澳洲北部强/弱越赤道气流对应的环流配置

The Circulation Configuration of Strong/Weak Cross-Equatorial Flow to the North of Australia

采用1980～2004年的NCEP/NCAR再分析资料,挑选5～8月中澳洲北部越赤道气流的极强和极弱年作为典型样本,探讨了强/弱越赤道气流对应的环流系统的配置特征。结果表明:强越赤道气流通常对应北半球辐合带维持较强,或南半球澳高维持较强,亦或澳洲冷空气活动频繁发生的环流形势,同期西太平洋副高通常偏东或偏北;弱越赤道气流通常对应西太平洋副高的偏西或偏南,或者是西太平洋副高-辐合带共同演进过程的多次发生。

Using the NCEP/NCAR reanalysis data during 1980-2004, The authors choose the strong and weak extrema of cross-equatorial flow （CEF） during May to August as typical samples, and then analyze the circulation configuration of strong/weak CEF to the north of Australia. The results show that the strong CEF always corresponds to the strong convergence zone in the Northern Hemisphere, or strong Australia high in the Southern Hemisphere, or frequent Australian cold air activities, and it also corresponds to the circulation situation that the location of the western Pacific subtropical high （WPSH） is more eastward or northward than normal; the weak CEF always corresponds to the circulation situation that the location of the WPSH is more westward or southward than normal, or the frequent occurrence of conjunct evolution processes of the WPSH and the convergence zone.