Ring current electron dynamics during geomagnetic storms based on the Van Allen Probes measurements

Authors

H. Zhao, University of Colorado Boulder
X. Li, University of Colorado Boulder
D. N. Baker, University of Colorado Boulder
S. G. Claudepierre, Aerospace Corporation, USA
J. F. Fennell, Aerospace Corporation, USA
J. B. Blake, Aerospace Corporation, USA
B. A. Larsen, Los Alamos National Laboratory
R. M. Skoug, Los Alamos National Laboratory
H. O. Funsten, Los Alamos National Laboratory
R. H.W. Friedel, Los Alamos National Laboratory
G. D. Reeves, Los Alamos National Laboratory
H. E. Spence, University of New Hampshire Durham
D. G. Mitchell, Johns Hopkins University Applied Physics Laboratory
L. J. Lanzerotti, New Jersey Institute of Technology

Document Type

Article

Publication Date

4-1-2016

Abstract

Based on comprehensive measurements from Helium, Oxygen, Proton, and Electron Mass Spectrometer Ion Spectrometer, Relativistic Electron-Proton Telescope, and Radiation Belt Storm Probes Ion Composition Experiment instruments on the Van Allen Probes, comparative studies of ring current electrons and ions are performed and the role of energetic electrons in the ring current dynamics is investigated. The deep injections of tens to hundreds of keV electrons and tens of keV protons into the inner magnetosphere occur frequently; after the injections the electrons decay slowly in the inner belt but protons in the low L region decay very fast. Intriguing similarities between lower energy protons and higher-energy electrons are also found. The evolution of ring current electron and ion energy densities and energy content are examined in detail during two geomagnetic storms, one moderate and one intense. The results show that the contribution of ring current electrons to the ring current energy content is much smaller than that of ring current ions (up to ∼12% for the moderate storm and ∼7% for the intense storm), and <35 keV electrons dominate the ring current electron energy content at the storm main phases. Though the electron energy content is usually much smaller than that of ions, the enhancement of ring current electron energy content during the moderate storm can get to ∼30% of that of ring current ions, indicating a more dynamic feature of ring current electrons and important role of electrons in the ring current buildup. The ring current electron energy density is also shown to be higher at midnight and dawn while lower at noon and dusk.

Identifier

84964691854 (Scopus)

Publication Title

Journal of Geophysical Research Space Physics

External Full Text Location

https://doi.org/10.1002/2016JA022358

e-ISSN

21699402

ISSN

21699380

First Page

3333

Last Page

3346

Issue

4

Volume

121

Grant

967399

Fund Ref

National Science Foundation

Recommended Citation

Zhao, H.; Li, X.; Baker, D. N.; Claudepierre, S. G.; Fennell, J. F.; Blake, J. B.; Larsen, B. A.; Skoug, R. M.; Funsten, H. O.; Friedel, R. H.W.; Reeves, G. D.; Spence, H. E.; Mitchell, D. G.; and Lanzerotti, L. J., "Ring current electron dynamics during geomagnetic storms based on the Van Allen Probes measurements" (2016). Faculty Publications. 10615.
https://digitalcommons.njit.edu/fac_pubs/10615