Maximum Wind Speeds Changes over China
【摘要】：An intensive analysis is undertaken for the characteristics of maximum wind speed(WSMax) change for 1956-2004 across China based on the observed station data,with further study of the changes of WSMax for 2046-2065 and 2080-2099 as projected by three global climate models(GFDL_CM2_0,CCCMA_CGCM3 and MRI_CGCM2) and their ensembles which proposed in the IPCC Fourth Assessment Report(AR4) . It is found that the observed annual and seasonal WSMax and the number of gale days show obviously the declining trends. The annual WSMax and the gale days reduced by about-1.46 m/s per decade and-3.0 days per decade during the study period 1956-2004,respectively. The amplitudes of annual and seasonal WSMax decreases were bigger than that of annual and seasonal average wind speeds(WSAvg) . Under the weakening of both East Asian winter and summer monsoons,the distinct decreases of WSMax associated with the weakening of cold wave in China and the decreasing number(weakening intensity) of landing typhoons in the northwestern Pacific Ocean. The global climate models GFDL_CM2_0,MRI_CGCM2 and EBGCM(the ensemble of GFDL_CM2_0,MRI_CGCM2 and CCCMA_CGCM3) areto project consistently that the annual and seasonal WSMax reduce during 2046-2065 and 2080-2099 to compare with 1981-2000,i.e. the WSMax for 2046-2065 decreases by-3.0m/s relative to 1981-2000. It is also noticed that the WSMax decreases during 2046-2065 and 2080-2099 have a good relationship with both the cold wave weakening as corresponding to the winter monsoon weakening and the decreasing numbers of tropical cyclones over the northwestern Pacific Ocean in the summer of the 21st century.