华北飑线系统中地闪活动与雷达回波顶高的关系及预警指标

Analysis of Correlation Between Cloud-to-Ground Lightning Activity and Echo Top of Doppler-radar Data in Squall Lines in North China

选取代表华北地区经常出现的三类飑线系统——拖曳层状型（TS）、先导层状型（LS）、平行层状型（PS）的3次强雷暴过程为研究对象,利用天津塘沽多普勒雷达资料、京津冀ADTD型地闪监测网资料和北京探空资料,在对资料进行全面质量控制的基础上,运用粗网格化分析方法,分别以飑线系统整体和飑线系统上局部的强回波块为研究对象,探讨6分钟内地闪频数与雷达回波顶高的关系,找寻雷电预警指标。结果表明：3次过程中,出现在云顶达到8-12km对流云塔中的地闪频数分别为85.8%、78.9%和80.5%;无论是在飑线系统整体,还是飑线系统上强回波块中,6分钟内地闪频数与对流云回波顶高高于11km或12km的回波面积有正相关关系;而且在飑线系统内的地闪活跃区,回波顶高高于11km的回波面积对地闪活动激烈程度具有预警意义。

3 squall line weather processes in North China were selected and studied,which represent three different types of typical squall line system with trailing stratiform（TS）,leading stratiform（LS） and parallel sratiform（PS）.The used data include Doppler radar,cloud-to-ground lightning,radiosonde and the data by variable width net-grids.The relationship between cloud-to-ground lightning frequency every 6 minutes and echo top parameter was studied by using the top height of whole squall line and its upper part.The results show that cloud-to-ground lightning frequency in period of 6 minutes appeared a range above 8km are 85.8%,78.9% and 80.5%,respectively for three squall processes,and they correlate positively to the areas of cloud tower height reaching above 11km or 12km（echo top above 11km）.Especially,at part intense lightning activity range of squall line systems,the total areas of echo top above 11km can be used as an indicator of lightning warning.These results are meaningful to the lightning now-casting and to understanding of lightning activity in squall line system in North China.