关键词: 闪电活动, 时空分布, 地形, 云南

Abstract: Based on lightning density grid data of lightning imaging sensors (LIS) on TRMM satellite and precipitation data at six weather stations of Yunnan Province during 1998-2013, the spatial and temporal distribution characteristics of lightning activities over Yunnan Province and its relationship with precipitation were analyzed. The results are as follows: (1) The mean lightning density over Yunnan Province was 4.7 fl·km-2·a-1. The distribution of lightning density was closely related with terrain, and it gradually increased from northwest to southeast with ‘V’ zonal shape. The lightning over Xishuangbanna, southeastern Puer and the border between China and Vietnam of southern Yunnan was active, and the maximum was 30.6 fl·km-2·a-1. (2) The lightning activity had obvious seasonal and diurnal variation over Yunnan. The lightning activity in spring and summer was obviously more than that in autumn and winter, and it  mainly occurred over southern Yunnan in spring and eastern Yunnan in summer. The monthly distribution of lightning activity appeared typical single peak pattern over northern Yunnan, the peak occurred in July or August, and the monthly lightning density was well related with monthly precipitation. However, the monthly distribution of lightning activity showed double peaks pattern over western, southern and southeastern Yunnan, and the peaks were in April and July or August, respectively, but the correlation between lightning density and precipitation was poor. The lightning over most regions of Yunnan occurred from 16:00 LT to 20:00 LT, and it usually occurred in the nighttime over high density areas. (3) The influence of terrain and altitude on lightning activity was significant over Yunnan, and lightning activity was closely related with monsoon.

Key words: lightning activity, temporal and spatial distribution, terrain, Yunnan