An explanation of auroral intensification during the substorm expansion   phase

doi:10.1002/2017JA024029

CORC > 北京大学 > 地球与空间科学学院

	An explanation of auroral intensification during the substorm expansion phase
	Yao, Zhonghua ; Rae, I. J. ; Lui, A. T. Y. ; Murphy, K. R. ; Owen, C. J. ; Pu, Z. Y. ; Forsyth, C. ; Grodent, D. ; Zong, Q.G. ; Du, A. M. ; Kalmoni, N. M. E.
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
	2017
关键词	substorm field-aligned current plasma sheet aurora magnetotail NEAR-EARTH TAIL MULTIPLE-ONSET SUBSTORMS PLASMA SHEET MAGNETIC-FIELD PSEUDO-BREAKUP FLOW BURSTS MAGNETOSPHERIC SUBSTORM DIPOLARIZATION FRONTS PARTICLE-ACCELERATION THEMIS OBSERVATIONS
DOI	10.1002/2017JA024029
英文摘要	A multiple auroral onset substorm on 28 March 2010 provides an opportunity to understand the physical mechanism in generating auroral intensifications during a substorm expansion phase. Conjugate observations of magnetic fields and plasma from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft, of field-aligned currents (FACs) from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) satellites, and from ground-based magnetometers and aurora are all available. The comprehensive measurements allow us to further our understanding of the complicated causalities among dipolarization, FAC generation, particle acceleration, and auroral intensification. During the substorm expansion phase, the plasma sheet expanded and was perturbed leading to the generation of a slow mode wave, which modulated electron flux in the outer plasma sheet. During this current sheet expansion, field-aligned currents formed, and geomagnetic perturbations were simultaneously detected by ground-based instruments. However, a magnetic dipolarization did not occur until about 3min later in the outer plasma sheet observed by THEMIS-A spacecraft (THA). We believe that this dipolarization led to an efficient Fermi acceleration to electrons and consequently the cause of a significant auroral intensification during the expansion phase as observed by the All-Sky Imagers (ASIs). This Fermi acceleration mechanism operating efficiently in the outer plasma sheet during the expansion phase could be a common explanation of the poleward auroral development after substorm onset. These results also show a good agreement between the upward FAC derived from AMPERE measurements and the auroral brightening observed by the ASIs.; NASA [NAS5-02099]; German Ministry for Economy and Technology; German Center for Aviation and Space (DLR) [50 OC 0302]; Canadian Space Agency; NSF of GIMNAST [AGS-1004736]; UK Science and Technology Facilities Council (STFC) at UCL/MSSL [ST/L005638/1]; STFC [ST/L000563/1]; National Environmental Research Council (NERC) [NE/L007495/1]; NERC [NE/L007495/1]; NSFC [41525016, 41404117]; European Union; SCI(E); ARTICLE; 8; 8560-8576; 122
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/471632]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Yao, Zhonghua,Rae, I. J.,Lui, A. T. Y.,et al. An explanation of auroral intensification during the substorm expansion phase[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2017.
APA	Yao, Zhonghua.,Rae, I. J..,Lui, A. T. Y..,Murphy, K. R..,Owen, C. J..,...&Kalmoni, N. M. E..(2017).An explanation of auroral intensification during the substorm expansion phase.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS.
MLA	Yao, Zhonghua,et al."An explanation of auroral intensification during the substorm expansion phase".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS (2017).