山西中部一次致灾暴雨中尺度特征  

Meso-Scale Analysis of a Disastrous Heavy Rain in Shanxi

作　　者：赵彩萍[1] 赵桂香[2] 

机构地区：[1]山西省太原市气象局,太原030002 [2]山西省气象台,太原030006

出　　处：《气象科技》2012年第5期807-813,共7页Meteorological Science and Technology

基　　金：山西省领军人才项目"山西省雾霾天气形成机理及其预报技术研究"资助

摘　　要：利用常规资料、自动站资料、卫星产品和雷达资料,对2010年9月19日发生在山西省中部的暴雨天气过程进行了综合分析,结果表明:①500hPa副高强盛,由块状转为带状以及对应200hPa图上东西向反气旋的稳定存在是低空横切变线形成和维持的背景因素,而低空低涡横切变线是暴雨的主要影响系统。②降水表现出典型的β中尺度特征,对流云团首先在低涡西侧形成,随着涡前西南气流的加强,迅速发展东移;横切变线上激发出的β中尺度强对流云团是暴雨的直接影响系统。TBB大小与未来1h降水量成反相关关系。700hPa水汽输送的变化和500hPa引导气流风向的变化对6h后对流云团的增强或减弱有指示意义。③此次强降水过程,与低空横切变线相对应,雷达强度回波上表现为线状回波带,其上大于45dBz的区域即是暴雨区。④850hPa上低涡西北侧冷平流的侵入使得低涡发展,500hPa正涡度平流的存在是横切变线维持和发展从而导致强降水的动力因子。Using the conventional, automatic, satellite, and radar data, a comprehensive analysis is conducted of the heavy rain occurred on 19 September 2010 in the middle Shanxi. The results show： （1） The subtropical high at 500 hPa, which changed from block pattern to zonal pattern, was strong, and the horizontal anticyclone at 200 hPa maintained stably, which were important background factors for the formation and maintenance of the horizontal shear line at lower levels. The vortex and horizontal shear line were mainly influencing systems. （2） There were typical ^-meso-scale characteristics in precipitation. A convective cloud mass first occurred in the west side of the vortex; with the strengthening of SW flow before the vortex, the convective cloud mass promptly developed and moved to east; and the heavy rain was caused by the β-meso-scale convective cloud mass triggered the shear line. Opposite correlation was found between TBB and rainfall in future 6 hours. （3） There was a line-shaped echo band in radar, and the heavy rain was located at the area of over 45 dBz. （4） There existed cold advection in the northwest of vortex, which enhanced the vortex, and there existed positive vortex advection at 500 hPa, which were the dynamical factors for the maintenance and development of the horizontal shear line that induced the heavy rain.

关 键 词：副高 横切变线 线状回波 Β中尺度 

分 类 号：P458.121.1[天文地球—大气科学及气象学]