邵阳地区闪电活动特征及其与降水的关系

Characteristics of lightning and its relations with precipitation in Shaoyang region

利用闪电定位资料和常规观测站24 h降水资料,对2008—2010年邵阳地区闪电特征进行分析,并探讨了邵阳地区闪电与降水的关系。结果表明:邵阳地区闪电以负地闪为主,地闪频次的最大值中心位于东北部,呈东北—西南减少的趋势;地闪频次有明显的日变化特征,闪电集中发生在13—19时;有闪电时,降水量不超过1 mm和10 mm的降水个例分别为29.63%和76.30%;无闪电时,其值分别为69.44%和96.30%;超过20 mm的降水多伴随有闪电,无闪电时发生概率极小;地闪频次与闪电对流降水的拟合系数优于其与所有降水的拟合系数,且随着统计尺度的增大,地闪与闪电对流降水的相关性变大。

Based on the data from a cloud-ground lightning location system and 24 hours precipitation data from the weather stations ,the characteristics of lightning in Shaoyang region from 2008 to 2010 were analyzed and its rela- tionship with precipitation was discussed. The results show that most lightning is negative and its large value center is located in the northeast, while its frequency decreases from northeast to southwest. The frequency of cloud-to- ground （CG） lightning has an obvious diurnal change, and the highest frequency usually occurs from 13：00 to 19：00. The cases under 1 mm and 10 mm accumulated precipitation account for 29. 63% and 76. 30% respectively with lightning ,while corresponding values are 69. 44% and 96. 30% without lightning. The rainfall events that 24 hours accumulated precipitation is over 20 mm usually occur with lightning, and it is seldom without lightning. The correlation coefficients between CG lightning frequency and convective rainfall are greater than that between CG lightning frequency and the total precipitation, and the former becomes stronger with the increasing of the time- scale.