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arXiv · 1306.2388

Hardening and termination of long-duration gamma rays detected prior to lightning

H. Tsuchiya·T. Enoto·K. Iwata·S. Yamada·T. Yuasa·T. Kitaguchi·M. Kawaharada·K. Nakazawa·M. Kokubun·H. Kato·M. Okano·T. Tamagawa·K. Makishima
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Abstract

We report the first observation of 3$-$30 MeV prolonged gamma-ray emission that was abruptly terminated by lightning. The gamma-ray detection was made during winter thunderstorms on December 30, 2010 by the Gamma-Ray Observation of Winter THunderclouds (GROWTH) experiment carried out in a coastal area along the Sea of Japan. The gamma-ray flux lasted for less than 3 min, continuously hardening closer to the lightning occurrence. The hardening at energies of 3$-$10 MeV energies was most prominent. The gamma-ray flux abruptly ceased less than 800 ms before the lightning flash that occurred over 5 km away from the experimental site. In addition, we observed a clear difference in the duration of the 3$-$10 MeV gamma rays and those $>$10 MeV, suggesting that the area of $>$10 MeV gamma-ray emission is considerably smaller than that of the lower-energy gamma rays. This work may give a manifestation that a local region emitting prolonged gamma rays connects with a distant region to initiate lightning.

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H. Tsuchiya, T. Enoto, K. Iwata, S. Yamada, T. Yuasa, T. Kitaguchi, M. Kawaharada, K. Nakazawa, M. Kokubun, H. Kato, M. Okano, T. Tamagawa, K. Makishima. 2013-06-11. Hardening and termination of long-duration gamma rays detected prior to lightning. https://doi.org/10.1103/physrevlett.111.015001

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