The Potential Role of Modified Electron Acoustic Wave and Nonlinear Mode Coupling in Mono‐Energetic Aurora
The Potential Role of Modified Electron Acoustic Wave and Nonlinear Mode Coupling in Mono‐Energetic Aurora
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DOI：
10.1029/2022gl102680
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发表时间：
2023-05
影响因子：
5.2
通讯作者：
R. Shi;Jun Liang;Zejun Hu;D. Han;Xia Li
中科院分区：
文献类型：
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作者：
R. Shi;Jun Liang;Zejun Hu;D. Han;Xia Li
一维动力学模拟的结果首次揭示了修饰电子声波（MEAW）在极光电子加速中的重要作用。在磁层和电离层的过渡区，由于动力学Alfven波（KAWs）和MEAWs之间的模式耦合而产生的平行电场，可以由来自磁层的Alfven波携带的连续能量输入来维持。在携带向上场向电流的长周期Alfven波的入射下，可以在过渡区形成平行的电位下降，导致单能电子加速。这种机制提供了剪切阿尔芬波与中尺度单能量极光电子加速之间的可能联系。
Results from a 1D kinetic simulation, for the first time, reveal the important role of modified electron acoustic wave (MEAW) in auroral electron acceleration. Parallel electric fields, generated due to the mode coupling between kinetic Alfven waves (KAWs) and MEAWs in the transition region from the magnetosphere and the ionosphere, can be sustained by continuous energy input carried by Alfven waves from the magnetosphere. Under the incidence of long‐period Alfven waves carrying upward field‐aligned currents, a parallel potential drop can be formed in the transition region, leading to mono‐energetic electron acceleration. Such a mechanism provides a possible link between shear Alfven waves and the mesoscale mono‐energetic auroral electron acceleration.