Multi-channel coupling of decay instability in three-dimensional low-beta plasma
Multi-channel coupling of decay instability in three-dimensional low-beta plasma
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DOI：
10.5194/angeo-37-835-2019
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发表时间：
2019-04
影响因子：
1.9
通讯作者：
H. Comişel;Y. Narita;U. Motschmann
中科院分区：
文献类型：
--
作者：
H. Comişel;Y. Narita;U. Motschmann
抽象的。已经进行了三维混合模拟来验证低β等离子体中大振幅Alfvén波的同时多通道衰减的假设，例如，在冲击波上游区域或日冕。倾斜传播的子模沿沿着垂直于平均磁场的方向以与由场对准衰减驱动的子模相同的平行波数和频率被激发。我们发现，波的横向谱是由低β等离子体中衰变过程的多通道耦合控制的，并且起源于剪切Alfvén波的色散态。
Abstract. Three-dimensional hybrid simulations have been carried out to verify the hypothesis of simultaneous multi-channel decay of a large-amplitude Alfvén wave in a low-beta plasma, e.g., in the shock-upstream region or the solar corona. Obliquely propagating daughter modes are excited along the perpendicular direction to the mean magnetic field at the same parallel wavenumbers and frequencies as the daughter modes driven by the field-aligned decay. We find that the transversal spectrum of waves is controlled by the multi-channel coupling of the decay process in low-beta plasmas and originates in the dispersion state of the shear Alfvén wave.