DOI: 10.1002/2016GL069114
论文题名: Substorm onset: A switch on the sequence of transport from decreasing entropy to increasing entropy
作者: Chen C.X.
刊名: Geophysical Research Letters
ISSN: 0094-9729
EISSN: 1944-9460
出版年: 2016
卷: 43, 期: 10 起始页码: 4834
结束页码: 4840
语种: 英语
英文关键词: aurora arc
; bubble
; substorm
Scopus关键词: Magnetic flux
; Magnetosphere
; Plasma diagnostics
; Plasma sheaths
; Plasma stability
; Aurora arc
; Bubble
; Increasing functions
; Interchange instability
; Magnetic flux tube
; Plasma sheet
; Substorm onset
; Substorms
; Entropy
英文摘要: In this study, we propose a scenario about the trigger for substorm onset. In a stable magnetosphere, entropy is an increasing function tailward. However, in the growth phase of a substorm, a later born bubble has lower entropy than earlier born bubbles. When a bubble arrives at its final destination in the near-Earth region, it will spread azimuthally because of its relatively uniform entropy. The magnetic flux tubes of a dying bubble, which cause the most equatorward aurora thin arc, would block the later coming bubble tailward of them, forming an unstable domain. Therefore, an interchange instability develops, which leads to the collapse of the unstable domain, followed by the collapse of the stretched plasma sheet. We regard the substorm onset as a switch on the sequence of transport, i.e., from a decreasing entropy process to an increasing entropy process. We calculated the most unstable growth rates and the wavelengths of instability, and both are in agreement with observations. ©2016. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84971265082&doi=10.1002%2f2016GL069114&partnerID=40&md5=345c3b98611e16a1a9040f69a6d2c3af
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/10692
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: CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
Recommended Citation:
Chen C.X.. Substorm onset: A switch on the sequence of transport from decreasing entropy to increasing entropy[J]. Geophysical Research Letters,2016-01-01,43(10).