华北夏季强降水的水汽来源

Anomalous Mositure Sources for the Severe Precipitation over North China during Summer

利用1980—1997年NCEP/NCAR再分析资料及中国6-8月逐日降水观测资料,分析了华北地区的夏季暴雨特征,并着重对暴雨发生的水汽来源进行了研究和讨论。结果表明,华北地区的夏季暴雨降水中心区与其夏季平均降水中心区的位置一致,且暴雨降水量占整个夏季降水量的主要部分。对暴雨日及其前4天水汽输送的逐日变化、异常特征及水汽输送的相关分析发现：来源于西太平洋及高纬西风带的水汽输送对华北暴雨产生有重要作用,而来自孟加拉湾的水汽输送对暴雨也存在一定的加强作用。

Using the daily NCEP/NCAR reanalysis data and observed rainfall data in China in 1980—1997,the features of rainstorm over North China in summer are analyzed.The sources of moisture contributing to rainstorm are examined with particular reference.The results show that the high value center of locates approximately over the one of climate rainfall.Correlation analyses between the moisture transport flux of rainstorm over North China and other regions,the day to day variation and anomaly of the moisture transport during the period of rainstorm find that the moisture tranport from the west Pacific through the South China Sea play an important role in the occarrence of rainstorm over North China, while the moisture transport from the Bay of Bangle enhances the rainstorm to some extent.