关键词: 江南春雨, 华南前汛期, 梅雨, 华西秋雨, 相关分析, EOF

Abstract: Based on the daily precipitation data from 784 meteorological stations in China during 1961 to 2013,the pentad variation of precipitation over central-eastern China,the spatial classifications of rainfall in the different rain stages in south China and their correlations with precipitation during rainy season in Hu'nan were investigated.Results show that a rain band enhanced in spring and weakened in autumn at 25°-30°N area is maintained throughout the year,which induces different processes including the spring persistent rains (SPR),the first rainy season in South China(FRSSC),the Meiyu over the mid-lower reaches of the Yangtze River (MYYR) and the autumn rainfall in West China(ARWC).Most of Hu'nan apart from west and northwest Hu'nan indicate a high correlation between the SPR and the contemporaneous rainfall in Hu'nan (CRHN).Central and southern Hu'nan is the area where the rainfall during the FRSSC is highly related to CRHN.Central and northern Hu'nan is the area where the precipitation during the MYYR closely connects with CRHN.However,northwest and north of Hu'nan are the areas where the rainfall during the ARWC intensively relates with CRHN.The rainfall amounts in the different rain stages have very good consistencies with those over high correlation areas in Hu'nan during the corresponding periods,more specifically,the best correlation for the SPR,followed in turn by the FRSSC and the ARWC.The first four spatial modes which are able to well represent the main spatial distribution characteristics of precipitation in the different rain stages are respectively the regional consistent variation tendency,the anti-phase variation tendencies between the north and the south region,the south region of the Yangtze River and other regions,as well as the east and the west region.

Key words: The spring persistent rains, The first rainy season in South China, Meiyu, The autumn rainfall in West China, Correlation analysis, EOF (Empirical orthogonal function)