DOI: 10.1029/2018JA025277
Scopus记录号: 2-s2.0-85046408708
论文题名: An Empirical Model of Radiation Belt Electron Pitch Angle Distributions Based On Van Allen Probes Measurements
作者: Zhao H. ; Friedel R.H.W. ; Chen Y. ; Reeves G.D. ; Baker D.N. ; Li X. ; Jaynes A.N. ; Kanekal S.G. ; Claudepierre S.G. ; Fennell J.F. ; Blake J.B. ; Spence H.E.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 5 起始页码: 3493
结束页码: 3511
语种: 英语
英文关键词: empirical model
; geomagnetic storms
; inner belt and slot region
; pitch angle distribution
; radiation belt electrons
英文摘要: Based on over 4 years of Van Allen Probes measurements, an empirical model of radiation belt electron equatorial pitch angle distribution (PAD) is constructed. The model, developed by fitting electron PADs with Legendre polynomials, provides the statistical PADs as a function of L-shell (L = 1–6), magnetic local time, electron energy (~30 keV to 5.2 MeV), and geomagnetic activity (represented by the Dst index) and is also the first empirical PAD model in the inner belt and slot region. For megaelectron volt electrons, model results show more significant day-night PAD asymmetry of electrons with higher energies and during disturbed times, which is caused by geomagnetic field configuration and flux radial gradient changes. Steeper PADs with higher fluxes around 90° pitch angle and lower fluxes at lower pitch angles for higher-energy electrons and during active times are also present, which could be due to electromagnetic ion cyclotron wave scattering. For hundreds of kiloelectron volt electrons, cap PADs are generally present in the slot region during quiet times and their energy-dependent features are consistent with hiss wave scattering, while during active times, cap PADs are less significant especially at outer part of slot region, which could be due to the complex energizing and transport processes. The 90°-minimum PADs are persistently present in the inner belt and appear in the slot region during active times, and minima at 90° pitch angle are more significant for electrons with higher energies, which could be a critical evidence in identifying the underlying physical processes responsible for the formation of 90°-minimum PADs. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113935
Appears in Collections: 气候减缓与适应
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作者单位: Laboratory for Atmospheric and Space Sciences, University of Colorado Boulder, Boulder, CO, United States; Los Alamos National Laboratory, Los Alamos, NM, United States; The New Mexico Consortium, Los Alamos, NM, United States; Goddard Space Flight Center, NASA, Greenbelt, MD, United States; Space Sciences Department, The Aerospace Corporation, El Segundo, CA, United States; Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, United States
Recommended Citation:
Zhao H.,Friedel R.H.W.,Chen Y.,et al. An Empirical Model of Radiation Belt Electron Pitch Angle Distributions Based On Van Allen Probes Measurements[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(5)