前期南方涛动对初夏西太平洋副高活动特征的影响

THE INFLUENCES OF PRECEDING SOUTHERN OSCILLATION ON THE ACTIVITIES OF WEST PACIFIC SUB-TROPICAL HIGH OF JUNE

摘要:

本文利用近34年资料,对前期各月南方涛动指数(SOI)与6月西太平洋副高活动各特征量的联系作了较全面的分析,发现上年夏—当年3月的SOI均对6月西太平洋副高强度、脊点经度和脊线纬度有相当的影响。冬春SOI与6月西太平洋副高偏北西伸频数—入梅期的相关值随时间发生很大变化。后者受到前期行星尺度和前冬地区性海温因子(黑潮和南海海温)的综合影响,前冬SOI只是其中一个因子。根据三个前期因子(前冬SOI和黑潮区海温距平,2—3月南海副高强度)的后延影响就能合理解释6月西太平洋副高活动特征,因此前者也就具有相当的隔季预报能力。

Abstract:

Using data for the past 34 years, a correlative analysis has been made for the relationship between each characteristic index of West Pacific Sub-tropical High in the months of June (WPHJ) and the Southern Oscillation indexes (SOI) during the preceding months. It was found that all montlhy SOIs from the past summer throngh March have substantial influence on the strength and locations (both meridional and zonal directions) of WPHJ. but the correlations between the preceding winter-spring SOI and the frequency of WPHJ stretching northwestly varied greatly with years.Through analyzing.it is found that the latter is influenced by the composite effect of SST anomalies both with planetary and regional scales, and the preceding winter SOI is only one factor of them.On the other hand.it reflects the fact that the winter-spring SST anomaly patterns of temperate-tropical Pacific are also changed with years.