DOI: 10.1002/2016GL068984
论文题名: Observations of a new foreshock region upstream of a foreshock bubble's shock
作者: Liu T.Z. ; Hietala H. ; Angelopoulos V. ; Turner D.L.
刊名: Geophysical Research Letters
ISSN: 0094-9594
EISSN: 1944-9325
出版年: 2016
卷: 43, 期: 10 起始页码: 4708
结束页码: 4715
语种: 英语
英文关键词: foreshock bubbles
; ion foreshock
; kinetic phenomena
; shock processes
Scopus关键词: Ions
; Plasma shock waves
; Solar wind
; Earth's bow shock
; Electron foreshock region
; Kinetic phenomena
; Particle acceleration
; Shock acceleration
; Solar wind dynamic pressure
; Solar wind particles
; Transient phenomenon
; Earthquakes
; concentration (composition)
; electron
; foreshock
; ion
; magnetopause
; obliquity
; observational method
; particle motion
; solar wind
英文摘要: Earth's foreshock is a region within the solar wind upstream of Earth's bow shock filled with backstreaming solar wind particles reflected at the shock. Within this region, when the interplanetary field is approximately radial, foreshock bubbles (FBs) can be formed when the backstreaming particles interact with approaching discontinuities embedded in the solar wind. Foreshock bubbles can grow to 5–10 RE in scale, well upstream of the bow shock. Having a high concentration of thermalized upstream ions and slow, or even sunward, speeds within them, these transient phenomena deflect the solar wind by forming a new shock ahead of them. Although FBs eventually succumb to solar wind dynamic pressure and crash onto Earth's bow shock and magnetopause, they may last long enough to allow solar wind reflection at their own shocks, which forms a new FB foreshock region upstream of them. The FB shock may be of different obliquity than the parent bow shock providing new and diverse opportunities for particle acceleration. Using a case study from Time History of Events and Macroscale Interactions during Substorms, we demonstrate that ions and electrons are reflected at the FB shock, where they acquire energies consistent with shock acceleration theory. These are the first definitive observations of a new ion and electron foreshock region upstream of the FB shock with implications for shock acceleration in general. ©2016. American Geophysical Union. All Rights Reserved.
URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84970949893&doi=10.1002%2f2016GL068984&partnerID=40&md5=b71b646a6cea9afe8a4c4bda6256f57f
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/10557
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, United States
Recommended Citation:
Liu T.Z.,Hietala H.,Angelopoulos V.,et al. Observations of a new foreshock region upstream of a foreshock bubble's shock[J]. Geophysical Research Letters,2016-01-01,43(10).