DOI: 10.1002/2015GL063289
论文题名: Substorm current wedge composition by wedgelets
作者: Liu J. ; Angelopoulos V. ; Chu X. ; Zhou X.-Z. ; Yue C.
刊名: Geophysical Research Letters
ISSN: 0094-8846
EISSN: 1944-8577
出版年: 2015
卷: 42, 期: 6 起始页码: 1669
结束页码: 1676
语种: 英语
英文关键词: dipolarization front
; dipolarizing flux bundle
; field-aligned current
; substorm
; substorm current wedge
; wedgelet
Scopus关键词: Ionosphere
; Magnetosphere
; Plasma flow
; Superconducting materials
; Dipolarization
; Field aligned currents
; Flux bundles
; Substorms
; Wedgelet
; Magnetoplasma
; asymmetry
; magnetic field
; magnetosphere
; magnetotail
; polarization
; statistical analysis
; transport process
英文摘要: Understanding how a substorm current wedge (SCW) is formed is crucial to comprehending the substorm phenomenon. One SCW formation scenario suggests that the substorm time magnetosphere is coupled to the ionosphere via "wedgelets," small building blocks of an SCW. Wedgelets are field-aligned currents (FACs) carried by elemental flux transport units known as dipolarizing flux bundles (DFBs). A DFB is a magnetotail flux tube with magnetic field stronger than that of the ambient plasma. Its leading edge, known as a "dipolarization front" or "reconnection front," is a product of near-Earth reconnection. Dipolarizing flux bundles, and thus wedgelets, are localized - each is only <3 RE wide. How these localized wedgelets combine to become large-scale (several hours of magnetic local time) region-1-sense SCW FACs is unclear. To determine how this occurs, we investigated wedgelets statistically using Time History of Events and Macroscale Interactions during Substorms (THEMIS) data. The results show wedgelet asymmetries: in the dawn (dusk) sector of the magnetotail, a wedgelet has more FAC toward (away from) the Earth than away from (toward) the Earth, so the net FAC is toward (away from) the Earth. The combined effect of many wedgelets is therefore the same as that of large-scale region-1-sense SCW, supporting the idea that they comprise the SCW. Key Points Each dipolarization front (DF) carries asymmetric field-aligned currents (FACs) The net FAC of a DF in tail's dawn (dusk) sector is toward (away from) the Earth Many DFs together produce the region-1-sense FAC of a substorm current wedge ©2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84927780584&doi=10.1002%2f2015GL063289&partnerID=40&md5=6c7449191f743ce8f309ac5e58258b7d
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8462
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, Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA, United States
Recommended Citation:
Liu J.,Angelopoulos V.,Chu X.,et al. Substorm current wedge composition by wedgelets[J]. Geophysical Research Letters,2015-01-01,42(6).