Rapid recharge and descent of thundercloud core producing gamma-ray glow

Wada, Yuki*; Wu, T.*; Kamogawa, Makoto*; Wang, D.*; Okada, Go*; Nanto, Hidehito*; Sawano, Tatsuya*; Kubo, Mamoru*; Yonetoku, Daisuke*; Diniz, G. Z.*; Tsuchiya, Harufumi 

We report two gamma-ray glows observed on December 22, 2023, during a winter thunderstorm in Japan, using an array of four radiation detectors. The first glow, detected by one sensor, was quenched by a lightning discharge. The second glow appeared 2-3 minutes later and was tracked by three other detectors. Radar observations suggest both glows originated from the same thundercloud cell. However, the detection timing of the second glow was inconsistent with simple thundercloud movement, indicating temporal variations in intrinsic glow brightness. A three-dimensional lightning mapping observation suggests that a discharge activity depleted the electric field that generated the first glow, and that the electric field having produced the second glow has been rapidly recovered. In addition, the radar observations also detected a descent of the thundercloud core between the two glows, which may have developed an electrified region and the second glow enough to be observed by the detectors. Tracking gamma-ray glows is crucial for understanding electrified regions in thunderclouds and associated gamma-ray glows.