气候变化领域集成服务门户(CCPortal): Episodic Occurrence of Field-Aligned Energetic Ions on the Dayside

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DOI	10.1029/2019GL086384
	Episodic Occurrence of Field-Aligned Energetic Ions on the Dayside
	Yue C.; Bortnik J.; Zou S.; Nishimura Y.; Foster J.C.; Coppeans T.; Ma Q.; Zong Q.; Hull A.J.; Henderson M.; Reeves G.D.; Spence H.E.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:2
英文摘要	The tens of kiloelectron volt ions observed in the ring current region at L ~ 3–7 generally have pancake pitch angle distributions, that is, peaked at 90°. However, in this study, by using the Van Allen Probe observations on the dayside, unexpectedly, we have found that about 5% time, protons with energies of ~30 to 50 keV show two distinct populations, having an additional field-aligned population overlapping with the original pancake population. The newly appearing field-aligned populations have higher occurrence rates at ~12–16 magnetic local time during geomagnetically active times. In particular, we have studied eight such events in detail and found that the source regions are located around 12 to 18 magnetic local time which coincides with our statistical result. Based on the ionospheric and geosynchronous observations, it is suggested that these energetic ions with field-aligned pitch angle distributions probably are accelerated near postnoon in association with ionospheric disturbances that are triggered by tail injections. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Ionospheric electromagnetic wave propagation; Ionospheric measurement; Energetic ion; field-aligned PADs; Ionospheric disturbance; Magnetic local time; Pitch angle distribution; Ring currents; Source region; Ions; day length; electron; electron probe analysis; energetics; geomagnetism; ion; ionosphere
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/170815
作者单位	Institute of Space Physics and Applied Technology, Peking University, Beijing, China; Department of Atmospheric and Oceanic Sciences, UCLA, Los Angeles, CA, United States; Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, United States; Center for Space Physics, Boston University, Boston, MA, United States; Haystack Observatory, Massachusetts Institute of Technology, Westford, MA, United States; Space Sciences Laboratory, University of California, Berkeley, CA, United States; Space Science and Applications Group, Los Alamos National Laboratory, Los Alamos, NM, United States; Space Sciences Division, New Mexico Consortium, Los Alamos, NM, United States; Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, United States
推荐引用方式 GB/T 7714	Yue C.,Bortnik J.,Zou S.,et al. Episodic Occurrence of Field-Aligned Energetic Ions on the Dayside[J],2020,47(2).
APA	Yue C..,Bortnik J..,Zou S..,Nishimura Y..,Foster J.C..,...&Spence H.E..(2020).Episodic Occurrence of Field-Aligned Energetic Ions on the Dayside.Geophysical Research Letters,47(2).
MLA	Yue C.,et al."Episodic Occurrence of Field-Aligned Energetic Ions on the Dayside".Geophysical Research Letters 47.2(2020).