天津一次突发性局地大暴雨中尺度分析  

Mesoscale Analysis of a Sudden Heavy Rain in Tianjin

作　　者：何群英[1] 东高红[1] 贾慧珍[1] 孟冬梅[2] 于莉莉[1] 朱男男[1] 

机构地区：[1]天津市气象台,300074 [2]天津市气象科学研究所

出　　处：《气象》2009年第7期16-22,I0001,共8页Meteorological Monthly

基　　金：国家科技支撑计划重点项目<城市群高影响天气预报系统的集成和业务示范>(2008BAC37B05)

摘　　要：利用加密自动气象站、天津MM5、NCEP1°×1°的6小时再分析资料以及多普勒雷达等资料,对2007年8月26日出现在天津东部地区的局地大暴雨进行了天气学、动力学诊断和中尺度分析。结果表明,暴雨是在大尺度环流形势由经向调整为纬向时期产生的,中低层西风槽、切变线以及地面中尺度辐合线是其主要影响系统;强降水的时空分布有明显的中尺度特征;暴雨区上空形成的斜升气流,有利于强雷暴云的稳定发展;低空东南急流和地面偏东风为暴雨区输送了大量的水汽;地面中尺度辐合线的存在和维持不仅增强了地面的辐合抬升,同时也是造成此次局地大暴雨的中尺度系统和触发条件。多普勒雷达图中明显的列车效应以及强回波伸展的高度与当天0℃层高度的对应关系也是产生强降水的主要原因。The intensive observations of automatic weather station, Tianjin MM5 model products,the NCEP used in the August 26, 1°× 1 ° of 6 hours analyzed data as well as conventional Doppler radar information are weather diagnosis and mesoscale analysis for the process of a heavy rainstorm on the 2007 in the eastern region of Tianjin. The results show that heavy rains occurred in the large-scale circulation to the zonal adjustment period. The affecting systems are the trough on 500 hPa, the shear line on 700 hPa and 850 hPa and ground mesoscale convective line. The main reason of the uneven heavy rainfall distribution is obvious scale in various physical characteristics. Ramps were formed over air flow of the storm zone which led ro stable development of a strong thunderstorm cloud, at the same time the easterly storm on ground transmitted a lot of water vapor. The existence and maintenance of the ground-mcmscale convergence line not only enhance the convergence uplift, but also cause the current to the large-scale storm in the system and trigger conditions. The obvious train effects in Doppler radar map, as well as correspondence between extended height of heavy echo and intraday zero height are the main reamns for the heavy rainfall.

关 键 词：大暴雨 动力学诊断 中尺度辐合线 列车效应 

分 类 号：P458.121.1[天文地球—大气科学及气象学] V321.22[航空宇航科学与技术—人机与环境工程]