基于闪电定位系统的重庆地区地闪日分布特征分析

On Analysis of Characteristics and Factor of Lightning Day Distribution of Chongqing

采用重庆地区闪电定位资料(1999-2008),通过数理统计等方法,重点分析重庆地区地闪日分布的特征.结果表明:全市闪电发生频率呈现双峰双谷状态,二个高频时期分别为0:00-3:00和13:00-16:00;闪电雷电流幅值的两个峰值时段分布在凌晨和正午前夕;夜间闪电比例达到60%以上,主要分布在22:00-04:00,为典型的夜间主导型地区;全市夜间闪电百分率可以分为5个等级.在此基础上,对夜闪分布进行了区划,得到了地形、太阳辐射的日循环和季节性变化是影响日分布特征形成的重要因素.

Based on the lightning fixed data of LIS and LLS in Chongqing from 1999 to 2008, the characteristics of lightning day distribution have been analyzed according to mathematical statistics. The final results suggest that the frequency of lightning occurrence presents doublet and double-dip with the 0：00 to 3：00 and 13：00 to 16：00 of each high frequency. The average of lightning intensity has two peaks, mainly before dawn and noon. The proportion of nightly lightning can reach up to 60 %, among which occupies the high frequency-from 22：00 to 4：00, and it is also the typical nightly-dominated area. The ratio of nightly lightning in the whole city of Chongqing can rank 5 levels. Based on the above mentioned, we can get that landscape, day-cycle and seasonal change of the solar radiation are the influential factors of day distribution according to the partition of the nightly lightning.