一次川渝大暴雨的中尺度分析  

Mesoscale Analysis of a Torrential Rain in Sichuan and Chongqing

作　　者：康岚[1] 冯汉中[1] 屠妮妮[2] 肖红茹[1] 张利红[2] 

机构地区：[1]四川省气象台,成都610072 [2]成都高原气象研究所

出　　处：《气象》2008年第10期40-49,共10页Meteorological Monthly

摘　　要：利用逐时FY-2CTBB资料、闪电资料、自动站雨量资料和经过再分析的中尺度格点分析场资料,分析2007年7月16—20日发生在川渝地区的暴雨天气过程中尺度特征,为评估、预报此类暴雨天气过程提供有价值的信息。分析结果表明:本次降水过程是高原涡和西南涡两个中尺度系统逐步耦合的结果,与上升气流相伴的强而深厚的正涡度柱是造成对流辐合体反复在相近区域生、消和暴雨反复在临近区域发生的重要因素之一;西南低涡环流中的三个中尺度云团系统(MCS)直接产生了本次暴雨过程的强降水,MCS的生消和青藏高原东部的对流云系具有翘翘板效应;对卫星云图Tbb值、闪电资料和强降水的综合分析表明闪电发生于降水之前约1～3小时,强降水基本出现在闪电密集区和低Tbb值重合区;闪电的移动方向基本可以代表对流旺盛区的移动方向,也就是未来可能出现强降水的方向。闪电突然增强或减弱对于追踪对流降水的发生和移向、判断强降水的增强或减弱、强降水出现时间、位置、变化趋势具有一定的指示意义。By using hourly Tbb data, lightning data, rainfall observations from automatic weather stations, the mesoscale characteristic of a torrential rain in Sichuan and Chongqing during July 16 - 20, 2007 was analyzed in order to obtain valuable information on evaluating and predicting such case of torrential rain. The study shows that this case was a coupling result of two mesoscale systems which are Plateau Vortex and Southwestern Vortex. The strong and thick positive vortex column and the accompanying updraft are the main factors, which cause the convection bodies generate and eliminate in turn and lead to torrential rain to occur repeatedly in the nearby area. Three mesoscale cloud systems （MCS） in the southwestern vortex initiate the heavy rain directly. In this case, generation and elimination of the MCS and the convective clouds in the western Tibetan plateau performed in a way of seesaw. The movement direction of lightning can represent the direction of movement in strong convection zone, which is also the direction of movement of heavy rainfall in the future. The emergence of lightning is before the precipitation, a sudden increase or decrease of lightning have a certain significance to the increase or decrease of precipitation in the future.

关 键 词：暴雨 西南涡 中尺度特征 

分 类 号：P458.121.1[天文地球—大气科学及气象学] S714.7[农业科学—林学]