河南地闪气候特征分析

Climatic Characteristics of Cloud-to-Ground Lightning over Henan Province

利用华北电网的多个DF站点所取得的闪电定位资料,对河南省地闪气候特征进行了分析,得到以下主要结论:河南省地闪绝大多数为负闪,正负闪之比约为1/13.地闪峰值电流强度以7,8月为最小,其中负闪峰值电流强度主要集中在4～24(KA),而正闪的则要高很多.多数正闪有一次以上的回击,而多数负闪有两次以上的回击.负闪频次有两个极大值(在4,8月),正闪频次有3个极大值(在4,6、11月).正负地闪出现的高频时间不同.但低频时间几乎相同.在总地闪较少的月份正闪百分比较大,而总地闪较多的月份正闪百分比较小.地闪在河南分布有明显的区域性.

By utilizing the lightning DF data from several sites over Henan province the results show that: most of the CG lightning flashes in Henan are negative and the proportion of positive to negative lighting is 1/13.The peak currents are lower at Jul and Aug.The peak currents of negative CG lightning flashes focuses on 4～24(KA),but the ones of positive flashes are much higher.Most positive CG lightning has more than one return strokes,but negative lightning has more than two.Negative CG lightning frequencies has two maximum values(in Apr. and Aug.) while positive ones has three maximum values(in Apr.,Jun.,and Nov.).The high frequency period of negative and positive lighting is different,but the low one is almost the same.The higher the percentage of positive CG lightning is,the less the total CG lightning is.The regional distribution characteristics of CG lightning flashes are very distinct.