盛夏副高脊线位置的变化规律及其成因分析

本文对盛夏7月份副高脊线位置的变化规律及其成因进行了分析,结果表明:副高脊线位置具有明显的低频变化,主要振荡周期为13年左右。它的变化在东亚具有明显的遥相关结构,其影响因子主要是东亚是否存在阻塞高压,黑潮区海温是否异常,菲律宾附近对流活动的强弱以及南印度副高的强弱变化。其中,东亚是否有阻塞高压存在和黑潮区海温是否异常变化,对盛夏7月份副高脊线位置的异常偏南或偏北有十分重要的影响。

The law in the variation of subtropical high ridge line in mid-summer and the cause to its formation

The law in the variation of the subtropical high ridge line in July and the cause to its formation were analyzed in the paper. The results indicate that the location of the subtropical high ridge line has an significance low-frequency variation. The cycle period of its oscillation covers about thirteen years. The variation is characterized with a teleconnection structure at 500hPa in East Asia. The effective factors are mainly concerned with the apperence of the atmospheric blocking over the East Asia , SST in the region of block current, convective activites surrounding the Philip-pins and the subtropical high over the southern Indian Ocean.