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Record Details

Record 89 of 49806
Analyzing Electric Field Morphology Through Data-Model Comparisons of the GEM IM/S Assessment Challenge Events
Author and Affiliation:
Liemohn, Michael W.(Michigan Univ., Atmospheric, Oceanic, and Space Sciences Dept., Ann Arbor, MI, United States)
Ridley, Aaron J.(Michigan Univ., Atmospheric, Oceanic, and Space Sciences Dept., Ann Arbor, MI, United States)
Kozyra, Janet U.(Michigan Univ., Atmospheric, Oceanic, and Space Sciences Dept., Ann Arbor, MI, United States)
Gallagher, Dennis L.(National Space Science and Technology Center, Huntsville, AL, United States)
Thomsen, Michelle F.(Los Alamos National Lab., NM, United States)
Henderson, Michael G.(Los Alamos National Lab., NM, United States)
Denton, Michael H.(Southampton Univ., United Kingdom)
Brandt, Pontus C.(Johns Hopkins Univ., Applied Physics Lab., Laurel, MD, United States)
Goldstein, Jerry(Southwest Research Inst., San Antonio, TX, United States)
Abstract: 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, April 22,2001 and October 21-23,2001, 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. 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 Mcllwain 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.
Publication Date: Jan 01, 2006
Document ID:
20060016374
(Acquired Jun 09, 2006)
Subject Category: GEOPHYSICS
Document Type: Preprint
Financial Sponsor: NASA Marshall Space Flight Center; Huntsville, AL, United States
Organization Source: NASA Marshall Space Flight Center; Huntsville, AL, United States
Description: 2p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: EXTREME ULTRAVIOLET RADIATION; MAGNETIC STORMS; ELECTRIC FIELDS; DYNAMIC MODELS; RING CURRENTS; REMOTE SENSING; SELF CONSISTENT FIELDS; MORPHOLOGY
Availability Source: Other Sources
Availability Notes: Abstract Only
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