Magnetic mapping effects of substorm currents leading to auroral   poleward expansion and equatorward retreat

doi:10.1002/2014JA020596

CORC > 北京大学 > 地球与空间科学学院

	Magnetic mapping effects of substorm currents leading to auroral poleward expansion and equatorward retreat
	Chu, Xiangning ; McPherron, Robert L. ; Hsu, Tung-Shin ; Angelopoulos, Vassilis ; Pu, Zuyin ; Yao, Zhonghua ; Zhang, Hui ; Connors, Martin
刊名	journal of geophysical research space physics
	2015
关键词	substorm current wedge auroral poleward expansion mapping magnetic dipolarization CURRENT WEDGE MAGNETOSPHERIC SUBSTORMS GROWTH-PHASE DIPOLARIZATION FRONTS MODEL FIELD TAIL SIGNATURES ONSET
DOI	10.1002/2014JA020596
英文摘要	Magnetotail fast flows, magnetic field dipolarization, and its relaxation are linked to auroral brightening, poleward expansion, and equatorward motion during substorm onset, expansion, and recovery, respectively. While auroral brightening is often attributed to the field-aligned currents produced by flow vorticity and pressure redistribution, the physical causes of auroral poleward expansion and equatorward retreat are not fully understood. Simplistically, such latitudinal changes can be directly associated to the tailward motion of the flux pileup region and the earthward flux transport toward the dayside that depletes the near-Earth plasma sheet. However, because the equatorial magnetic field profile and the magnetospheric field-aligned current system change significantly, mapping is severely distorted. To investigate this distortion, we superimpose a substorm current wedge model (dynamically driven by ground-based observations) on the global Tsyganenko model T96 during an isolated substorm on 13 February 2008, observed by the Time History of Events and Macroscale Interactions during Substorms and GOES 10 spacecraft and by ground all-sky imagers. We validate our model by showing that the timing and ionospheric projection of the flux pileup region and flow bursts observed at the spacecraft match auroral activations. We then use the improved mapping enabled by the model to demonstrate that in this event, auroral poleward expansion and equatorward retreat are mainly caused by substorm-current-wedge-induced mapping changes.; Astronomy & Astrophysics; SCI(E); 1; ARTICLE; xnchu@igpp.ucla.edu; 1; 253-265; 120
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/206491]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Chu, Xiangning,McPherron, Robert L.,Hsu, Tung-Shin,et al. Magnetic mapping effects of substorm currents leading to auroral poleward expansion and equatorward retreat[J]. journal of geophysical research space physics,2015.
APA	Chu, Xiangning.,McPherron, Robert L..,Hsu, Tung-Shin.,Angelopoulos, Vassilis.,Pu, Zuyin.,...&Connors, Martin.(2015).Magnetic mapping effects of substorm currents leading to auroral poleward expansion and equatorward retreat.journal of geophysical research space physics.
MLA	Chu, Xiangning,et al."Magnetic mapping effects of substorm currents leading to auroral poleward expansion and equatorward retreat".journal of geophysical research space physics (2015).