.1002/2015GB005248},
volume = {30},
year = {2016}
}
@article{Worthington2021,
abstract = {Abstract. A decline in Atlantic meridional overturning circulation (AMOC) strength has been observed between 2004 and 2012 by the RAPID-MOCHA-WBTS (RAPID – Meridional Overturning Circulation and Heatflux Array – Western Boundary Time Series, hereafter RAPID array) with this weakened state of the AMOC persisting until 2017. Climate model and paleo-oceanographic research suggests that the AMOC may have been declining for decades or even centuries before this; however direct observations are sparse prior to 2004, giving only “snapshots” of the overturning circulation. Previous studies have used linear models based on upper-layer temperature anomalies to extend AMOC estimates back in time; however these ignore changes in the deep circulation that are beginning to emerge in the observations of AMOC decline. Here we develop a higher-fidelity empirical model of AMOC variability based on RAPID data and associated physically with changes in thickness of the persistent upper, intermediate, and deep water masses at 26∘ N and associated transports. We applied historical hydrographic data to the empirical model to create an AMOC time series extending from 1981 to 2016. Increasing the resolution of the observed AMOC to approximately annual shows multi-annual variability in agreement with RAPID observations and shows that the downturn between 2008 and 2012 was the weakest AMOC since the mid-1980s. However, the time series shows no overall AMOC decline as indicated by other proxies and high-resolution climate models. Our results reinforce that adequately capturing changes to the deep circulation is key to detecting any anthropogenic climate-change-related AMOC decline.},
author = {Worthington, Emma L and Moat, Ben I and Smeed, David A and Mecking, Jennifer V and Marsh, Robert and McCarthy, Gerard D},
doi = {10.5194/os-17-285-2021},
issn = {1812-0792},
journal = {Ocean Science},
month = {feb},
number = {1},
pages = {285--299},
publisher = {Copernicus Publications},
title = {{A 30-year reconstruction of the Atlantic meridional overturning circulation shows no decline}},
url = {https://os.copernicus.org/preprints/os-2020-71/os-2020-71.pdf https://os.copernicus.org/articles/17/285/2021/},
volume = {17},
year = {2021}
}
@article{WRIGHT2020103293,
abstract = {Long-term variations in eustatic sea level in an ice-free world, which existed through most of the Mesozoic and early Cenozoic eras, are partly driven by changes in the volume of ocean basins. Previous studies have determined ocean basin volume changes from plate tectonic reconstructions since the Mesozoic; however, these studies have not considered a number of important elements that contribute to ocean basin volume, such as regional differences in sedimentation, or uncertainties within the plate tectonic model itself, such as spreading asymmetries and the incomplete representation of back-arc basins in the Mesozoic. Additionally, studies on long-term changes in sea level related to the extension and rifting of passive margins have not been performed on a global-scale and likely significantly underestimated the influence of this process. In order to improve reconstructions of sea level on geologic time scales and assess the uncertainty in deriving the volume of ocean basins based on a global plate kinematic model, we investigate the influence of back-arc basins, spreading asymmetry, large igneous provinces (LIPs), sediment thickness, and passive margins on ocean basin volume since 200 Ma. We find that less-constrained plate tectonic elements, such as the presence of back-arc basins or spreading asymmetry, may contribute up to {\~{}}120 m or {\~{}}150 m to sea level respectively. Changes in the sea level related to sedimentation and LIPs are respectively {\~{}}75–165 m and {\~{}}45 m. Changes in sea level associated with passive margin formation are almost negligible at present day, though were much larger in the Cretaceous, and the assumed sedimentation style strongly influences the rate and magnitude of sea-level change. We incorporate predictions for these components during times where ocean basins are predominantly synthetic reconstructions and find that sea level driven by fluctuating ocean basin volume has changed by {\~{}}200 m since the Jurassic, which is comparable to previous estimates. Our revised estimates will need to be combined with other processes driving long-term sea-level change, including mantle convection-driven dynamic topography and glacio-eustasy for constructing a complete eustatic sea-level curve. Understanding and quantifying the uncertainties in the volume of ocean basins has implications for modelling subduction flux, the oceanic carbon cycle, and heatflow, and is important for exploring Earth's evolutionary cycles, especially during times in the geologic past where much of the ocean basin history has been lost.},
author = {Wright, Nicky M and Seton, Maria and Williams, Simon E and Whittaker, Joanne M and M{\"{u}}ller, R Dietmar},
doi = {10.1016/j.earscirev.2020.103293},
issn = {0012-8252},
journal = {Earth-Science Reviews},
keywords = {Ocean basins,Paleobathymetry,Plate tectonics,Sea level,Seafloor spreading},
pages = {103293},
title = {{Sea-level fluctuations driven by changes in global ocean basin volume following supercontinent break-up}},
url = {http://www.sciencedirect.com/science/article/pii/S0012825220303391},
volume = {208},
year = {2020}
}
@article{refId0,
author = {Wu, C.-J. and Krivova, N. A. and Solanki, S. K. and Usoskin, I. G.},
doi = {10.1051/0004-6361/201832956},
journal = {Astronomy {\&} Astrophysics},
pages = {A120},
title = {{Solar total and spectral irradiance reconstruction over the last 9000 years}},
url = {https://doi.org/10.1051/0004-6361/201832956},
volume = {620},
year = {2018}
}
@article{Wu2012a,
abstract = {An analysis indicates that the warm, powerful currents that flow along the western edges of ocean basins warmed more than twice as quickly than the global ocean as a whole over the past century. This enhanced warming could have important effects on climate because these currents affect the air–sea exchange of heat, moisture and carbon dioxide.},
author = {Wu, Lixin and Cai, Wenju and Zhang, Liping and Nakamura, Hisashi and Timmermann, Axel and Joyce, Terry and McPhaden, Michael J and Alexander, Michael and Qiu, Bo and Visbeck, Martin and Chang, Ping and Giese, Benjamin},
doi = {10.1038/nclimate1353},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {3},
pages = {161--166},
title = {{Enhanced warming over the global subtropical western boundary currents}},
url = {https://doi.org/10.1038/nclimate1353},
volume = {2},
year = {2012}
}
@article{Wu2013b,
abstract = {The impact of climate change on the global hydrological cycle is unclear, with land precipitation and river discharges not increasing as expected. This discrepancy is investigated and tropospheric aerosols are found to have weakened the hydrological cycle between the 1950s and 1980s. The increase in greenhouse gases since the 1980s strengthened the cycle, indicating a further increase in precipitation if the current trend continues.},
author = {Wu, Peili and Christidis, Nikolaos and Stott, Peter},
doi = {10.1038/nclimate1932},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {9},
pages = {807--810},
title = {{Anthropogenic impact on Earth's hydrological cycle}},
url = {https://doi.org/10.1038/nclimate1932},
volume = {3},
year = {2013}
}
@article{Wu2018,
author = {Wu, J and Zha, J and Zhao, D and Yang, Q},
doi = {10.1007/s00382-017-3997-y},
journal = {Climate Dynamics},
pages = {2039--2078},
title = {{Changes in terrestrial near-surface wind speed and their possible causes: an overview}},
volume = {51},
year = {2018}
}
@article{doi:10.1080/16000870.2018.1471911,
author = {Wunsch, Carl},
doi = {10.1080/16000870.2018.1471911},
journal = {Tellus A: Dynamic Meteorology and Oceanography},
number = {1},
pages = {1--14},
publisher = {Taylor {\&} Francis},
title = {{Towards determining uncertainties in global oceanic mean values of heat, salt, and surface elevation}},
url = {https://doi.org/10.1080/16000870.2018.1471911},
volume = {70},
year = {2018}
}
@article{Wurtzel2018a,
abstract = {Abrupt changes in Atlantic Meridional Overturning Circulation are known to have affected the strength of the Indian and Asian Monsoons during glacial and deglacial climate states. However, there is still much uncertainty around the hydroclimate response of the Indo-Pacific Warm Pool (IPWP) region to abrupt climate changes in the North Atlantic. Many studies suggest a mean southward shift in the intertropical convergence zone (ITCZ) in the IPWP region during phases of reduced Atlantic meridional overturning, however, existing proxies have seasonal biases and conflicting responses, making it difficult to determine the true extent of North Atlantic forcing in this climatically important region. Here we present a precisely-dated, high-resolution record of eastern Indian Ocean hydroclimate variability spanning the last 16 ky (thousand years) from $\delta$18O measurements in an aragonite–calcite speleothem from central Sumatra. This represents the western-most speleothem record from the IPWP region. Precipitation arrives year-round at this site, with the majority sourced from the local tropical eastern Indian Ocean and two additional long-range seasonal sources associated with the boreal and austral summer monsoons. The Sumatran speleothem demonstrates a clear deglacial structure that includes 18O enrichment during the Younger Dryas and 18O depletion during the B{\o}lling–Aller{\o}d, similar to the pattern seen in speleothems of the Asian and Indian monsoon realms. The speleothem $\delta$18O changes at this site are best explained by changes in rainfall amount and changes in the contributions from different moisture pathways. Reduced rainfall in Sumatra during the Younger Dryas is most likely driven by reductions in moisture transport along the northern or southern monsoon transport pathways to Sumatra. Considered with other regional proxies, the record from Sumatra suggests the response of the IPWP to North Atlantic freshwater forcing is not solely driven by southward shifts of the ITCZ, but also a reduction in moisture transport along both monsoon pathways.},
author = {Wurtzel, Jennifer B and Abram, Nerilie J and Lewis, Sophie C and Bajo, Petra and Hellstrom, John C and Troitzsch, Ulrike and Heslop, David},
doi = {10.1016/j.epsl.2018.04.001},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
keywords = {ITCZ,Indo-Pacific,Younger Dryas,deglaciation,oxygen isotopes,speleothem},
pages = {264--278},
title = {{Tropical Indo-Pacific hydroclimate response to North Atlantic forcing during the last deglaciation as recorded by a speleothem from Sumatra, Indonesia}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X18301961},
volume = {492},
year = {2018}
}
@article{Xia2018,
author = {Xia, Jiangjiang and Jin, Shaofei and Yan, Zhongwei and Xiong, Zhe and Zheng, Ziyan and Han, Zuoqiang},
doi = {10.1007/s00704-018-2698-8},
issn = {14344483},
journal = {Theoretical and Applied Climatology},
pages = {1637--1642},
title = {{Shifts in timing of local growing season in China during 1961–2012}},
volume = {137},
year = {2018}
}
@article{acp-2018-945,
author = {Xian, T and Homeyer, C R},
doi = {10.5194/acp-19-5661-2019},
journal = {Atmospheric Chemistry and Physics},
number = {8},
pages = {5661--5678},
title = {{Global Tropopause Altitudes in Radiosondes and Reanalyses}},
url = {https://www.atmos-chem-phys-discuss.net/acp-2018-945/},
volume = {19},
year = {2019}
}
@article{Xiao2017,
abstract = {As an important vegetation biophysical variable, leaf area index (LAI) is a critical input parameter in many climate and ecological models. There exist four long time-series global LAI products since the 1980s, namely GLASS AVHRR, NCEI AVHRR, GIMMS3g and GLOBMAP. Currently, no inter-comparison studies exist to evaluate these LAI products and understand their differences for effective applications. In this study, the four long time-series global LAI products were inter-compared to evaluate their temporal and spatial discrepancies. These LAI products were also compared with MODIS LAI product and LAI values derived from high-resolution reference maps at VAlidation of Land European Remote sensing Instruments (VALERI) sites. The results show that the GLASS AVHRR and GLOBMAP LAI products are spatially complete, but the NCEI AVHRR and GIMMS3g LAI products contain many missing pixels, especially in rainforest regions. These LAI products reasonably represent the global vegetation characteristics and their seasonal variability. A relatively large discrepancy among these LAI products was observed in tropical forest regions, where the GLASS AVHRR and NCEI AVHRR LAI values achieved good agreement with the MODIS LAI values, but were between 0.5 and 1.0 LAI units lower than the GLOBMAP LAI values and higher than the GIMMS3g LAI values (more than 0.5 LAI units). Over the last three decades, the GLASS AVHRR, NCEI AVHRR, GIMMS3g LAI products show increasing trends for all biome types except evergreen needleleaf forests and deciduous needleleaf forests, but the GLOBMAP LAI product shows positive trends only for the grasses/cereal crops and shrubs. A comparison of these LAI products against the LAI values derived from high-resolution reference maps demonstrated that the GLASS AVHRR LAI values provided the better performance (RMSE = 0.9014 and Bias = −0.1885) than the NCEI AVHRR LAI values (RMSE = 1.0459 and Bias = −0.5695), the GIMMS3g LAI values (RMSE = 1.0971 and Bias = −0.3904) and the GLOBMAP LAI values (RMSE = 1.6145 and Bias = −0.9414).},
author = {Xiao, Zhiqiang and Liang, Shunlin and Jiang, Bo},
doi = {10.1016/j.agrformet.2017.06.016},
isbn = {0168-1923},
issn = {01681923},
journal = {Agricultural and Forest Meteorology},
keywords = {AVHRR,GIMMS3g,GLASS,GLOBMAP,Inter-comparison,LAI,MODIS,NCEI},
pages = {218--230},
title = {{Evaluation of four long time-series global leaf area index products}},
volume = {246},
year = {2017}
}
@article{Xie1997a,
author = {Xie, Pingping and Arkin, Phillip A},
doi = {10.1175/1520-0477(1997)078<2539:GPAYMA>2.0.CO;2},
journal = {Bulletin of the American Meteorological Society},
number = {11},
pages = {2539--2558},
title = {{Global Precipitation: A 17-Year Monthly Analysis Based on Gauge Observations , Satellite Estimates , and Numerical Model Outputs}},
volume = {78},
year = {1997}
}
@article{Xie2019,
abstract = {Abstract The Indonesian Throughflow (ITF), the only oceanic tropical pathway linking the Pacific and Indian Oceans, plays a critical role in the redistribution of heat and mass, affecting both the regional and global climate systems. Based on the distributions and changes in the tritium inventories, and tritium budgets in and between the South Pacific and South Indian Oceans from the Geochemical Ocean Sections Study and World Ocean Circulation Experiment programs, the long-term mean water mass transport of the ITF is estimated. The total throughflow of the ITF is estimated as 16.2 ± 3.5 Sv. The North Pacific contributes 14.1 ± 2.7 Sv to the total throughflow, of which the layers between 0?250, 250?650, and 650?1,000 m carry 7.3 ± 0.6, 5.4 ± 1.3, and 1.4 ± 3.0 Sv, respectively. Along with the water transport, the North Pacific component of the ITF transfers 0.84 ± 0.14 PW of heat into the Indian Ocean, of which almost 90{\%} exits from the Indian Ocean at 30°S. The net nitrate flux into the photic zone associated with the ITF is 2.71 ± 2.60 mmol{\textperiodcentered}m?2{\textperiodcentered}d?1 in the Indonesian Seas, {\~{}}90{\%} of which is induced by vertical diffusion.},
