A Tale of Two Radiation Belts: The Energy‐Dependence of Self‐Limiting Electron Space Radiation
A Tale of Two Radiation Belts: The Energy‐Dependence of Self‐Limiting Electron Space Radiation
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DOI：
10.1029/2021gl095779
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发表时间：
2021-10
影响因子：
5.2
通讯作者：
L. Olifer;I. Mann;A. Kale;B. Mauk;S. Claudepierre;D. Baker;H. Spence;L. Ozeke
中科院分区：
文献类型：
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作者：
L. Olifer;I. Mann;A. Kale;B. Mauk;S. Claudepierre;D. Baker;H. Spence;L. Ozeke
在磁暴期间，地球货车艾伦带中的高能电子通量会发生数量级的变化。在这里，我们展示了这些电子的动力学是如何被能量清楚地分成两个不同的群体，这两个群体由不同的风暴时间行为所控制。我们揭示了Kennel和Petschek（1966）理论上描述的自限制过程如何控制电子的能量相关动力学。https：//doi.org/10.1029/JZ071i001p00001。对于地球磁暴，能量低于10850 keV的加速电子很快达到最大能量依赖的微分通量水平，这在每次磁暴中几乎是相同的。较高能量的电子通常不会达到极限通量，而是受到竞争加速和损耗机制的不同影响的控制。一般来说，电子通量首先在较低能量下达到Kennel-Petschek极限，然后在风暴中撞击较高能量。对于最强烈的风暴，通量上限的最大能量也会增加。
The flux of energetic electrons in the terrestrial Van Allen Belts varies by orders of magnitude during a magnetic storm. Here, we show how the dynamics of these electrons are clearly separated by energy into two distinct populations which are governed by different storm time behavior. We reveal how self‐limiting processes, described theoretically by Kennel and Petschek (1966), https://doi.org/10.1029/JZ071i001p00001, govern the energy‐dependent dynamics of the electrons. For terrestrial magnetic storms, accelerated electrons with energies below ∼ 850 keV quickly reach a maximum energy‐dependent differential flux level which is almost the same in every storm. Higher energy electrons typically do not reach a limiting flux and instead are governed by the differential impacts of competing acceleration and loss mechanisms. In general, electron fluxes saturate at the Kennel‐Petschek limit first at lower energies, impacting higher energies later in the storm. For the most intense storms, the maximum energy at which the fluxes are capped can also increase.