Jac In May-july Precipitation Anomalies And The China Sea Temperature Anomalies Of The Relationship

Based on the precipitation analyses during the May-July period in JiangHuai valleys is divided objectively into north and south regions. Based on this, investigation of precipitation anomalies during the Meiyu period and corresponding general circulation has been performed. In the study of the mechanism of precipitation anomalies, the discovery is then chiefly to study the effect of SSTA on rainfall during the Meiyu period in each region, concluding that there is a high correlation between the Meiyu precipitation in each region and SSTA, SSTA distribution in Key regions. The main conclusions are followed:(1) The rainy season in the south region of JiangHuai valleys is May to July, the peaks of its precipitation anomalies appear separately in June. But The rainy season in the north region of JiangHuai valleys is June to July, the peaks of its precipitation anomalies appear separately in July.(2) In the recent frfity years, precipitation during the May-July period shows a light increase tendency. The trend of variation in the south region of JiangHuai valleys is obvious in comparison with that in the north region, but tow regions have remarkable characteristics of interannual and interdecadal change in recent 50 years. The distribution of JiangHuai valleys the May-July period precipitation anomalies shows different phase in different years.(3) The May-July period precipitation anomalies show complex periodic variation in different regions and in different years. In the recent fifty years, precipitation the May-July period in the south region shows periodic variation of 3.3-3.6years. but precipitation the May-July period in the north region shows periodic variation of 2.5years and 6.3 years.(4) Precipitation departures during the May-July period in the JiangHuai valleys is in phase to many areas of China in more precipitation years and less precipitation years. But not only in the more precipitation years but also in the less precipitation years, the precipitation departure in north region is still out phase to that in the south of China.(5) There exists close relationship between the Meiyu period precipitation in JiangHuai valleys and the anomalies of subtropical summer monsoon, the anomalies of cold air, not the same so the Indian summer monsoon.(6) There is a apparent positive correlation between the Meiyu period precipitation in the south region and SSTA(10-12 monthly averaged in former year)in Southwest Pacific Ocean, especially the higher correlation in the "Key regions" (4°~242N, 112° ~122°E) The whole the south region and the "Key regions" are significant regions in couple.(7) There is a apparent positive correlation between the Meiyu period precipitation in the north region and SSTA(1-2 monthly averaged in present year) in the "Key regions"(44°-50°N, 152°-166°E) of North Pacific Ocean. The north of the north region and the "Key regions" are significant regions in couple.