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AGU: Journal of Geophysical Research, Space Physics

 

Keywords

  • magnetic storms
  • plasmapause location
  • ring current

Index Terms

  • Magnetospheric Physics: Plasma convection
  • Magnetospheric Physics: Electric fields
  • Magnetospheric Physics: Magnetic storms and substorms
  • Magnetospheric Physics: Magnetosphere/ionosphere interactions
Abstract
Cited By (10)
 

Abstract

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, A11S11, 25 PP., 2006
doi:10.1029/2006JA011700

Analyzing electric field morphology through data-model comparisons of the Geospace Environment Modeling Inner Magnetosphere/Storm Assessment Challenge events

Michael W. Liemohn

Atmospheric, Oceanic, and Space Sciences Department, University of Michigan, Ann Arbor, Michigan, USA

Aaron J. Ridley

Atmospheric, Oceanic, and Space Sciences Department, University of Michigan, Ann Arbor, Michigan, USA

Janet U. Kozyra

Atmospheric, Oceanic, and Space Sciences Department, University of Michigan, Ann Arbor, Michigan, USA

Dennis L. Gallagher

National Space Science and Technology Center, NASA Marshall Space Flight Center, Huntsville, Alabama, USA

Michelle F. Thomsen

ISR-1, Los Alamos National Laboratory, Los Alamos, New Mexico, USA

Michael G. Henderson

ISR-1, Los Alamos National Laboratory, Los Alamos, New Mexico, USA

Michael H. Denton

University of Southampton, Southampton, UK

Pontus C. Brandt

Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA

Jerry Goldstein

Southwest Research Institute, San Antonio, Texas, USA

The storm time inner magnetospheric electric field morphology and dynamics are assessed by comparing numerical modeling results of the plasmasphere and ring current with many in situ and remote sensing data sets. Two magnetic storms are analyzed, 22 April 2001 and 21–23 October 2001, which are the events selected for the Geospace Environment Modeling (GEM) Inner Magnetosphere/Storms (IM/S) Assessment Challenge (IMSAC). The IMSAC seeks to quantify the accuracy of inner magnetospheric models as well as synthesize our understanding of this region. For each storm, the ring current-atmosphere interaction model (RAM) and the dynamic global core plasma model (DGCPM) were run together with various settings for the large-scale convection electric field and the nightside ionospheric conductance, while keeping all other simulation settings the same. DGCPM plasmaspheric parameters were compared with IMAGE-EUV plasmapause extractions and LANL-MPA plume locations and velocities. RAM parameters were compared with Dst*, LANL-MPA fluxes and moments, IMAGE-MENA images, and IMAGE-HENA images. Both qualitative and quantitative comparisons were made to determine the electric field morphology that allows the model results to best fit the plasma data at various times during these events. The simulations with self-consistent electric fields were, in general, better than those with prescribed field choices. This indicates that the time-dependent modulation of the inner magnetospheric electric fields by the nightside ionosphere is quite significant for accurate determination of these fields (and their effects). It was determined that a shielded Volland-Stern field description driven by the 3-hour Kp index yields accurate results much of the time but can be quite inconsistent. The modified McIlwain field description clearly lagged in overall accuracy compared to the other fields, but matched some data sets (like Dst*) quite well. The rankings between the simulations varied depending on the storm and the individual data sets, indicating that each field description did well for some place, time, and energy range during the events, as well as doing less well in other places, times, and energies. Several unresolved issues regarding the storm time inner magnetospheric electric field are discussed.

Received 1 March 2006; accepted 30 August 2006; published 9 November 2006.

Citation: Liemohn, M. W., A. J. Ridley, J. U. Kozyra, D. L. Gallagher, M. F. Thomsen, M. G. Henderson, M. H. Denton, P. C. Brandt, and J. Goldstein (2006), Analyzing electric field morphology through data-model comparisons of the Geospace Environment Modeling Inner Magnetosphere/Storm Assessment Challenge events, J. Geophys. Res., 111, A11S11, doi:10.1029/2006JA011700.

Cited By

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