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

In 2015, the Gamma-Ray Observation of Winter Thunderstorms (GROWTH) collaboration launched a mapping observation campaign for high-energy atmospheric phenomena related to thunderstorms and lightning discharges. This has developed detection network gamma rays with up 10 radiation monitors installed in cities Kanazawa Komatsu, Ishikawa Prefecture, Japan, where low-charge-center winter frequently occur. During four seasons from October 2016 April 2020, total 70 gamma-ray glows, i.e., minute-lasting bursts originating thunderclouds, were detected. Their average duration is 58.9 s. Among detected events, 77% observed at night. The glows can be classified into temporally symmetric, asymmetric, lightning-terminated types based on their count-rate histories. An averaged energy spectrum well fitted power-law function an exponential cutoff, whose photon index, cutoff energy, flux are $0.613\ifmmode\pm\else\textpm\fi{}0.009$ MeV, $4.68\ifmmode\pm\else\textpm\fi{}0.04$ $(1.013\ifmmode\pm\else\textpm\fi{}0.003)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ erg ${\mathrm{cm}}^{\ensuremath{-}2}\phantom{\rule{0.16em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$ (0.2--20.0 MeV), respectively. present paper provides catalog statistical analysis during Komatsu areas.