The Summer Precipitation in North China of Different Interdecadal Background Between in 1963 and in 1996 and the Contrastive Analysis of the Cause

Based on the ECWMF monthly reanalysis data and the precipitation data obtained from 160 stations in China,the different characteristics and the causes of the summer precipitation in the North China between in 1963 and 1996 are analyzed by using synthetic analysis and Statistical t-test.This paper analyses and contrasts the causes of the summer precipitation in the North China of 1963 and 1996 from atmospheric circulation to different large-scale precipitation conditions.The results can be generalized as follows: the North China summer precipitation in 1963 was more than in 1996.The North China summer precipitation in 1963 was a monsoon rainfall and was a system rainfall in 1996.In 1963,the anomalies distribution characteristics of the eastern China 500hPa geopotential height was northern high and southern low,but was western high and eastern low in 1996.