Impact of the Convective Activities over the Western Tropical Pacific Warm Pool on the Intraseasonal Variability of the East Asian Summer Monsoon
热带西太平洋暖池上空对流活动对东亚夏季风季节内变化的影响

In this paper, impact of the convective activities over the western tropical Pacific warm pool on theintraseasonal variability of the East Asian summer monsoon is analysed by using the observed data in-cluding the daily OLR over the western tropical Pacific warm pool, daily 500 hPa height field and10-day precipitation in China. The analysed results show that in the summers with the strongconvective activities around the Philippins, the abrupt northward shift of the western Pacific subtropicalhigh is obvious in the early summer, i.e., the abrupt shift in June is obvious. Moreover, there is often anabrupt northward shift of the subtropical high again in July. The result is an obvious abrupt northwardshift of the East Asian summer psonsoon rain band. Thus, the monsoon rainfall cannot be maintained inthe Yangtze River valIey and the Huai River valley. On the contrary, in the summers with the weakconvective activities around the Philippines, the abrupt northward shift of the western Paciticsubtropical high is not obvious in the early summer, i.e., abrupt shift is not obvious in June. It may bemaintained over the south to the Yangtze River for long time. As a consequence, the East Asian sum-mer monsoon rain band is maintained in the middle and lower reaches of the Yangtze River and theHuai River valley.