105°E越赤道气流与亚洲夏季风的相互关系

THE INTERRELATION BETWEEN THE CROSS EQUATORIAL AIRFLOW NEAR 105°E AND THE SUMMER MONSOON OVER ASIA

本文分析了北半球夏季105°E低空越赤道气流的若干气候特征及其与850 hPa风场、亚洲夏季风的关系。研究结果表明,105°E越赤道气流具有显著的准二年和准双周周期,但30～60天周期并不明显。在105°E越赤道气流加强的同期和其后1候时,东亚热带夏季风发展,而印度热带夏季风和东亚副热带夏季风减弱或中断。当这支气流加强之后2候时,西北太平洋副热带反气旋及其西侧(东海附近)的副热带夏季风趋于加强。

Some climatic features of the low-level cross equatorial airflow near 105癊 in the Northern Summer and its relation with the wind field at 850 hpa as also the summer monsoon over Asia are analysed.The results show that the airfLow has the significant periods with quasi梑iennial and quasi-biweekly, but the period of 30~60 days is not clear. During the simultaneity of the intensification of the airflow or one pentad lag, the tropical summer monsoon over East Asia come into development,while both summer monsoons over the tropic India and over the subtropical East Asia are in a state of weakening or breaking. After it increases for two pentads, the subtropic anticyclone over NW Pacific Ocean and its western monsoon tend to intensify.