海南岛低压槽类天气系统雷达回波和地闪特征分析

Analysis of Radar Echo and CG Lightning Characteristics under the Weather System of Low Pressure Trough in Hainan Island

采用20142018年68月海口多普勒雷达、闪电定位、海南省天气分型等数据资料,分析海南岛分别在西南低压槽、南海低压槽、华南沿海槽影响下40 dBZ回波伸展到0℃层高度的概率,0℃层上强度≥40 dBZ的回波面积,地闪次数与0℃层上强度≥40 dBZ的回波面积比值,地闪次数及地闪发生概率等变量的时空分布特征,结果表明:(1)0℃层上强度≥40 dBZ的回波面积与地闪次数呈正相关。(2)午后40 dBZ回波伸展到0℃层高度的概率与地闪发生概率呈正相关。(3)午后40 dBZ回波伸展到0℃层高度的概率中心与地闪发生概率中心完全重合。(4)在华南沿海槽影响下,0℃层上强度≥40 dBZ的回波面积最大,同时地闪次数最多,午后地闪发生概率中心分布在以海口市南部为中心的海南岛东北部内陆。(5)在南海低压槽影响下,40 dBZ回波伸展到0℃层高度的概率最高,同时午后地闪发生概率最高,午后地闪发生概率中心分布在以儋州市南部为中心的海南岛西北部内陆。(6)在西南低压槽影响下,午后40 dBZ回波伸展到0℃层高度的概率、0℃层上强度≥40 dBZ的回波面积、地闪发生概率、地闪次数等指标在3种天气分型中最低,午后地闪发生概率中心分布在以澄迈县南部为中心的海南岛北部内陆。

ccording to the data of Haikou Doppler radar,lightning location,Hainan weather typing in JuneAugust,20142018,the spatial and temporal distribution characteristics of related variables of radar and CG lightning in Hainan island under the influence of low-pressure trough weather are analyzed.The results are as follows:(1)The echo area with intensity≥40 dBZ at the 0℃layer is positively correlated with the number of CG lightning.(2)In the afternoon,the probability for the 40 dBZ echo to reach the height of 0℃is positively correlated with the occurrence probability of CG lightning.(3)The afternoon probability center of 40 dBZ echo reaching the height of 0℃layer coincides completely with the occurrence probability center of CG lightning.(4)Influenced by the south China coastal trough,the echo area with the intensity≥40 dBZ at the 0℃layer is the largest and,at the same time,the number of CG lightning is the highest.The occurrence probability center of the afternoon CG lightning is distributed in the northeast inland of Hainan Island,centered on the south of Haikou.(5)Affected by the south China Sea trough,the probability of that the 40 dBZ echo reaching gets to the height of 0℃layer is the largest.Meanwhile and the occurrence probability of the afternoon CG lightning is the largest,with the occurrence probability center of afternoon CG lightning is distributed in the northwest inland of Hainan Island,centered on with the south of Danzhou as the center.(6)Under the impact enfluenced by of the southwest low pressure trough,in the afternoon,the probability that for the 40 dBZ echo to reaches the height of 0℃,the echo area with intensity≥40 dBZ on at the 0℃layer,the occurrence probability of CG lightning and the number of CG lightning are the lowest among the three weather types.The occurrence probability center of the afternoon CG lightning is distributedlies in the northern inland of Hainan Island,centered on with the south of Chengmai county as the center.