annote = {doi: 10.1029/2018JC014863},
author = {Xie, Tengxiang and Newton, Robert and Schlosser, Peter and Du, Chuanjun and Dai, Minhan},
doi = {10.1029/2018JC014863},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
month = {jun},
number = {6},
pages = {3859--3875},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Long-Term Mean Mass, Heat and Nutrient Flux Through the Indonesian Seas, Based on the Tritium Inventory in the Pacific and Indian Oceans}},
url = {https://doi.org/10.1029/2018JC014863},
volume = {124},
year = {2019}
}
@article{Xu2018,
abstract = {A new dataset of integrated and homogenized monthly surface air temperature over global land for the period since 1900 [China Meteorological Administration global Land Surface Air Temperature (CMA-LSAT)] is developed. In total, 14 sources have been collected and integrated into the newly developed dataset, including three global (CRUTEM4, GHCN, and BEST), three regional and eight national sources. Duplicate stations are identified, and those with the higher priority are chosen or spliced. Then, a consistency test and a climate outlier test are conducted to ensure that each station series is quality controlled. Next, two steps are adopted to assure the homogeneity of the station series: (1) homogenized station series in existing national datasets (by National Meteorological Services) are directly integrated into the dataset without any changes (50{\%} of all stations), and (2) the inhomogeneities are detected and adjusted for in the remaining data series using a penalized maximal t test (50{\%} of all stations). Based on the dataset, we re-assess the temperature changes in global and regional areas compared with GHCN-V3 and CRUTEM4, as well as the temperature changes during the three periods of 1900--2014, 1979--2014 and 1998--2014. The best estimates of warming trends and there 95{\%} confidence ranges for 1900--2014 are approximately 0.102{\{}$\backslash$thinspace{\}}{\{}$\backslash$textpm{\}}{\{}$\backslash$thinspace{\}}0.006{\{}$\backslash$thinspace{\}}{\{}$\backslash$textdegree{\}}C/decade for the whole year, and 0.104{\{}$\backslash$thinspace{\}}{\{}$\backslash$textpm{\}}{\{}$\backslash$thinspace{\}}0.009, 0.112{\{}$\backslash$thinspace{\}}{\{}$\backslash$textpm{\}}{\{}$\backslash$thinspace{\}}0.007, 0.090{\{}$\backslash$thinspace{\}}{\{}$\backslash$textpm{\}}{\{}$\backslash$thinspace{\}}0.006, and 0.092{\{}$\backslash$thinspace{\}}{\{}$\backslash$textpm{\}}{\{}$\backslash$thinspace{\}}0.007{\{}$\backslash$thinspace{\}}{\{}$\backslash$textdegree{\}}C/decade for the DJF (December, January, February), MAM, JJA, and SON seasons, respectively. MAM saw the most significant warming trend in both 1900--2014 and 1979--2014. For an even shorter and more recent period (1998--2014), MAM, JJA and SON show similar warming trends, while DJF shows opposite trends. The results show that the ability of CMA-LAST for describing the global temperature changes is similar with other existing products, while there are some differences when describing regional temperature changes.},
author = {Xu, Wenhui and Li, Qingxiang and Jones, Phil and Wang, Xiaolan L and Trewin, Blair and Yang, Su and Zhu, Chen and Zhai, Panmao and Wang, Jinfeng and Vincent, Lucie and Dai, Aiguo and Gao, Yun and Ding, Yihui},
doi = {10.1007/s00382-017-3755-1},
issn = {1432-0894},
journal = {Climate Dynamics},
month = {apr},
number = {7},
pages = {2513--2536},
title = {{A new integrated and homogenized global monthly land surface air temperature dataset for the period since 1900}},
url = {https://doi.org/10.1007/s00382-017-3755-1},
volume = {50},
year = {2018}
}
@article{Xu2016b,
abstract = {Knowledge of spatial and temporal hydroclimatic differences is critical in understanding climatic mechanisms. Here we show striking hydroclimatic contrasts between northern and southern parts of the eastern margin of the Tibetan Plateau (ETP), and those between East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) areas during the past ∼2,000 years. During the Medieval Period, and the last 100 to 200 years, the southern ETP (S-ETP) area was generally dry (on average), while the northern ETP (N-ETP) area was wet. During the Little Ice Age (LIA), hydroclimate over S-ETP areas was wet, while that over N-ETP area was dry (on average). Such hydroclimatic contrasts can be broadly extended to ISM and EASM areas. We contend that changes in sea surface temperatures (SSTs) of the tropical Pacific Ocean could have played important roles in producing these hydroclimatic contrasts, by forcing the north-south movement of the Intertropical Convergence Zone (ITCZ) and intensification/slowdown of Walker circulation. The results of sensitivity experiments also support such a proposition.},
author = {Xu, Hai and Lan, Jianghu and Sheng, Enguo and Liu, Bin and Yu, Keke and Ye, Yuanda and Shi, Zhengguo and Cheng, Peng and Wang, Xulong and Zhou, Xinying and Yeager, Kevin M.},
doi = {10.1038/srep33177},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {33177},
publisher = {Nature Publishing Group},
title = {{Hydroclimatic contrasts over Asian monsoon areas and linkages to tropical Pacific SSTs}},
url = {http://www.nature.com/articles/srep33177},
volume = {6},
year = {2016}
}
@article{Xue2018,
author = {Xue, Daokai and Zhang, Yaocun},
doi = {10.1007/s00382-016-3325-y},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {jul},
number = {1},
pages = {37--52},
title = {{Concurrent variations in the location and intensity of the Asian winter jet streams and the possible mechanism}},
url = {http://link.springer.com/10.1007/s00382-016-3325-y},
volume = {49},
year = {2017}
}
@article{yan_enhanced_2016,
abstract = {Given the threats that tropical cyclones (TC) pose to people and infrastructure, there is significant interest in how the climatology of these storms may change with climate. The global historical record has been extensively examined, but it is short and plagued with recurring questions about its homogeneity, limiting its effectiveness at assessing how TCs vary with climate. Past warm intervals provide an opportunity to quantify TC behavior in a warmer-than-present world. Here, we use a TC-resolving (∼25 km) global atmospheric model to investigate TC activity during the mid-Pliocene warm period (3.264−3.025 Ma) that shares similarities with projections of future climate. Two experiments, one driven by the reconstructed sea surface temperatures (SSTs) and the other by the SSTs from an ensemble of mid-Pliocene simulations, consistently predict enhanced global-average peak TC intensity during the mid-Pliocene coupled with longer duration, increased power dissipation, and a poleward migration of the location of peak intensity. The simulations are similar to global TC changes observed during recent global warming, as well as those of many future projections, providing a window into the potential TC activity that may be expected in a warmer world. Changes to power dissipation and TC frequency, especially in the Pacific, are sensitive to the different SST patterns, which could affect the viability of the role of TCs as a factor for maintaining a reduced zonal SST gradient during the Pliocene, as recently hypothesized.},
author = {Yan, Qing and Wei, Ting and Korty, Robert L and Kossin, James P and Zhang, Zhongshi and Wang, Huijun},
doi = {10.1073/pnas.1608950113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {nov},
number = {46},
pages = {12963--12967},
title = {{Enhanced intensity of global tropical cyclones during the mid-Pliocene warm period}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1608950113},
volume = {113},
year = {2016}
}
@article{Yan2019,
abstract = {Over the past eight hundred thousand years, glacial–interglacial cycles oscillated with a period of one hundred thousand years (‘100k world'1). Ice core and ocean sediment data have shown that atmospheric carbon dioxide, Antarctic temperature, deep ocean temperature, and global ice volume correlated strongly with each other in the 100k world2–6. Between about 2.8 and 1.2 million years ago, glacial cycles were smaller in magnitude and shorter in duration (‘40k world'7). Proxy data from deep-sea sediments suggest that the variability of atmospheric carbon dioxide in the 40k world was also lower than in the 100k world8–10, but we do not have direct observations of atmospheric greenhouse gases from this period. Here we report the recovery of stratigraphically discontinuous ice more than two million years old from the Allan Hills Blue Ice Area, East Antarctica. Concentrations of carbon dioxide and methane in ice core samples older than two million years have been altered by respiration, but some younger samples are pristine. The recovered ice cores extend direct observations of atmospheric carbon dioxide, methane, and Antarctic temperature (based on the deuterium/hydrogen isotope ratio $\delta$Dice, a proxy for regional temperature) into the 40k world. All climate properties before eight hundred thousand years ago fall within the envelope of observations from continuous deep Antarctic ice cores that characterize the 100k world. However, the lowest measured carbon dioxide and methane concentrations and Antarctic temperature in the 40k world are well above glacial values from the past eight hundred thousand years. Our results confirm that the amplitudes of glacial–interglacial variations in atmospheric greenhouse gases and Antarctic climate were reduced in the 40k world, and that the transition from the 40k to the 100k world was accompanied by a decline in minimum carbon dioxide concentrations during glacial maxima.},
author = {Yan, Yuzhen and Bender, Michael L and Brook, Edward J and Clifford, Heather M and Kemeny, Preston C and Kurbatov, Andrei V and Mackay, Sean and Mayewski, Paul A and Ng, Jessica and Severinghaus, Jeffrey P and Higgins, John A},
doi = {10.1038/s41586-019-1692-3},
issn = {1476-4687},
journal = {Nature},
number = {7780},
pages = {663--666},
title = {{Two-million-year-old snapshots of atmospheric gases from Antarctic ice}},
url = {https://doi.org/10.1038/s41586-019-1692-3},
volume = {574},
year = {2019}
}
@article{yang_strengthened_2018,
author = {Yang, Shiling and Ding, Zhongli and Feng, Shaohua and Jiang, Wenying and Huang, Xiaofang and Guo, Licheng},
doi = {10.1016/j.jseaes.2017.10.020},
issn = {13679120},
journal = {Journal of Asian Earth Sciences},
month = {apr},
pages = {124--133},
shorttitle = {A strengthened {\{}East{\}} {\{}Asian{\}} {\{}Summer{\}} {\{}Monsoon{\}} d},
title = {{A strengthened East Asian Summer Monsoon during Pliocene warmth: Evidence from ‘red clay' sediments at Pianguan, northern China}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1367912017305758},
volume = {155},
year = {2018}
}
@article{Yang2017a,
abstract = {Abstract. Understanding processes controlling the atmospheric methane (CH4) mixing ratio is crucial to predict and mitigate future climate changes in this gas. Despite recent detailed studies of the last ∼ 1000 to 2000 years, the mechanisms that control atmospheric CH4 still remain unclear, partly because the late Holocene CH4 budget may be comprised of both natural and anthropogenic emissions. In contrast, the early Holocene was a period when human influence was substantially smaller, allowing us to elucidate more clearly the natural controls under interglacial conditions more clearly. Here we present new high-resolution CH4 records from Siple Dome, Antarctica, covering from 11.6 to 7.7 thousands of years before 1950AD (ka). We observe four local CH4 minima on a roughly 1000-year spacing, which correspond to cool periods in Greenland. We hypothesize that the cooling in Greenland forced the Intertropical Convergence Zone (ITCZ) to migrate southward, reducing rainfall in northern tropical wetlands. The inter-polar difference (IPD) of CH4 shows a gradual increase from the onset of the Holocene to ∼ 9.5ka, which implies growth of boreal source strength following the climate warming in the northern extratropics during that period.},
author = {Yang, Ji-Woong and Ahn, Jinho and Brook, Edward J. and Ryu, Yeongjun},
doi = {10.5194/cp-13-1227-2017},
issn = {1814-9332},
journal = {Climate of the Past},
month = {sep},
number = {9},
pages = {1227--1242},
title = {{Atmospheric methane control mechanisms during the early Holocene}},
url = {https://www.clim-past.net/13/1227/2017/},
volume = {13},
year = {2017}
}
@article{Yang2016b,
author = {Yang, Hu and Lohmann, Gerrit and Wei, Wei and Dima, Mihai and Ionita, Monica and Liu, Jiping},
doi = {10.1002/2015JC011513},
isbn = {2169-9291},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Gulf Stream,Kuroshio Current,global warming,intensification,poleward shift,western boundary currents},
month = {jul},
number = {7},
pages = {4928--4945},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Intensification and poleward shift of subtropical western boundary currents in a warming climate}},
url = {https://doi.org/10.1002/2015JC011513},
volume = {121},
year = {2016}
}
@article{Yang2020,
abstract = {Abstract Recent evidence shows that wind-driven ocean currents, like the western boundary currents, are strongly affected by global warming. However, due to insufficient observations both on temporal and spatial scales, the impact of climate change on large-scale ocean gyres is still not clear. Here, based on satellite observations of sea surface height and sea surface temperature, we find a consistent poleward shift of the major ocean gyres. Due to strong natural variability, most of the observed ocean gyre shifts are not statistically significant, implying that natural variations may contribute to the observed trends. However, climate model simulations forced with increasing greenhouse gases suggest that the observed shift is most likely to be a response of global warming. The displacement of ocean gyres, which is coupled with the poleward shift of extratropical atmospheric circulation, has broad impacts on ocean heat transport, regional sea level rise, and coastal ocean circulation.},
annote = {doi: 10.1029/2019GL085868},
author = {Yang, Hu and Lohmann, Gerrit and Krebs-Kanzow, Uta and Ionita, Monica and Shi, Xiaoxu and Sidorenko, Dimitry and Gong, Xun and Chen, Xueen and Gowan, Evan J},
doi = {10.1029/2019GL085868},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {climate change,global warming,ocean circulation,ocean gyre,poleward shift,sea level rise},
month = {mar},
number = {5},
pages = {e2019GL085868},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Poleward Shift of the Major Ocean Gyres Detected in a Warming Climate}},
url = {https://doi.org/10.1029/2019GL085868},
volume = {47},
year = {2020}
}
@article{Yang2018,
