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, and outer rainband lightning activity was observed in diverse areas across storms of varying intensities. Moreover, as storm intensity increased, the outer rainband lightning activity expanded radially outward, and it contracted to a 160~400 km range when the storm’s intensity abated. (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.