Evolution of Radiation Belt Electron Pitch Angle Distribution Due to Combined Scattering by Plasmaspheric Hiss and Magnetosonic Waves
Evolution of Radiation Belt Electron Pitch Angle Distribution Due to Combined Scattering by Plasmaspheric Hiss and Magnetosonic Waves
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DOI：
10.1029/2018gl081828
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发表时间：
2019-03
影响因子：
5.2
通讯作者：
M. Hua;B. Ni;Wen Li;X. Gu;S. Fu;R. Shi;Z. Xiang;Xing Cao;Wenxun Zhang;Yingjie Guo
中科院分区：
文献类型：
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作者：
M. Hua;B. Ni;Wen Li;X. Gu;S. Fu;R. Shi;Z. Xiang;Xing Cao;Wenxun Zhang;Yingjie Guo
磁声波和等离子体嘶嘶都能共振散射外辐射带电子，导致电子俯仰角分布的变化。基于电子扩散系数计算和二维Fokker - Planck扩散模拟，我们进行了参数化研究，定量研究了同时发生的不同波幅组合的hiss波和MS波的净电子散射效应和相对贡献。发现在L = 4处，当其振幅与MS波相当或更强时，由噪声发射引起的俯仰角散射主导了组合散射效应，从而产生了蝴蝶、顶帽、平顶和煎饼俯仰角分布，而当MS波加入组合散射效应时，蝴蝶分布可以在更宽的能量范围内演化。我们的结果表明，各种等离子体波的相对强度在控制辐射带电子动力学中起着至关重要的作用。
Both magnetosonic (MS) waves and plasmaspheric hiss can resonantly scatter outer radiation belt electrons, leading to various electron pitch angle distribution. Based on electron diffusion coefficients calculations and 2‐D Fokker‐Planck diffusion simulations, we perform a parametric study to quantitatively investigate the net electron scattering effect and the relative contributions of simultaneously occurring hiss and MS waves with groups of different wave amplitude combinations. It is found that the combined scattering effects are dominated by pitch angle scattering due to hiss emissions at L = 4, when their amplitude is comparable to or stronger than that of MS waves, thereby producing the butterfly, top‐hat, flat‐top, and pancake pitch angle distributions, while the butterfly distributions can evolve over a broader energy range when MS waves join the combined scattering effects. Our results demonstrate that the relative intensities of various plasma waves play an essential role in controlling the radiation belt electron dynamics.