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1998年 4月 2 3日下午在中尺度对流系统 (MCS)的影响下 ,山东潍坊地区出现了一次大范围的冰雹强对流天气。应用闪电定位系统、卫星和雷达观测资料 ,研究了这次降雹过程形成和发展不同阶段闪电的变化特征。分析发现 :雹云在形成发展和减弱消亡阶段 ,每 5分钟闪电频数低于 2 0次 ,且正闪电频数明显低于负闪电 ;雹云在成熟阶段 ,闪电频数每 5分钟平均值大于 2 0次 ,且正、负闪电频数相当 ,而在强降雹前短时会出现正闪电频数超过负闪电现象。此外还发现 ,在降雹前 2 0～ 30分钟闪电频数有跃增现象 ,其增加速率和降雹强度呈正相关关系 ,降雹的起始时刻与总闪电和负闪电每 5分钟频数出现极大值的时刻有明显的一致性。
Under the influence of the mesoscale convective system (MCS) in the afternoon of April 23, 1998, a large area of hail storm was observed in Weifang, Shandong. Lightning positioning system, satellite and radar observations were used to study the characteristics of lightning in different stages of the formation and development of this hail hail process. The analysis found that the hail cloud formed and developed and weakened, the lightning frequency was less than 20 times every 5 minutes and the frequency of positive lightning was significantly lower than that of the negative lightning. At the mature stage, the average lightning lightning frequency was more than 20 Times, positive and negative lightning frequency is quite, and in the short time before strong hail will appear positive lightning frequency exceeds negative lightning phenomenon. In addition, it was found that there was a sharp increase of lightning frequency between 20 and 30 minutes before hailfall, and the increase rate and hail intensity had a positive correlation. The moment when the hail started and the frequency of total lightning and negative lightning appeared every 5 minutes was the highest There is a clear consistency.