东半球越赤道气流的年际变化特征及其与我国同期气温、降水的相关性

利用NCEP/NCAR全球再分析资料分析了东半球冬、夏两季越赤道气流的年际变化特征,以及与中国160个站点同期气温、降水的相关性.分析表明:越赤道气流的年际变化夏季强于冬季,索马里急流并不显著影响到总量的变化,而冬季最强通道与总量变化关系密切.夏季越赤道气流总量在1950年代后期和1970年代中期有两次剧增,并与冬季一样都在1994～1995年有一次剧减.东半球夏季越赤道气流与中国同期降水的相关性很小,但在1970年代突变前后的相关性明显不同,原因与东亚夏季风的关系密切.冬季越赤道气流与中国同期南北的气温的相关随着越赤道气流与不同地区海平面气压的相关性的不同而不同.

INTERANNUAL VARIATION CHARACTERISTICS OF EAST HEMISPHERIC CROSS-EQUATORIAL FLOW AND ITS CONTEMPORANEOUS RELATIONSHIPS WITH TEMPERATURE AND RAINFALL IN CHINA

The NCEP/NCAR reanalysis data were used to analyze the interannual variation characteristics of CEF(cross-equatorial flow) and its contemporaneous relationships with temperature and rainfall in China.The results indicated that CEF changes more in summer than in winter.As the main flow channel in summer,the Somali CEF changes in a way that does not markedly influence the total's trend except for winter.The summer total of CEF had two sudden enhancements and one sudden decrease during the last century,and the winter total of CEF had just one decrease.Long-period data values show that the correlation between CEF and China rainfall in summer is not very significant,but is different before and after the 1970s,which is closely related to its relationship with the East Asia summer monsoon.Winter CEF has marked correlation with China winter temperature that differs in north and south,due to the relation between CEF and the sea-level pressure over different fields.