Butterfly distribution of Earth's radiation belt relativistic electrons induced by dayside chorus
Butterfly distribution of Earth's radiation belt relativistic electrons induced by dayside chorus
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日边合唱引起的地球辐射带相对论电子的蝶形分布
DOI：
10.1007/s11431-017-9067-y
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Fuliang Xiao
中科院分区：
文献类型：
--
作者：
Jin YuYue;Yang Chang;He YiHua;Liu Si;Zhou QingHua;Fuliang Xiao
以往的理论研究表明，昼侧合唱可以通过优先加速中等俯仰角的电子，在地球辐射带中产生蝴蝶分布的高能电子，但这需要高分辨率卫星观测的进一步证实。在这里，我们报告相关的货车艾伦探测器数据的波和粒子在2014年4月11日至13日的磁暴。我们发现在L = 4.52附近形成了相对论电子的蝶形俯仰角分布，对应于增强的昼侧合唱的存在。利用高斯分布拟合观测到的合唱谱，我们计算的反弹平均扩散率和解决二维福克-普朗克方程。数值结果表明，利用昼侧合唱加速产生的电子通量在能量和蝶形俯仰角分布上的演化与观测结果相当，为甚低频（VLF）等离子体波驱动下相对论电子蝶形分布的形成提供了进一步的证据.
Previous theoretical studies have shown that dayside chorus can produce butterfly distribution of energetic electrons in the Earth’s radiation belts by preferentially accelerating medium pitch angle electrons, but this requires the further confirmation from high-resolution satellite observation. Here, we report correlated Van Allen Probes data on wave and particle during the 11–13 April, 2014 geomagnetic storm. We find that a butterfly pitch angle distribution of relativistic electrons is formed around the locationL= 4.52, corresponding to the presence of enhanced dayside chorus. Using a Gaussian distribution fit to the observed chorus spectra, we calculate the bounce-averaged diffusion rates and solve two-dimensional Fokker-Planck equation. Numerical results demonstrate that acceleration by dayside chorus can yield the electron flux evolution both in the energy and butterfly pitch angle distribution comparable to the observation, providing a further evidence for the formation of butterfly distribution of relativistic electrons driven by very low frequency (VLF) plasma waves.