Energetic Electron Precipitation Associated With Pulsating Aurora Observed by VLF Radio Propagation During the Recovery Phase of a Substorm on 27 March 2017
Energetic Electron Precipitation Associated With Pulsating Aurora Observed by VLF Radio Propagation During the Recovery Phase of a Substorm on 27 March 2017
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2017 年 3 月 27 日亚暴恢复阶段 VLF 无线电传播观测到的与脉动极光相关的高能电子降水
DOI：
10.1029/2018gl080222
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发表时间：
2018
影响因子：
5.2
通讯作者：
Shinohara I.
中科院分区：
文献类型：
--
作者：
Tsuchiya F.;Hirai A.;Obara T.;Misawa H.;Kurita S.;Miyoshi Y.;Shiokawa K.;Connors M.;Ozaki M.;Kasahara Y.;Kumamoto A.;Kasaba Y.;Matsuoka A.;Shoji M.;Shinohara I.
最近的研究表明，能量高达几百keV的电子沉淀到与脉动极光（PsA）相关的大气中。人们一直在争论与PsA相关的沉淀电子的最高能量。在这里，我们首次报道了能量扩展到相对论能量。在2017年3月27日发生的一次亚暴期间，THEMIS全天成像仪观测到了PsA。高能电子沉淀是通过甚低频亚层传播探测到的。我们发现，当PsA发生在射电路径上时，极光强度和接收到的无线电信号强度的扰动之间存在相似的时间变化。扰动恢复时间较短，约为2 s。恢复时间表示由于高能电子沉淀引起的电离层修饰的松弛，并取决于电子的停止高度。恢复时间要求停止高度为50 ~ 60 km，表明PsA伴随着相对论性电子沉淀。
Recent studies suggest that electrons with energies up to several hundred keV precipitate into the atmosphere associated with pulsating aurora (PsA). It is debated the highest energy of precipitating electrons associated with PsA. Here we report for the first time that the energy extends to relativistic energies. PsA was observed by THEMIS all‐sky imagers during a substorm that occurred on 27 March 2017. Energetic electron precipitation was detected by very low frequency subionospheric propagation. We found similar time variations between the auroral intensity and perturbation of the received radio signal intensity when the PsA occurred on the radio path. The perturbation showed a short recovery time of ~2 s. The recovery time indicates relaxation from ionospheric modification due to energetic electron precipitation and depends on the stopping altitude of the electrons. The recovery time required a stopping altitude of 50–60 km and indicates that the PsA is accompanied by relativistic electron precipitation.