Mirror modes in the Earth's magnetosheath: Results from a global hybrid‐Vlasov simulation
Mirror modes in the Earth's magnetosheath: Results from a global hybrid‐Vlasov simulation
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DOI：
10.1002/2015ja022026
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发表时间：
2016-05
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通讯作者：
S. Hoilijoki;M. Palmroth;B. Walsh;Y. Pfau‐Kempf;S. von Alfthan;U. Ganse;O. Hannuksela;R. Vainio
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文献类型：
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作者：
S. Hoilijoki;M. Palmroth;B. Walsh;Y. Pfau‐Kempf;S. von Alfthan;U. Ganse;O. Hannuksela;R. Vainio
我们使用全局动力学 Vlasiator 模拟研究地球磁鞘中的镜像模式结构，该模拟通过分布函数对离子行为进行建模，并将电子视为电荷中和流体。我们跟踪波沿着速度流线平流穿过磁鞘时的演变。我们发现，镜像模式波优先在准垂直磁鞘中沿速度流线观察到，该速度流线进入前震 ULF 波边界附近的鞘，其中等离子体中有足够的初始扰动使镜像模式生长，并且等离子体特性比磁鞘中的其他地方更好地满足镜像不稳定条件。我们测试了先前研究定义的选择标准，并表明镜面模式发生的空间范围范围从太阳下点准垂直侧的大部分磁鞘到非常小的孤立区域，具体取决于标准。
We investigate mirror mode structures in the Earth's magnetosheath using our global kinetic Vlasiator simulation, which models ion behavior through their distribution function and treats electrons as a charge‐neutralizing fluid. We follow the evolution of waves as they advect along velocity streamlines through the magnetosheath. We find that mirror mode waves are observed preferentially in the quasi‐perpendicular magnetosheath along velocity streamlines that enter the sheath in the vicinity of the foreshock ULF wave boundary where there are enough initial perturbations in the plasma for the mirror modes to grow, and the plasma properties fulfill the mirror instability condition better than elsewhere in the magnetosheath. We test selection criteria defined by previous studies and show that the spatial extent over which mirror modes occur ranges from much of the magnetosheath on the quasi‐perpendicular side of the subsolar point to very small isolated regions depending on the criteria.