夏季雷州半岛强降水雨滴谱个例分析及降水与闪电相关性统计分析

The raindrop size distribution of a thunderstorm event and the relationship between precipitation and lightning over Leizhou Peninsula in summer

利用2007年8月在雷州半岛观测雷暴获得的雨滴谱和地闪资料,重点分析了8月6日遂溪、湛江一次雷暴云降水个例的雨滴谱特征,对闪电特征与降水的相关性进行了统计分析。结果表明,遂溪站的雨滴谱谱型多为双峰或多峰型,而湛江站的雨滴谱谱型多呈单峰型分布;平均雨滴谱符合Gamma分布;雨强I>10mm/h时发生地闪的频率较高,且发生地闪频率随着距测站的距离减少而增加;随着雨强的增大发生正地闪的概率明显增加;降水过程中的闪电频率和距离校准后闪电电流强度的相关性表明,地闪发生的距离越近,频率越高对应雨滴谱谱宽越宽和降水强度越大。

Based on the data of raindrop size distributions （RSDs） and lightening over the Leizhou pen-insula in August 2007, this paper analyzed the （RSDs） of a thunderstorm at Suixi and Zhanjiang on 6August 2007 and the relationship between lightening and precipitation.The results showed that the RSDswere mostly bi-peak or multi-peak spectra at Suixi while they were mainly single-peak spectra at Zhan-jiang.The spectra were all fitted with Gamma distribution.The lightning strokes were higher in heavyrain（I〉 10 mm/h） than in the precipitation with lower rain rate.The strokes of lightning also increasedwhen it got closer to the station in heavy rain（I〉10 mm/h）.The positive ground flash frequency roseobviously with increasing rain rates.The relationship between lightning frequency and distance-normal-ized current intensity in the precipitation suggested that a higher occurrence frequency of cloud-ground（CG） lightning in shorter distance was associated with broader raindrop size spectrum and higher rainrates.