Figure 8.1: Decadal mean
SST errors relative to the GISST climatology for (a) the non-flux adjusted model
HadCM3 (Gordon et al., 2000), (b) the previous generation, flux adjusted model
HadCM2 (Johns et al. 1997), (c) the HadCM2 model when run without flux adjustments
(Gregory and Mitchell, 1997). The figures are from representative periods after
at least 100 years of each control run. Multi-century drifts in each run are much
smaller than the differences between the runs. The errors are smallest in (b),
because the flux adjustments were chosen specifically to minimise the errors.
The errors in (c) result from a number of complex feedbacks. The model was designed
to work in flux adjusted mode and it is possible that the non-flux adjusted SST
errors could have been reduced by relatively minor “tuning” of the model.