南京周边地区雷暴过境时电场特征及其在预警中的应用  

Application of Atmospheric Electric Field Data on Lightning Prediction Around Nanjing

作　　者：周俊驰[1,2] 王振会[2,3] 冯民学[1,2,3] 沈刚[1] 程琳[1] 张艳华[1] 

机构地区：[1]江苏省防雷中心,江苏南京210009 [2]南京信息工程大学气象灾害教育部重点实验室,江苏南京210044 [3]南京信息工程大学大气物理学院,江苏南京210044

出　　处：《高原气象》2013年第5期1470-1477,共8页Plateau Meteorology

基　　金：国家公益性行业科研专项(GYHY200806014);江苏省"科技支撑计划-社会发展"项目(BE2009693);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：利用2009年6-8月南京周边地区11台大气电场仪观测网络和ADTD闪电定位系统资料,分析了雷暴过境时的电场特征,按照闪电定位仪观测到的闪击点到电场仪站点的距离以及电场曲线的特点,将雷暴过程的电场变化分为外围闪击阶段、雷云临近阶段、雷云到达阶段和雷云过境后阶段这四个阶段。第一和第二阶段为雷电预警提供了重要信息,因此从幅值特点、差分变化率特点、波形特点、极性反转及时间特点等方面探讨了这两个阶段的电场特征,并基于这些特征,建立了多元回归预报方程,经拟合分析得到:从闪电定位仪观测到电场仪站点25km首次闪击开始,若电场观测数据同时出现以下任意二个特征:(1)幅值达到该地区晴天大气电场的21.5倍以上;(2)差分变化率环比增大2.6倍以上;(3)斜率k的绝对值达到0.61以上;(4)出现电场极性反转,则可发出预警,预计该地区在30min左右(计算值为33.6min后)发生闪击的可能性很大。Using the atmospheric electric field （AEF） data and ADTD lightning positioning system （LPS） data around Nanjing from June to September 2009, the characteristics of AEF during thunderstorm were analyzed. The four stages were obtained in a thunderstorm according to distance from lightning position to AEF instrument and characteristics of AEF profiles： Far-distance strokes, approaching strokes, overhead strokes and fading strokes. AEF traits in terms of amplitude, difference rate, profiles and polarity reversal were analyzed at the first and the second stages which are of high importance to lightning warning. Multi- ple regression equations were set up based on the characteristics discussed above and a lightning warning approach was given： （1） amplitude increasing by 21.5 times as in fine weather; （2） link relative difference rate increasing by 2. 6 times; （3）absolute gradient of the profile reaching 0. 61; （4） polarity reversal, when a stroke within 25 km around the site detected, a lightning warning should be issued in emergence of the 2 traits of the four above, it is likely that thunderstorms is about to come in 33.6 min.

关 键 词：大气电场仪 闪电定位仪 预报方程 

分 类 号：P427.3[天文地球—大气科学及气象学]