Depletions of Multi-MeV Electrons and Their Association to Minima in Phase Space Density.
Depletions of Multi-MeV Electrons and Their Association to Minima in Phase Space Density.
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DOI：
10.1029/2021gl097620
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发表时间：
2022-04-28
影响因子：
5.2
通讯作者：
Wang, D.
中科院分区：
文献类型：
--
作者：
Drozdov, A. Y.;Allison, H. J.;Shprits, Y. Y.;Usanova, M. E.;Saikin, A.;Wang, D.
与电磁离子回旋(EMIC)波相互作用产生的快速局域电子损失会在相空间密度(PSD)径向分布中产生加深的极小值。在这里，我们对局部PSD最小值进行统计分析，以量化这些最小值与辐射带耗竭的关联程度。将一年来观测到的PSD极小值的统计数据与通用的电子辐射带(VERB)模拟进行了比较，其中包括和排除了EMIC波。观测到的极小值分布只能在包括EMIC波的模拟中获得，这表明它们在辐射带动力学中的重要性。通过结合观测到的PSD极小值分析电子通量损耗，我们发现，在外辐射带(L和Lt；5)的中心，平均有53%的多MeV电子损耗与PSD极小值有关，这表明与EMIC波相互作用的快速局域损失是极端相对论电子布居的一个常见而关键的过程。通常在一年的观测中观察到功率谱密度极小值，这表明多MeV电子的快速局域损失的主要作用。仅当平均包括EMIC波时，模型年才再现了与观测值相同的μ和K范围内功率谱密度极小值的分布。53%的低于L**=0.5(α等式；75°)的多MeV磁通损耗与功率谱密度极小值有关
Fast‐localized electron loss, resulting from interactions with electromagnetic ion cyclotron (EMIC) waves, can produce deepening minima in phase space density (PSD) radial profiles. Here, we perform a statistical analysis of local PSD minima to quantify how readily these are associated with radiation belt depletions. The statistics of PSD minima observed over a year are compared to the Versatile Electron Radiation Belts (VERB) simulations, both including and excluding EMIC waves. The observed minima distribution can only be achieved in the simulation including EMIC waves, indicating their importance in the dynamics of the radiation belts. By analyzing electron flux depletions in conjunction with the observed PSD minima, we show that, in the heart of the outer radiation belt (L* < 5), on average, 53% of multi‐MeV electron depletions are associated with PSD minima, demonstrating that fast localized loss by interactions with EMIC waves are a common and crucial process for ultra‐relativistic electron populations. PSD minima are commonly observed throughout a year of observations, indicating a major role of fast‐localized losses of multi‐MeV electrons A modeled year reproduces the distribution of PSD minima over the same range of μ and K as observations only when EMIC waves are included On average, 53% of multi‐MeV flux depletions below L* = 5 (αeq < 75 °) are associated with PSD minima