Modeling the Simultaneous Dropout of Energetic Electrons and Protons by Magnetopause Shadowing
Modeling the Simultaneous Dropout of Energetic Electrons and Protons by Magnetopause Shadowing
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DOI：
10.1029/2023gl106681
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发表时间：
2024-01
影响因子：
5.2
通讯作者：
X. Lyu;Weichao Tu;Jinbei Huang;Qianli Ma;Zhi‐Gu Li
中科院分区：
文献类型：
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作者：
X. Lyu;Weichao Tu;Jinbei Huang;Qianli Ma;Zhi‐Gu Li
磁层顶遮蔽效应（MPS）可以驱动辐射带电子和环流质子的同时脱落。然而，其在两种血浆群体脱落中的相对作用尚未得到很好的量化。在这项工作中，我们研究了在2017年5月强烈的地磁风暴期间MeV电子和100 keV质子的同时脱落。使用具有事件特异性最后闭合漂移壳的径向扩散模型来模拟两个群体的MPS损失。该模型很好地捕捉到了两个群体在L* > 4.6时的快速遮蔽损失，而在L* < 4.6时的损失（可能是由于电磁离子回旋波散射）没有被捕捉到。该模型较好地再现了初始损失阶段电子通量的蝶形俯仰角分布。在低俯仰角的初始质子损失被低估，也可能由其他机制，如场线曲率散射。
Magnetopause shadowing (MPS) effect could drive a concurrent dropout of radiation belt electrons and ring current protons. However, its relative role in the dropout of both plasma populations has not been well quantified. In this work, we study the simultaneous dropout of MeV electrons and 100s keV protons during an intense geomagnetic storm in May 2017. A radial diffusion model with an event‐specific last closed drift shell is used to simulate the MPS loss of both populations. The model well captures the fast shadowing loss of both populations at L* > 4.6, while the loss at L* < 4.6, possibly due to the electromagnetic ion cyclotron wave scattering, is not captured. The observed butterfly pitch angle distributions of electron fluxes in the initial loss phase are well reproduced by the model. The initial proton losses at low pitch angles are underestimated, potentially also contributed by other mechanisms such as field line curvature scattering.