冰雹与雷暴大风的云对地闪电特征

THE CHANACTERISTICS OF LICHTNING FROM CLOUDS TO GROUND ACCOMPANYING WITH HAILSTONES,THUNDERSTORMS AND GUSTS

利用京津冀中尺度试验基地三站闪电定位资料，对１９８９—１９９２年２０个冰雹大风实例进行了分析。发现云对地闪电（简称地闪）活动表现为一次冰雹大风天气过程。且正的云对地闪电（简称正闪）占绝对优势，而负的云对地闪电（简称负闪）则与强降水相关。其开始发生时间与雷雨同步，比冰雹平均提前２５ｍｉｎ左右，出现在雹云前进方向右侧（下风方）１０—５０ｋｍ。当正闪发生在雹云后部时是冰雹发生与加强阶段，而闪电密集区与云体重叠时是冰雹过程强盛阶段，当位于云体的前方且散开时是冰雹减弱消亡阶段。这个特征对超短期预报具有指示意义。

ccording to the data from 3 stations of mesoscale weather system experimertal base in Beijing. Tianjing and Hebei, 20 cases of hailstones with gusts weather process from 1989 to 1992 were analyzed. The results showed that the activity of lightning from cloud to ground was a process with gusts. The positive charge of lightning from clouds to ground was dominant. The negative charge,of lighthing from clouds to ground correlated to heaVy rainfall.The occurence of lighthing coincided with the thunderstorms twenty five minutes earlier than hailstones on an average. It appeared 10- 50km righthand in front of hailstone clouds . When positive charge lightning occurred at the rear part of hailstone clouds. it was the occuring and strengthening stage of hailstones, when the concentrating area of lightning overlapped with the body of clouds. it was the strongest stage of the hailstone process: when the lightning was at the frontal part of the clouds and separating it was the weakening and disappearing stage of the hailstone clouds. These characteristics were suggestions for nowcasting.