Positive Cloud-to-Ground Lightning Characteristics in the Eyewall of Typhoon Faxai (2019) Observed by Tokyo Lightning Mapping Array

• DOI: 10.2151/jmsj.2022-051
• Publication Date: 2022-09-14T22:10:00Z
• Authors: Namiko SAKURAI; Hironori FUDEYASU; Paul R. KREHBIEL; Ronald J. THOMAS; William RISON; Daniel RODEHEFFER
• Keywords: Typhoon; Lightning; Upper-atmospheric lightning; Storm Surge; Eye

Although a number of studies have been conducted the lightning activity in hurricanes and typhoons, little information has obtained on 3-dimensional structure lightning, or how it is related to precipitation structures within storms. Here we utilize observational data from 3-D Tokyo Lightning Mapping Array (Tokyo LMA), Japan Meteorological Agency C-band Doppler radar, Japanese Detection Network (JLDN) conduct study during Typhoon Faxai (2019) comparison with storm's structure. This done for dissipating stage typhoon, when eyewall was well range instruments undergoing surge activity. Of particular interest occurrence numerous positive cloud-to-ground (+CG) flashes. Detailed LMA JLDN show that, out 52 flashes surge, 29 56 % produced strokes ground, an unheard-of considering radar structures, storm appeared be normally-electrified, under such circumstances would produce negative rather than ground. It also focuses attention question +CGs are tropical cyclones first place. Based lack −CG observations showing that +CG mid-way toward end normal-polarity intracloud (IC) flashes, appears cells depleted horizontally-sheared mid-level charge, IC flash propagating into through upper charge effectively funnels steadily increasing amount initiation region, eventually causing breakdown turn downward producing stroke.