Parallel Acceleration of Suprathermal Electrons Caused by Whistler‐Mode Hiss Waves
Parallel Acceleration of Suprathermal Electrons Caused by Whistler‐Mode Hiss Waves
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DOI：
10.1029/2019gl085562
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发表时间：
2019-11
影响因子：
5.2
通讯作者：
Jinxing Li;Q. Ma;J. Bortnik;Wen Li;X. An;G. Reeves;H. Funsten;H. Spence;D. Baker;W. Kurth;G. Hospodarsky;D. Hartley
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文献类型：
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作者：
Jinxing Li;Q. Ma;J. Bortnik;Wen Li;X. An;G. Reeves;H. Funsten;H. Spence;D. Baker;W. Kurth;G. Hospodarsky;D. Hartley
内磁层中的超热电子（~0.1-10 keV）通常以90°峰值俯仰角分布观察到，这是由于第一和第二绝热不变量在从等离子体片传输时守恒而形成的。利用货车艾伦探针测量了一种特殊的场向超热电子（FASE）分布，其中平行流强比垂直流强1个数量级.这些FASE被发现与大振幅嘶嘶波密切相关，并在朗道共振能量附近观察到。我们证明，使用准线性扩散模拟，嘶嘶声波可以迅速加速超热电子通过朗道共振，并创建所观察到的FASE人口。所提出的机制可能具有广泛的影响，超热电子动力学以及哨声模式波在地球的磁层，并已被证明在木星的磁层。
Suprathermal electrons (~0.1–10 keV) in the inner magnetosphere are usually observed in a 90°‐peaked pitch angle distribution, formed due to the conservation of the first and second adiabatic invariants as they are transported from the plasma sheet. We report a peculiar field‐aligned suprathermal electron (FASE) distribution measured by Van Allen Probes, where parallel fluxes are 1 order of magnitude higher than perpendicular fluxes. Those FASEs are found to be closely correlated with large‐amplitude hiss waves and are observed around the Landau resonant energies. We demonstrate, using quasilinear diffusion simulations, that hiss waves can rapidly accelerate suprathermal electrons through Landau resonance and create the observed FASE population. The proposed mechanism potentially has broad implications for suprathermal electron dynamics as well as whistler mode waves in the Earth's magnetosphere and has been demonstrated in the Jovian magnetosphere.