Evaluation of Wind Speeds in China as simulated by Global Climate Models

In recent years, with the rapid development of climate model studies, the global climate models have made fruitful results in simulated 20th century climate and climate change, especially in simulated temperature, precipitation and other el ements and human activities on the impact of these factors. However, there are l ess relevant researches on simulated or tested surface layer wind speed. The win d speeds change over China from 1956 to 1999 were evaluated, which has been simu lated by twenty global climate models with both anthropogenic and natural forcing (named 20C3M). Nineteen models of those models were provided by IPCC fourth as sessment report, another one (BCC-CSM1.0.1) was contributed by National Climat e Center that has been studied for IPCC fifth assessment report. The studies fin d that the models have the certain capabilities to simulate the patterns of the annual or seasonal mean wind speeds in China, to compare with the observation. B ut the simulated wind speeds are less than observations generally, especially in the northern and northwestern regions where simulated wind speed is significa ntly smaller and observed mean wind speed is larger than that of other regions. The simulated wind speeds for winter and spring are bigger than t hat of summer and fall. It is the same as the observations. However, these model s can not simulate the seasonal variable features of the wind speeds reasonably that is the decreasing characters in turn spring, winter, summer and fall. Both these models and model ensembles can not simulate the obviously decreased trend. Only a few of them simulate the slightly decrease trend of annual (or seasonal) wind speed changes in China for the last 50 years. With regard to regions in China, the simulated results of the northern and southwest regions are better th an that of the southeastsouth region.