重庆一次暴雨天气过程诊断  

Diagnosis of a Heavy Rain Process in Chongqing

作　　者：陈鹏 刘德 周盈颖 孔祥伟[3] 郑丽君 

机构地区：[1]重庆市气象台,重庆400039 [2]重庆市万州区气象台,重庆404100 [3]兰州中心气象台,甘肃兰州730020 [4]江西省上饶市气象台,江西上饶334000

出　　处：《干旱气象》2013年第2期333-341,共9页Journal of Arid Meteorology

基　　金：重庆气象关键技术集成与应用面上项目(CMAGJ2013M42)资助

摘　　要：利用雷达资料、每小时实况降水资料、TBB资料以及NCEP格点再分析资料对2011年7月26日发生在重庆东北部的大暴雨过程进行了诊断分析。结果表明:(1)此次降水主要是低层切变线激发重庆中尺度对流系统的发生发展从而带来强降水,并且低层切变线与此次MCS的发生有着很好的对应关系。垂直风切变最大时,强降水的区域辐合达到最大,垂直上升运动最强;(2)低层来自南海的水汽沿西太平洋副热带高压的西南侧经过云贵高原进入重庆,并在重庆东北部强烈辐合上升,为重庆强降水的发生提供充足的水汽;(3)TBB资料分析显示,强降水发生时重庆上空存在2个中尺度对流云团,其中一个中尺度对流系统由中γ尺度逐渐发展到中β尺度,另一个中尺度对流云团则在移动过程中分裂发展;(4)从雷达资料来看,暴雨发生过程中各仰角上有逆风区出现,说明了垂直环流的强度较强,有利于低层水汽向上输送。同时,中气旋的生成也有利于低层暖湿空气不断向上输送,促进暴雨的发展。Based on radar data, hourly rainfall data, TBB and NCEP reanalysis data, a heavy rain process on July 26, 2011 in north- east Chongqing was analyzed in this paper. The results are as follows ： （ 1 ） The low - level shear line triggered the formation and devel- opment of mesoscale convective system, and low level shear line had a good corresponding relation with the occurrence of the MCS, when vertical wind shear got to maximum, the convergence and the vertical ascending motion in the heavy rainfall area also got to maxi- mum; （2） The lower water vapor from the South China Sea transported along the southwest side of west Pacific subtropical high, which convergeneed and moved upward in the northeast Chongqing and provided sufficient water vapor for heavy rain ; （ 3 ） TBB data analysis showed that two mesoseale convective clouds existed over Chongqing when strong rainfall occured, one of the~ - mesoscale convective system developed intol3 - mesoscale system, and the other one split during moving process ; （4） The radar data analysis showed that up- wind area appeared during heavy rainfall process, which indicated that the vertical circulation was stronger and it was useful for low lev- el water vapor transportation upward. At the same time, the mesoscyclone generation was also helpful for warm wet air continuous trans- portation, and promoted the development of the heavy rain.

关 键 词：暴雨 中尺度对流云团 逆风区 中气旋 切变线 

分 类 号：P458.121.1[天文地球—大气科学及气象学]