Burch J L, Webster J M, Genestreti K J, Torbert R B, Giles B L, Fuselier S A, Dorelli J C, Rager A C, Phan T D, Allen R C, Chen L-J, Wang S, Le Contel O, Russell C T, Strangeway R J, Ergun R E, Jaynes A N, Lindqvist P-A, Graham D B, Wilder F D, Hwang K-J, Goldstein J
Southwest Research Institute San Antonio TX USA.
Department of Physics and Astronomy Rice University Houston TX USA.
J Geophys Res Space Phys. 2018 Feb;123(2):1118-1133. doi: 10.1002/2017JA024789. Epub 2018 Feb 3.
This paper reports on Magnetospheric Multiscale observations of whistler mode chorus and higher-frequency electrostatic waves near and within a reconnection diffusion region on 23 November 2016. The diffusion region is bounded by crescent-shaped electron distributions and associated dissipation just upstream of the X-line and by magnetic field-aligned currents and electric fields leading to dissipation near the electron stagnation point. Measurements were made southward of the X-line as determined by southward directed ion and electron jets. We show that electrostatic wave generation is due to magnetosheath electron beams formed by the electron jets as they interact with a cold background plasma and more energetic population of magnetospheric electrons. On the magnetosphere side of the X-line the electron beams are accompanied by a strong perpendicular electron temperature anisotropy, which is shown to be the source of an observed rising-tone whistler mode chorus event. We show that the apex of the chorus event and the onset of electrostatic waves coincide with the opening of magnetic field lines at the electron stagnation point.
本文报道了2016年11月23日磁层多尺度卫星对哨声波合唱及更高频率静电波在重联扩散区附近及内部的观测结果。扩散区由X线正上游新月形电子分布及相关耗散界定，以及由磁场对齐电流和电场界定，这些电流和电场导致电子停滞点附近的耗散。测量是在由南向离子和电子喷流确定的X线南侧进行的。我们表明，静电波的产生是由于电子喷流与冷背景等离子体以及磁层中能量更高的电子群体相互作用形成的磁鞘电子束。在X线的磁层一侧，电子束伴随着强烈的垂直电子温度各向异性，这被证明是观测到的上升调哨声波合唱事件的源头。我们表明，合唱事件的顶点和静电波的起始与电子停滞点处磁力线的打开相吻合。
