Numerical Simulation and Evaluation of Regional Climate Change in Southwest China by a Regional Climate Model

摘要

Climate change over five provinces of southwest China including Yunnan,Guangxi,Guizhou, Sichuan,Chongqing are simulated by a regional climate model(RegCM3) using the output of a global coupled atmosphere-ocean model( ECHAM5/MPI-OM) as lateral and boundary conditions. Two sets of 15-year simulations at 20 km gird spacing for present day (1986-2000) and future (2011-2025, IPCC SRES A1B scenario) are conducted with surface air temperature and precipitation as a focal area in analysis. Results show that (1) RegCM3 can reproduce well the spatial disturbution of surface air temperature in soutwest China, while the simulated value is lower than observation.The spatial distribution of precipitation increase from northwest to southeast can also be simulated by RegCM3. Precipitation simulation for the annual mean and in summer is much better than that in winter. The simulaed value in winter is highter than observation. (2) During 2010-2025, there may be a remarkably warming either in annual or seasons.The temperature change in north is larger than that in south. The daily maximum, minimum temperature change in winter is larger than that in summer. (3)Precipitation increase in annual, autumn and winter is agreenment, while precipitation increase is signifcantly in winter. Precipictation decrease in spring and summer isn't obviously. Overall, temperature increase and precipitation decrease in spring and summer might bring on the risk of high temperature and drought in some regions.