基于大气电场资料的雷电临近预警研究

通过分析深圳地区2012年6—9月17次雷暴过程的电场观测资料,并结合广东省闪电定位资料,发现当雷暴云移近电场仪测站时,在测站的防护区内(距测站10 km半径范围内),闪电发生前的电场幅值快速增加且伴随有快变抖动的现象,并且快变抖动和闪电的发生具有0-1化对应关系,即当有电场的快变抖动出现的情况下,电场达到一定阈值并维持一段时间后,防护区内发生闪电的可能性很大.因此根据大气电场的波形特征,提取出与闪电相关性较高的因子,利用多元回归技术建立一套预报方程,根据该预报方程得出最佳预警参数.结果表明:当大气电场阈值达到0.86 kV/m,且在10.73 min内电场能维持在阈值上,并伴随有电场的抖动时,在防护区内发生闪电的可能性很大,预警准确率达53%.

Lightning nowcasting based on electric field data

Through the atmospheric electric field data of 17 typical thunderstorm processes around Shenzhen recorded from June to Septemberof 2012,in combination with the lightning position data,we found very importantrelationship between the electrified variation and lightning strike occurrence.The amplitude of the electric field increases quickly accompanied bydithering when the thunderstorm cloud comes close to field instrument stations.The relationship between the electric field and the lightning stroke occurrence is 0-1,that is,when the electric field reaches and maintains a certain threshold for some time,the possibility of lightning is great in protection zone(within 10 km from electricfield station).Therefore,according to the characteristics of the atmospheric electric field waveform,predictors highly correlated with lightning are chosen,and a forecasting equation is established using multiple regression techniques.According to the equation,when the atmospheric electric field reachesthe threshold of 0.86 kV/m and maintains that value for a continuing of 10.73 minutes accompanied by electric field dithering,it can bepredicted that the lightning will occur within the range of 10 km from the station,with accuracy as high as 53%.