Electron Dynamics in the Electron Current Sheet During Strong Guide‐Field Reconnection
Electron Dynamics in the Electron Current Sheet During Strong Guide‐Field Reconnection
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DOI：
10.1029/2023gl103046
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发表时间：
2023-05
影响因子：
5.2
通讯作者：
H.‐W. Wang;B. Tang;W. Li;Y.‐C. Zhang;D. Graham;Y. Khotyaintsev;C. Gao;X.‐C. Guo;C. Wang
中科院分区：
文献类型：
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作者：
H.‐W. Wang;B. Tang;W. Li;Y.‐C. Zhang;D. Graham;Y. Khotyaintsev;C. Gao;X.‐C. Guo;C. Wang
在这项研究中，我们研究了强引导场重联（归一化引导场为1.5）中的详细电子动力学。磁层多尺度（MMS）航天器在磁尾磁通绳的中心观测到了这种重连事件。由于在电子电流片中存在大的平行电场（E），电子在从一个方向流入该E区域时被加速，并且从另一个方向被减速。一些减速的电子可以将平行速度降低到100，以在电子电流片的一侧形成相对各向同性的电子分布，因为估计的加速电势满足关系式eΦ k ≥ kTe，k，其中Te，k是平行于磁场的电子温度。因此，产生大的E_p以平衡电子电流片上的平行电子压力梯度，因为电流片另一侧的电子仍然是各向异性的。在此基础上，我们进一步证明了电子β是重联中的一个重要参数，为解决重联中的大平行电场难题提供了新的视角.
In this study, we investigate detailed electron dynamics in strong guide‐field reconnection (the normalized guide field is ∼1.5). This reconnection event is observed by the Magnetospheric Multiscale (MMS) spacecraft at the center of a flux rope in the magnetotail. With the presence of a large parallel electric field (E‖) in the electron current sheet, electrons are accelerated when streaming into this E‖ region from one direction, and decelerated from the other direction. Some decelerated electrons can reduce the parallel speed to ∼0 to form relatively isotropic electron distributions at one side of the electron current sheet, as the estimated acceleration potential satisfies the relation eΦ‖ ≥ kTe,‖, where Te,‖ is the electron temperature parallel to the magnetic field. Therefore, a large E‖ is generated to balance the parallel electron pressure gradient across the electron current sheet, since electrons at the other side of the current sheet are still anisotropic. Based on these observations, we further show that the electron beta is an important parameter in guide‐field reconnection, providing a new perspective to solve the large parallel electric field puzzle in guide‐field reconnection.