1982年夏季热带大气环流异常与ElNio事件发展机制的探讨

Primary Study on the Anomaly of Tropical Circulations and the Mechanism of El Nio Development in the Summer of 1982

本文利用1980—1983年四个夏季(以7月平均为代表)的ECMRWF资料,分析了1982—1983年El Nino事件强烈发展前的1982年夏季热带大气环流的异常.从一系列显著异常的观测事实分析中得出:1982年夏季异常强的东亚高空东风急流是1982～1983年El Nino事件发展的一个可能促发机制;1982年澳大利亚冬季冷空气的异常堆积导致澳大利亚至东太平洋纬向热力对比的增强,是赤道太平洋偏东信风迅速减弱的一个重要原因.

The relationship between the anomaly of tropical circulation and development of 1982 -1983 El Nino event was studied through the analysis on interannual variations of tropical circulations during 1980- 1983 summer with ECMRWF data. The abnormally strong east jet in the upper troposphere in East-Asia in the summer of 1982 is a possible mechanism which results in the great development of the 1982- 1983 El Nino event after July of 1982. The thermal contrast between Australia and the eastern Pacific due to the abnormal activities of the cold air in Australia is an important reason why the trade wind over Equatorial Pacific is weakened largely.