【摘要】 分析SODA同化资料 ( 1 95 0～ 1 999年 )所描述的北太平洋副热带海区表层—次表层的东向逆流的空间分布和季节变化特征。从气候平均场看 ,北太平洋副热带的东向流主要包括东、西两部分 ,其中 ,太平洋中部夏威夷岛西侧的东支逆流位置偏南 ,强度夏季最大 ,春季最弱。海表风应力的旋度异常产生的Ekman抽吸是东支逆流形成的主要原因。位于西太平洋的西支逆流位置偏北 ,春季—夏季强度较大。西支逆流的形成和季节变化可以由副热带模态水的辐合解释更多还原

【Abstract】 The upper\|layer eastward countercurrents in the subtropical region of the North Pacific is presented in the Simple Ocean Data Assimilation (SODA) data set. The countercurrents comprise two branches in climatology, i e., the east branch and the west branch. The east branch locates at the middle Pacific with its east limit to the west of Hawaiian Islands and a somewhat lower latitude than the other. The velocity of the east branch has an annual variation with its maximum occurs in the summer while the minimum in the spring. The Ekman pumping deduced by the curl of wind stress accounts mainly for the formation of the east branch. The west branch is seen over the western Pacific and has a larger intensity in both seasons of the spring and the summer. The cause of the formation, as well as the annual variation, of the west branch is explained by the convergence of subtropical mode water.更多还原