初秋孟加拉湾－日本海遥相关的特征及其与大气环流和中国降水的关系

CHARACTERISTICS OF THE BAY OF BENGAL THROUGH SEA OF JAPAN TELECONNECTION IN EARLY AUTUMN AND ITS RELATION TO GENERAL CIRCULATION AND CHINA'S PRECIPITATION

关键词:  孟加拉湾  初秋  遥相关  厄尔尼诺  热带东风急流  中国降水

Key words:  The Bay of Bengal  Early autumn  Teleconnection  Tropical easterly jet  El Nino  China’s precipitation

摘要:

研究了北半球初秋(9月)500hPa孟加拉湾(15°N,85°E)与日本海(40°N,130°E)的遥相关结构、年际变化及其与热带东风急流、厄尔尼诺事件、中国降水的关系。指出,当孟加拉湾500hPa高度上升时,日本海高度下降。这时通常是低南方涛动指数或发生厄尔尼诺、并且在100hPa上热带东风入口区为西风距平。这些特征造成中国东部初秋降水偏少。利用这些结果可以清楚地诊断近40年中发生的厄尔尼诺事件。

Abstract:

In this paper, studies are made of the structure and interannual variation of the 500hPa teleconnection between the Bay of Bengal(15°N, 85°E) and the Sea of Japan(40°N, 130°E) during the Northern early autumn and its relation to tropical easterly jet, El Nino and China's precipitation. It is noted that when the height of 500 hPa over the Bay of Bengal increases and that over the Sea of Japan decreases, there is usually the low Southern Oscillation Index or the occurrence of El Nino and the west wind departure at the 100hPa entrance region of tropical east winds. These characteristics cause the deficiency of rainfall in eastern China during early autumn. by using these results, the El Nino events during the recent 40 years and in 1991 can be clearly diagnosed.