印度夏季风的年际变异与北半球大气环流的特征

INTERANNUAL CHANGE OF INDIAN SUMMER MONSOON AND THE FEATURES OF ATMOSPHERIC CIRCULATION OF NORTHERN HEMISPHERE

印度夏季风的年际变异是大范围大气环流相互联系、相互影响的结果。本文应用１９５１—１９８５年印度夏季风资料，选取强季风年４年和弱季风年６年，分别对北半球５００ｈＰａ高度场进行距平合成分析和复自然正交函数（ＣＥＯＦ）分析。结果指出，大西洋和鄂霍次克海阻塞高压的稳定存在以及乌拉尔山低压槽的频繁活动与强印度季风年相联系，而大西洋和鄂霍次克海低压系统的频繁活动以及欧洲阻塞高压的稳定存在与弱印度季风年相联系。印度夏季风强弱不同年份，春季北半球大气环流已经出现了一些不同特征，这对于当年夏季风的强弱和北半球气候异常有预示作用。印度夏季风强弱的不同年份和不同季节，北半球存在极地和赤道低纬位相函数大而中高纬度位相函数小。

The interannual change of Indian summer monsoon is owing to the results of the relations and influences each other of large scale atmospheric circulation systems.In this paper,using the data acquired from Mid Indian rainfall in 1951 to 1985,the four typical years of the stronger monsoon and the six typical years of the weaker monsoon were chosen,in which 500hPa height fields were analyzed by the anomaly synthetic analysis and CEOF(complex empirical orthogonal function) respectively.The results are shown:The stronger monsoon years were related to the stationary high over the Atlantic Ocean and Ochotsk Sea and the appearance of repeatedly trough over Uralskiy mountain.The weaker monsoon years were related to the frequently low systems over the Atlantic Ocean and Ochotsk Sea and the stationary blocking high over European.The spring atmospheric circulation of Northern Hemisphere has appeared some different features for the stronger and weaker Indian summer monsoon years,which will be possible for predicting of the stronger or weaker Indian summer monsoon and the abnormal climate of Northern Hemisphere in same year.The phase function of Northern Hemisphere was large value in the polar region and equatorial low latitude zone,but it was small value in the mid high latitude for the distinctive seasons of each year of the stronger or weaker summer monsoon in Indian.And then,the disturbances were propagated from the mid high latitude to the polar and equatorial area.