The lower hybrid drift instability at the magnetopause
The lower hybrid drift instability at the magnetopause
复制标题
磁层顶的混合漂移不稳定性较低
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
A. Sgro
中科院分区：
文献类型：
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作者：
S. Gary;A. Sgro
当行星际磁场向北时，波粒交叉场传输可能有助于太阳风-磁层耦合。这里通过使用混合计算机模拟（粒子离子、非零质量的流体电子）来研究这种传输，在等离子体的 x-y 平面上进行，x 方向上有密度梯度，没有平均流速，磁场 B = B(x){cflx z}。在早期，较低的混合漂移不稳定性在等离子体梯度上增长。然而，与离子回旋周期相比，有时波动会在 y 方向上合并为更长的波长，并且会出现非扩散密度 x 剖面，其表现出与 ISEE 在磁层顶附近观察到的定性相似的平台和夹杂物。这些结果对这种不稳定性导致的跨场传输准线性理论的关键假设提出了质疑。
When the interplanetary magnetic field is northward, wave-particle cross-field transport may contribute to solar wind-magnetosphere coupling. Such transport is studied here through the use of hybrid computer simulations (particle ions, fluid electrons with nonzero mass) carried out in the x-y plane of plasma with a density gradient in the x direction, no average flow speed, and a magnetic field B = B(x){cflx z}. At early times, the lower hybrid drift instability grows on the plasma gradient. However, at times long compared to an ion gyroperiod, the fluctuations coalesce to longer wavelengths in the y-direction and nondiffusive density x-profiles emerge which exhibit plateaus and inclusions qualitatively similar to those observed by ISEE near the magnetopause. These results call into question critical assumptions of quasilinear theories of cross-field transport by this instability.