DOI: 10.1002/2017JA024838
Scopus记录号: 2-s2.0-85042329288
论文题名: Ion Acceleration Inside Foreshock Transients
作者: Liu T.Z. ; Lu S. ; Angelopoulos V. ; Lin Y. ; Wang X.Y.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 1 起始页码: 163
结束页码: 178
语种: 英语
英文关键词: ion foreshock
; kinetic phenomena
; particle acceleration
; shock processes
英文摘要: Recent observations upstream of Earth's bow shock have revealed that foreshock transients can not only accelerate solar wind ions by reflection at their upstream boundaries but may also accelerate ions inside them. Evidence for the latter comes from comparisons of ion spectra inside and outside the cores, and from evidence of leakage of suprathermal ions from the cores. However, definite evidence for, and the physics of, ion acceleration in the foreshock transients are still open questions. Using case studies of foreshock transients from Time History of Events and Macroscale Interactions during Substorms observations, we reveal an ion acceleration mechanism in foreshock transients that is applicable to ~25% of the transients. The ion energy flux is enhanced between several keV to tens of keV in the cores. We show that these energetic ions are reflected at the earthward moving boundary of foreshock transients, are accelerated through partial gyration along the convection electric field, and can leak out both upstream and downstream of the foreshock transients. Using ions moving self-consistently with a generic 3-D global hybrid simulation of a foreshock transient, we confirm this physical picture of ion acceleration and leakage. These accelerated ions could be further accelerated at the local bow shock and repopulate the foreshock, increasing the efficacy of solar wind-magnetosphere interactions. ©2017. 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/114790
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; Physics Department, Auburn University, Auburn, AL, United States
Recommended Citation:
Liu T.Z.,Lu S.,Angelopoulos V.,et al. Ion Acceleration Inside Foreshock Transients[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(1)