Banded electron structure formation in the inner magnetosphere
Banded electron structure formation in the inner magnetosphere
复制标题
内磁层中带状电子结构的形成
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
J. Kozyra
中科院分区：
文献类型：
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作者：
M. Liemohn;G. Khazanov;J. Kozyra
在能量-时间谱图中，在磁层内部观察到带状电子结构与地磁活动的突然松弛同时发生。在这项研究中，这些带状结构的形成是用一个全局的、弹跳平均的电子传输模型来考虑的，并得出结论，当等离子体片电子在地球附近的封闭漂移路径上被捕获时，这种结构是自然发生的，随后是一段超过一天的延长的安静时间。除非捕获等离子体层电子，否则这些带不会出现；沿着开放漂移路径绕地球一周的对流没有时间发展这一特征。由于梯度曲率漂移的优先平流，高能量带从注入种群中分离出来，在keV以上的能量分布中产生尖峰，这些尖峰重叠形成一系列的能量带。最低的波段是在亚keV能量范围内注入的大部分人口。利用观测到的带状结构事件的Kp历史，捕获了等离子体片电子云，并对其分布函数的形成进行了研究。
Banded electron structures in energy‐time spectrograms have been observed in the inner magnetosphere concurrent with a sudden relaxation of geomagnetic activity. In this study, the formation of these banded structures is considered with a global, bounce‐averaged model of electron transport, and it is concluded that this structure is a natural occurrence when plasma sheet electrons are captured on closed drift paths near the Earth followed by an extended period of quiet time for more than a day. These bands do not appear unless there is capture of plasma sheet electrons; convection along open drift paths making one pass around the Earth do not have time to develop this feature. The separation of high‐energy bands from the injected population due to the preferential advection of the gradient‐curvature drift creates spikes in the energy distribution above a keV, which overlap to form a series of bands in energy. The lowest band is the bulk of the injected population in the sub‐keV energy range. Using the Kp history for an observed banded structure event, a cloud of plasma sheet electrons is captured and the formation of their distribution function is examined.