Catalog of gamma-ray glows during four winter seasons in Japan

Characteristics of Low‐Frequency Pulses Associated With Downward Terrestrial Gamma‐Ray Flashes

“…The positions of detectors and LF pulses associated with the TGFs reported by JLDN are presented in Figure 1. As reported in Wada et al (2021), 70 gamma-ray glows, another high-energy phenomenon in thunderstorms (Chilingarian et al, 2012;Kochkin et al, 2021;Torii et al, 2002;Tsuchiya et al, 2007;Wada et al, 2018), were detected at only the Kanazawa site, in contrast to three detections of downward TGFs in the same area and the same period. Besides the seven events, another one was detected at the Kanazawa site.…”

“…Besides the seven events, another one was detected at the Kanazawa site. It coincided with a termination of a gamma‐ray glow (Wada et al., 2021) and was followed by photonuclear reactions. However, it is not included in the analysis of the present paper because the detector system (phototubes and scintillation crystals) is different from the present study and we have to validate behavior against TGFs.…”

“…Multiple gamma‐ray detectors are installed in the Hokuriku region, a coastal area of Sea of Japan where low‐charge‐center winter thunderstorms frequently develop. In four winter seasons from 2016–2017 to 2019–2020 periods, up to 10 gamma‐ray monitors were deployed in Kanazawa area in Ishikawa Prefecture (Wada et al., 2021), and up to four detectors at Kashiwazaki‐Kariwa nuclear power plant of Tokyo Electric Power Company Holdings in Niigata Prefecture (Enoto et al., 2017). Among the gamma‐ray monitors, downward TGFs were detected by three monitors in Kanazawa (Kanazawa Izumigaoka High School, Kanazawa University High School, and Kanazawa University), and up to four monitors at the Kashiwazaki‐Kariwa nuclear power station.…”

“…The absolute timing accuracy is 100 μs in the 2016-2017 season and <1 μs in the other seasons if signals of the global positioning system (GPS) are properly received. Our observation network and detector system are described in Wada et al (2021) and Yuasa et al (2020).…”

“…Our observation network and detector system are described in Wada et al. (2021) and Yuasa et al. (2020).…”