雷暴过程中的大气电场特征与地闪活动分析

Atmospheric electric field characteristics and CG lighting activities in the thunderstorm

本文利用云南省闪电定位系统监测资料和大气电场仪资料分析了滇中2007-04-30的雷暴天气过程,结果表明:这次由午后强对流活动引发的雷暴过程主要分布在滇中地区,负地闪所占比例较高,正负地闪为中等偏弱电流,在时间上正地闪落后于负地闪;大气电场不仅能很好的反映带电云的产生、聚集、消亡过程,也能较好的反映出地闪发生频数、性质;结合地闪发生频数,可将大气电场的演变可分为6个阶段,各个阶段显示出不同的电场特征,其中地闪初期阶段电场的变化对雷电预警具有重要意义。

Based on the monitoring data of lightning location system and atmospheric electric field device,a thunderstorm weather in Yunnan were analyzed on April 30,2007. The results show that the strong convective activity from the afternoon causes thunderstorm, which mainly distributes in center of Yunnan. Proportion of negative CG lightning is high. Average current of positive and negative CG lightning is moderate weakness,and positive CG lightning is always behind the negative CG lightning. Atmospheric electric field not only can reflect the produce, accumulation and extinction process of charged cloud, but also reflect the frequency and nature of CG lightning. The evolution of CG lightning and the electric field can be divided into six phases. Each phase shows different characteristics and the change of early electric field is important for lightning warning.