The MMD-A1B models project a median warming of 3.3°C (Table 11.1) by the end of the 21st century, which varies seasonally from 3.0°C in JJA to 3.6°C in DJF. The warming tends to be largest in winter, especially in the northern inland area (Figure 11.9), but the area-mean difference from the other seasons is not large. There is no obvious relationship between model bias and the magnitude of the warming. The spatial pattern of larger warming over northwest EAS (Figure 11.9) is very similar to the ensemble mean of pre-MMD models. Regional Climate Model simulations show mean temperature increases similar to those simulated by AOGCMs (Gao et al., 2001, 2002; Kwon et al., 2003; Jiang, 2005; Kurihara et al., 2005; Y.L. Xu et al., 2005).
Daily maximum and minimum temperatures are very likely to increase in East Asia, resulting in more severe warm but less severe cold extremes (Gao et al., 2002; Mizuta et al., 2005; Y.L. Xu et al., 2005; Boo et al., 2006). Mizuta et al. (2005) analyse temperature-based extreme indices over Japan with a 20-km mesh AGCM and find the changes in the indices to be basically those expected from the mean temperature increase, with changes in the distribution around the mean not playing a large role. Boo et al. (2005) report similar results for Korea. Gao et al. (2002) and Y.L. Xu et al. (2005) find a reduced diurnal temperature range in China and larger increases in daily minimum than maximum temperatures.