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

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.