abstract = {A positive change in the southern annular mode (SAM), which is the primary pattern of climate variability in the Southern Hemisphere, has been induced predominantly by polar stratospheric ozone depletion. However, the lack of long-term observational records limits our understanding of the long-term SAM behaviour. In this study, we found that the geochemical record of the LGB69 ice core from the eastern coast of Antarctica was significantly correlated with the winter SAM index (SAMI). In addition, we developed an annual mean SAMI beginning in 1701 based on 15 annually resolved ice cores and relevant proxy–climate relationships. Our reconstruction accounted for 54.8{\%} of the total variance from 1957 to 2000 (the calibration period). We demonstrate that the recent positive phase shift in the annual mean SAMI since the 1970s is unprecedented, with the estimate for the latest regime in the 1990s reaching values 2.5 times the standard deviation above the baseline (1701–2000). This peak value also coincides with the largest 30-and 50-year trends, which have occurred at the end of the 20th century. From the reconstructed SAMI, we also found that the response to large volcanic events was likely positive in the 3 years after the eruption, but this positive response can be masked by internal climate variability when a strong El Ni{\~{n}}o event occurs in the eruption year.},
author = {Yang, Jiao and Xiao, Cunde},
doi = {10.1002/joc.5290},
issn = {10970088},
journal = {International Journal of Climatology},
keywords = {Antarctic,ice core,reconstruction,southern annular mode,volcanic forcing},
number = {4},
pages = {1706--1717},
title = {{The evolution and volcanic forcing of the southern annular mode during the past 300 years}},
volume = {38},
year = {2018}
}
@article{Yao2018a,
abstract = {The consequences of global warming for fisheries are not well understood, but the geological record demonstrates that carbon cycle perturbations are frequently associated with ocean deoxygenation. Of particular interest is the Paleocene-Eocene Thermal Maximum (PETM), where the carbon dioxide input into the atmosphere was similar to the IPCC RCP8.5 emission scenario. Here we present sulfur-isotope data that record a positive 1 per mil excursion during the PETM. Modeling suggests that large parts of the ocean must have become sulfidic. The toxicity of hydrogen sulfide will render two of the largest and least explored ecosystems on Earth, the mesopelagic and bathypelagic zones, uninhabitable by multicellular organisms. This will affect many marine species whose ecozones stretch into the deep ocean.},
author = {Yao, Weiqi and Paytan, Adina and Wortmann, Ulrich G.},
doi = {10.1126/science.aar8658},
issn = {0036-8075},
journal = {Science},
month = {jul},
number = {6404},
pages = {804--806},
publisher = {American Association for the Advancement of Science (AAAS)},
title = {{Large-scale ocean deoxygenation during the Paleocene-Eocene Thermal Maximum}},
volume = {361},
year = {2018}
}
@article{Yashayaev2016a,
author = {Yashayaev, Igor and Loder, John W},
doi = {10.1002/2016JC012046},
journal = {Journal of Geophysical Research: Oceans},
number = {11},
pages = {8095--8114},
publisher = {Wiley Online Library},
title = {{Recurrent replenishment of Labrador Sea Water and associated decadal-scale variability}},
volume = {121},
year = {2016}
}
@article{Yau9710,
abstract = {This work contributes to the scientific effort focused on developing an accurate assessment of the impact that global warming will have on the Greenland ice sheet. By focusing on the last interglacial, a period warmer than today, we learn about the sensitivity of the ice sheet to climate change. We combine data and model simulations to characterize the Eemian history of the Greenland ice sheet. Our data and insights will be useful for simulating the future of the ice sheet in response to climate change.The Eemian (last interglacial, 130{\{}$\backslash$textendash{\}}115 ka) was likely the warmest of all interglacials of the last 800 ka, with summer Arctic temperatures 3{\{}$\backslash$textendash{\}}5 {\{}$\backslash$textdegree{\}}C above present. Here, we present improved Eemian climate records from central Greenland, reconstructed from the base of the Greenland Ice Sheet Project 2 (GISP2) ice core. Our record comes from clean, stratigraphically disturbed, and isotopically warm ice from 2,750 to 3,040 m depth. The age of this ice is constrained by measuring CH4 and $\delta$18O of O2, and comparing with the historical record of these properties from the North Greenland Ice Core Project (NGRIP) and North Greenland Eemian Ice Drilling (NEEM) ice cores. The $\delta$18Oice, $\delta$15N of N2, and total air content for samples dating discontinuously from 128 to 115 ka indicate a warming of {\~{}}6 {\{}$\backslash$textdegree{\}}C between 127{\{}$\backslash$textendash{\}}121 ka, and a similar elevation history between GISP2 and NEEM. The reconstructed climate and elevation histories are compared with an ensemble of coupled climate-ice-sheet model simulations of the Greenland ice sheet. Those most consistent with the reconstructed temperatures indicate that the Greenland ice sheet contributed 5.1 m (4.1{\{}$\backslash$textendash{\}}6.2 m, 95{\%} credible interval) to global eustatic sea level toward the end of the Eemian. Greenland likely did not contribute to anomalously high sea levels at {\~{}}127 ka, or to a rapid jump in sea level at {\~{}}120 ka. However, several unexplained discrepancies remain between the inferred and simulated histories of temperature and accumulation rate at GISP2 and NEEM, as well as between the climatic reconstructions themselves.},
author = {Yau, Audrey M and Bender, Michael L and Robinson, Alexander and Brook, Edward J},
doi = {10.1073/pnas.1524766113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {35},
pages = {9710--9715},
publisher = {National Academy of Sciences},
title = {{Reconstructing the last interglacial at Summit, Greenland: Insights from GISP2}},
url = {https://www.pnas.org/content/113/35/9710},
volume = {113},
year = {2016}
}
@article{Yeh2018,
author = {Yeh, S-W. and Cai, W. and Min, S.-K. and McPhaden, M.J. and Dommenget, D. and Dewitte, B. and Collins, M. and Karumuri, A. and An, S.-I. and Yim, B.-Y. and Kug, J.-S.},
doi = {10.1002/2017RG000568},
journal = {Reviews of Geophysics},
keywords = {10.1002/2012RG000419 and gravity waves,atmosphere,fronts,jets,stratosphere,weather},
number = {1},
pages = {185--206},
title = {{ENSO Atmospheric Teleconnections and Their Response to Greenhouse Gas Forcing}},
volume = {56},
year = {2018}
}
@article{doi:10.1002/2016JA023733,
abstract = {Abstract We present a new empirical model of total and spectral solar irradiance (TSI and SSI) variability entitled EMPirical Irradiance REconstruction (EMPIRE). As with existing empirical models, TSI and SSI variability is given by the linear combination of solar activity indices. In empirical models, UV SSI variability is usually determined by fitting the rotational variability in activity indices to that in measurements. Such models have to date relied on ordinary least squares regression, which ignores the uncertainty in the activity indices. In an advance from earlier efforts, the uncertainty in the activity indices is accounted for in EMPIRE by the application of an error-in-variables regression scheme, making the resultant UV SSI variability more robust. The result is consistent with observations and unprecedentedly, with that from other modeling approaches, resolving the long-standing controversy between existing empirical models and other types of models. We demonstrate that earlier empirical models, by neglecting the uncertainty in activity indices, underestimate UV SSI variability. The reconstruction of TSI and visible and IR SSI from EMPIRE is also shown to be consistent with observations. The EMPIRE reconstruction is of utility to climate studies as a more robust alternative to earlier empirical reconstructions.},
author = {Yeo, K L and Krivova, N A and Solanki, S K},
doi = {10.1002/2016JA023733},
journal = {Journal of Geophysical Research: Space Physics},
keywords = {solar irradiance},
number = {4},
pages = {3888--3914},
title = {{EMPIRE: A robust empirical reconstruction of solar irradiance variability}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JA023733},
volume = {122},
year = {2017}
}
@article{doi:10.1002/2015JA021277,
abstract = {Abstract Total solar irradiance and UV spectral solar irradiance has been monitored since 1978 through a succession of space missions. This is accompanied by the development of models aimed at replicating solar irradiance by relating the variability to solar magnetic activity. The Naval Research Laboratory Solar Spectral Irradiance (NRLSSI) and Spectral And Total Irradiance REconstruction for the Satellite era (SATIRE-S) models provide the most comprehensive reconstructions of total and spectral solar irradiance over the period of satellite observation currently available. There is persistent controversy between the various measurements and models in terms of the wavelength dependence of the variation over the solar cycle, with repercussions on our understanding of the influence of UV solar irradiance variability on the stratosphere. We review the measurement and modeling of UV solar irradiance variability over the period of satellite observation. The SATIRE-S reconstruction is consistent with spectral solar irradiance observations where they are reliable. It is also supported by an independent, empirical reconstruction of UV spectral solar irradiance based on Upper Atmosphere Research Satellite/Solar Ultraviolet Spectral Irradiance Monitor measurements from an earlier study. The weaker solar cycle variability produced by NRLSSI between 300 and 400 nm is not evident in any available record. We show that although the method employed to construct NRLSSI is principally sound, reconstructed solar cycle variability is detrimentally affected by the uncertainty in the SSI observations it draws upon in the derivation. Based on our findings, we recommend, when choosing between the two models, the use of SATIRE-S for climate studies.},
author = {Yeo, K L and Ball, W T and Krivova, N A and Solanki, S K and Unruh, Y C and Morrill, J},
doi = {10.1002/2015JA021277},
journal = {Journal of Geophysical Research: Space Physics},
keywords = {solar irradiance,solar variability},
number = {8},
pages = {6055--6070},
title = {{UV solar irradiance in observations and the NRLSSI and SATIRE-S models}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015JA021277},
volume = {120},
year = {2015}
}
@article{Yeo2020,
abstract = {How the solar electromagnetic energy entering the Earth's atmosphere varied since preindustrial times is an important consideration in the climate change debate. Detrimental to this debate, estimates of the change in total solar irradiance (TSI) since the Maunder minimum, an extended period of weak solar activity preceding the industrial revolution, differ markedly, ranging from a drop of 0.75 W m−2 to a rise of 6.3 W m−2. Consequently, the exact contribution by solar forcing to the rise in global temperatures over the past centuries remains inconclusive. Adopting a novel approach based on state-of-the-art solar imagery and numerical simulations, we establish the TSI level of the Sun when it is in its least-active state to be 2.0 ± 0.7 W m−2 below the 2019 level. This means TSI could not have risen since the Maunder minimum by more than this amount, thus restricting the possible role of solar forcing in global warming.},
author = {Yeo, K. L. and Solanki, S. K. and Krivova, N. A. and Rempel, M. and Anusha, L. S. and Shapiro, A. I. and Tagirov, R. V. and Witzke, V.},
doi = {10.1029/2020GL090243},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {19},
pages = {e2020GL090243},
title = {{The Dimmest State of the Sun}},
volume = {47},
year = {2020}
}
@article{Yeung2019a,
abstract = {Tropospheric ozone (O3) is a key component of air pollution and an important anthropogenic greenhouse gas1. During the twentieth century, the proliferation of the internal combustion engine, rapid industrialization and land-use change led to a global-scale increase in O3 concentrations2,3; however, the magnitude of this increase is uncertain. Atmospheric chemistry models typically predict4–7 an increase in the tropospheric O3 burden of between 25 and 50 per cent since 1900, whereas direct measurements made in the late nineteenth century indicate that surface O3 mixing ratios increased by up to 300 per cent8–10 over that time period. However, the accuracy and diagnostic power of these measurements remains controversial2. Here we use a record of the clumped-isotope composition of molecular oxygen (18O18O in O2) trapped in polar firn and ice from 1590 to 2016 ad, as well as atmospheric chemistry model simulations, to constrain changes in tropospheric O3 concentrations. We find that during the second half of the twentieth century, the proportion of 18O18O in O2 decreased by 0.03 ± 0.02 parts per thousand (95 per cent confidence interval) below its 1590–1958 ad mean, which implies that tropospheric O3 increased by less than 40 per cent during that time. These results corroborate model predictions of global-scale increases in surface pollution and vegetative stress caused by increasing anthropogenic emissions of O3 precursors4,5,11. We also estimate that the radiative forcing of tropospheric O3 since 1850 ad is probably less than +0.4 watts per square metre, consistent with results from recent climate modelling studies12.},
author = {Yeung, Laurence Y and Murray, Lee. T and Martinerie, Patricia and Witrant, Emmanuel and Hu, Huanting and Banerjee, Asmita and Orsi, Ana{\"{i}}s and Chappellaz, J{\'{e}}r{\^{o}}me},
doi = {10.1038/s41586-019-1277-1},
issn = {1476-4687},
journal = {Nature},
number = {7760},
pages = {224--227},
title = {{Isotopic constraint on the twentieth-century increase in tropospheric ozone}},
volume = {570},
year = {2019}
}
@article{Yim2017,
abstract = {Strengthening or weakening of the Walker circulation can highly influence the global weather and climate variability by altering the location and strength of tropical heating. Therefore, there is considerable interest in understanding the mechanisms that lead to the trends in the Walker circulation intensity. Conventional wisdom indicates that a strengthening or weakening of the Walker circulation is primarily controlled by inhomogeneous sea surface temperature (SST) patterns across the tropical Pacific basin. However, we show that Atmospheric Model Intercomparison Project climate model simulations with identical SST forcing have different Walker circulation trends that can be linked to differences in land surface temperatures. More prominently, stronger land-sea thermal contrast leads to increases in the precipitation in South America as well as the sea level pressure in the eastern tropical Pacific through a local circulation, resulting in a strengthening of the Walker circulation trend. This implies that correctly simulating the land temperature in atmospheric models is crucial to simulating the intensity of the Walker circulation in the present climate as well as its future change.},
author = {Yim, Bo Young and Yeh, Sang Wook and Song, Hwan Jin and Dommenget, Dietmar and Sohn, B. J.},
doi = {10.1002/2017GL073778},
issn = {19448007},
journal = {Geophysical Research Letters},
keywords = {AMIP climate models,Walker circulation,land-sea thermal contrast,sea surface temperature},
number = {11},
pages = {5854--5862},
title = {{Land-sea thermal contrast determines the trend of Walker circulation simulated in atmospheric general circulation models}},
volume = {44},
year = {2017}
}
@article{Yokoyama2018,
