The Study On Time-spatial Characteristics Of Summer Extreme Precipitation Over Eastern China And Its Teleconnection

This paper is concerned with the time-spatial characteristics of summer extreme precipitation over eastern china and with the teleconnection between summer extreme precipitation and SST of the north Pacific and SOI, based on the daily rainfall data of 59 stations from 1951 to 2000. Firstly regulations of summer extreme precipitation over eastern china have been discussed. Extreme precipitation and extreme rain days are increased in SiChuan Basin, and decreased in Beijing area and coastal area of Shan-dong Province. One-day maximum precipitation tends to increase in area of Shandong Peninsula and Leizhou Peninsula, but decrease to a great extent in Beijing area and the south of Fujian Provence. The sum of maximum long-standing rain days tends to decrease obviously in huanghuai area and Beijing area. Intensity of extreme precipitation is decreased very obvious in central area of North-east China and Biejing area. Extreme precipitation index tend to decrease marked in Beijing area, but increase marked in Sichuan-Basin and Leizhou-Peninsula. The characteristics of extreme rainfall over eastern china are different in 10-annual change din four areas of South China, East China, North China, Northeast China. The characteristic of all is decrease in!980s, but increase to a great extent in 1990s. Their oscillation periods, anomaly years and years of catastrophe etc are also analyzed in this paper.The Empirical Orthogonal Function (EOF) if employed to analyze the precipitation over big rain and precipitation over rainstorm in summer in recent 50 years. There are main spatial patterns: same distribution all over the eastern china; the seesaw between the regions of Huanghuai and Northeast China, and the regions in the south of Yangtze; the seesaw between the min-lower reaches of Yangtze and the regions of Huanghuai, South China and Northeast China. The connection is also analyzed between the index of horse latitudes and index of East Asian monsoon and index of North Pacific oscillation, and thesummer extreme precipitation over eastern China.By using the method of Singular Value Decomposition(SVD), this work also analyzed season by season the teleconnection between extreme precipitation in East China and SST of north Pacific and North Oscillation Index, so to inspect the north Pacific SST key area and seasons (or months) of SOI, which are essential to spatial of extreme precipitation of East China. Results show, 1) the teleconnection between extreme precipitation of Ease China and the same season SST of north Pacific is mainly in NINO area (NINO 1-2 area most); the plus connection area between NINO1 area and the next summer extreme precipitation is in middle and lower reaches of Yangtze River. 2) The spring SST of The Black Current area and NINO area with summer precipitation is obviously negative connection. 3) The teleconnection between winter SST of north Pacific and summer precipitation is the areas of equator East pacific and Black Current with the areas of middle and lower reaches of Yangtze River and Hetao. 4) The autumn SST of NINO1area and West Pacific with the summer extreme precipitation are plus connection.