2011年11月5日贵州梵净山强雷电特征及天气成因分析

Characteristics and Formation Causes Analysis of the Strong Lightning in Fanjing Mountain of Guizhou on November 5,2011

2011年11月5日贵州东北部梵净山景区出现强雷电天气,导致34名游客遭遇不同程度的雷击伤害。利用闪电定位资料、天气图、雷达卫星资料、高空资料,对这次雷击事故的雷电特征和雷电天气成因的分析结果表明:1)雷击事故发生时,闪电密度不大,但正闪强度高达259 kA,这在铜仁的冬季属于万分之二的小概率事件。2)高山以及山体上的金属物充当了引雷载体,完全石质结构的山体,因防雷设施不健全,强雷电不能扩散,而产生了直接雷击伤人。3)复杂的大气电场产生球形闪电接地后不能顺利放电,发生爆炸,分解成多个球形闪电,四处飞窜伤人。4)500 hPa波动气流与850 hPa弱切变配合,为对流天气产生提供了条件,但高空要素和相关的对流参数量级较小,不具备强对流产生的条件。5)地形辐合(边界层辐合带)叠加在移入的切变系统上,使风场气旋式切变增强,D(散度)值大幅度降低,ζ(涡度)值大幅度增加,垂直上升运动加强,促成了弱对流向强对流演变;同时辐合线附近冷暖空气交替,使得条件不稳定能量增加,促进暖湿气流加速上升,产生梵净山景区强雷电天气。

A strong lightning weather happened in Fanjing Mountain scenic area of northeastern Guizhou on November 5, 2011, and led 34 tourists to encounter different degrees of lightning damage. By using location lightning data, weather maps, radar satellite data, sounding data, the lightning character- istics of lightning accident and the formation causes of lightning weather were analyzed and the results were as follows： 1 ） When lightning accident occurs, lightning density is small, but positive lightning strength reaches 259 kA, which in the winter of this area belongs to little probability events with 2/10000. 2） The mountains and metal objects on mountain act as lightning carrier, mountain is completely struc- ture of stone, lightning protection facilities is not perfect, strong lightning can＇ t diffusion, so the direct lightning stroke injury happened. 3 ） Ball lightning generates by complex atmospheric electric field, which can＇ t normally discharge when grounding, so it explodes, and divides into an amount of ball light- ning which flies to every direction and hurts people. 4） The 500 hPa fluctuating flow and 850 hPa weak shear provides the weather conditions, but the level of high altitude elements and the associated convec- tion parameter are smaller, which can not reach the strong convection generated conditions. 5） Topo- graphic convergence （the boundary layer convergence zone） is superimposed on the immigrant shear sys- tem, so that the wind filed cyclonic shear is strengthened, D （divergence） value is reduced greatly, and ξ（vortex） value is increased substantially, vertical convection is strengthened, and the convective is con- tributed from weak to strong. At the same time the cold and warm air alternate near the convergence line, making the conditional instability energy increase and the warm moist air rise quickly, so Fanjing Moun- tain scenic area happen strong lightning weather.