一次中尺度对流系统的电场演变特征

综合雷达、卫星、电场、闪电定位仪等资料,分析了2009年6月5日经过南京地区的中尺度对流系统(MCS)的地闪、电场演变过程及特征。本次过程中,MCS的发展阶段正地闪占主导地位,成熟阶段负地闪占主要地位,消亡阶段层状云区的正地闪相对较频繁。将该过程电场划分为4个阶段,重点对MCS对流区的电场进行了演变过程和特征分析,并用准正态分布模式模拟了MCS的对流区电场。结果表明,准正态分布模式能够更细微地反映电场变化,模拟得到的电场和实际观测相符。

Evolutional Characteristics of Electric Field in a Mesoscale Convective System

Combining the radar,satellite,lightning positioning system data,etc,the characteristics and evolution of cloud-to-ground lightning and the electric field of the Mesoscale Convective System（MCS） in Nanjing on 5 June 2009 are analyzed.Positive cloud-to-ground lightning played a dominant role in the developing stage of MCS;negative cloud-to-ground flashes are dominant in the mature stage;positive flashes are relatively frequent over the stratiform cloud areas in the extinction stage.This process of the electric field evolution can be divided into four stages,and the evolution and characteristics of the electric field in convective areas are analyzed.The electric field of MCS over the convective area is simulated with the quasi-normal distribution model.It is found that the simulated electric field accords with observation, and the quasi-normal distribution model can response to slight changes in the electric field.