HR: 1330h
AN: SA23A-10    [Abstracts]
TI: GAIM Derived Variations in Electron Density during Active Geomagnetic Conditions
AU: * thonnard, s e
EM: sthonnard@ssd5.nrl.navy.mil
AU: dandenault, p b
EM: pdandenault@ssd5.nrl.navy.mil
AU: budzien, s a
EM: sbudzien@ssd5.nrl.navy.mil
AB: For more than a year, the Naval Research Laboratory has been evaluating the Global Assimilation of Ionospheric Measurements (GAIM), developed by Utah State University, for potential application to a number of Navy ionospheric mitigation needs. Of particular interest is the capability of any ionospheric model to capture the variations in electron density during disturbed period of high geomagnetic activity. Within the past 18 months several significant geomagnetic storms have occurred where GPS monitoring stations have indicated large fluctuations in total electron content. The density of GPS monitoring stations over the continental United States (CONUS) provides an excellent laboratory for testing the capability of GAIM to recreate the observed ionospheric structure. This presentation focuses on the ability of GAIM to recreate the ionospheric variability observed by the GPS ground stations for several significant storms such at the October 31 2003 and the July 17 2004. For these tests, GAIM was used to assimilate a subset of the available CONUS GPS stations, in situ electron density measurements from the DMSP, and ionosondes. The output of GAIM was compared to GPS measurements that were not assimilated to verify accuracy. Further examination is given to the density of measurements required to reproduce the ionospheric variability observed during storm conditions in comparison to quiet geomagnetic conditions.
DE: 2435 Ionospheric disturbances
DE: 2437 Ionospheric dynamics
DE: 2439 Ionospheric irregularities
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly