东亚地区春冬季与夏季大气环流异常相互关系的研究

A STUDY OF RELATIONSHIPS BETWEEN SPRING/WINTER AND SUMMER GENERAL CIRCULATION ANOMALIES

利用 1 95 1～ 2 0 0 0年共 5 0年的北半球 5 0 0hPa月平均高度距平场资料和奇异值分解技术 (SVD) ,重点对东亚地区季节间大气环流异常的相互关系进行了初步探讨。结果表明 ,东亚地区季节间大气环流异常存在着较为密切的关联 ,并且这种明显的非同步联系具有时空相关显著的特点 ,尤其是夏季大气环流异常与其前冬和前春大气环流异常的联系更为密切。当前冬和前春北半球东亚大槽和北美大槽及蒙古高压偏强 (或偏弱 ) ,极涡偏弱 (或偏强 ) ,中高纬度盛行经向环流 (或纬向环流 ) ,以及低纬和热带地区高度正距平 (或负距平 )明显时 ,则对应于夏季东亚地区西太平洋副高和鄂霍次克海阻高强度偏强 (或偏弱 ) ,位置偏南 (或偏北 ) ,贝加尔湖阻高强度也偏强 (或偏弱 ) ,但位置偏西 (或偏东 )的大尺度环流形势出现。当春季北半球大气环流具有上述特点以及夏季鄂霍次克海阻高和西太平洋副高强度偏强 (或偏弱 ) ,位置偏南 (或偏北 ) ,且极涡较弱 (较强 )时 ,则东亚地区秋季大气环流对应于蒙古高压加强 (或较弱 ) ,西太平洋副高减弱 (或加强 ) ,并向南和向东移动 (或移动较慢 ) ,极涡向南扩散 (或扩散减弱 ) ,大气环流向冬季过渡加快 (或减慢 )。另外 ,大气环流异常还具有一定的持续性特征。

By using Singular Value Decomposition(SVD)technique and monthly mean 500 hPa height data in the Northern Hemisphere from 1951 to 2000,the inter seasonal relationships of general circulation anomalies are studied. The results show that the first mode derived from SVD indicates the key coupled characteristics-there exists close temporal and spatial correlation between seasonal 500 hPa height anomalies and its former seasonal 500 hPa height anomalies. Especially there are obvious connections between the general circulation anomalies in summer and those in past winter and spring. The variations of the East Asian trough, North American trough, polar low, North Pacific oscillation and Siberian high of the North Hemisphere 500 hPa in winter and spring play important roles in the general circulation anomalies in the following summer and autumn in East Asian.