DOI: 10.1002/2017JA025095
Scopus记录号: 2-s2.0-85047504511
论文题名: Formation of Dawn-Dusk Asymmetry in Earth's Magnetotail Thin Current Sheet: A Three-Dimensional Particle-In-Cell Simulation
作者: Lu S. ; Pritchett P.L. ; Angelopoulos V. ; Artemyev A.V.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 4 起始页码: 2801
结束页码: 2814
语种: 英语
英文关键词: dawn-dusk asymmetry
; Hall effect
; magnetic reconnection
; magnetotail
; particle-in-cell simulation
; thin current sheet
英文摘要: Using a three-dimensional particle-in-cell simulation, we investigate the formation of dawn-dusk asymmetry in Earth's magnetotail. The magnetotail current sheet is compressed by an external driving electric field down to a thickness on the order of ion kinetic scales. In the resultant thin current sheet (TCS) where the magnetic field line curvature radius is much smaller than ion gyroradius, a significant portion of the ions becomes unmagnetized and decoupled from the magnetized electrons, giving rise to a Hall electric field Ez and an additional cross-tail current jy caused by the unmagnetized ions being unable to comove with the electrons in the Hall electric field. The Hall electric field transports via E × B drift magnetic flux and magnetized plasma dawnward, causing a reduction of the current sheet thickness and the normal magnetic field Bz on the duskside. This leads to an even stronger Hall effect (stronger jy and Ez) in the duskside TCS. Thus, due to the internal kinetic effects in the TCS, namely, the Hall effect and the associated dawnward E × B drift, the magnetotail dawn-dusk asymmetry forms in a short time without any global, long-term effects. The duskside preference of reconnection and associated dynamic phenomena (such as substorm onsets, dipolarizing flux bundles, fast flows, energetic particle injections, and flux ropes), which has been pervasively observed by spacecraft in the past 20 years, can thus be explained as a consequence of this TCS asymmetry. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114119
Appears in Collections: 气候减缓与适应
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作者单位: Department of Earth, Planetary, and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA, United States; Department of Physics and Astronomy, University of California, Los Angeles, CA, United States; Space Research Institute, RAS, Moscow, Russian Federation
Recommended Citation:
Lu S.,Pritchett P.L.,Angelopoulos V.,et al. Formation of Dawn-Dusk Asymmetry in Earth's Magnetotail Thin Current Sheet: A Three-Dimensional Particle-In-Cell Simulation[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(4)