abstract = {The approximately 10,000-year-long Last Glacial Maximum, before the termination of the last ice age, was the coldest period in Earth's recent climate history1. Relative to the Holocene epoch, atmospheric carbon dioxide was about 100 parts per million lower and tropical sea surface temperatures were about 3 to 5 degrees Celsius lower2,3. The Last Glacial Maximum began when global mean sea level (GMSL) abruptly dropped by about 40 metres around 31,000 years ago4 and was followed by about 10,000 years of rapid deglaciation into the Holocene1. The masses of the melting polar ice sheets and the change in ocean volume, and hence in GMSL, are primary constraints for climate models constructed to describe the transition between the Last Glacial Maximum and the Holocene, and future changes; but the rate, timing and magnitude of this transition remain uncertain. Here we show that sea level at the shelf edge of the Great Barrier Reef dropped by around 20 metres between 21,900 and 20,500 years ago, to −118 metres relative to the modern level. Our findings are based on recovered and radiometrically dated fossil corals and coralline algae assemblages, and represent relative sea level at the Great Barrier Reef, rather than GMSL. Subsequently, relative sea level rose at a rate of about 3.5 millimetres per year for around 4,000 years. The rise is consistent with the warming previously observed at 19,000 years ago1,5, but we now show that it occurred just after the 20-metre drop in relative sea level and the related increase in global ice volumes. The detailed structure of our record is robust because the Great Barrier Reef is remote from former ice sheets and tectonic activity. Relative sea level can be influenced by Earth's response to regional changes in ice and water loadings and may differ greatly from GMSL. Consequently, we used glacio-isostatic models to derive GMSL, and find that the Last Glacial Maximum culminated 20,500 years ago in a GMSL low of about −125 to −130 metres.},
author = {Yokoyama, Yusuke and Esat, Tezer M and Thompson, William G and Thomas, Alexander L and Webster, Jody M and Miyairi, Yosuke and Sawada, Chikako and Aze, Takahiro and Matsuzaki, Hiroyuki and Okuno, Jun'ichi and Fallon, Stewart and Braga, Juan-Carlos and Humblet, Marc and Iryu, Yasufumi and Potts, Donald C and Fujita, Kazuhiko and Suzuki, Atsushi and Kan, Hironobu},
doi = {10.1038/s41586-018-0335-4},
issn = {1476-4687},
journal = {Nature},
number = {7715},
pages = {603--607},
title = {{Rapid glaciation and a two-step sea level plunge into the Last Glacial Maximum}},
url = {https://doi.org/10.1038/s41586-018-0335-4},
volume = {559},
year = {2018}
}
@article{https://doi.org/10.1029/2008GL036571,
abstract = {Proxy data constraining land and ocean surface paleo-temperatures indicate that the Middle Miocene Climate Optimum (MMCO), a global warming event at ∼15 Ma, had a global annual mean surface temperature of 18.4°C, about 3°C higher than present and equivalent to the warming predicted for the next century. We apply the latest National Center for Atmospheric Research (NCAR) Community Atmosphere Model CAM3.1 and Land Model CLM3.0 coupled to a slab ocean to examine sensitivity of MMCO climate to varying ocean heat fluxes derived from paleo sea surface temperatures (SSTs) and atmospheric carbon dioxide concentrations, using detailed reconstructions of Middle Miocene boundary conditions including paleogeography, elevation, vegetation and surface temperatures. Our model suggests that to maintain MMCO warmth consistent with proxy data, the required atmospheric CO2 concentration is about 460–580 ppmv, narrowed from the most recent estimate of 300–600 ppmv.},
author = {You, Y and Huber, M and M{\"{u}}ller, R D and Poulsen, C J and Ribbe, J},
doi = {10.1029/2008GL036571},
journal = {Geophysical Research Letters},
keywords = {Miocene climatic optimum,paleoclimate,paleoclime modeling},
number = {4},
pages = {L04702},
title = {{Simulation of the Middle Miocene Climate Optimum}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2008GL036571},
volume = {36},
year = {2009}
}
@article{Young2019a,
author = {Young, I R; and Ribal, A},
doi = {10.1126/science.aav9527},
journal = {Science},
number = {6440},
pages = {548--552},
title = {{Multiplatform evaluation of global trends in wind speed and wave height}},
volume = {364},
year = {2019}
}
@article{YOUNG2020106091,
abstract = {Understanding patterns of ice-sheet deglaciation is key for predicting the rate of future ice-sheet melt, yet the processes underlying deglaciation remain elusive. The early Holocene (11.7 ka to 8.2 ka; Greenlandian Stage) represents the most recent period when the Laurentide and Greenland ice sheets underwent large-scale recession. Moreover, this ice-sheet recession occurred under the backdrop of regional temperatures that were similar to or warmer than today, and comparable to those projected for the upcoming centuries. Reconstructing Laurentide and Greenland ice sheet behavior during the early Holocene, and elucidating the mechanisms dictating this behavior may serve as a partial analog for future Greenland ice-sheet change in a warming world. Here, we present 123 new 10Be surface exposure ages from two sites on Baffin Island and southwestern Greenland that constrain the behavior of the Laurentide and Greenland ice sheets, and an independent alpine glacier during the early Holocene. On Baffin Island, we focus on a unique area where moraines deposited by the Laurentide Ice Sheet rest directly adjacent to moraines deposited by an independent alpine glacier. Sixty-one 10Be ages reveal that advances and/or stillstands of the Laurentide Ice Sheet and an alpine glacier occurred in unison around 11.8 ka, 10.3 ka, and 9.2 ka. Sixty-two 10Be ages from southwestern Greenland indicate that the Greenland Ice Sheet margin experienced re-advances or stillstands around 11.6 ka, 10.4 ka, 9.1 ka, 8.1 ka, and 7.3 ka. Our results reveal that ice sheets respond to climate perturbations on the same centennial timescale as small alpine glaciers. We hypothesize that during the warming climate of the early Holocene, freshening of the North Atlantic Ocean induced by ice-sheet melt resulted in regional cooling and brief periods of ice-sheet stabilization superimposed on net glacier recession. These observations point to a negative feedback mechanism inherent to melting ice sheets in the Baffin Bay region that slows ice-sheet recession during intervals of otherwise rapid deglaciation.},
author = {Young, Nicol{\'{a}}s E and Briner, Jason P and Miller, Gifford H and Lesnek, Alia J and Crump, Sarah E and Thomas, Elizabeth K and Pendleton, Simon L and Cuzzone, Joshua and Lamp, Jennifer and Zimmerman, Susan and Caffee, Marc and Schaefer, Joerg M},
doi = {10.1016/j.quascirev.2019.106091},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
pages = {106091},
title = {{Deglaciation of the Greenland and Laurentide ice sheets interrupted by glacier advance during abrupt coolings}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379119309849},
volume = {229},
year = {2020}
}
@article{YOUNG20151,
abstract = {Geophysical ice-sheet models are used to predict future ice-sheet dimensions and, in turn, these projections help estimate the magnitude of eustatic sea-level rise. Before models can confidently predict ice-sheet behavior, they must be validated by being able to duplicate the geological record of ice-sheet change. Here, we review geological records of Greenland Ice Sheet (GrIS) change, with emphasis on the warmer-than-present middle Holocene, and compare these records to published studies that numerically simulate GrIS behavior through the Holocene. Geological records are concentrated in West and Southwest Greenland, which are also the regions where the GrIS margin likely experienced the greatest distance of inland retreat during the middle Holocene. Several records spanning from Melville Bugt to Jakobshavn Isfjord in western Greenland indicate the GrIS achieved its minimum extent between ∼5 and 3 ka, and farther south in the Kangerlussuaq region, new data presented here indicate the ice margin reached its minimum extent between ∼4.2 and 1.8 ka. In the Narsarsuaq region in southern Greenland, the GrIS likely achieved its minimum configuration between ∼7 and 4 ka. We highlight key similarities and discrepancies between these reconstructions and model results, and finally, we suggest that despite some degree of inland retreat, the West and Southwest GrIS margin remained relatively stable and close to its current position through the Holocene thermal maximum.},
author = {Young, Nicol{\'{a}}s E and Briner, Jason P},
doi = {10.1016/j.quascirev.2015.01.018},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Be dating,Greenland Ice Sheet,Holocene,Ice-margin reconstructions,Lake sediments},
pages = {1--17},
title = {{Holocene evolution of the western Greenland Ice Sheet: Assessing geophysical ice-sheet models with geological reconstructions of ice-margin change}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379115000426},
volume = {114},
year = {2015}
}
@article{doi:10.1002/joc.5702,
abstract = {Previous studies have indicated that the relationship between El Ni{\~{n}}o-Southern Oscillation (ENSO) and the East Asian winter monsoon (EAWM) weakened significantly after the late 1970s. In this study, the relationship is further analysed based on the impact of different ENSO types. It is found that the relationship between ENSO and the EAWM is related to the ENSO's types. The relationship with the EAWM is strong for eastern Pacific (EP) ENSO but weak for central Pacific (CP) ENSO. The blend of EP and CP ENSO events in the Ni{\~{n}}o3 index results in a weakened statistical relationship between ENSO and the EAWM. If the pure CP ENSO events are removed from the Ni{\~{n}}o3 index, the results show that EP ENSO still exerts influence on the EAWM after the late 1970s via its strong connections with the Philippine Sea anticyclone (PSAC) and East Asian trough (EAT), similar to the period before the late 1970s. In contrast, the connections between CP ENSO and the PSAC and EAT are relatively weak, consequently resulting in a weakened relationship between CP ENSO and the EAWM. The influence of mixed (MIX) ENSO on the EAWM is similar to that of EP ENSO. Thus, the EP and MIX ENSO events have had a stable influence on the East Asian winter climate over the past half century, which is significant for the prediction of the East Asian winter climate.},
author = {Yu, Shui and Sun, Jianqi},
doi = {10.1002/joc.5702},
journal = {International Journal of Climatology},
keywords = {East Asian winter monsoon,El Ni{\~{n}}o-Southern Oscillation,decadal changes},
number = {13},
pages = {4846--4859},
title = {{Revisiting the relationship between El Ni{\~{n}}o-Southern Oscillation and the East Asian winter monsoon}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.5702},
volume = {38},
year = {2018}
}
@article{Yu2020,
author = {Yu, Hongbin and Yang, Yang and Wang, Hailong and Tan, Qian and Chin, Mian and Levy, Robert C. and Remer, Lorraine A. and Smith, Steven J. and Yuan, Tianle and Shi, Yingxi},
doi = {10.5194/acp-20-139-2020},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jan},
number = {1},
pages = {139--161},
title = {{Interannual variability and trends of combustion aerosol and dust in major continental outflows revealed by MODIS retrievals and CAM5 simulations during 2003–2017}},
url = {https://www.atmos-chem-phys.net/20/139/2020/},
volume = {20},
year = {2020}
}
@article{Yu2020a,
abstract = {The ocean plays a dominant role in the global water cycle. It is the center of action for global evaporation and precipitation and supplies the moisture that falls as continental precipitation. It also acts to some extent as nature's rain gauge, as it tells us about the long-term changes in the global water cycle through monitoring of the changes in ocean surface salinity. As climate warms, the global water cycle is expected to intensify as a result of the strong nonlinear dependence of water vapor pressure (moisture-holding capacity) on temperature. Such change is of great concern, as it has profound socioeconomic impacts throughout the globe. Despite the evidence of an intensified global water cycle, two important questions remain: What is the pattern of the warming-induced intensification of the water cycle? and What is the rate of intensification? Our article provides a synthesis review of recent progress in diagnosing and understanding the changes in both the global water cycle and ocean salinity in recent decades. Targeted numerical ocean model experiments are also reviewed to provide insights into the response of salinity to the changes in evaporation-minus-precipitation flux, meltwater runoff, and ocean warming.},
author = {Yu, Lisan and Josey, Simon A. and Bingham, Frederick M. and Lee, Tong},
doi = {10.1111/nyas.14354},
issn = {17496632},
journal = {Annals of the New York Academy of Sciences},
keywords = {evaporation,global water cycle,long-term trends,ocean salinity,precipitation,surface freshwater flux},
number = {1},
pages = {76--94},
pmid = {32386251},
title = {{Intensification of the global water cycle and evidence from ocean salinity: a synthesis review}},
volume = {1472},
year = {2020}
}
@article{doi:10.1002/joc.3575,
abstract = {Abstract This study develops a pattern correlation method to determine the type of major El Ni{\~{n}}o events since 1870 from a reconstructed sea surface temperature dataset. Different from other identification methods, this method allows an El Ni{\~{n}}o event to be of the Central-Pacific (CP) type, the Eastern-Pacific (EP) type, or the Mixed type (i.e. the both types coexist). Application of this method to the 39 major El Ni{\~{n}}o events identified by the Ocean Ni{\~{n}}o Index during the period 1870–2010 results in 8 events that are categorized to be of the EP type, 16 of the CP type, and 15 of Mixed type. Before the 1910s, the El Ni{\~{n}}o events are mostly of the EP type, but are mostly the CP type after 2000, while in between both types occurred. The consistencies and inconsistencies between the El Ni{\~{n}}o types identified by this method and other three methods, which have been proposed recently for El Ni{\~{n}}o-type classification, are examined and discussed. All four methods consistently identify the El Ni{\~{n}}o events occurring in the following years to be of the EP types: 1876–1877, 1881, 1884–1885, 1895–1896, 1896–1897, 1918–1919, 1982–1983, and 1997–1998; and the events occurring in the following years to be of the CP type: 1968–1969, 1977–1978, 1994–1995, 2004–2005, and 2009–2010. It is evident that the characteristics of the EP type of El Ni{\~{n}}o are more robust in the 19th century and the early part of the 20th century, whereas the characteristics of the CP type of El Ni{\~{n}}o is more robust in the late 20th century and the early 21st century. The list of the El Ni{\~{n}}o types produced by this study can be used for selecting El Ni{\~{n}}o events to further study the dynamics and climate impacts of the EP, CP, and Mixed types of El Ni{\~{n}}o. Copyright {\textcopyright} 2012 Royal Meteorological Society},
author = {Yu, Jin-Yi and Kim, Seon Tae},
doi = {10.1002/joc.3575},
journal = {International Journal of Climatology},
keywords = {Central-Pacific El Ni{\~{n}}o,Eastern-Pacific El Ni{\~{n}}o,identifying El Ni{\~{n}}o types,pattern correlation method},
number = {8},
pages = {2105--2112},
title = {{Identifying the types of major El Ni{\~{n}}o events since 1870}},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.3575},
volume = {33},
year = {2013}
}
