HR: 10:35h
AN: SA32C-02    [Abstracts]
TI: Modeling Low Latitude Ion Densities During Magnetic Storms
AU: * de La Beaujardiere, O
EM: odile.delabeaujardiere@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Retterer, J
EM: john.retterer@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Crowley, G
EM: crowley@picard.space.swri.edu
AF: South West Research Institute, Space Sciences, San Antonio, TX 78228 United States
AU: Basu, B
EM: bamandas.basu@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Welsh, J
EM: judith.welsh@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Baker, C
EM: craig.baker2@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Mellein, J
EM: jason.mellein@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Valladares, C
EM: valladar@bc.edu
AF: Boston College, Ins. of Space Research, Chestnut Hill, MA 02467 United States
AU: Rich, F
EM: frederick.rich@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Cooke, D
EM: david.cooke@hanscom.af.mil
AF: Air Force Research Laboratory, Space Vehicle directorate (VSBXP), Hanscom AFB, MA 01731 United States
AU: Doherty, P
EM: patricia.doherty@bc.edu
AF: Boston College, Ins. of Space Research, Chestnut Hill, MA 02467 United States
AB: The impact of magnetic storms in the low-latitude ionosphere is examined. The April 17-18, 2002 and October 29-31, 2003 storms have been simulated using two models: TIME-GCM and the Communication/Navigation Outage Forecasting System (C/NOFS) ionospheric model (PBMod). TIME-GCM was driven with high-latitude AMIE data, providing energy input from Joule heating and particle precipitation. PBMod was driven by ion drift measured at the magnetic equator (at Jicamarca, Peru) and empirical neutral winds. The ground truth data include in situ density from the Challenging Minisatellite Payload (CHAMP) and the Defense Meteorological Satellite Program (DMSP) satellites, as well as ground-based data from ionosondes, GPS receivers and scintillation receivers. Close to Jicamarca, given limitations inherent in the input data, both models show significant agreement with the ground truth data before the storms, and at the beginning of the storms. However, at the end of the storms, the ionospheric densities derived from the C/NOFS model are too high and the densities derived from TIME-GCM are too low. The variations as a function of latitude are not well represented by either model. Several factors contribute to these mediocre results, including, for the C/NOFS model, lack of knowledge of the neutral wind, neutral density composition, and ions production terms. In particular, we illustrate with a few examples how the neutral wind model influences the electron density profiles and total electron content. These magnetic storm simulations clearly demonstrate the need for improved measurements of ionospheric and thermospheric parameters in the equatorial regions, such as will become available from C/NOFS and other satellites.
UR: http://www.vs.afrl.af.mil/factsheets/cnofs.html
DE: 2415 Equatorial ionosphere
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 0355 Thermosphere--composition and chemistry
DE: 0358 Thermosphere--energy deposition
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting