2004—2007年江西雷电分布特征分析

Distribution Characteristics of CG Lightning from 2004 to 2007 in Jiangxi Province

基于2004—2007年江西省地闪监测资料,分析江西雷电分布特征。统计表明,江西大部分县(市)年平均地闪5000～15000次。从时间分布看,江西雷电全年都有发生,主要出现在4—9月,其中6—8月最为活跃,1d中地闪主要发生在12—20时。从空间分布看,年平均地闪10000～15000次的高密集区主要分布在吉安、赣州、宜春、南昌、上饶和鹰潭等地。从雷电流的特性看,负闪居多,年正、负闪数之比为0.0202～0.0431。从雷电流强度上看,地闪雷电流强度绝对值主要为2～20kA,其中正闪主要为3～55kA,负闪主要为-3～-16kA,正闪平均强度是负闪的2.95倍。

Based on the 2004--2007 CG lightning data of jiangxi province, the distribution characteristics of CG lightning in Jiangxi are analyzed. The result shows that CG lightning occurs 5 000--15 000 times per year in most area of Jiangxi, which occurs all the yearround but is active from April to September and the most from June to August. It mainly happens from 12：00 to 20：00 in a day. The high-density areas with 10 000 to 15 000 average annual CG lightning number are Ji＇an, Ganzhou, Yiehun, Nanchang, Shangrao and Yingtan. Most CG lightning in Jiangxi is negative and the ratio of the annual amount of the positive to the negative is 0.020 2 to 0.043 1. The absolute values of current intensity are mainly 2--20 kA, with the positive CG lightning current intensity being 3--55 kA, the negative one being -3---16 kA, and the mean positive CG lightning current intensity being 2.95 times of the negative one.