Climate Changes In China Mainland Based On K?ppen Climate Classification For 1961-2010

K?ppen climate classification,which is based on temperature and precipitation,has been used worldwide.Besides temperature and precipitation,the distribution of natural vegetation is also considered as a major factor of the system.With clearly quantitative limits,the classification system can be easily used to distinguish different climate types.A variety of climatic classification methods have been attempted in China to explore Chinese climate classification and climate change in recent years,but most of them are not in line with international classification methods.In this paper,the K?ppen climate classification was used to classify the climate zones of China mainland.According to the results,there are 4 major climate zones,including arid climate(B),warm temperate climates(C),snow climates(D)and polar climates(E).Major climatic subtypes include steppe climate(Bs),desert climate(Bw),warm temperate climate with dry winter(Cw),warm temperate climate,fully humid(Cf),snow temperate climate with dry winter(Dw)and tundra climate(ET).As a geographic concept,climate zone contains comprehensive climate information.Research into changes in climate zones is an important way to study climate change.Here,as a geographic indicator,area of climate zone is used to explore China mainland interannualinterdecadal climate variation from 1961 to 2010.Climatic zones were based on K?ppen climate classification.East Asia summer monsoon index(EASMI),South Asia summer monsoon index(SASMI),summer westerly index(SWI),East Asia winter monsoon index(EAWMI),and Sea Ice Index(SII)were used to analyze the impacts of climate change.According to the results,East Asia summer monsoon(EASM)has an impact on desert climate(Bw).South Asia summer monsoon(SASM)has an impact on desert climate(Bw),snow temperate climate without dry season(Df)and Savannah climate(Aw).Summer westerly(SW)has an impact on tundra climate(ET)and warm temperate climate without dry season(Df).East Asia winter monsoon(EAWM)has an impact on savannah climate(Aw),steppe climate(Bs),snow temperate climate with dry winter(Dw),and snow temperate climate without dry season(Df).Sea Ice(SI)has an impact on savannah climate(Aw).The most important index in China mainland is the East Asia winter monsoon(EAWM).The northern Tianshan Mountains,western Qinghai-Tibet Plateau,both sides of the Aihui-Tengchong line and edge of the Meiyu Area were the most sensitive to climatechange.Interdecadal changes in climate zones show that China mainland has became warmer,and the North China has became drier.Interannual changes in climate zones show that China mainland has became warming,but not show it has been drier or wetter.Based on climate regionalization and its changes,a new definition method of climate sensitive regions whose climate types changed frequently was proposed in this paper.We calculated temperature and precipitation trends during 1961-2010 of China mainland,and compared with climate sensitive regions in the same period.In addition,we predicted climate sensitive regions in the 2040 s and 2090 s with Community Earth System Model(CESM).The results showed that the most sensitive regions of China mainland which are roughly coincides with precipitation change hot-spots are distributed near the Aihui-Tengchong line,the Qinling Mountains-Huaihe River line,in the Western Tibetan Plateau,and to the north of Tianshan Mountains.The most climatically stable regions are mainly distributed in the Eastern Tibetan Plateau,the north of Kunlun Mountains and Qilian Mountains,and the west of Tianshan Mountains and Helan Mountains.Furthermore,climate sensitive regions to the west of Helan Mountains and the Hengduan Mountains would be basically unchanged,while climate sensitive regions in Eastern China would move northward in the next decades.