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Title: Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions

Abstract

Here, we present observations of the radiation belts from the Helium Oxygen Proton Electron and Magnetic Electron Ion Spectrometer particle detectors on the Van Allen Probes satellites that illustrate the energy dependence and L shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on 1 March in more detail. The observations show the following: (a) at all L shells, lower energy electrons are enhanced more often than higher energies; (b) events that fill the slot region are more common at lower energies; (c) enhancements of electrons in the inner zone are more common at lower energies; and (d) even when events do not fully fill the slot region, enhancements at lower energies tend to extend to lower L shells than higher energies. During enhancement events the outer zone extends to lower L shells at lower energies while being confined to higher L shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L shells for lower energies. Both boundaries are nearly straight in log(energy) versus L shell space. At energies below a few 100 keV, radiation belt electron penetration through the slot region into the innermore » zone is commonplace, but the number and frequency of “slot filling” events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy- and L shell-dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.« less

Authors:
 [1];  [1];  [1];  [2];  [2];  [3];  [3];  [3];  [4];  [5];  [3];  [6]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); The New Mexico Consortium, Los Alamos, NM (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. The Aerospace Corporation, Los Angeles, CA (United States)
  4. The New Mexico Consortium, Los Alamos, NM (United States)
  5. Univ. of New Hampshire, Durham, NH (United States)
  6. Univ. of Colorado Boulder, Boulder, CO (United States)
Publication Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1255852
Report Number(s):
LA-UR-15-24562
Journal ID: ISSN 2169-9380
Grant/Contract Number:  
NAS5-01072; AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Volume: 121; Journal Issue: 1; Journal ID: ISSN 2169-9380
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Reeves, Geoffrey D., Friedel, Reiner H. W., Larsen, Brian A., Skoug, Ruth M., Funsten, Herbert O., Claudepierre, Seth G., Fennell, Joseph F., Turner, Drew L., Denton, Mick H., Spence, Harlan E., Blake, J. Bernard, and Baker, Daniel N. Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions. United States: N. p., 2016. Web. doi:10.1002/2015JA021569.
Reeves, Geoffrey D., Friedel, Reiner H. W., Larsen, Brian A., Skoug, Ruth M., Funsten, Herbert O., Claudepierre, Seth G., Fennell, Joseph F., Turner, Drew L., Denton, Mick H., Spence, Harlan E., Blake, J. Bernard, & Baker, Daniel N. Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions. United States. https://doi.org/10.1002/2015JA021569
Reeves, Geoffrey D., Friedel, Reiner H. W., Larsen, Brian A., Skoug, Ruth M., Funsten, Herbert O., Claudepierre, Seth G., Fennell, Joseph F., Turner, Drew L., Denton, Mick H., Spence, Harlan E., Blake, J. Bernard, and Baker, Daniel N. 2016. "Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions". United States. https://doi.org/10.1002/2015JA021569. https://www.osti.gov/servlets/purl/1255852.
@article{osti_1255852,
title = {Energy-dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions},
author = {Reeves, Geoffrey D. and Friedel, Reiner H. W. and Larsen, Brian A. and Skoug, Ruth M. and Funsten, Herbert O. and Claudepierre, Seth G. and Fennell, Joseph F. and Turner, Drew L. and Denton, Mick H. and Spence, Harlan E. and Blake, J. Bernard and Baker, Daniel N.},
abstractNote = {Here, we present observations of the radiation belts from the Helium Oxygen Proton Electron and Magnetic Electron Ion Spectrometer particle detectors on the Van Allen Probes satellites that illustrate the energy dependence and L shell dependence of radiation belt enhancements and decays. We survey events in 2013 and analyze an event on 1 March in more detail. The observations show the following: (a) at all L shells, lower energy electrons are enhanced more often than higher energies; (b) events that fill the slot region are more common at lower energies; (c) enhancements of electrons in the inner zone are more common at lower energies; and (d) even when events do not fully fill the slot region, enhancements at lower energies tend to extend to lower L shells than higher energies. During enhancement events the outer zone extends to lower L shells at lower energies while being confined to higher L shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L shells for lower energies. Both boundaries are nearly straight in log(energy) versus L shell space. At energies below a few 100 keV, radiation belt electron penetration through the slot region into the inner zone is commonplace, but the number and frequency of “slot filling” events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Energy- and L shell-dependent losses (that are consistent with whistler hiss interactions) return the belts to more quiescent conditions.},
doi = {10.1002/2015JA021569},
url = {https://www.osti.gov/biblio/1255852}, journal = {Journal of Geophysical Research. Space Physics},
issn = {2169-9380},
number = 1,
volume = 121,
place = {United States},
year = {Thu Jan 28 00:00:00 EST 2016},
month = {Thu Jan 28 00:00:00 EST 2016}
}

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Works referencing / citing this record:

Space Weather Effects Produced by the Ring Current Particles
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Space Weather Effects in the Earth’s Radiation Belts
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The Response of the Energy Content of the Outer Electron Radiation Belt to Geomagnetic Storms
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Earth's Van Allen Radiation Belts: From Discovery to the Van Allen Probes Era
journal, November 2019


On the Initial Enhancement of Energetic Electrons and the Innermost Plasmapause Locations: Coronal Mass Ejection‐Driven Storm Periods
journal, November 2018


Observations and Fokker‐Planck Simulations of the L ‐Shell, Energy, and Pitch Angle Structure of Earth's Electron Radiation Belts During Quiet Times
journal, February 2019


Dynamics of Megaelectron Volt Electrons Observed in the Inner Belt by PROBA‐V/EPT
journal, March 2019


Characterization and Evolution of Radiation Belt Electron Energy Spectra Based on the Van Allen Probes Measurements
journal, June 2019


Understanding Electron Dropout Echoes Induced by Interplanetary Shocks: Test Particle Simulations
journal, August 2019


Explaining the apparent impenetrable barrier to ultra-relativistic electrons in the outer Van Allen belt
journal, May 2018


From solar sneezing to killer electrons: outer radiation belt response to solar eruptions
journal, May 2019

  • Daglis, Ioannis A.; Katsavrias, Christos; Georgiou, Marina
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 377, Issue 2148
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Explaining the Apparent Impenetrable Barrier to Ultra-relativistic Electrons in the Outer Van Allen Belt
conference, May 2018


Space Weather Effects in the Earth’s Radiation Belts
book, January 2017


Dynamics of Megaelectron Volt Electrons Observed in the Inner Belt by PROBA-V/EPT
text, January 2019