海南岛5月暴雨的异常与马来半岛的夏季风

普查1931～1990年4～5月逐日850hPa风场,发现马来半岛夏季风爆发的平均日期在5月20日前后,自它爆发后海南逐渐进入讯期首次高峰,文中重点对比了暴雨日异常少和多的1983年和1936年5月的月平均850hPa流场和逐日资料,结果表明,这两年夏季风爆发时间出现了异常,而且夏季风的强度、低纬环流、暴雨天气系统都有明显差异,受热带辐合带和热带气旋影响是夏季风爆发后海南岛5月暴雨偏多甚至异常多的主要原因。

The Relationship between the Anomalies of Heavy Rain in May in Hainan Island and the Summer Monsoon over Malay Peninsula

In this paper, Using the regular and ECMWF datum of Mays from 1981 to 1990, We discuss the relationship between the anomalies of heavy rain in May in Hainan Island and the summer monsoon over Malay peninsula. It is found br- iefly that: I. The mean onset date of the summer monsoon over Malay peninsula is about May 20, afterword the precipitation in Hainan Island reaches its first peak in the flood season gradually. 2. The number of heavy rain days was anomalously small in May, 1933: on the contrast, that was anomalously large in May, 1986. There are remarkable differences in the strength of summer monsoon, low-latitude circulation and the heavy rain caussing systems between the Mays of 1983 and 1986. 3. The influences of ITCZ and tropical cyclones are the main cause of anomalous frequency of heavy rain in May in Hainan Island after the onset of Sumer monsoon over Malay peninsula