基于多资料的超强台风“彩虹”(2015)闪电活动与雷达回波特征分析

Analysis of Lightning Activity and Radar Echo Characteristics of Super Typhoon Mujigae (2015) Based on Multi-Source Data

关键词:  超强台风  彩虹  闪电活动  ENTLS  GPM/DPR

Key words:  super typhoon  Mujigae  lightning  ENTLS  GPM/DPR

摘要:

利用地球网络全闪系统(ENTLS)资料、CMA-STI 热带气旋最佳路径集的台风数据和 GPM(GlobalPrecipitation Measurement)/DPR(Dual-frequency Precipitation Radar)卫星资料，分析超强台风“彩虹”全生命期的闪电活动和雷达回波特征。(1) 增强阶段 TC 呈现出明显的三圈结构特征，内核区(0～80 km)存在一个闪电密集区，内雨带(80～160 km)内少有闪电活动，大于 160 km 的外围雨带的闪电活动又显著增加。(2) 径向分布随时间的变化指出，内核闪电与外雨带闪电的活跃期不一致；在台风最大风速达到峰值的前 1 h，内核闪电活动爆发；闪电密度于生成阶段 10月 2日 15时在 320 km附近达到峰值。(3) 径向分布随强度的变化表明，内核区闪电主要出现在超强台风等级，内雨带的闪电活动仅在热带风暴和强热带风暴级别有体现。外雨带的闪电活动，不同等级 TC展现的活跃区域不同，且随着 TC强度的增强，活跃区沿径向方向向外移动；强度减弱，闪电活动区域沿径向向里缩小至 160～400 km。(4) 闪电活动和雷达回波参数关系表明，零度层高度超过 5 km为彩虹台风闪电发生的前提条件，且回波顶高至少要发展到 10 km 以上，混相层中有过冷水或大冰晶粒子，才有利于闪电的发生。

Abstract:

Utilizing data from the Earth Networks Total Lightning System (ENTLS), typhoon data from the CMA Tropical Cyclone Best Track Dataset, and GPM / DPR satellite data, this study analyzed lightning activity and radar echo characteristics throughout the lifecycle of Super Typhoon Mujigae. The findings indicate that: (1) During its intensification, the typhoon exhibited a distinct triple-ring structure, with a dense lightning zone in the inner core (0-80 km), sparse lightning activity in the inner rainband (80-160 km), and significantly increased lightning activity in the outer rainband extending beyond 160 km. (2) Temporal changes in the radial distribution reveal asynchronous inner core and outer rainband lightning activity. A surge in inner core lightning activity occurred one hour before the typhoon reached its peak wind speed. This surge peaked in terms of lightning density within a 320 km radius at 15:00 on October 2, 2015, during the genesis process. (3) Changes in intensity-related radial distribution show that inner core lightning primarily occurred in super typhoons, inner rainband lightning was evident only in tropical storms and strong tropical storms.Outer rainband lightning activity was showed different active regions of varying intensities. Moreover, as TC intensity increased, the outer rainband lightning activity expanded radially outward, and the area of lightning activity shrinks radial inward to 160-400 km range when the TC intensity decreases. (4) The relationship between lightning activity and radar echo parameters reveals that a zero-degree layer height exceeding 5 km was a prerequisite for the lightning of Typhoon Mujigae, and a cloud top height of at least 10 km was necessary for the upward transport of ice-water mixtures. The presence of supercooled water or large ice crystals in the mixed-phase layer was found to be conducive to lightning occurrence.