DOI: 10.1029/2018JA025497
Scopus记录号: 2-s2.0-85052483327
论文题名: Electron Flux Enhancements at L = 4.2 Observed by Global Positioning System Satellites: Relationship With Solar Wind and Geomagnetic Activity
作者: Zhang X.-J. ; Mourenas D. ; Artemyev A.V. ; Angelopoulos V. ; Thorne R.M.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 8 起始页码: 6189
结束页码: 6206
语种: 英语
英文关键词: chorus waves
; electron energization
; electron flux enhancements
; GPS satellites
; radiation belt
; solar wind and geomagnetic activities
英文摘要: Determining solar wind and geomagnetic activity parameters most favorable to strong electron flux enhancements is an important step toward forecasting radiation belt dynamics. Using electron flux measurements from Global Positioning System satellites at L = 4.2 in 2009–2016, we seek statistical relationships between flux enhancements at different energies and solar wind dynamic pressure Pdyn, AE, and Kp, from hundreds of events inside and outside the plasmasphere. Most ≥1-MeV electron flux enhancements occur during nonstorm (or weak storm) times. Flux enhancements of 4-MeV electrons outside the plasmasphere occur during periods of low Pdyn and high AE. We perform superposed epoch analyses of Global Positioning System electron fluxes, along with solar wind and geomagnetic indices, 40-keV electron flux, ultralow frequency (ULF) wave index from Geostationary Operational Environmental Satellite, and chorus wave intensity from the Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms mission. We demonstrate that 4-MeV electron flux enhancements outside the plasmasphere start when the interplanetary magnetic field (Bz) reaches a minimum and develop during periods of low Pdyn, high AE, low but increasing Dst, moderate ULF wave index, and intense chorus waves. Flux enhancements at 100 keV occur under conditions with higher Pdyn, higher ULF wave index, and elevated 40-keV electron flux at L = 6.6. Moreover, electron flux enhancements take much more time to develop at higher energies. This suggests that 100-keV flux enhancements are dominated by injections, while MeV electron energization is predominantly induced by chorus waves with further amplification by inward transport. ©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/113315
Appears in Collections: 气候减缓与适应
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作者单位: Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, United States; Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, United States; CEA, DAM, DIF, Arpajon, France
Recommended Citation:
Zhang X.-J.,Mourenas D.,Artemyev A.V.,et al. Electron Flux Enhancements at L = 4.2 Observed by Global Positioning System Satellites: Relationship With Solar Wind and Geomagnetic Activity[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(8)