Local Excitation of Whistler Mode Waves and Associated Langmuir Waves at Dayside Reconnection Regions
Local Excitation of Whistler Mode Waves and Associated Langmuir Waves at Dayside Reconnection Regions
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DOI：
10.1029/2018gl078287
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发表时间：
2018-09
影响因子：
5.2
通讯作者：
Jinxing Li;J. Bortnik;X. An;Wen Li;C. Russell;Meng Zhou;J. Berchem;Cong Zhao;Shan Wang;R. Torbert;O. Le Contel;R. Ergun;P. Lindqvist;C. Pollock;J. Burch
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文献类型：
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作者：
Jinxing Li;J. Bortnik;X. An;Wen Li;C. Russell;Meng Zhou;J. Berchem;Cong Zhao;Shan Wang;R. Torbert;O. Le Contel;R. Ergun;P. Lindqvist;C. Pollock;J. Burch
在地球白天的重联边界层中，哨声模波与磁场开口和由此产生的各向异性电子的形成相吻合。根据各向异性电子的能量范围，哨声可以在较高和/或较低频段的频率上生长。观测结果表明，哨声模波在沿X线传播时会调制朗缪尔波的振幅。哨声模波相和朗缪尔波包的观测以及符合电子测量表明，哨声模波可以通过朗道共振在E||与波传播方向相反的位置加速电子。加速的电子产生局域光束，随后驱动周期性调制的朗缪尔波。这两个波模的密切联系揭示了排气区的微尺度电子动力学，所提出的机制可能被用来解释在行星磁层和太阳风中观察到的调制事件。
In the Earth's dayside reconnection boundary layer, whistler mode waves coincide with magnetic field openings and the formation of the resultant anisotropic electrons. Depending on the energy range of anisotropic electrons, whistlers can grow at frequencies in the upper and/or lower band. Observations show that whistler mode waves modulate Langmuir wave amplitude as they propagate toward the X line. Observations of whistler mode wave phase and Langmuir waves packets, as well as coincident electron measurements, reveal that whistler mode waves can accelerate electrons via Landau resonance at locations where E||is antiparallel to the wave propagation direction. The accelerated electrons produce localized beams, which subsequently drive the periodically modulated Langmuir waves. The close association of those two wave modes reveals the microscale electron dynamics in the exhaust region, and the proposed mechanism could potentially be applied to explain the modulation events observed in planetary magnetospheres and in the solar wind.