上海“010805”特大暴雨与“080825”大暴雨对比分析  

Contrast Analysis on '010805' and '080825' Heavy Rainstorm in Shanghai

作　　者：曹晓岗[1] 王慧[1] 邹兰军[1] 陈永林[1] 张吉[1] 

机构地区：[1]上海中心气象台,上海200030

出　　处：《高原气象》2011年第3期739-748,共10页Plateau Meteorology

基　　金：中国气象局气象新技术推广项目(CMATG2007M160);上海市科委世博专项"2010年上海世博会重大活动预报技术的集成与应用"(10dz0581300)共同资助

摘　　要：通过对"010805"特大暴雨和"080825"大暴雨两次过程的天气环流背景、产生强降水的热力、水汽和动力条件以及卫星云图对比分析,得到一些异同点:"010805"特大暴雨是热带低压(简称010805TD)影响产生的,"080825"大暴雨是由中纬度低涡切变引起的,但是登陆减弱的2008年第12号热带风暴"鹦鹉"为"080825"大暴雨提供了大量的水汽和能量。两次过程都有来自北方的弱冷空气影响,中低纬度不同气团的相互作用对暴雨的产生有十分重要的作用。移动缓慢的010805TD东侧的偏南、东南急流不断为"010805"特大暴雨提供水汽和能量,维持了010805TD强度。西太平洋副热带高压西北侧与低空切变之间存在强的西南低空急流,给下游的上海输送了水汽和能量。"010805"过程开始前24h对流不稳定能量开始积聚,而"080825"过程则是在产生前12h才快速增加,其大气的对流不稳定发展更为强烈。上海在两次降水过程开始前都变得不稳定,K指数增加到36℃以上。两次过程开始前12～24h的水汽输送就开始了。"010805"特大暴雨由偏南、东南急流输送来自东海的水汽;"080825"大暴雨由西南急流输送来自南海及西南地区的水汽,而且也有低空偏东气流输送来自东海的水汽和能量。两次过程上海上空的大气可降水量都在60mm以上,正涡度和上升气流都集中在上海上空非常窄的地区,这从一个侧面说明了仅在上海产生特强降水的原因。对流云团有向后传递的特点,在减弱的对流云团后部再生新的云亮核与其合并是中尺度云团迅速发展、加强的原因之一,多个云团合并同样是中尺度云团迅速、发展加强的原因,有很强的突发性。＇010805＇ and ＇080825＇ heavy rainstorm in Shanghai are two most influential processes in the recent years.The same and different characteristics are presented by atmospheric circulation background,thermal,vapor,dynamic condition and satellite cloud images,leading to heavy rainfall.＇010805＇ heavy rainstorm was caused by tropical depression（for short 010805TD）,while ＇080825＇ heavy rainstorm was irritated by mid-latitude vortex shear,and landing typhoon NURI（0812） provided the plenty of vapor and energy for the heavy rainstorm.The two heavy rainstorm processes are affected by weak cold air from north and interactions among different air masses in middle and low latitudes play a significant role in the occurrence of heavy rainstorm.Southerly and south-east jets on the east side of slow-moving 010805TD continuously provided the vapor and energy for ＇010805＇ heavy rainstorm and maintained the strength of 010805TD.Strong southwest low-level jet existed between the north-west sides of the western Pacific subtropical high and low-level shear,which provid the vapor and energy for downstream Shanghai.Convective instability energy accumulated 24 h before the start of ＇010805＇ heavy rainstorm,but the convective instability energy rapidly accumulated 12 h before the start of ＇080825＇,whose the atmospheric convective instability is stronger.Atmosphere over Shanghai became unstable before the starting of two processes,while K index rise up more than 36 ℃.Vapor transportation started 12~24 h before the starting of the two processes.Vapor in ＇010805＇ heavy rainstorm was transported by southerly and south-east jets from East China Sea,while vapor in ＇080825＇ heavy rainstorm was transported by south-west jets from South China Sea and south-west region of China.Both of the precipitable water of atmosphere were above 60 mm in the two heavy rainstorm processes of Shanghai.Their positive vorticity and updraft gathered in very narrow area over Shanghai,as illustrated the reason why heavy rains

关 键 词：上海 大暴雨 环流背景 热力条件 水汽条件 动力条件 中尺度云团 

分 类 号：P458.121[天文地球—大气科学及气象学]