@article{doi:10.1002/2017GL076912,
abstract = {Abstract The strength of the El Ni{\~{n}}o-Southern Oscillation (ENSO)-Indian summer monsoon rainfall (ISMR) relationship shows considerable decadal fluctuations, which have been previously linked to low-frequency climatic processes such as shifts in ENSO's center of action or the Atlantic Multidecadal Oscillation. However, random variability can also cause similar variations in the relationship between climate phenomena. Here we propose a statistical test to determine whether the observed time-evolving correlations between ENSO and ISMR are different from those expected from a simple stochastic null hypothesis model. The analysis focuses on the time evolution of moving correlations, their expected variance, and probabilities for rapid transitions. The results indicate that the time evolution of the observed running correlation between these climate modes is indistinguishable from a system in which the ISMR signal can be expressed as a stochastically perturbed ENSO signal. This challenges previous deterministic interpretations. Our results are further corroborated by the analysis of climate model simulations.},
author = {Yun, Kyung-Sook and Timmermann, Axel},
doi = {10.1002/2017GL076912},
journal = {Geophysical Research Letters},
keywords = {ENSO-monsoon relationship,deterministic process,stochastic process},
number = {4},
pages = {2014--2021},
title = {{Decadal Monsoon-ENSO Relationships Reexamined}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL076912},
volume = {45},
year = {2018}
}
@article{Zachos2008,
author = {Zachos, James C. and Dickens, Gerald R. and Zeebe, Richard E.},
doi = {10.1038/nature06588},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7176},
pages = {279--283},
title = {{An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics}},
url = {http://www.nature.com/articles/nature06588},
volume = {451},
year = {2008}
}
@article{Zanna1126,
abstract = {Since the 19th century, rising greenhouse gas concentrations have caused the ocean to absorb most of the Earth{\{}$\backslash$textquoteright{\}}s excess heat and warm up. Before the 1990s, most ocean temperature measurements were above 700 m and therefore, insufficient for an accurate global estimate of ocean warming. We present a method to reconstruct ocean temperature changes with global, full-depth ocean coverage, revealing warming of 436 {\{}$\backslash$texttimes{\}}1021 J since 1871. Our reconstruction, which agrees with other estimates for the well-observed period, demonstrates that the ocean absorbed as much heat during 1921{\{}$\backslash$textendash{\}}1946 as during 1990{\{}$\backslash$textendash{\}}2015. Since the 1950s, up to one-half of excess heat in the Atlantic Ocean at midlatitudes has come from other regions via circulation-related changes in heat transport.Most of the excess energy stored in the climate system due to anthropogenic greenhouse gas emissions has been taken up by the oceans, leading to thermal expansion and sea-level rise. The oceans thus have an important role in the Earth{\{}$\backslash$textquoteright{\}}s energy imbalance. Observational constraints on future anthropogenic warming critically depend on accurate estimates of past ocean heat content (OHC) change. We present a reconstruction of OHC since 1871, with global coverage of the full ocean depth. Our estimates combine timeseries of observed sea surface temperatures with much longer historical coverage than those in the ocean interior together with a representation (a Green{\{}$\backslash$textquoteright{\}}s function) of time-independent ocean transport processes. For 1955{\{}$\backslash$textendash{\}}2017, our estimates are comparable with direct estimates made by infilling the available 3D time-dependent ocean temperature observations. We find that the global ocean absorbed heat during this period at a rate of 0.30 {\{}$\backslash$textpm{\}} 0.06 W/m2 in the upper 2,000 m and 0.028 {\{}$\backslash$textpm{\}} 0.026 W/m2 below 2,000 m, with large decadal fluctuations. The total OHC change since 1871 is estimated at 436 {\{}$\backslash$textpm{\}} 91 {\{}$\backslash$texttimes{\}}1021 J, with an increase during 1921{\{}$\backslash$textendash{\}}1946 (145 {\{}$\backslash$textpm{\}} 62 {\{}$\backslash$texttimes{\}}1021 J) that is as large as during 1990{\{}$\backslash$textendash{\}}2015. By comparing with direct estimates, we also infer that, during 1955{\{}$\backslash$textendash{\}}2017, up to one-half of the Atlantic Ocean warming and thermosteric sea-level rise at low latitudes to midlatitudes emerged due to heat convergence from changes in ocean transport.},
author = {Zanna, Laure and Khatiwala, Samar and Gregory, Jonathan M and Ison, Jonathan and Heimbach, Patrick},
doi = {10.1073/pnas.1808838115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {4},
pages = {1126--1131},
publisher = {National Academy of Sciences},
title = {{Global reconstruction of historical ocean heat storage and transport}},
url = {https://www.pnas.org/content/116/4/1126},
volume = {116},
year = {2019}
}
@article{doi:10.1002/2016JC012271,
abstract = {Abstract Over the past 17 years, the western boundary current system of the Labrador Sea has been closely observed by maintaining the 53°N observatory (moorings and shipboard station data) measuring the top-to-bottom flow field offshore from the Labrador shelf break. Volume transports for the North Atlantic Deep Water (NADW) components were calculated using different methods, including gap filling procedures for deployment periods with suboptimal instrument coverage. On average the Deep Western Boundary Current (DWBC) carries 30.2 ± 6.6 Sv of NADW southward, which are almost equally partitioned between Labrador Sea Water (LSW, 14.9 ± 3.9 Sv) and Lower North Atlantic Deep Water (LNADW, 15.3 ± 3.8 Sv). The transport variability ranges from days to decades, with the most prominent multiyear fluctuations at interannual to near decadal time scales (±5 Sv) in the LNADW overflow water mass. These long-term fluctuations appear to be in phase with the NAO-modulated wind fluctuations. The boundary current system off Labrador occurs as a conglomerate of nearly independent components, namely, the shallow Labrador Current, the weakly sheared LSW range, and the deep baroclinic, bottom-intensified current core of the LNADW, all of which are part of the cyclonic Labrador Sea circulation. This structure is relatively stable over time, and the 120 km wide boundary current is constrained seaward by a weak counterflow which reduces the deep water export by 10–15{\%}.},
author = {Zantopp, R and Fischer, J and Visbeck, M and Karstensen, J},
doi = {10.1002/2016JC012271},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {NAO forcing,decadal variations,deep western boundary current,subpolar North Atlantic},
month = {mar},
number = {3},
pages = {1724--1748},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{From interannual to decadal: 17 years of boundary current transports at the exit of the Labrador Sea}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012271 https://doi.org/10.1002/2016JC012271},
volume = {122},
year = {2017}
}
@article{Zeebe2016,
abstract = {Carbon release rates from anthropogenic sources reached a record high of ∼10 Pg C yr−1 in 2014. Geologic analogues from past transient climate changes could provide invaluable constraints on the response of the climate system to such perturbations, but only if the associated carbon release rates can be reliably reconstructed. The Palaeocene–Eocene Thermal Maximum (PETM) is known at present to have the highest carbon release rates of the past 66 million years, but robust estimates of the initial rate and onset duration are hindered by uncertainties in age models. Here we introduce a new method to extract rates of change from a sedimentary record based on the relative timing of climate and carbon cycle changes, without the need for an age model. We apply this method to stable carbon and oxygen isotope records from the New Jersey shelf using timeseries analysis and carbon cycle–climate modelling. We calculate that the initial carbon release during the onset of the PETM occurred over at least 4,000 years. This constrains the maximum sustained PETM carbon release rate to less than 1.1 Pg C yr−1 . We conclude that, given currently available records, the present anthropogenic carbon release rate is unprecedented during the past 66 million years. We suggest that such a ‘no-analogue' state represents a fundamental challenge in constraining future climate projections. Also, future ecosystem disruptions are likely to exceed the relatively limited extinctions observed at the PETM.},
author = {Zeebe, Richard E. and Ridgwell, Andy and Zachos, James C.},
doi = {10.1038/ngeo2681},
isbn = {1752-0894},
issn = {17520908},
journal = {Nature Geoscience},
month = {apr},
number = {4},
pages = {325--329},
pmid = {25376268},
publisher = {Nature Publishing Group},
title = {{Anthropogenic carbon release rate unprecedented during the past 66 million years}},
volume = {9},
year = {2016}
}
@article{https://doi.org/10.1029/2019GL085578,
abstract = {Abstract Glaciers in the European Alps rapidly lose mass to adapt to changes in climate conditions. Here, we investigate the relationship and lag between climate forcing and geometric glacier response with a regional glacier evolution model accounting for ice dynamics. The volume loss occurring as a result of the glacier-climate imbalance increased over the early 21st century, from about 35{\%} in 2001 to 44{\%} in 2010. This committed loss reduced to {\~{}}40{\%} by 2018, indicating that temperature increase was outweighing glacier retreat in the early 2000s but that the fast retreat effectively somewhat diminished glacier imbalances. We analyze the lag in glacier response for each individual glacier and find mean response times of 50 ± 28 years. Our findings indicate that the response time is primarily controlled by glacier slope and secondarily by elevation range and mass balance gradient, rather than by glacier size.},
annote = {e2019GL085578 2019GL085578},
author = {Zekollari, Harry and Huss, Matthias and Farinotti, Daniel},
doi = {10.1029/2019GL085578},
journal = {Geophysical Research Letters},
keywords = {alps,climate change,dynamics,glacier,response time},
number = {2},
pages = {e2019GL085578},
title = {{On the Imbalance and Response Time of Glaciers in the European Alps}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL085578},
volume = {47},
year = {2020}
}
@article{Zemp2019,
abstract = {Glaciers distinct from the Greenland and Antarctic ice sheets cover an area of approximately 706,000 square kilometres globally1, with an estimated total volume of 170,000 cubic kilometres, or 0.4 metres of potential sea-level-rise equivalent2. Retreating and thinning glaciers are icons of climate change3 and affect regional runoff4 as well as global sea level5,6. In past reports from the Intergovernmental Panel on Climate Change, estimates of changes in glacier mass were based on the multiplication of averaged or interpolated results from available observations of a few hundred glaciers by defined regional glacier areas7–10. For data-scarce regions, these results had to be complemented with estimates based on satellite altimetry and gravimetry11. These past approaches were challenged by the small number and heterogeneous spatiotemporal distribution of in situ measurement series and their often unknown ability to represent their respective mountain ranges, as well as by the spatial limitations of satellite altimetry (for which only point data are available) and gravimetry (with its coarse resolution). Here we use an extrapolation of glaciological and geodetic observations to show that glaciers contributed 27 ± 22 millimetres to global mean sea-level rise from 1961 to 2016. Regional specific-mass-change rates for 2006–2016 range from −0.1 metres to −1.2 metres of water equivalent per year, resulting in a global sea-level contribution of 335 ± 144 gigatonnes, or 0.92 ± 0.39 millimetres, per year. Although statistical uncertainty ranges overlap, our conclusions suggest that glacier mass loss may be larger than previously reported11. The present glacier mass loss is equivalent to the sea-level contribution of the Greenland Ice Sheet12, clearly exceeds the loss from the Antarctic Ice Sheet13, and accounts for 25 to 30 per cent of the total observed sea-level rise14. Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century, while heavily glacierized regions will continue to contribute to sea-level rise beyond 2100.},
author = {Zemp, M and Huss, M and Thibert, E and Eckert, N and McNabb, R and Huber, J and Barandun, M and Machguth, H and Nussbaumer, S U and G{\"{a}}rtner-Roer, I and Thomson, L and Paul, F and Maussion, F and Kutuzov, S and Cogley, J G},
doi = {10.1038/s41586-019-1071-0},
issn = {1476-4687},
journal = {Nature},
number = {7752},
pages = {382--386},
title = {{Global glacier mass changes and their contributions to sea-level rise from 1961 to 2016}},
url = {https://doi.org/10.1038/s41586-019-1071-0},
volume = {568},
year = {2019}
}
@article{Zemp2020,
abstract = {Comprehensive assessments of global glacier mass changes based on a variety of observations and prevailing methodologies have been published at multi-annual intervals. For the years in between, the glaciological method provides annual observations of specific mass changes but is suspected to not be representative at the regional to global scales due to uneven glacier distribution with respect to the full sample. Here, we present a simple approach to estimate and correct for this bias in the glaciological sample and, hence, to provide an ad hoc estimate of global glacier mass changes and corresponding sea-level equivalents for the latest years, i.e. about-300 ± 250 Gt in 2016/17 and-500 ± 200 Gt in 2017/18.},
author = {Zemp, Michael and Huss, Matthias and Eckert, Nicolas and Thibert, Emmanuel and Paul, Frank and Nussbaumer, U. Samuel and G{\"{a}}rtner-Roer, Isabelle},
doi = {10.5194/tc-14-1043-2020},
issn = {19940424},
journal = {Cryosphere},
number = {3},
pages = {1043--1050},
title = {{Brief communication: Ad hoc estimation of glacier contributions to sea-level rise from the latest glaciological observations}},
volume = {14},
year = {2020}
}
@article{doi:10.1175/JTECH-D-18-0105.1,
abstract = {AbstractGlobal Positioning System (GPS) radio occultation (RO) is capable of retrieving vertical profiles of atmospheric parameters with high resolution ({\textless}100 m) which can be achieved in spherically-symmetric atmosphere. Horizontal inhomogeneity of real atmosphere results in representativeness errors of retrieved profiles. In most cases these errors increase with a decrease of vertical scales of atmospheric structures and may not allow one to fully utilize the physical resolution of RO. Also, GPS RO retrieved profiles are affected by observational noise of different types which, in turn, affect the representation of small-scale atmospheric structures. This study investigates the effective resolution and optimal smoothing of GPS RO retrieved temperature profiles using high-pass filtering and cross-correlation with collocated high-resolution radiosondes. The effective resolution is a trade-off between representation of real atmospheric structures and suppression of observational noise, which varies for different latitudes (15°S – 75°N) and altitudes (10-27 km). Our results indicate that at low latitudes the effective vertical resolution is about 0.2 km near the tropical tropopause layer and about 0.5 km in the lower stratosphere. The best resolution of 0.1 km is at the cold-point tropical tropopause. The effective resolutions at the middle latitudes are slightly worse than at low latitudes, varying from {\~{}}0.2 to 0.6 km. At high latitudes, the effective resolutions change notably with altitude from {\~{}}0.2 km at 10-15 km to {\~{}}1.4 km at 22-27 km. Our results suggest that the atmospheric inhomogeneity plays an important role in the representation of the vertical atmospheric structures by RO measurements.},
