The Influence of Vertical Atmospheric Circulation Pattern over East Asia on Summer Precipitation in the East of China and Its Forecasting Test

Based on the analysis of characteristics of temporal and spatial distribution of summer precipitation in the east of China,the correlativity between the anomalies of high-,mid-and low-level general circulation over East Asia and the typical spatial distribution of summer precipitation over the east of China are discussed.The key areas of atmospheric circulation as prediction factors that cause the abnormal summer precipitation are confirmed.Then,on the basis of prediction factors from the forecast results of CAM3.1,and by using the statistical downscaling methods,a prediction model of summer precipitation in eastern China is built and applied to the forecasting test during 1981-2000.Results show that there are four typical spatial rainfall patterns in the east of China.The summer precipitation not only has significant quasi-biennial oscillation but also has significant interdecadal oscillation.The rainfall patterns in the east of China are influenced by the vertical atmospheric circulation pattern over East Asia significantly.The forecast skill of rainfall pattern in the east of China is improved by using the forecast model combining the dynamic model and statistical downscale methods.