Analysis On The Changes Of The Extreme Climate Events Under The SRES A1B Scenario Over China With PRECIS

In this paper, we first analyzed the climate simulation capability of the regional climate model system PRECIS under the SRES A1B scenario over China in the climate baseline period (bs,1961-1990), then we analyzed the changes of daily average temperature (Tmp), daily maximum temperature (Tmax), daily minimum temperature (Tmin), diurnal temperature range(DTR), daily precipitation (Pre), high temperature days, frost days, consecutive dry days, the maximum precipitation in5days, wet days and simple precipitation intensity in the three future periods of2011-2040(2020s),2041-2070(2050s),2071-2100(2080s) relative to the bs. The results showed that:(1) PRECIS can well simulate the climate indexes’distribution over China, meanwhile, the model has an underestimation in temperature and overestimation in precipitations for the Tibetan Plateau, while an overestimation in temperature for the Tarim Basin.(2) With respect to the bs, in the future three time periods Tmp would be increase for1.8℃,3.7℃,4.7℃, Tmax would be increase for1.7℃C,3.2℃,3.9℃, Tmin would be increase for1.9℃,3.6℃,4.7℃, and Pre would be increase for8.9%,15.8%,18.3%; the increasing of Tmin compare to Tmax would be up to1.1times, which resulted to a decreasing trend in DTR.(3) Seasonal changes show that, in future Tmp, Tmax, T min would have maximum increasing in winter and minimum increasing in spring, DTR would have a maximum decreasing in winter while minimum decreasing in summer. Changes of Pre would be inconsistent in the four seasons, but all showed an increasing trend.(4) The temperature increasing is larger in north China than in south China, the large value area of warming is in the northwest and northeast China, while a smallest warming in the south China coastal areas; in most parts of China the DTR would have a decreasing trend, especially in the northern Qinghai-Tibet Plateau, but in the Yunnan-Guizhou Plateau the DTR would be increase; in most parts of China the Pre would have an increasing trend, especially in southern coastal areas, but a decreasing in the Shanganning area. (5) The probability of occurrence of extreme weather events in future over China will increase:high temperature days in "stove city" would be increase; frost days’ reduce in Qinghai-Tibet Plateau may lead to landslides, mudslides and other disasters; in Southwest China, the consecutive dry days would increased and the wet days would decreased, so the drought situation may be further continued; in the southeast coastal areas of China, the maximum precipitation in5days and the simple precipitation intensity would increased, so the intensity and probability of occurrence of extreme rain and other precipitation may increase in the future.