东亚夏季风异常的研究

A STUDY ON EAST ASIA SUMMER MONSOON ANOMALY

本文运用经验正交函数分析方法,对10～65°N,90°E～175°W范围内近30年逐年7月和8月平均海平面气压场进行了分析研究.结果表明,第一、第三特征向量与东亚季风异常有关,第二特征向量与西风环流异常有关.讨论了东亚季风异常与大气环流的关系,以及季风异常对华北东部地区降水时空分布的影响.

In order to gain a further insight into East Asia summer monsoon ano- maly (SMA), sea-level pressure (SLP) anomaly, patterns over East Asia and western part of North Pacific Ocean are determined via empirical orthogonal function (EOF) analysis, based on SLP data over 26 years. It is found that EOF_1 and EOF_3 are associated with SMA while EOF_2 is linked with the ano- malies of westerlies. The time coefficent series of EOF_1 can effectively repre- sent the inter-annual varation of East Asia summer monsoon. The relations- hip between SMA and westerly anomaly as well as that between SMA and the anomalies of subtropical high is discussed. The spatial and temporal var- iablity of summer rainfall in the eastern part of North China is also studied.