中国各季节气候对热盐环流减弱的不同响应

摘要

In a ＂water-hosing experiment＂ by using model CCSM3,different seasonal responses of the climate to the weakening of thermohaine circulation（THC） in China are studied.Results show that CCSM3 can reasonably represent the magnitude and pattern of the surface air temperature（SAT） and precipitation in China.Both SAT and precipitation decrease significantly in winter and summer after reducing annual mean THC intensity by 80%,but the magnitude and pattern of decreased SAT and precipitation are quite different in summer and in winter.The maginitude of reduced winter SAT is more robust and its cooling distribution is more homogenous than that of summer.The averaged cooling magnitude in winter is about 2.2 ℃ with a maximum of 4 ℃.The averaged cooling magnitude in summer is about 1.3 ℃ with a maximum of 3 ℃.The magintude of reduced winter/summer precipitation are all around 6%,but the anomaly patterns and the causes are significantly different.%使用CCSM3（community climate system model version 3）模式的＂淡水扰动试验＂结果,对热盐环流强度减弱后中国区域冬、夏气候的不同响应特征进行了研究。结果表明：CCSM3可较为准确地再现中国附近区域表面气温及降水量的量值和分布形态。当热盐环流年平均强度减弱约80%之后,中国区域冬、夏季的表面气温与降水量显著降低,但冬、夏季的降低幅度与空间分布形态存在显著的差异。冬季的降温幅度较大且分布较为一致,平均降温幅度可达2.2℃,最大的降温幅度可达4℃;夏季的降温幅度相对较小且南北差异较大,平均降温幅度为1.3℃,最大的降温幅度为3℃。冬、夏季降水量的降低幅度都在6%左右,但其成因及其分布形态都存在显著差异。