Rapid enhancement of low-energy (&lt; 100eV) ion flux in response to   interplanetary shocks based on two Van Allen Probes case studies:   Implications for source regions and heating mechanisms

doi:10.1002/2016JA022808

CORC > 北京大学 > 地球与空间科学学院

	Rapid enhancement of low-energy (< 100eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms
	Yue, Chao ; Li, Wen ; Nishimura, Yukitoshi ; Zong, Qiugang ; Ma, Qianli ; Bortnik, Jacob ; Thorne, Richard M. ; Reeves, Geoffrey D. ; Spence, Harlan E. ; Kletzing, Craig A. ; Wygant, John R. ; Nicolls, Michael J.
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
	2016
关键词	enhancement of low-energy ion flux response to IP shocks adiabatic accelerations ionospheric ion outflows DAWN-DUSK ASYMMETRY INNER MAGNETOSPHERE GEOSYNCHRONOUS ORBIT IMAGER OBSERVATIONS CYCLOTRON WAVES MAGNETIC-FIELD SUBSTORMS WIND ENERGIZATION LOCATION
DOI	10.1002/2016JA022808
英文摘要	Interactions between interplanetary (IP) shocks and the Earth's magnetosphere manifest many important space physics phenomena including low-energy ion flux enhancements and particle acceleration. In order to investigate the mechanisms driving shock-induced enhancement of low-energy ion flux, we have examined two IP shock events that occurred when the Van Allen Probes were located near the equator while ionospheric and ground observations were available around the spacecraft footprints. We have found that, associated with the shock arrival, electromagnetic fields intensified, and low-energy ion fluxes, including H+, He+, and O+, were enhanced dramatically in both the parallel and perpendicular directions. During the 2 October 2013 shock event, both parallel and perpendicular flux enhancements lasted more than 20min with larger fluxes observed in the perpendicular direction. In contrast, for the 15 March 2013 shock event, the low-energy perpendicular ion fluxes increased only in the first 5min during an impulse of electric field, while the parallel flux enhancement lasted more than 30min. In addition, ionospheric outflows were observed after shock arrivals. From a simple particle motion calculation, we found that the rapid response of low-energy ions is due to drifts of plasmaspheric population by the enhanced electric field. However, the fast acceleration in the perpendicular direction cannot solely be explained by ExB drift but betatron acceleration also plays a role. Adiabatic acceleration may also explain the fast response of the enhanced parallel ion fluxes, while ion outflows may contribute to the enhanced parallel fluxes that last longer than the perpendicular fluxes.; NASA Living With a Star Jack Eddy Postdoctoral Fellowship Program; NASA [NNX15AI62G, NNX13AI61G, NNX14AI18G, NAS5-01072]; NSF [PLR-1341359, AGS-1405054, 1564510]; AFOSR [FA9550-15-1-0179]; SCI(E); ARTICLE; yuechao@atmos.ucla.edu; 7; 6430-6443; 121
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/456987]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Yue, Chao,Li, Wen,Nishimura, Yukitoshi,et al. Rapid enhancement of low-energy (< 100eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2016.
APA	Yue, Chao.,Li, Wen.,Nishimura, Yukitoshi.,Zong, Qiugang.,Ma, Qianli.,...&Nicolls, Michael J..(2016).Rapid enhancement of low-energy (< 100eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS.
MLA	Yue, Chao,et al."Rapid enhancement of low-energy (< 100eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS (2016).