Lightning activity and its associations with cloud structures in a rainstorm yielding extreme precipitation

It is the data associated with the figures in the paper titiled "Lightning activity and its associations with cloud structures in a rainstorm yielding extreme precipitation" which is being in the process of submission. The following is the abstract of this paper. Lightning activity and its associations with cloud structures during a rainstorm dominated by warm cloud precipitation were studied in Guangdong, China on 7 May 2017, using three-dimensional lightning location and polarimetric radar data. The overall convection and lightning activities of the rainstorm were weak. The rainstorm generally showed a typical tripolar charge structure with the main negative charge core between about –15 and –8 °C levels in the first 4 hours, and the height of the charge regions was clearly decreased afterwards, with the main negative charge core being below approximately –8 °C level. The lightning discharges were more concentrated in areas featuring relatively weak convection and relatively low precipitation intensity. Most of the positions with lightning discharges were dominated by the dry aggregated snow and weak updrafts and downdrafts. The investigation showed that the lightning discharges spatially deviated from the charging origin area in this rainstorm. It was suggested that, with the weak convection in the rainstorm, the charging speed was slower than the speed of charge transfer from the origin area, causing relatively low charge density and then the low frequency of lightning in the charging origin area. Meanwhile, the aggregation of small charged particles in the regions away from the charging origin area might be conducive to the form of relatively large charge density and therefore the relatively frequent lightning flashes. This situation is different from a typical thunderstorm with strong convection.本数据集与一篇处于投稿阶段的论文《极端降水暴雨中的闪电活动及其与云结构的关联》中的配图数据相关。 以下为该论文的摘要： 2017年5月7日，针对中国广东地区一次以暖云降水为主的暴雨过程，本研究利用三维闪电定位（three-dimensional lightning location）与偏振雷达（polarimetric radar）观测数据，分析了该过程中的闪电活动及其与云结构的关联。本次暴雨的整体对流活动与闪电活动均较弱。该暴雨在初始4小时内整体呈现典型的三极性电荷结构（tripolar charge structure），主负电荷核心位于约-15℃至-8℃的高度层；此后电荷区高度显著降低，主负电荷核心下移至约-8℃高度层以下。闪电放电事件更多集中在对流相对较弱、降水强度相对较低的区域。多数闪电放电发生区域以干聚合雪粒子（dry aggregated snow）为主，且伴随较弱的上升与下沉气流。 研究发现，本次暴雨过程中的闪电放电在空间上偏离了电荷起电源区。分析表明，由于本次暴雨对流活动较弱，起电速率慢于电荷从起电源区的转移速度，导致起电源区电荷密度相对较低，进而闪电活动频次偏低。与此同时，远离起电源区的区域内带电小粒子的聚集，可能有利于形成较高的电荷密度，因此该区域闪电闪击相对频繁。该现象与典型强对流雷暴过程存在显著差异。