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Title: Van Allen Probes, THEMIS, GOES, and cluster observations of EMIC waves, ULF pulsations, and an electron flux dropout

We examined an electron flux dropout during the 12–14 November 2012 geomagnetic storm using observations from seven spacecraft: the two Van Allen Probes, Time History of Events and Macroscale Interactions during Substorms (THEMIS)-A (P5), Cluster 2, and Geostationary Operational Environmental Satellites (GOES) 13, 14, and 15. The electron fluxes for energies greater than 2.0 MeV observed by GOES 13, 14, and 15 at geosynchronous orbit and by the Van Allen Probes remained at or near instrumental background levels for more than 24 h from 12 to 14 November. For energies of 0.8 MeV, the GOES satellites observed two shorter intervals of reduced electron fluxes. The first interval of reduced 0.8 MeV electron fluxes on 12–13 November was associated with an interplanetary shock and a sudden impulse. Cluster, THEMIS, and GOES observed intense He+ electromagnetic ion cyclotron (EMIC) waves from just inside geosynchronous orbit out to the magnetopause across the dayside to the dusk flank. The second interval of reduced 0.8 MeV electron fluxes on 13–14 November was associated with a solar sector boundary crossing and development of a geomagnetic storm with Dst <–100 nT. At the start of the recovery phase, both the 0.8 and 2.0 MeV electron fluxes finallymore » returned to near prestorm values, possibly in response to strong ultralow frequency (ULF) waves observed by the Van Allen Probes near dawn. A combination of adiabatic effects, losses to the magnetopause, scattering by EMIC waves, and acceleration by ULF waves can explain the observed electron behavior.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10]
  1. Univ. of Iowa, Iowa City, IA (United States)
  2. Univ. of New Hampshire, Durham, NH (United States)
  3. NASA Goddard Space Flight Center, Greenbelt, MD (United States)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  5. Aerospace Corp., El Segundo, CA (United States)
  6. Univ. of Colorado, Boulder, CO (United States)
  7. Space Hazards Applications, Golden, CO (United States)
  8. National Oceanic and Atmospheric Administration, Boulder, CO (United States)
  9. Imperial College, London (United Kingdom)
  10. Institute of Atmospheric Physics AS CR, Prague (Czech Republic); Charles Univ. in Prague, Prague (Czech Republic)
Publication Date:
OSTI Identifier:
1258442
Report Number(s):
LA-UR--15-27241
Journal ID: ISSN 2169-9380
Grant/Contract Number:
921647; 967399; NAS5-01072; NAS5-02099; 50 OC 0302; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Volume: 121; Journal Issue: 3; Journal ID: ISSN 2169-9380
Publisher:
American Geophysical Union
Research Org:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES EMIC waves; ULF pulsations; electron flux dropouts; Dst effect; magnetopause shadowing; Van Allen Probes