近百年广州汛期降水变化特征及其影响因子  

THE CHARACTERISTICS OF PRECIPITATION IN THE RAINING SEASON IN GUANGZHOU AND ITS AFFECTING FACTORS OVER THE PAST 100 YEARS

作　　者：李春晖[1] 梁建茵[1] 吴尚森[1] 

机构地区：[1]中国气象局广州热带海洋气象研究所,广东广州510080

出　　处：《热带气象学报》2004年第4期365-374,共10页Journal of Tropical Meteorology

基　　金：国家自然科学基金重大研究计划项目(90211010)资助

摘　　要：利用1908～2000年广州市逐月降水资料、Hadisst海温资料和NCEP再分析资料,讨论了广州前汛期(4～6月)和后汛期(7-9月)降水的旱涝等级分布特征、长期变化趋势以及影响因子。结果表明,近百年来广州前汛期旱涝事件出现的连续性和间歇性比后汛期明显。前、后汛期降水分别经历4个偏湿时期、3个偏干时期和2个偏湿时期、2个偏干时期变化。前汛期年降水量呈上升趋势,后汛期年降水量呈下降趋势,但两者均没有达到0.1显著性检验标准,所以年降水量仍处在自然振动变化范围之内。机制分析表明,前期春季(3-5月)西太平洋暖池海温异常通过海气相互作用影响后期(4～6月)的大气环流,导致广州前汛期的降水异常。南海夏季风则通过与北半球500hPa位势高度场的遥相关来影响广州后汛期的降水异常。The characteristics of drought and floods grades, long-term change trend and affecting factors of the first raining period (April to June) and the second raining period (July to September) in Guangzhou are analyzed by using the monthly rainfall data in Guangzhou for the years of 1908-2000, Hadisst SST datasets and NCEP reanalysis data. The results show that continuity and intermittence of the drought and flood events of the first raining period were more obvious than that of the second one in Guangzhou over the past 100 years. Precipitation of the first and the second raining periods underwent four wet and three dry periods and two wet and two dry periods, respectively. The annual precipitation presented an ascending trend in the first raining season but a descendent one in the second raining season. Because they did not exceed the 10% significance level, so they still locate in the range of the natural oscillation. The mechanism analysis indicated that air-sea interactions make it possible for preceding spring (April to June) SST anomalies in the Western Pacific warm pool to affect the coming general circulations (July to September), causing precipitation anomalies in the first raining season in Guangzhou. The teleconnection between the South China Sea summer monsoon and the 500hPa geopotential height field affects the precipitation anomalies in the second raining season in Guangzhou.

关 键 词：广州 汛期降水 旱涝变化 西太平洋暖池海温 南海夏季风 

分 类 号：P426.61[天文地球—大气科学及气象学]