Termination of Electron Acceleration in Thundercloud by Intracloud/Intercloud Discharge
Termination of Electron Acceleration in Thundercloud by Intracloud/Intercloud Discharge
复制标题
云内/云间放电终止雷云中的电子加速
DOI：
10.1029/2018gl077784
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发表时间：
2018
影响因子：
5.2
通讯作者：
Tsuchiya H.
中科院分区：
文献类型：
--
作者：
Wada Y.;Bowers G. S.;Enoto T.;Kamogawa M.;Nakamura Y.;Morimoto T.;Smith D. M.;Furuta Y.;Nakazawa K.;Yuasa T.;Matsuki A.;Kubo M.;Tamagawa T.;Makishima K.;Tsuchiya H.
通过测量伽马射线辐射、大气电场和低频无线电频段，对日本海沿岸冬季雷暴中的高能大气现象进行了地面观测。 2017 年 2 月 11 日，辐射探测器记录到持续 75 秒的伽马射线发射，然后因附近的闪电放电而突然终止。伽马射线谱延伸至 20 MeV，并通过截止幂律模型再现，光子指数为 ，与雷雨云的轫致辐射一致（称为伽马射线辉光或雷暴地面增强）。安装在距伽马射线观测站约 50 公里处的低频无线电监测仪记录了云内/云间放电的主要发展，该放电分布在约 60 公里的区域内，持续时间约 300 毫秒。伽马射线终止的时间与云内/云间放电的先导发展经过距辐射监测器水平 0.7 公里的时刻一致。云内/云间放电开始于距伽马射线观测点约 15 公里处。因此，辉光因先导发展而终止，但在本例中并未引发闪电放电。
An on‐ground observation program for high‐energy atmospheric phenomena in winter thunderstorms along the Japan Sea has been performed via measurements of gamma ray radiation, atmospheric electric field, and low‐frequency radio band. On 11 February 2017, the radiation detectors recorded gamma ray emission lasting for 75 s, and then abruptly terminated with a nearby lightning discharge. The gamma ray spectrum extended up to 20 MeV and was reproduced by a cutoff power law model with a photon index of , being consistent with Bremsstrahlung radiation from a thundercloud (known as a gamma‐ray glow or a thunderstorm ground enhancement). The low‐frequency radio monitors, installed ∼50 km away from the gamma ray observation site recorded leader development of an intracloud/intercloud discharge spreading over ∼60 km area with a ∼300‐ms duration. The timing of the gamma ray termination coincided with the moment when the leader development of the intracloud/intercloud discharge passed 0.7 km horizontally away from the radiation monitors. The intracloud/intercloud discharge started ∼15 km away from the gamma ray observation site. Therefore, the glow was terminated by the leader development, while it did not trigger the lightning discharge in the present case.