DOI: 10.1029/2018JA025292
Scopus记录号: 2-s2.0-85050387532
论文题名: Carriers and Sources of Magnetopause Current: MMS Case Study
作者: Dong X.-C. ; Dunlop M.W. ; Wang T.-Y. ; Cao J.-B. ; Trattner K.J. ; Bamford R. ; Russell C.T. ; Bingham R. ; Strangeway R.J. ; Fear R.C. ; Giles B.L. ; Torbert R.B.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 7 起始页码: 5464
结束页码: 5475
语种: 英语
英文关键词: current carriers
; current sources
; magnetopause current
; two-fluid MHD
英文摘要: We investigate the current carriers and current sources of an ion scale tangential magnetopause current layer using the Magnetospheric Multiscale four spacecraft data. Within this magnetopause current layer, ions and electrons equally contribute to the perpendicular current, while electrons carry nearly all the parallel current. The energy range of all these current carriers is predominantly from middle to high (>100 eV), where particles with higher energies are more efficient in producing the current. By comparing each term, two-fluid magnetohydrodynamic (MHD) theory is able to describe the current sources to a large degree because the sum of all the perpendicular currents from MHD theory could account for the currents observed. In addition, we find that the ion diamagnetic current is the main source of the total perpendicular current, while the curvature current can be neglected. Nevertheless, ions and electrons both carry comparable current due to the redistribution of the electric field and show features beyond the classic Chapman-Ferraro model, particularly on the front side of the boundary layer where the electric field reversal is most intense. We also show a second, comparative event in which ions do not satisfy MHD theory, while the electrons do. The small-scale, adiabatic parameter (square of curvature radius/gyroradius) supports our interpretation that this second event contains ion scale substructure. We suggest that comparing the predicted MHD current with plasma current can be a good method to judge whether the MHD theory is satisfied in each specific circumstance, especially for high-precision Magnetospheric Multiscale data. ©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/113648
Appears in Collections: 气候减缓与适应
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作者单位: School of Space and Environment, Beihang University, Beijing, China; RAL Space, STFC, Oxfordshire, United Kingdom; LASP University of Colorado, Boulder, CO, United States; Department of Earth, Planetary and Space Sciences, UCLA, Los Angeles, CA, United States; Department of Physics and Astronomy, University of Southampton, Southampton, United Kingdom; NASA Goddard Space Flight Center, Greenbelt, MD, United States; Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, United States; Southwest Research Institute, San Antonio, TX, United States
Recommended Citation:
Dong X.-C.,Dunlop M.W.,Wang T.-Y.,et al. Carriers and Sources of Magnetopause Current: MMS Case Study[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(7)