author = {Zeng, Zhen and Sokolovskiy, Sergey and Schreiner, William S and Hunt, Doug},
doi = {10.1175/JTECH-D-18-0105.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {2},
pages = {199--211},
title = {{Representation of vertical atmospheric structures by radio occultation observations in the UTLS: comparison to high resolution radiosonde profiles}},
url = {https://doi.org/10.1175/JTECH-D-18-0105.1},
volume = {58},
year = {2019}
}
@article{Zeng2019,
author = {Zeng, Z and Ziegler, A D and T, Searchinger and Yang, L and Chen, A and Ju, K and Piao, S and Li, L Z X and Ciais, P and Chen, D and Liu, J G and Azorin-Molina, C and Chappell, A and Medvigy, D and Wood, E F},
doi = {10.1038/s41558-019-0622-6},
journal = {Nature Climate Change},
pages = {979--985},
title = {{A reversal in global terrestrial stilling and its implications for wind energy production}},
volume = {9},
year = {2019}
}
@article{Zeng2018,
abstract = {Southeast Asia is a hotspot of tropical deforestation for agriculture. Most of the deforestation is thought to occur in lowland forests, whereas the region's mountainous highlands undergo very limited deforestation. However, regional reports of cropland expansion in some highland areas suggest that this assumption is inaccurate. Here we investigate patterns of forest change and cropland expansion in the region for the twenty-first century, based on multiple streams of state-of-the-art satellite imagery. We find large increases in cultivated areas that have not been documented or projected. Many of these cultivated areas have evolved from forests that vary in health and status, including primary and protected forests, or from recovering lands that were on a trajectory to become secondary forests. These areas all have different biophysical features than croplands. We estimate that an area of 82 billion m2 has been developed into croplands in the Southeast Asian highlands. Some portion of this land-use change is probably attributable to agricultural intensification on formerly swidden agriculture lands; however, a substantial proportion is from new forest loss. Our findings are in marked contrast with projections of land-cover trends that currently inform the prediction of future climate change, terrestrial carbon storage, biomass, biodiversity, and land degradation.},
author = {Zeng, Zhenzhong and Estes, Lyndon and Ziegler, Alan D. and Chen, Anping and Searchinger, Timothy and Hua, Fangyuan and Guan, Kaiyu and Jintrawet, Attachai and {F. Wood}, Eric},
doi = {10.1038/s41561-018-0166-9},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {aug},
number = {8},
pages = {556--562},
title = {{Highland cropland expansion and forest loss in Southeast Asia in the twenty-first century}},
url = {http://www.nature.com/articles/s41561-018-0166-9},
volume = {11},
year = {2018}
}
@article{Zhang2018a,
abstract = {Abstract. The duration of dry or wet hydrological epochs (run lengths) associated with positive or negative Inter-decadal Pacific Oscillation (IPO) or Pacific Decadal Oscillation (PDO) phases, termed Pacific decadal variability (PDV), is an essential statistical property for understanding, assessing and managing hydroclimatic risk. Numerous IPO and PDO paleoclimate reconstructions provide a valuable opportunity to study the statistical signatures of PDV, including run lengths. However, disparities exist between these reconstructions, making it problematic to determine which reconstruction(s) to use to investigate pre-instrumental PDV and run length. Variability and persistence on centennial scales are also present in some millennium-long reconstructions, making consistent run length extraction difficult. Thus, a robust method to extract meaningful and consistent run lengths from multiple reconstructions is required. In this study, a dynamic threshold framework to account for centennial trends in PDV reconstructions is proposed. The dynamic threshold framework is shown to extract meaningful run length information from multiple reconstructions. Two hydrologically important aspects of the statistical signatures associated with the PDV are explored: (i) whether persistence (i.e. run lengths) during positive epochs is different to persistence during negative epochs and (ii) whether the reconstructed run lengths have been stationary during the past millennium. Results suggest that there is no significant difference between run lengths in positive and negative phases of PDV and that it is more likely than not that the PDV run length has been non-stationary in the past millennium. This raises concerns about whether variability seen in the instrumental record (the last ∼100 years), or even in the shorter 300–400-year paleoclimate reconstructions, is representative of the full range of variability.},
author = {Zhang, Lanying and Kuczera, George and Kiem, Anthony S and Willgoose, Garry},
doi = {10.5194/hess-22-6399-2018},
issn = {16077938},
journal = {Hydrology and Earth System Sciences},
number = {12},
pages = {6399--6414},
title = {{Using paleoclimate reconstructions to analyse hydrological epochs associated with Pacific decadal variability}},
volume = {22},
year = {2018}
}
@article{Zhang2015,
abstract = {Abstract Previous studies reported that positive phases of the Indian Ocean Dipole (IOD) tend to accompany El Ni{\~{n}}o during boreal autumn. Here we show that the El Ni{\~{n}}o/IOD relationship can be better understood when considering two different El Ni{\~{n}}o flavors. Eastern Pacific El Ni{\~{n}}o events exhibit a strong correlation with the IOD dependent on their magnitude. In contrast, the relationship between Central Pacific (CP) El Ni{\~{n}}o events and the IOD depends mainly on the zonal location of the sea surface temperature anomalies rather than their magnitude. CP El Ni{\~{n}}o events lying farther west than normal are not accompanied by significant anomalous easterlies over the eastern Indian Ocean along the Java/Sumatra coast, which is unfavorable for the local Bjerknes feedback and correspondingly for an IOD development. The El Ni{\~{n}}o/IOD relationship has experienced substantial changes due to the recent decadal El Ni{\~{n}}o regime shift, which has important implications for seasonal prediction.},
annote = {doi: 10.1002/2015GL065703},
author = {Zhang, Wenjun and Wang, Yalan and Jin, Fei-Fei and Stuecker, Malte F and Turner, Andrew G},
doi = {10.1002/2015GL065703},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {El Niňo flavors,Indian Ocean Dipole,relationship},
month = {oct},
number = {20},
pages = {8570--8576},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Impact of different El Ni{\~{n}}o types on the El Ni{\~{n}}o/IOD relationship}},
url = {https://doi.org/10.1002/2015GL065703},
volume = {42},
year = {2015}
}
@article{Zhang2018,
author = {Zhang, Yehui and Xu, Jiawei and Yang, Na and Lan, Ping},
doi = {10.3390/atmos9050174},
issn = {2073-4433},
journal = {Atmosphere},
keywords = {atmospheric water vapor,precipitable water,radiosonde,satellite},
month = {may},
number = {5},
pages = {174},
title = {{Variability and Trends in Global Precipitable Water Vapor Retrieved from COSMIC Radio Occultation and Radiosonde Observations}},
url = {http://www.mdpi.com/2073-4433/9/5/174},
volume = {9},
year = {2018}
}
@article{Zhang2018e,
author = {Zhang, Hongbin and Griffiths, Michael L and Chiang, John C H and Kong, Wenwen and Wu, Shitou and Atwood, Alyssa and Huang, Junhua and Cheng, Hai and Ning, Youfeng and Xie, Shucheng},
doi = {10.1126/science.aat9393},
journal = {Science},
pages = {580--583},
title = {{East Asian hydroclimate modulated by the position of the westerlies during Termination I}},
volume = {362},
year = {2018}
}
@article{Zhang2019,
abstract = {Terrestrial vegetation, as the key component of the biosphere, has a greening trend since the beginning of this century. However, how this substantial greening translated to global gross carbon sequestration or gross primary production (GPP) is not clear. Here we investigated terrestrial GPP dynamics and the respective contributions of climate change and vegetation cover change (VCC) from 2000 to 2015. We adopted a remote sensing based data-driven model, which was calibrated based on the global eddy flux data set (FLUXNET2015) and Moderate Resolution Imaging Spectroradiometer vegetation index data (Collection 6). A series of simulation experiments were conducted to disaggregate the effects of climate and VCC. We found a much weaker increase in global GPP (0.08{\%}/year; P = 0.07) when compared with the global greening rate (0.23{\%}/year; P {\textless} 0.001). The positive effect of VCC on GPP was reduced by 53{\%} due to climate stress. Enhanced global GPP were largely contributed by nonforests, especially croplands. However, tropical forests, once a major driver of the global GPP increase, negatively contributed to global GPP trend due to warming-induced moisture stress and deforestation. Given the limited potential of cropland carbon storage due to harvest and consumption, the contrasting GPP changes (i.e., cropland GPP increase vs. forest GPP reduction) may have shifted the distribution of the land carbon sink. Our study highlights the potential vulnerability of terrestrial gross carbon sequestration under climate and land use changes and has important implications in the global carbon cycle and climate warming mitigation.},
author = {Zhang, Yulong and Song, Conghe and Band, Lawrence E. and Sun, Ge},
doi = {10.1029/2018JG004917},
issn = {2169-8953},
journal = {Journal of Geophysical Research: Biogeosciences},
month = {aug},
number = {8},
pages = {2540--2553},
title = {{No Proportional Increase of Terrestrial Gross Carbon Sequestration From the Greening Earth}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2018JG004917},
volume = {124},
year = {2019}
}
@article{Zhang2016,
abstract = {The wintertime Arctic stratospheric polar vortex has weakened over the past three decades, and consequently cold surface air from high latitudes is now more likely to move into the middle latitudes. However, it is not known if the location of the polar vortex has also experienced a persistent change in response to Arctic climate change and whether any changes in the vortex position have implications for the climate system. Here, through the analysis of various data sets and model simulations, we show that the Arctic polar vortex shifted persistently towards the Eurasian continent and away from North America in February over the past three decades. This shift is found to be closely related to the enhanced zonal wavenumber-1 waves in response to Arctic sea-ice loss, particularly over the Barents–Kara seas (BKS). Increased snow cover over the Eurasian continent may also have contributed to the shift. Our analysis reveals that the vortex shift induces cooling over some parts of the Eurasian continent and North America which partly offsets the tropospheric climate warming there in the past three decades. The potential vortex shift in response to persistent sea-ice loss in the future and its associated climatic impact, deserve attention to better constrain future climate changes.},
author = {Zhang, Jiankai and Tian, Wenshou and Chipperfield, Martyn P. and Xie, Fei and Huang, Jinlong},
doi = {10.1038/nclimate3136},
isbn = {1758-678X},
issn = {17586798},
journal = {Nature Climate Change},
number = {12},
pages = {1094--1099},
title = {{Persistent shift of the Arctic polar vortex towards the Eurasian continent in recent decades}},
volume = {6},
year = {2016}
}
@article{Zhang2018,
abstract = {The Montreal Protocol has succeeded in limiting major ozone-depleting substance emissions, and consequently stratospheric ozone concentrations are expected to recover this century. However, there is a large uncertainty in the rate of regional ozone recovery in the Northern Hemisphere. Here we identify a Eurasia-North America dipole mode in the total column ozone over the Northern Hemisphere, showing negative and positive total column ozone anomaly centres over Eurasia and North America, respectively. The positive trend of this mode explains an enhanced total column ozone decline over the Eurasian continent in the past three decades, which is closely related to the polar vortex shift towards Eurasia. Multiple chemistry-climate-model simulations indicate that the positive Eurasia-North America dipole trend in late winter is likely to continue in the near future. Our findings suggest that the anticipated ozone recovery in late winter will be sensitive not only to the ozone-depleting substance decline but also to the polar vortex changes, and could be substantially delayed in some regions of the Northern Hemisphere extratropics.},
author = {Zhang, Jiankai and Tian, Wenshou and Xie, Fei and Chipperfield, Martyn P. and Feng, Wuhu and Son, Seok Woo and Abraham, N. Luke and Archibald, Alexander T. and Bekki, Slimane and Butchart, Neal and Deushi, Makoto and Dhomse, Sandip and Han, Yuanyuan and J{\"{o}}ckel, Patrick and Kinnison, Douglas and Kirner, Ole and Michou, Martine and Morgenstern, Olaf and O'Connor, Fiona M. and Pitari, Giovanni and Plummer, David A. and Revell, Laura E. and Rozanov, Eugene and Visioni, Daniele and Wang, Wuke and Zeng, Guang},
doi = {10.1038/s41467-017-02565-2},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1--8},
title = {{Stratospheric ozone loss over the Eurasian continent induced by the polar vortex shift}},
volume = {9},
year = {2018}
}
@article{Zhang2013,
abstract = {Themodes andmechanisms of the annual water vapor variations over the twentieth century are investigated based on a newly developed twentieth-century atmospheric reanalysis product. It is found that the leading modes of global water vapor variations over the twentieth century are controlled by global warming, the At- lantic multidecadal oscillation (AMO), and ENSO. On the global scale, the variations in water vapor syn- chronize with the sea surface temperature, which can be explained by the simple thermal Clausius–Clapeyron theory under conditions of constant relative humidity.However, on regional scales, the spatial patterns ofwater vapor variations associated with global warming, AMO, and ENSO are largely attributed to the atmospheric circulation dynamics, particularly the planetary divergent circulation change induced by the sea surface tem- perature changes. In the middle and high latitudes, the transient eddy fluxes and thermodynamics also play significant roles.},
author = {Zhang, Liping and Wu, Lixin and Gan, Bolan},
doi = {10.1175/JCLI-D-12-00585.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Aerosols,Anthropogenic effects,Climate change,Climate models,Monsoons,Radiative forcing},
number = {15},
pages = {5578--5593},
title = {{Modes and mechanisms of global water vapor variability over the twentieth century}},
volume = {26},
year = {2013}
}
@article{Zhang2019e,
