一次江淮梅雨中的涡旋合并过程分析  

A Case Analysis of Vortex-Merging Process in a Jianghuai River Valley Meiyu Rainstorm

作　　者：雷正翠[1] 任健[2] 马镜娴[1] 周慧[1] 

机构地区：[1]南京信息工程大学大气科学系 [2]江苏省气象局,江苏南京210008

出　　处：《南京气象学院学报》2006年第3期358-363,共6页Journal of Nanjing Institute of Meteorology

基　　金：国家自然科学基金重点资助项目(40333028)

摘　　要：利用2003年7月每日4个时次的1°×1°NCEP风场、湿度场、高度场等再分析资料,对2003年7月8—9日江淮流域暴雨过程进行了分析,结果表明:(1)江淮流域上空的中尺度涡旋合并与此次暴雨过程密切相关。涡旋合并使得低层辐合、高层辐散加强,垂直速度、水汽输送、湿螺旋度加强,从而导致暴雨增幅。(2)低层辐合、高层辐散的高低空配置有利于强上升运动的维持,强上升气流所携带的水汽和能量有利于对流云团的发生发展,有利于暴雨的维持。(3)来自孟加拉湾和南海的暖湿气流为江淮流域提供了充足的水汽。A strong rainstorm occurred in the Jianghuai River Valley from 8th to 9th July 2003. The rainstorm case has been analyzed using the NCEP/NCAR reanalyzed data（4 times per day） including wind, humidity and height fields. The results show that the heavy rain was mainly associated with the merging of mesoscale vortices. The strengthening of the lower level convergence and upper level divergence was associated with the vortex-merging enhanced the updraft, moisture transfer and moist helicity, resulting in heavy precipitation. The allocation of lower level convergence and upper level divergence was favorable to the maintenance of strong updrafts,and the moisture and energy carried by the updrafts was in turn favorable to the genesis and development of convective cloud cluster. The warm moist flow from the Bay of Bengal and the South China Sea provided the rainstorm sufficient moisture.

关 键 词：江淮流域 涡旋合并 暴雨 

分 类 号：P458.121[天文地球—大气科学及气象学]