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Title: Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ("dropouts") in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere–ionosphere (M–I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US–CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open–closed boundary) during substormmore » activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M–I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global model results enable the reconstruction of a more complete system-level picture of the dropout events and provides insight into M–I coupling aspects that have not previously been investigated.« less
 [1] ;  [2] ;  [3] ; ORCiD logo [3] ; ORCiD logo [2] ;  [4] ; ORCiD logo [5] ;  [5]
  1. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States). Heliophysics Science Division; Univ. of Maryland, College Park, MD (United States). Astronomy Dept.
  2. Univ. of Texas, San Antonio, TX (United States); Southwest Research Inst., San Antonio, TX (United States)
  3. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States). Heliophysics Science Division
  4. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  5. Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.
Publication Date:
Accepted Manuscript
Journal Name:
Annales Geophysicae (Online)
Additional Journal Information:
Journal Name: Annales Geophysicae (Online); Journal Volume: 36; Journal Issue: 1; Journal ID: ISSN 1432-0576
European Geophysical Union
Research Org:
NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE; National Aeronautic and Space Administration (NASA)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; magnetospheric physics; magnetosphere-ionosphere interactions; magnetospheric configuration and dynamics; space plasma physics; numerical simulation studies
OSTI Identifier: