气候变化领域集成服务门户(CCPortal): Alfvénic Acceleration Sustains Ganymede's Footprint Tail Aurora

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DOI	10.1029/2019GL086527
	Alfvénic Acceleration Sustains Ganymede's Footprint Tail Aurora
	Szalay J.R.; Allegrini F.; Bagenal F.; Bolton S.J.; Bonfond B.; Clark G.; Connerney J.E.P.; Ebert R.W.; Gershman D.J.; Giles R.S.; Gladstone G.R.; Greathouse T.; Hospodarsky G.B.; Imai M.; Kurth W.S.; Kotsiaros S.; Louarn P.; McComas D.J.; Saur J.; Sulaiman A.H.; Wilson R.J.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:3
英文摘要	Integrating simultaneous in situ measurements of magnetic field fluctuations, precipitating electrons, and ultraviolet auroral emissions, we find that Alfvénic acceleration mechanisms are responsible for Ganymede's auroral footprint tail. Magnetic field perturbations exhibit enhanced Alfvénic activity with Poynting fluxes of ~100 mW/m2. These perturbations are capable of accelerating the observed broadband electrons with precipitating fluxes of ~11 mW/m2, such that Alfvénic power is transferred to electron acceleration with ~10% efficiency. The ultraviolet emissions are consistent with in situ electron measurements, indicating 13 ± 3 mW/m2 of precipitating electron flux. Juno crosses flux tubes with both upward and downward currents connected to the auroral tail exhibiting small-scale structure. We identify an upward electron conic in the downward current region, possibly due to acceleration by inertial Alfvén waves near the Jovian ionosphere. In concert with in situ observations at Io's footprint tail, these results suggest that Alfvénic acceleration processes are broadly applicable to magnetosphere-satellite interactions. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Electrons; Ionosphere; Magnetic fields; Magnetosphere; Acceleration mechanisms; Electron acceleration; Electron measurements; In-situ observations; Magnetic field fluctuations; Magnetic field perturbations; Small-scale structures; Ultraviolet emission; Acceleration; acceleration; aurora; electromagnetic field; electron; in situ measurement; integrated approach; ionosphere; magnetic field; magnetosphere; precipitation (climatology); satellite; Aurora [Central Luzon]
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170750
作者单位	Department of Astrophysical Sciences, Princeton University, Princeton, NJ, United States; Southwest Research Institute, San Antonio, TX, United States; Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, United States; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, United States; Space Sciences, Technologies and Astrophysics Research Institute, LPAP, Université de Liège, Liège, Belgium; Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States; Space Research Corporation, Annapolis, MD, United States; Goddard Space Flight Center, Greenbelt, MD, United States; Department of Physics and Astronomy, University of Iowa, Iowa City, IA, United States; Institut de Recherche en Astrophysique et Planétologie, Toulouse, France; Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany
推荐引用方式 GB/T 7714	Szalay J.R.,Allegrini F.,Bagenal F.,et al. Alfvénic Acceleration Sustains Ganymede's Footprint Tail Aurora[J],2020,47(3).
APA	Szalay J.R..,Allegrini F..,Bagenal F..,Bolton S.J..,Bonfond B..,...&Wilson R.J..(2020).Alfvénic Acceleration Sustains Ganymede's Footprint Tail Aurora.Geophysical Research Letters,47(3).
MLA	Szalay J.R.,et al."Alfvénic Acceleration Sustains Ganymede's Footprint Tail Aurora".Geophysical Research Letters 47.3(2020).