安徽闪电与雷达资料的相关分析以及机理初探

ANALYSIS AND MECHANISM STUDY ON THE CORRELATION BETWEEN LIGHTNING AND RADAR DATA IN SEVERE WEATHER

WSR-98D多普勒天气雷达和新型闪电定位仪是监测灾害性天气十分有效的手段,利用合肥多普勒天气雷达的物理量产品和中国科技大学研制的新型闪电定位仪资料,对2001年7月24日、2002年5月27日、2004年4月6日发生在安徽省的冰雹和强降水的3次天气过程的闪电与雷达回波特征做相关性分析和机理初探,发现一些有意义的统计规律:(1)闪电发生的数目和变化与回波顶高(ET)有较好的对应关系,而与垂直含水量积分(VIL)对应关系不明显;(2)强对流天气的云地闪中正地闪与负地闪发生频次相当,甚至超过负地闪,但正地闪比较分散,负地闪比较集中,闪电发生的位置与强回波位置不一致,云下一般存在一个次正电荷层;(3)强降水天气的负地闪占优势,闪电发生的位置比较集中并且与强回波位置一致,云下没有正电荷层;(4)垂直累积液态水含量(VIL)和回波顶(ET)很小处出现的闪电是由云砧和对流云分裂的碎云产生的。

The physical parameters product of WSR-98D Doppler Radar and the lightning data provided by localization instrument have been showed on the same interface. And with these two efficient means for monitoring severe weather, the mechanism of the severe weather has been analyzed and studied. The statistic analysis on lightning character has been studied for three weather progresses which respectively took place on 24 July 2001,27 May 2002 and 6 April 2004.The results show some significant statistic regularity： （1） The quantity and the variety of the lightning flashes have better relation to the echo top （ET）, whereas they have no evident relation to the vertical integral of liquid water（VIL）; （2）In intense convective weather, the quantity and frequency of the plus Cloud-to-Ground（CG） lightning flashes are almost equal to even more than that of minus CG lightning flashes and the plus CG lightning flashes are dispersion whereas the minus CG lightning flashes are relative dense The position of the lightning flashes is not consistent with that of strong echo. There is normally a secondary plus-charge layer; （3） In strong precipitation weather the minus CG lightning flashes dominate normally. The position of the lightning flashes are relatively dense and consistent with that of strong echo. There is no plus-charge layer at the bottom of the cloud; （4） The fact that a great deal of lightning flashes taking place where VIL and ET are very small is due to the cloud anvil and broken cloud breaking from the convective cloud.