Simulation evaluation and future prediction of the IPCC-AR4 GCMs on the extreme temperatures in China

On the basis of the temperature observations during 1961-2000 in China, seven coupled general circulation models' (GCMs) extreme temperature products are evaluated supplied by the Intergovernmental Panel on Climate Change's 4th Assessment Report (IPCC-AR4).The extreme temperature indices in use are frost days (FD), growing season length (GSL), extreme temperature range (ETR), warm nights (TN90), and heat wave duration index (HWDI).Results indicate that all the seven models are capable of simulating spatial and temporal variations in temperature characteristics, and their ensemble acts more reliable than any single one.Among the seven models, GFDL-Cm2.0 and MIROC3.2 performances are much better.Besides, most of the models are able to present linear trends of the same positive/negative signs as the observations but for weaker intensities.The simulation effects are different on a nationwide basis, with 110°N as the division, east (west) of which the effects are better (worse) and the poorer over the Qinghai-Tibetan Plateau in China.The predictions for the 21st century on emissions scenarios show that except decreases in the FD and ETR, other indices display significant increasing trend, especially for the indices of HWDI and TN90, which represent the notable extreme climate.This indicates that the temperature-related climate is moving towards the extreme.In the late 21st century, the GSL and TN90 (HWDI) increase most notably in southwest China (the Qinghai-Tibetan Plateau), and the FD decrease most remarkably in the Qinghai-Tibetan Plateau, northwest and northeast of China.Apart from South China, the yearly change range of the extreme temperature is reduced in most of China.