1979年东亚夏季风环流建立过程的分析

AN ANALYSIS OF THE ESTABLISHMENT PROCESSES OF THE EAST ASIA SUMMER MONSOON CIRCULATION

摘要:

本文用1979年5—7月低纬地区的格点风资料,对东亚季风地区的逐日平均经圈环流进行了分析,发现东亚夏季风环流的建立过程和印度季风有很大不同。东亚夏季风环流建立时间较早,它是由副热带季风环流和南海热带季风环流组成的。副热带季风环流与源于南亚副热带地区的偏南风,北支高空东风相联系;而南海热带季风环流与源于澳大利亚的跨赤道气流,南支高空东风相联系。印度夏季风环流建立时间较晚,它与索马里低空急流,北支高空东风急流相联系。在季风环流的结构上,两者也是不同的,东亚季风环流是一个准经向环流圈,而印度季风环流则是一个准纬

Abstract:

With grid wind data for low latitudes from May through July, 1979, an analysis in this paper of the mean daily meridional circulation for the areas of East Asia monsoon found that the establishment processes of summer monsoon circulation in East Asia was considerably different from that in India. The former, made up of monsoonal circulations in both the subtropics and the tropical South China Sea, began at an earlier time. The subtropical monsoonal circulation is associated with the Southerlies from the subtropical South Asia and the northern upper Easterlies; whereas the monsoonal circulation in the tropical South China Sea is related to the cross-equatorial current from Australia and the southern upper Easterlies. The summer monsoon circulation in India was established somewhat later, accompanying with the Somali low jer and the northern upper Easterlies. The structures of the two systems are different from each other in that the monsoonal circulation in East Asia is a quasi-meridional cell while that in India a quasi-zonal one.