成都地区一次强对流天气中地闪产生的天气动力学条件分析  

Analysis of Weather Dynamic Conditions for the Formation of Cloud-to-Groud Lightning in a Severe Convective Weather in Chengdu

作　　者：柳臣中 周筠珺[1,3] 张凌[2] 徐毅[2] 张晓露[1] 

机构地区：[1]成都信息工程大学大气科学学院高原大气与环境四川省重点实验室 [2]中国人民解放军69008部队 [3]南京信息工程大学气象灾害预报预警与评估协同创新中心

出　　处：《成都信息工程学院学报》2015年第5期512-520,共9页Journal of Chengdu University of Information Technology

基　　金：973计划资助项目(2014CB441401);四川省学术和技术带头人培养资金资助项目(004185)

摘　　要：针对成都地区独特地形下强对流天气动力过程和地闪活动特征,通过对比分析闪电定位系统资料、卫星资料、常规观测资料,重点研究了2013年6月20日一次中尺度对流系统(MCS)中地闪产生的天气动力学条件。结果表明:对流稳定度指数能够很好的反映强对流天气的演变。地闪活动与降水及云顶亮温有很好的对应关系。地闪主要发生在云顶亮温≤-60℃且温度梯度较大的区域,地闪密集区常常出现在MCS云团中部及前部。MCS发展阶段,1500 m高度以下风速增大并由偏北风转向西南风,地闪数量明显增多。MCS成熟阶段的地闪密集区恰好位于垂直螺旋度大值中心(500×10-6m·s-2)范围内。垂直螺旋度大值区与云顶亮温≤-60℃冷云区有很好的对应关系,或许能够作为研究强对流天气的指标之一。In order to help the understanding of dynamic process and cloud-to-ground（ CG） lightning activity of severe convective weather under Chengdu area＇s unique terrain features,by comparing and analyzing the lightning location detection data,satellite data and synoptic information,the paper emphatically discusses the weather dynamic conditions for the formation of CG lightning in a Mesoscale Convective System（ MCS） on 20 Jun 2013. The results show that the convective stability index can reflect the evolution of the severe convective weather by observing the evolution of environmental factors during the MCS life cycle. The CG lightning activities have good corresponding relationship with precipitation and cloud top brightness temperature. CG Lightning mainly occurred in the area with cloud top brightness temperature lower than- 60 ℃ with maximum temperature gradient. The concentrated regions of CG lightning often appear in centre and front of MCS clouds. In MCS development phase,the wind speed increases suddenly and the wind direction changes from north to southwest which below the height of 1500 m,the number of CG lightning and precipitation significantly increase. MCS mature stage flash concentrated area is located in the vertical helicity value centre（ 500 × 10- 6m·s- 2）range. The vertical helicity value area has good corresponding relationship with cloud top brightness temperature of cold cloud area lower than- 60 ℃,and it may be as index in severe convection weather research.

关 键 词：大气科学 大气物理学与大气环境 中尺度对流系统 地闪 天气动力学 

分 类 号：P446[天文地球—大气科学及气象学]