摘要
利用闪电定位每分钟的实测资料和加密雨量站每分钟的雨量资料，对山西省2006年8月13～14日副热带高压东退南压过程中，产生的局地大暴雨过程的地闪特征进行了分析。结果表明：对流风暴中，负地闪出现在强度达40dBz且与径向速度图的逆风区或附近正速度的大值区相重叠的区域内，正地闪出现在强度达30dBz风暴后部的正速度小值区；混合性降水云系中，地闪出现在500 hPa 5880gpm与5840gpm等高线所包嗣区域内的辐合带或逆风区，且正地闪靠近5840线一侧，负地闪靠近5880线一侧。局地地闪频数与雨强随时间的变化有很好的相关性，负地闪的出现及其频数的增加意味着影响该地区的对流风暴正在发展并向本地移来，地闪频数峰值的出现表示雨强峰值的迅速到来，正地闪的出现表示该对流风暴对本地区的影响即将结束。利用地闪频数峰值准确地预报强对流风暴产生的局地强降水只有30～45min的提前量，而对于混合性强降水的预报则可有1～2h的提前量；逆风区的水平尺度、垂直厚度、逆风区附近的正、负速度差值直接影响风暴降水的范围、强度和持续时间。
Using the minutely real time data of the lightning location and the minutely precipitation data of the encrypted precipitation station, the cloud to-ground lightning character of the local severe rainstorm process generated during the horse latitude high withdrew eastern and suppressed southern in Shanxi Province on August 13-14, 2006 is analyzed. The result showed that in the convective rainstorm, the negative cloud to ground appeared in the area which intensity reached to 40 dBz, and superposed with the wind shadow of the radial speed picture or the near high value area of the positive speed, the positive cloud to ground lightning appeared in the positive speed small value area which was behind the storm whose intensity reached to 30 dBz. In the mixed precipitation cloud system, cloud-to-ground lightning appeared in the convergence zone or wind shadow which was encircled with 5880 gpm and 5840 gpm, and the positive cloud-to ground lightning was close to 5840 line, the negative one was close to 5880 line. The local cloud to ground lightning frequency and the rain intensity have excellent relativity with time changing. The appearance of negative cloud-to ground lightning and the increment of its frequency means the convective rainstorm influenced this area had been dcvcloping and moving to this region. The appearance of the cloud to ground lightning frequency peak value implies the immediate coming of rain intensity peak value, the appearance of positive cloud-to ground lightning means the influence of that convective storm to this region will come to the end at once. We only have 30-45 minutes ahead of time to exactly forecast the local severe precipitation produced by the severe convective rainstorm with the cloud-to-ground lightning freration.
出处
《高原气象》
CSCD
北大核心
2008年第4期873-880,共8页
Plateau Meteorology
基金
山西省科技攻关项目“山西省中短期气象灾害预警系统”(041088)资助
关键词
山西省
大暴雨
地闪特征
Shanxi
Heavy rainstorm
Cloud to ground lightning character