author = {Zhang, Ran and Jiang, Dabang and Zhang, Zhongshi and Yan, Qing and Li, Xiangyu},
doi = {10.1007/s00382-019-04834-w},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {7},
pages = {4871--4886},
title = {{Modeling the late Pliocene global monsoon response to individual boundary conditions}},
url = {https://doi.org/10.1007/s00382-019-04834-w},
volume = {53},
year = {2019}
}
@article{Zhang2014d,
author = {Zhang, Ran and Jiang, Dabang},
doi = {10.1007/s00376-014-4015-5},
issn = {1861-9533},
journal = {Advances in Atmospheric Sciences},
number = {6},
pages = {1407--1416},
title = {{Impact of vegetation feedback on the mid-Pliocene warm climate}},
url = {https://doi.org/10.1007/s00376-014-4015-5},
volume = {31},
year = {2014}
}
@article{ZHANG2020118,
abstract = {Haptophyte algal biomarkers called alkenones are widely used to reconstruct atmospheric CO2 in Earth's Cenozoic history. This method is based on the notion that the algal carbon isotope fractionation during photosynthesis, as represented by $\epsilon$p37:2, is a function of seawater CO2 concentration and algal physiology. Constraining the algal physiological parameter, known as the ‘b' term, is the key for successful applications of the alkenone-CO2 method. Using sensitivity analyses, we show that the growth rate ($\mu$), cell size (r), and membrane permeability (P) are the most important variables to determine b. For all life on Earth, body size is a key factor that regulates metabolic rates. Exploiting the interdependence between phytoplankton cell size and growth rate, and specifically, the r – $\mu$ relationship for coccolithophores, we show that the length of fossil coccoliths (Lcoccolith) produced by ancient alkenone-synthesizers can be used to estimate r and therefore $\mu$. Combining our new Lcoccolith data and published $\epsilon$p37:2 from the South China Sea Site MD01-2392, existing results from ODP Site 925, and ice core CO2, we determined the cell membrane permeability (P = 5.09 × 10−5 m s−1) for the Pleistocene community employing a bootstrap resampling technique. These new methods of constraining r, $\mu$ and P, combined with proxy-derived temperature (T), led us to rebuild b as a variable for each sample individually, which is subsequently used for alkenone-CO2 calculations. Application of this approach established pCO2 of the last 3 glacial-interglacial cycles, which turns out to be comparable with the ice core data in both the amplitude of changes and absolute values. It also reconciles the published Eocene – Oligocene alkenone-CO2 data which showed large geographical differences, with the new estimates much more consistent among different sites, and in line with other proxy-based results and ice sheet model predictions.},
author = {Zhang, Yi Ge and Henderiks, Jorijntje and Liu, Xiaoqing},
doi = {10.1016/j.gca.2020.05.002},
issn = {0016-7037},
journal = {Geochimica et Cosmochimica Acta},
keywords = {Algal physiological term ‘',Alkenone-CO,CO records,Coccolith size,Growth rate,Membrane permeability},
pages = {118--134},
title = {{Refining the alkenone-pCO2 method II: Towards resolving the physiological parameter ‘b'}},
url = {http://www.sciencedirect.com/science/article/pii/S0016703720303069},
volume = {281},
year = {2020}
}
@article{Zhang2014,
abstract = {The El Ni{\~{n}}o-Southern Oscillation (ENSO) represents the largest perturbation to the climate system on an inter-annual time scale, but its evolution since the end of the last ice age remains debated due to the lack of unambiguous ENSO records lasting longer than a few centuries. Changes in the concentration and hydrogen isotope ratio of lipids produced by the green alga Botryococcus braunii, which blooms during El Ni{\~{n}}o rains in the Gal{\'{a}}pagos Islands, indicate that the early Holocene (9200–5600 yr BP) was characterized by alternating extremes in the intensity and/or frequency of El Ni{\~{n}}o events that lasted a century or more. Our data from the core of the ENSO region thus calls into question earlier studies that reported a lack of El Ni{\~{n}}o activity in the early Holocene. In agreement with other proxy evidence from the tropical Pacific, the mid-Holocene (5600–3500 yr BP) was a time of consistently weak El Ni{\~{n}}o activity, as were the Early Middle Ages (∼1000–1500 yr BP). El Ni{\~{n}}o activity was moderate to high during the remainder of the last 3500 years. Periods of strong or frequent El Ni{\~{n}}o tended to occur during peaks in solar activity and during extended droughts in the United States Great Plains linked to La Ni{\~{n}}a. These changing modes of ENSO activity at millennial and multi-centennial timescales may have been caused by variations in the seasonal receipts of solar radiation associated with the precession of the equinoxes and/or changes in solar activity, respectively.},
author = {Zhang, Zhaohui and Leduc, Guillaume and Sachs, Julian P},
doi = {10.1016/j.epsl.2014.07.013},
issn = {0012-821X},
journal = {Earth and Planetary Science Letters},
pages = {420--434},
title = {{El Ni{\~{n}}o evolution during the Holocene revealed by a biomarker rain gauge in the Gal{\'{a}}pagos Islands}},
volume = {404},
year = {2014}
}
@article{Zhao2019b,
abstract = {The present paper uses the satellite era data from 1979 to 2015 to examine the relationship between El Ni{\~{n}}o-Southern Oscillation (ENSO) and tropical cyclones (TCs) in the western North Pacific (WNP) during the boreal summer from June to August. It is found that WNP TC variability is characterized by two major feature changes: (1) a significant reduction of the TC number since 1998 and (2) a stronger interannual relationship between ENSO and TCs since 1998. Results suggested that such changes are largely due to the synergy effects of a shifting ENSO and the Pacific climate regime shift. Since 1998 with a cool Pacific decadal oscillation phase switching from a warm phase, more La Ni{\~{n}}a and central Pacific (CP) El Ni{\~{n}}o events occur. The decreased low-level relative vorticity and increased vertical wind shear during 1998--2015 compared to 1979--1997 are responsible for the TC reduction. The stronger interannual relationship between ENSO and TCs since 1998 is closely associated the change of CP sea surface temperature. It enhances the associations of environmental factors including vertical wind shear and mid-level relative humidity with TCs and thus increases the interannual relationship between ENSO and TCs. These two feature changes also manifest in the mean TC genesis location, with a northwestward shift of the TC genesis location during 1998--2015 and an increased relation to El Ni{\~{n}}o Modoki index since 1998. This study has an important implication for TC outlooks in the WNP based on climate predictions and projections.},
author = {Zhao, Haikun and Wang, Chunzai},
doi = {10.1007/s00382-018-4136-0},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {jan},
number = {1-2},
pages = {275--288},
title = {{On the relationship between ENSO and tropical cyclones in the western North Pacific during the boreal summer}},
url = {http://link.springer.com/10.1007/s00382-018-4136-0},
volume = {52},
year = {2019}
}
@article{Zhao2015,
abstract = {Vegetation phenology is a key biological indicator for monitoring terrestrial ecosystems and global change, and regions with the most obvious phenological changes in vegetation are primarily located at high latitudes and altitudes. Over the past three decades, investigations of obvious phenological changes in vegetation at middle and high latitudes in the Northern Hemisphere have provided significant contributions to understanding global climate change. In this study, phenological parameters were extracted from the Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) to analyze the spatial and temporal characteristics of vegetation phenological changes above 40°N in the Northern Hemisphere from 1982–2013. The results showed that the start of season (SOS) was significantly advanced (−2.2 ± 0.6 days{\textperiodcentered}decade−1, p {\textless} 0.05) and that the end of season (EOS) was slightly delayed (0.78 ± 0.6 days{\textperiodcentered}decade−1, p = 0.21) over the entire study area in the initial 21 years (1982–2002). When the time scale was extended to 2013, the change rate of the SOS and EOS was significantly reduced; in addition, the SOS was delayed (3.2 ± 1.7 days{\textperiodcentered}decade−1, p {\textless} 0.05), and the EOS was advanced (4.5 ± 0.9 days{\textperiodcentered}decade−1, p {\textless} 0.05) over the entire study area in the last 11 years (2003–2013). The trends of advanced SOS and delayed EOS over the past three decades were slower than those over the initial two decades on a hemispheric scale. The change trends showed obvious variability with different vegetation types and were greater for woody plants than for herbaceous plants. For broad-leaved forest, the SOS was significantly advanced (2 ± 0.5 days{\textperiodcentered}decade−1, p {\textless} 0.05) and the EOS was significantly delayed (2.7 ± 0.6 days{\textperiodcentered}decade−1, p {\textless} 0.05) from 1982–2013. The trend of delayed EOS was greater than that of advanced SOS for different vegetation types. With respect to the spatial distribution of phenological trends in the Northern Hemisphere, the trends of advanced SOS and delayed EOS were strongest in Europe followed by North America, and the trends were least significant in Asia. Coniferous forest, shrub forest, grassland, and the entire study area have the same change trends for the two time periods (1982–2002 and 2003–2013), and the increased rate of the phenology parameters has decelerated over the most recent decade. The length of season (LOS) of broad-leaved forest and mixed forest over the past 32 years shows a strong increased trend, and simultaneously, the SOS and EOS show an advanced trend and a delayed trend, respectively},
author = {Zhao, Jianjun and Zhang, Hongyan and Zhang, Zhengxiang and Guo, Xiaoyi and Li, Xuedong and Chen, Chun},
doi = {10.3390/rs70810973},
issn = {20724292},
journal = {Remote Sensing},
keywords = {GIMMS NDVI3g,Long time series,Mid and high latitude,Northern Hemisphere,Vegetation phenology},
number = {8},
pages = {10973--10995},
title = {{Spatial and temporal changes in vegetation phenology at middle and high latitudes of the northern hemisphere over the past three decades}},
volume = {7},
year = {2015}
}
@article{Zhao2019a,
author = {Zhao, Xueying and Allen, Robert J},
doi = {10.1088/2515-7620/ab0dab},
journal = {Environmental Research Communications},
keywords = {article is available online,el ni{\~{n}}o,la ni{\~{n}}a,natural variability,supplementary material for this,walker circulation},
number = {2},
pages = {021003},
publisher = {IOP Publishing},
title = {{Strengthening of the Walker Circulation in recent decades and the role of natural sea surface temperature variability}},
volume = {1},
year = {2019}
}
@article{Zhao2020,
author = {Zhao, Lin and Zou, Defu and Hu, Guojie and Du, Erji and Pang, Qiangqiang and Xiao, Yao and Li, Ren and Sheng, Yu and Wu, Xiaodong and Sun, Zhe and Wang, Lingxiao and Wang, Chong and Ma, Lu and Zhou, Huayun and Liu, Shibo},
doi = {10.1002/ppp.2056},
issn = {1045-6740},
journal = {Permafrost and Periglacial Processes},
month = {jul},
number = {3},
pages = {396--405},
title = {{Changing climate and the permafrost environment on the Qinghai–Tibet (Xizang) plateau}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ppp.2056},
volume = {31},
year = {2020}
}
@article{Zhao2017a,
abstract = {The performance of simple permafrost distribution models widely used on the Qinghai-Tibet Plateau (QTP) has not been fully evaluated. In this study, two empirical models (the elevation model and mean annual ground temperature model) and three semi-physical models (the surface frost number model, the temperature at the top of permafrost model and the Kudryavtsev model) were investigated. The simulation results from the models were compared to each other and validated against existing permafrost maps of the entire QTP and in three representative areas investigated in the field. The models generally overestimated permafrost distribution in the investigated areas, but they captured the broad characteristics of permafrost distribution on the entire QTP, and performed best in areas with colder, continuous permafrost. Large variations in performance occurred at elevations of 3800-4500m asl and in areas with thermally unstable permafrost. The two empirical models performed best in areas where permafrost is strongly controlled by elevation, such as eastern QTP. In contrast, the three semi-physical models were better in southern island permafrost areas with relatively flat terrain, where local factors considerably impact the distribution of permafrost. Model performance could be enhanced by explicitly considering the effects of elevation zones and regional conditions. Copyright (c) 2017 John Wiley {\&} Sons, Ltd.},
author = {Zhao, Shu-Ping and Nan, Zhuo-Tong and Huang, Ying-Bing and Zhao, Lin},
doi = {10.1002/ppp.1939},
issn = {10456740},
journal = {Permafrost and Periglacial Processes},
number = {2},
pages = {391--404},
title = {{The Application and Evaluation of Simple Permafrost Distribution Models on the Qinghai-Tibet Plateau}},
volume = {28},
year = {2017}
}
@article{Zheng2018a,
author = {Zheng, Bo and Tong, Dan and Li, Meng and Liu, Fei and Hong, Chaopeng and Geng, Guannan and Li, Haiyan and Li, Xin and Peng, Liqun and Qi, Ji and Yan, Liu and Zhang, Yuxuan and Zhao, Hongyan and Zheng, Yixuan and He, Kebin and Zhang, Qiang},
doi = {10.5194/acp-18-14095-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {oct},
number = {19},
pages = {14095--14111},
title = {{Trends in China's anthropogenic emissions since 2010 as the consequence of clean air actions}},
url = {https://www.atmos-chem-phys.net/18/14095/2018/},
volume = {18},
year = {2018}
}
@article{Zhou2017a,
annote = {doi: 10.1080/16000870.2017.1308055},
author = {Zhou, Xiaobing and Alves, Oscar and Marsland, Simon J and Bi, Daohua and Hirst, Anthony C},
doi = {10.1080/16000870.2017.1308055},
issn = {null},
journal = {Tellus A: Dynamic Meteorology and Oceanography},
month = {jan},
number = {1},
pages = {1308055},
publisher = {Taylor {\&} Francis},
title = {{Multi-decadal variations of the South Indian Ocean subsurface temperature influenced by Pacific Decadal Oscillation}},
url = {https://doi.org/10.1080/16000870.2017.1308055},
volume = {69},
year = {2017}
}
@article{Zhou2020d,
abstract = {The performance of 20 models participating in the atmospheric model intercomparison project (AMIP) is evaluated concerning surface latent (QLH) and sensible (QSH) heat flux over the tropical oceans (30°S–30°N). Biases were calculated by comparing model fluxes to observations from moored buoys and the objectively analyzed air–sea fluxes (OAFlux) database. All 20 AMIP models overestimate QLH with an ensemble mean bias of 20 W m−2, and 18 of the 20 models overestimate QSH with an ensemble mean bias of 5 W m−2 when compared to OAFlux, implying a systematic positive bias over the tropical oceans. A comparison with buoy observations also showed similar biases. To obtain insights into the causes behind model bias, we quantified the contribution from near-surface winds, specific humidity, and temperatures. It is found that near-surface humidity contributes more to the bias in QLH than wind speed, while air temperature contributes more to bias in QSH than wind speed. On the other hand, the root mean squared error (RMSE) in QLH has contributions from both near-surface humidity and wind. The contribution from humidity to the mean bias in QLH is 13 W m−2, with RMSE of 15 W m−2, suggesting a systematic overestimation of sea-air humidity difference in models. The model ensemble, in general, simulates QLH and QSH better than individual models. Models with higher horizontal and vertical resolutions perform better than coarse resolution models.},
