超强台风“威马逊”的地闪活动及大气电场特征

The ground flashing activity and atmospheric electric field characteristics of the super typhoon Weimason

利用海南省气象局在海南岛内布设的地闪定位网、海口地区组网大气平均电场仪及雷达对超强台风“威马逊”过程的监测资料,分析了该过程在海南岛过境(2014年18日12时至19日12时)时陆地及附近海域的地闪活动的时空分布特征。闪电监测结果显示,18日18时起,发生的地闪数目开始增多,至18日22时达到顶峰,至19日8时以前仍保持较强的频数。地电主要发生在东方市境内及近海,最大密度值出现于洋面,达到了4.7次/km^2(海面),陆地最大地闪密度为1.6次/km^2。通过对地面电场的演变特征分析来看,嵌于台风外围雨带里的对流云具有三极性电荷结构特征,这与大部分常规夏季雷暴云具有一致性。

The temporal and spatial distribution characteristics of land and adjacent sea areas during the transit of the super typhoon Wimason in Hainan Island (from 12:00 on 18th to 12:00 on 19th, 2014) are analyzed based on the monitoring data of the geostrophic positioning network, the average electric field meter in Haikou and the radar set up by the Hainan Provincial Meteorological Service. Lightning monitoring results show that the number of ground flashes began to increase from 6pm on the 18th, peaked at 10pm, and maintained a strong frequency until 8am on the 19th. Geoelectricity mainly occurred in Dongfang City and offshore waters. The maximum density appeared on the ocean surface, reaching 4.7 times/km^2 (sea surface), and the maximum land flash density is 1.6 times/km^2. According to the analysis of the evolution characteristics of the ground electric field, the convective cloud embedded in the rainband around typhoon has the characteristics of tripolar charge structure, which is consistent with most conventional summer thunderstorm clouds.