A global synthesis model of dipolarization at substorm expansion onset

	A global synthesis model of dipolarization at substorm expansion onset
	Pu, ZY ; Korth, A ; Chen, ZX ; Liu, ZX ; Fu, SY ; Zong, G ; Hong, MH ; Wang, XM
刊名	JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
	2001-05-01
卷号	63 期号:7 页码:671-681
关键词	magnetospheric substorms dipolarization magnetic reconnection current disruption ballooning instability
ISSN号	1364-6826
文献子类	Article
英文摘要	In this paper, we describe a global synthesis dipolarization model combining coupled processes in the midtail, inner tail and auroral ionosphere: In the late growth phase, magnetic reconnection releases the magnetic energy stored in the magnetotail. Magnetic flux and energy are transported earthward and tailward. As earthward flow slows down in the near-earth plasma sheet (NEPS), it compresses the magnetic field acid plasmas near and earthward of the inner edge of the NEPS and pushes them further inward (earthward and equatorward). This sets up a favorable condition for generating the drift ballooning mode (DBM) instability in the inner tail. The unstable DBMs generate coupled Alfven-slow magnetosonic waves and field-aligned currents (FACs), resulting in a turbulent state in the equatorial region and enhancing the ionospheric conductance Sigma. As soon as Sigma and FACs increase to a threshold level, the substorm current wedge is formed, leading to an explosive intensification of the auroral electrojet and magnetic field dipolarization at substorm onset. Moreover, we regard the "substorm trigger phase" (Ohtani et al., Planet. Space Sci. 37 (1989) 579-588) as the interval during which the inner tail is being further compressed inward and the DBMs explosively develop to trigger magnetic field dipolarization. We suggest that the dawn-dusk electric field E-y which causes further compression of the inner tail may either be associated with flow braking, or produced by storm SSC and other magnetospheric processes. The present model is thus applicable to the cases either with or without neutral-line formation. Furthermore, in the former case, the enhanced E-y in the inner tail may either appear somewhat later than or simultaneously with magnetic reconnection in the midtail. It seems that a variety of expansion onset features can be explained in terms of this synthesis dipolarization model. (C) 2001 Elsevier Science Ltd. All rights reserved.
WOS关键词	NEAR-EARTH MAGNETOTAIL ; BALLOONING INSTABILITY ; CURRENT DISRUPTION ; CURRENT WEDGE ; PLASMA SHEET ; MAGNETOSPHERIC SUBSTORMS ; TAIL RECONNECTION ; FLOW ; WAVES ; IONOSPHERE
WOS研究方向	Geochemistry & Geophysics ; Meteorology & Atmospheric Sciences
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000168679300005
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/76855]
专题	中国科学院地质与地球物理研究所
通讯作者	Pu, ZY
作者单位	1.Peking Univ, Dept Geophys, Beijing 100871, Peoples R China 2.Chinese Acad Sci, Ctr Space Sci & Applicat Res, Space Weather Lab, Beijing, Peoples R China 3.Max Planck Inst Aeron, Katlenburg Lindau, Germany 4.Chinese Acad Sci, Inst Geophys, Beijing, Peoples R China 5.Inst Space Medicoengn, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Pu, ZY,Korth, A,Chen, ZX,et al. A global synthesis model of dipolarization at substorm expansion onset[J]. JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS,2001,63(7):671-681.
APA	Pu, ZY.,Korth, A.,Chen, ZX.,Liu, ZX.,Fu, SY.,...&Wang, XM.(2001).A global synthesis model of dipolarization at substorm expansion onset.JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS,63(7),671-681.
MLA	Pu, ZY,et al."A global synthesis model of dipolarization at substorm expansion onset".JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS 63.7(2001):671-681.