[M-IS24] Atmospheric electricity: High energy phenomena

[MIS24-01] Surface Electric-field Variations during Gamma-ray Glows in WInter Thunderstorms

★Invited Papers

*Yuuki Wada¹, Masashi Kamogawa², Mamoru Kubo³, Teruaki Enoto⁴, Syugo Hayashi⁵, Tatsuya Sawano³, Daisuke Yonetoku³, Harufumi Tsuchiya⁶ (1.Osaka University, 2.University of Shizuoka, 3.Kanazawa University, 4.Kyoto University, 5.Meteorological Research Insitute, 6.Japan Atomic Energy Agency)

Keywords:gamma-ray glow, high-energy atmospheric physics, atmospheric electric field

Strong electric fields in thunderclouds can accelerate electrons to relativistic energies, even in dense atmospheres, and cause a high-energy atmospheric phenomenon called gamma-ray glow. Due to the low-charge-center structures of winter thunderclouds in the Hokuriku region, it is possible to observe high-energy photons of a gamma-ray glow on the ground before they are absorbed by the atmosphere. From December 2020 to March 2021, we performed a simultaneous observation campaign of gamma rays and surface electric fields at the Kakuma Campus of Kanazawa University and detected a total of six gamma-ray glows. In all cases, the gamma-ray glows occurred in negative surface electric fields, five of which were observed in strong electric fields below -12 kV/m. It is suggested that the gamma-ray glows originated in a strong electric field formed between a developed negative-charge layer and a localized positive-charge layer underlying.