一次西南低涡特大暴雨的中尺度对流云团特征  

The Mesoscale Convective Cloud Cluster Features of a Severe Torrential Rain Caused by Southwest Vortex

作　　者：陈茂强[1,2] 顾清源[3] 汪延波 青泉[3] 

机构地区：[1]四川省内江市气象台,内江641000 [2]云南大学大气科学系,云南650034 [3]四川省气象台,成都610072

出　　处：《高原山地气象研究》2008年第4期66-71,共6页Plateau and Mountain Meteorology Research

基　　金：国家自然科学基金项目--青藏高原低涡切变线形成维持机制研究40775032;四川省气象局重点科研课题--市州短临预报业务初步研究2007-39

摘　　要：针对2007年7月8～10日四川盆地南部的特大暴雨天气过程，利用逐小时红外云顶黑体亮度温度结合地面加密雨量资料对其进行了对比分析。分析指出此次特大暴雨是由西南低涡内几个中尺度对流云团连续生消造成的，在其开始阶段有一中尺度对流复合体沿基本气流方向强烈发展，此阶段云团虽发展旺盛，但由于雨团随系统移动较快，并未造成洪灾。此云团减弱后，低涡环流仍维持并少动，又依次触发了3个中尺度对流的生成，这3个中尺度对流云团逆基本气流向SSW方向缓慢移动，造成的降水落区集中，中心雨强大，持续时间长，由此导致了暴雨洪涝的产生。强降水位置对于前向传播系统，一是在其发展的前端，二是在冷云中心的略偏后的位置，最大雨强出现在云团成熟之前发展最剧烈时，而后向传播的低涡云团强降水主要在冷云中心附近，最大雨强出现在云团发展最旺盛（冷云中心TBB最低）时。By using TBB data of FY2 - C infrared images, radiosonde data and the rainfall data （ including National weather observation stations and the region weather observation stations） at 1 hour intervals, the rare torrential rain weather event happened at south region of Sichuan Basin from 8th to 10th, July, 2007 is compared. The results show that the extremely heavy rainstorm is caused by four mesoscale convective systems （two MCC and two MCS） , which continual appearing and disappearing in the Southwest Vortex weather system. At its initial stage, there was a huge mesoscale convective complex （MCC） developed intensively along the basic air current direction. Because the rain region was quick along with the system migration, it had not led to the flood disaster, although the cloud cluster developed exuberantly in this stage. After this cloud cluster weakened, the Southwest Vortex circulation still maintained and kept little movements, and triggered three mesoscale convective systems （MCSs） one by one , which moved against basic air current slowly with the more obvious characteristic of low vortex. The later three MCS created rainfall region centralized, precipitation intensity strong, long - time maintained, all these results in the severe torrential rain. The heavy precipitation of forward development system are in front of its development and behind cold cloud center, The heaviest precipitation appeared when the cloud cluster development was fiercest, before being mature. The strong precipitation of the low vortex cloud cluster which backward development was mainly nearby cold cloud center, and the strongest precipitation appears when the cloud cluster was strongest （TBB of cloud center to be lowest）.

关 键 词：西南低涡 特大暴雨 MCC MCS 

分 类 号：P458[天文地球—大气科学及气象学]