author = {Zhou, Xin and Ray, Pallav and Barrett, Bradford S and Hsu, Pang-Chi},
doi = {10.1007/s00382-020-05431-y},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {11},
pages = {2957--2978},
title = {{Understanding the bias in surface latent and sensible heat fluxes in contemporary AGCMs over tropical oceans}},
url = {https://doi.org/10.1007/s00382-020-05431-y},
volume = {55},
year = {2020}
}
@article{Zhueaax1874,
abstract = {The Early Eocene, a period of elevated atmospheric CO2 ({\textgreater}1000 ppmv), is considered an analog for future climate. Previous modeling attempts have been unable to reproduce major features of Eocene climate indicated by proxy data without substantial modification to the model physics. Here, we present simulations using a state-of-the-art climate model forced by proxy-estimated CO2 levels that capture the extreme surface warmth and reduced latitudinal temperature gradient of the Early Eocene and the warming of the Paleocene-Eocene Thermal Maximum. Our simulations exhibit increasing equilibrium climate sensitivity with warming and suggest an Eocene sensitivity of more than 6.6{\{}$\backslash$textdegree{\}}C, much greater than the present-day value (4.2{\{}$\backslash$textdegree{\}}C). This higher climate sensitivity is mainly attributable to the shortwave cloud feedback, which is linked primarily to cloud microphysical processes. Our findings highlight the role of small-scale cloud processes in determining large-scale climate changes and suggest a potential increase in climate sensitivity with future warming.},
author = {Zhu, Jiang and Poulsen, Christopher J and Tierney, Jessica E},
doi = {10.1126/sciadv.aax1874},
journal = {Science Advances},
number = {9},
pages = {eaax1874},
publisher = {American Association for the Advancement of Science},
title = {{Simulation of Eocene extreme warmth and high climate sensitivity through cloud feedbacks}},
url = {https://advances.sciencemag.org/content/5/9/eaax1874},
volume = {5},
year = {2019}
}
@article{Zhu2016,
abstract = {Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system and provision of ecosystem services1,2. Yet how global vegetation is responding to the changing environment is not well established. Here we use three long-term satellite leaf area index (LAI) records and ten global ecosystem models to investigate four key drivers of LAI trends during 1982–2009. We show a persistent and widespread increase of growing season integrated LAI (greening) over 25{\%} to 50{\%} of the global vegetated area, whereas less than 4{\%} of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization eects explain 70{\%} of the observed greening trend, followed by nitrogen deposition (9{\%}), climate change (8{\%}) and land cover change (LCC) (4{\%}). CO2 fertilization eects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau. LCC contributed most to the regional greening observed in southeast China and the eastern United States. The regional eects of unexplained factors suggest that the next generation of ecosystem models will need to explore the impacts of forest demography, dierences in regional management intensities for cropland andpastures,andother emerging productivity constraints such as phosphorus availability.},
author = {Zhu, Zaichun and Piao, Shilong and Myneni, Ranga B. and Huang, Mengtian and Zeng, Zhenzhong and Canadell, Josep G. and Ciais, Philippe and Sitch, Stephen and Friedlingstein, Pierre and Arneth, Almut and Cao, Chunxiang and Cheng, Lei and Kato, Etsushi and Koven, Charles and Li, Yue and Lian, Xu and Liu, Yongwen and Liu, Ronggao and Mao, Jiafu and Pan, Yaozhong and Peng, Shushi and Peuelas, Josep and Poulter, Benjamin and Pugh, Thomas A.M. and Stocker, Benjamin D. and Viovy, Nicolas and Wang, Xuhui and Wang, Yingping and Xiao, Zhiqiang and Yang, Hui and Zaehle, S{\"{o}}nke and Zeng, Ning},
doi = {10.1038/nclimate3004},
isbn = {1758-6798},
issn = {17586798},
journal = {Nature Climate Change},
pages = {791--795},
title = {{Greening of the Earth and its drivers}},
volume = {6},
year = {2016}
}
@article{https://doi.org/10.1002/2017GL073406,
abstract = {Abstract Studying the El Ni{\~{n}}o–Southern Oscillation (ENSO) in the past can help us better understand its dynamics and improve its future projections. However, both paleoclimate reconstructions and model simulations of ENSO strength at the Last Glacial Maximum (LGM; 21 ka B.P.) have led to contradicting results. Here we perform model simulations using the recently developed water isotope-enabled Community Earth System Model (iCESM). For the first time, model-simulated oxygen isotopes are directly compared with those from ENSO reconstructions using the individual foraminifera analysis (IFA). We find that the LGM ENSO is most likely weaker comparing with the preindustrial. The iCESM suggests that total variance of the IFA records may only reflect changes in the annual cycle instead of ENSO variability as previously assumed. Furthermore, the interpretation of subsurface IFA records can be substantially complicated by the habitat depth of thermocline-dwelling foraminifera and their vertical migration with a temporally varying thermocline.},
author = {Zhu, Jiang and Liu, Zhengyu and Brady, Esther and Otto-Bliesner, Bette and Zhang, Jiaxu and Noone, David and Tomas, Robert and Nusbaumer, Jesse and Wong, Tony and Jahn, Alexandra and Tabor, Clay},
doi = {10.1002/2017GL073406},
journal = {Geophysical Research Letters},
keywords = {El Ni{\~{n}}o–Southern Oscillation,Last Glacial Maximum,direct model-data comparison,isotope-enabled simulation},
number = {13},
pages = {6984--6992},
title = {{Reduced ENSO variability at the LGM revealed by an isotope-enabled Earth system model}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL073406},
volume = {44},
year = {2017}
}
@article{Zhuang2013,
abstract = {AbstractSea levels in the southern Indian Ocean (SIO) display significant interannual to decadal variability. Off the northwest Australian coast, it has been demonstrated that sea level variability is mostly modulated by remote wind forcing from the tropical Pacific through equatorial and coastal waveguides. In this study, a linear reduced gravity model is used to investigate relative contributions of local wind forcing and remote forcing from the Pacific to the sea level variability of the SIO, with a focus on the western SIO. North of the South Equatorial Current bifurcation latitude (17{\textordmasculine}S), model simulated sea levels are well correlated with altimeter observations at the dissipation timescale of about 3?years, suggesting that sea level variability on interannual-to-decadal timescales could well be explained by nondispersive baroclinic Rossby wave adjustment. The large sea level variability of the western SIO is primarily caused by westward-propagating Rossby waves driven by wind stress curl in 70°E-95°E, with a minor influence from the remote Pacific forcing. To the south, sea level variability at around 20{\textordmasculine}S displays lower amplitude due to weaker wind variations at this latitude band, and the modeled sea level variability is weaker than observations. There is a close linkage between the cross-basin sea level difference at 15{\textordmasculine}S and the interior meridional ocean transport across this latitude on decadal timescales, as assessed with outputs from a data-assimilation model. Thus, the meridional overturning cell of the SIO is influenced by both remote forcing from equatorial Pacific and local winds in the SIO.},
annote = {doi: 10.1002/jgrc.20129},
author = {Zhuang, Wei and Feng, Ming and Du, Yan and Schiller, Andreas and Wang, Dongxiao},
doi = {10.1002/jgrc.20129},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {interannual to decadal variability,oceanic transports,sea level,southern Indian Ocean},
month = {mar},
number = {3},
pages = {1302--1315},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Low-frequency sea level variability in the southern Indian Ocean and its impacts on the oceanic meridional transports}},
url = {https://doi.org/10.1002/jgrc.20129},
volume = {118},
year = {2013}
}
@article{Zika2018,
author = {Zika, Jan David and Skliris, Nikolaos and Blaker, Adam and Marsh, Robert and Nurser, A. J. George and Josey, Simon},
doi = {10.1088/1748-9326/aace42},
issn = {1748-9326},
journal = {Environmental Research Letters},
number = {7},
pages = {074036},
title = {{Improved estimates of water cycle change from ocean salinity: the key role of ocean warming}},
url = {http://iopscience.iop.org/article/10.1088/1748-9326/aace42},
volume = {13},
year = {2018}
}
@article{Zinke2014a,
author = {Zinke, J and Rountrey, A and Feng, M and Xie, S.-P. and Dissard, D and Rankenburg, K and Lough, J M and McCulloch, M T},
doi = {10.1038/ncomms4607},
journal = {Nature Communications},
month = {apr},
pages = {3607},
publisher = {The Author(s)},
title = {{Corals record long-term Leeuwin current variability including Ningaloo Ni{\~{n}}o/Ni{\~{n}}a since 1795}},
url = {https://doi.org/10.1038/ncomms4607 10.1038/ncomms4607 https://www.nature.com/articles/ncomms4607{\#}supplementary-information},
volume = {5},
year = {2014}
}
@article{doi:10.1175/JTECH-D-16-0018.1,
abstract = {AbstractObservations from the Stratospheric Sounding Unit (SSU) on board historical NOAA polar-orbiting satellites have played a vital role in investigations of long-term trends and variability in the middle- and upper-stratospheric temperatures during 1979–2006. The successor to SSU is the Advanced Microwave Sounding Unit-A (AMSU-A) starting from 1998 until the present. Unfortunately, the two observations came from different sets of atmospheric layers, and the SSU weighting functions varied with time and location, posing a challenge to merge them with sufficient accuracy for development of an extended SSU climate data record. This study proposes a variational approach for the merging problem, matching in both temperatures and weighting functions. The approach yields zero means with a small standard deviation and a negligible drift over time in the temperature differences between SSU and its extension to AMSU-A. These features made the approach appealing for reliable detection of long-term climate trends. The approach also matches weighting functions with high accuracy for SSU channels 1 and 2 and reasonable accuracy for channel 3. The total decreases in global mean temperatures found from the merged dataset were from 1.8 K in the middle stratosphere to 2.4 K in the upper stratosphere during 1979–2015. These temperature drops were associated with two segments of piecewise linear cooling trends, with those during the first period (1979–97) being much larger than those of the second period (1998–2015). These differences in temperature trends corresponded well to changes of the atmospheric ozone amount from depletion to recovery during the respective time periods, showing the influence of human decisions on climate change.},
author = {Zou, Cheng-Zhi and Qian, Haifeng},
doi = {10.1175/JTECH-D-16-0018.1},
journal = {Journal of Atmospheric and Oceanic Technology},
number = {9},
pages = {1967--1984},
title = {{Stratospheric Temperature Climate Data Record from Merged SSU and AMSU-A Observations}},
url = {https://doi.org/10.1175/JTECH-D-16-0018.1},
volume = {33},
year = {2016}
}
@article{doi:10.1002/2014JD021603,
abstract = {Abstract Long-term observations from the Stratospheric Sounding Unit (SSU) during 1979–2006 onboard NOAA historical polar orbiting satellites were recalibrated for climate change investigation. A two-point linear calibration equation, with cold space and an internal blackbody warm target as end-point references, was used to transfer SSU raw counts data into radiances. The warm target temperature was represented by measurements from the space side thermistor on the blackbody, and the cold space radiance was assumed to be zero. Space view corrections due to an electrical interference were applied. Intersatellite calibration was conducted simultaneously by applying calibration offsets determined from residual intersatellite biases. The recalibration reached an accuracy of 0.1–0.2 K for global means and thus is expected to improve the consistency in stratospheric temperature time series in climate reanalyses. The recalibrated SSU radiances were further adjusted to develop Version 2 of the NOAA stratospheric temperature time series. The effects being adjusted included those from changes in instrument cell pressure and atmospheric carbon dioxide concentration, viewing angle differences, and semidiurnal tides due to orbital drift. Intersatellite biases were carefully removed to ensure smooth transitions between satellite pairs. Differences from Version 1 included improved radiance calibration, improved adjusting schemes for diurnal drift and intersatellite biases, removal of time-varying cell pressure adjustment for NOAA-9 channel 1, and excluding NOAA-7 channel 2 in the time series. In addition to the final merged data set, intermediate synthetic time series corresponding to different adjustments were also created to quantify their impact on the final trend as well as its reliability and uncertainty. Excellent matching between satellite pairs, especially the 7 year overlaps between NOAA-11 and NOAA-14 during 1997–2004, in intermediate as well as the final time series provided strong evidence on the validity of adjustments and thus confidence on the resulting trends. The Version 2 global mean trends for 1979–2006 were −0.69 ± 0.18, −0.77 ± 0.15, and −0.85 ± 0.15 K/decade for SSU channels 1, 2, and 3, representing temperatures of middle stratosphere, upper stratosphere, and stratosphere-mesosphere, respectively. Among these, cooling of channel 2 was stronger and channel 3 weaker than those in UK Met Office (UKMO) data by about 1 K during the entire SSU period from 1979 to 2006. Finally, the average of the channel 1 and channel 3 anomalies in Version 2 was close to channel 2 anomalies to within 0.2 K for the entire 1979–2006 period with identical trends. This feature was found consistent with chemistry-climate model simulations.},
author = {Zou, Cheng-Zhi and Qian, Haifeng and Wang, Wenhui and Wang, Likun and Long, Craig},
doi = {10.1002/2014JD021603},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {SSU recalibration,global warming,satellite observations,stratospheric cooling,stratospheric temperature trends},
number = {23},
pages = {13180--13205},
title = {{Recalibration and merging of SSU observations for stratospheric temperature trend studies}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JD021603},
volume = {119},
year = {2014}
}
@article{Zuo2016a,
author = {Zuo, Jinqing and Ren, Hong-Li and Li, Weijing and Wang, Lei},
doi = {10.1175/JCLI-D-15-0873.1},
journal = {Journal of Climate},
pages = {7477--7493},
title = {{Interdecadal Variations in the Relationship between the Winter North Atlantic Oscillation and Temperature in South-Central China}},
volume = {29},
year = {2016}
}