Global features of Kelvin-Helmholtz waves at the magnetopause for northward interplanetary magnetic field
Global features of Kelvin-Helmholtz waves at the magnetopause for northward interplanetary magnetic field
复制标题
向北行星际磁场磁层顶开尔文-亥姆霍兹波的整体特征
DOI：
10.1002/jgra.50498
复制
发表时间：
2013-08-01
影响因子：
2.8
通讯作者：
Lin, Dong
中科院分区：
文献类型：
--
作者：
Li, Wenya;Wang, Chi;Lin, Dong
利用全球磁流体模拟研究了恒定向北行星际磁场条件下低纬磁层顶开尔文-亥姆霍兹波(KHW)的全球特征。利用体积速度X分量的根积分功率(RIP)分析了KHW沿边界层的磁层顶模式。外KHW的RIP分布比内KHW宽得多，全球KHW的最大幅值出现在黎明/黄昏终止区附近。在日侧磁层顶，中纬度的波位相导致低纬的波位相，而夜侧的情况则相反。KHW相的全球演化代表了一个有趣的特征，即开尔文-亥姆霍兹涡旋的轴与地磁场线一致。我们认为，所报道的特征也可能存在于其他具有流动剪切等离子体的KHW活动区。
We investigate the global features of Kelvin-Helmholtz waves (KHW) at the low-latitude magnetopause for constant northward interplanetary magnetic field conditions, using global magnetohydrodynamic simulations. The root-integrated power (RIP) of X component of bulk velocity is employed to analyze the magnetopause mode of KHW along the boundary layer. The RIP distribution of the outer KHW is much broader than that of the inner one, and the maximum amplitude of global KHW occurs near the dawn/dusk terminator regions. In the dayside magnetopause, the phase of the waveform at middle latitudes leads to that at low latitudes, while the situation reversed in the nightside. The global evolution of KHW phases is a representation of an interesting feature that the axis of the Kelvin-Helmholtz vortex aligns with the geomagnetic field lines. We suggest that the reported features may also exist in other KHW active regions with flow-sheared plasma.