Kelvin‐Helmholtz Waves and Magnetic Reconnection at the Earth's Magnetopause Under Southward Interplanetary Magnetic Field
Kelvin‐Helmholtz Waves and Magnetic Reconnection at the Earth's Magnetopause Under Southward Interplanetary Magnetic Field
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DOI：
10.1029/2023gl105539
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发表时间：
2023-10
影响因子：
5.2
通讯作者：
Tongkuai Li;Wenya Li;B. Tang;Y. Khotyaintsev;D. Graham;Akhtar Ardakani;J. Burch;D. Gershman-D.-Gershm
中科院分区：
文献类型：
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作者：
Tongkuai Li;Wenya Li;B. Tang;Y. Khotyaintsev;D. Graham;Akhtar Ardakani;J. Burch;D. Gershman-D.-Gershm
我们提出了一个K-H波事件在向南IMF条件下，伴随着持续的磁重联磁层多尺度（MMS）的观测。非线性K-H波的特征在于准周期波动、低密度和高速离子的存在以及前缘和后缘的边界法向量的变化。我们的观测通过识别Alfvénic离子喷流和高能磁层电子的逃逸揭示了正在进行的磁重联的明确证据。在这次事件中的36个磁层顶电流片交叉点中，有19个在前缘（7）和后缘（12）都表现出明确的重联特征。值得注意的是，在两个边缘的估计电流片厚度与离子惯性尺度相当，证实了K-H波的大尺度演化导致的压缩效应。重联喷流可能有助于通过边界层加宽和复杂的流动和磁场模式的发展抑制K-H增长。
We present Magnetospheric Multiscale (MMS) observations of a K‐H wave event under southward IMF conditions, accompanied by ongoing magnetic reconnection. The nonlinear K‐H waves are characterized by quasi‐periodic fluctuations, the presence of low‐density and high‐speed ions, and variations in the boundary normal vectors at both the leading and trailing edges. Our observations reveal clear evidence of on‐going magnetic reconnection through the identification of Alfvénic ion jets and the escape of energetic magnetospheric electrons. Among the 36 magnetopause current‐sheet crossings in this event, 19 exhibit unambiguous signatures of reconnection at both the leading (7) and trailing (12) edges. Notably, the estimated current‐sheet thicknesses at both edges are comparable to the ion‐inertial scale, confirming the compression effect resulting from the large‐scale evolution of the K‐H waves. The reconnection jets potentially contribute to the suppression of K‐H growth through boundary‐layer broadening and the development of complex flow and magnetic field patterns.