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Title: Survey of radiation belt energetic electron pitch angle distributions based on the Van Allen Probes MagEIS measurements: Electron Pitch Angle Distributions

Journal Article · · Journal of Geophysical Research. Space Physics
DOI:https://doi.org/10.1002/2015JA021724· OSTI ID:1402597
 [1];  [1];  [2];  [3];  [3];  [4];  [5]
  1. Memorial Univ. of Newfoundland, St. John's, Newfoundland and Labrador (Canada)
  2. Wuhan Univ. (China). Dept. of Space Physics, School of Electronic Information
  3. Aerospace Corporation, El Segundo, CA (United States). Space Science Applications Lab.
  4. Univ. of New Hampshire, Durham, NH (United States)
  5. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
+ Show Author Affiliations

A statistical survey of electron pitch angle distributions (PADs) is performed based on the pitch angle-resolved flux observations from the Magnetic Electron Ion Spectrometer (MagEIS) instrument on board the Van Allen Probes during the period from 1 October 2012 to 1 May 2015. By fitting the measured PADs to a sinnα form, where α is the local pitch angle and n is the power law index, we investigate the dependence of PADs on electron kinetic energy, magnetic local time (MLT), the geomagnetic Kp index, and L shell. The difference in electron PADs between the inner and outer belt is distinct. In the outer belt, the common averaged n values are less than 1.5, except for large values of the Kp index and high electron energies. The averaged n values vary considerably with MLT, with a peak in the afternoon sector and an increase with increasing L shell. In the inner belt, the averaged n values are much larger, with a common value greater than 2. The PADs show a slight dependence on MLT, with a weak maximum at noon. A distinct region with steep PADs lies in the outer edge of the inner belt where the electron flux is relatively low. The distance between the inner and outer belt and the intensity of the geomagnetic activity together determine the variation of PADs in the inner belt. Finally, besides being dependent on electron energy, magnetic activity, and L shell, the results show a clear dependence on MLT, with higher n values on the dayside.

Research Organization:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
National Aeronautics and Space Administration (NASA); National Natural Science Foundation of China (NSFC); USDOE
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1402597
Report Number(s):
LA-UR-15-28231; TRN: US1702999
Journal Information:
Journal of Geophysical Research. Space Physics, Vol. 121, Issue 2; ISSN 2169-9380
Publisher:
American Geophysical UnionCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 21 works
Citation information provided by
Web of Science

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Cited By (3)

Determination of the Equatorial Electron Differential Flux From Observations at Low Earth Orbit journal November 2018
New Homogeneous Composite Of Energetic Electron Fluxes From POES: 2. Intercalibration of SEM‐1 and SEM‐2 journal July 2019
Effects of VLF Transmitter Waves on the Inner Belt and Slot Region journal July 2019

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Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
Heliospheric and Magnetospheric Physics
pitch angle distributions
Van Allen Probes