Surface Air Temperature Simulations over China with CMIP5 and CMIP3

Historical simulations of annual mean surface air temperature over China with 25 CMIP5 models were assessed. The observational data from CRUT3v and CN05 were used and further compared with historical simulations of CMIP3. The results show that CMIP5 models were able to simulate the observed warming over China from 1906 to 2005 (0.84 degrees C per 100 years) with a warming rate of 0.77 degrees C per 100 years based on the multi-model ensemble (MME). The simulations of surface air temperature in the late 20th century were much better than those in the early 20th century, when only two models could reproduce the extreme warming in the 1940s. The simulations for the spatial distribution of the 20-yearmean (1986-2005) surface air temperature over China fit relatively well with the observations. However, underestimations in surface air temperature climatology were still found almost all over China, and the largest cold bias and simulation uncertainty were found in western China. On sub-regional scale, northern China experienced stronger warming than southern China during 1961-1999, for which the CMIP5 MME provided better simulations. With CMIP5 the difference of warming trends in northern and southern China was underestimated. In general, the CMIP5 simulations are obviously improved in comparison with the CMIP3 simulations in terms of the variation in regional mean surface air temperature, the spatial distribution of surface air temperature climatology and the linear trends in surface air temperature all over China.