2008年华南前汛期异常降水的大尺度环流特征及成因分析  

A Study on the Causes and the Atmospheric Circulation Characteristics of Abnormal Rainfall in South China during 2008

作　　者：王红军[1] 潘维玉[2] 

机构地区：[1]西安卫星测控中心,陕西渭南714000 [2]气象灾害省部共建教育部重点实验室,南京信息工程大学,南京210000

出　　处：《热带地理》2009年第3期219-224,共6页Tropical Geography

基　　金：921工程项目基金资助(2005装司字13号)

摘　　要：利用NCC/CMA资料分析了2008年5月下旬至6月中旬华南降水异常事件的成因。研究表明:2007年7月至2008年2月赤道西太平洋海表温度异常偏低,以及2008年前冬今春青藏高原积雪面积偏大是华南异常降水事件的前期气候背景;2008年5月下旬至6月中旬东亚阻塞高压的异常强大及乌拉尔山长波槽的异常发展,促进了经向环流异常增强;偏强冷空气以阶梯槽的形式频繁入侵华南,为异常降水事件提供了动力条件。此外,副高较常年偏强、偏北,强劲的季风潮为华南地区输送了巨大的水汽和热量,冷暖空气在华南上空频繁交汇是深圳异常降水事件的直接成因。上述多种因素的异常并同时出现,共同导致了华南异常降水事件的发生。The cause of abnormal rainfall in South China from the last ten-day of May to the middle ten days of June in 2008 is analyzed using NCC/CMA data. The results indicate that the anomalously lower sea surface temperature in equatorial western Pacific Ocean from July of 2007 to February of 2008 and the spacious snow area over Tibetan Plateau in winter of 2007 and spring of 2008 were the climatic background for the abnormal rainfall. Moreover, the blocking high pressure in East Asia was much strong, and the Urals long-wave trough was abnormally deep from the last ten-day of May to the middle ten days of June in 2008, which strengthened the longitudinal circulation. At the same time, strong cold air mass entered into South China frequently with the form of ladder troughs, and provided dynamical energy for rainfall in Shenzhen. At last, the subtropical high pressure was much stronger and stayed in more northerly region than ever; Strong monsoon transmitted huge water vapor and heat to South China; the cold and warm air masses met in South China frequently, which are all causes of the abnormal rainfall. In summary, all above conditions acted commonly and resulted in the abnormal rainfall in South China.

关 键 词：大尺度环流 副热带高压 海表温度 高低空急流 西南季风 

分 类 号：P466[天文地球—大气科学及气象学]