HR: 1400h
AN: SM33A-01    [Abstracts]
TI: Modeling the O+ trough region in the polar cap ionosphere-magnetosphere coupling region
AU: Jaaffari, F B
EM: fajer@uta.edu
AF: Department of Physics, The University of Texas at Arlington, Arlington, TX 76019, United States
AU: * Horwitz, J L
EM: horwitz@uta.edu
AF: Department of Physics, The University of Texas at Arlington, Arlington, TX 76019, United States
AU: Zeng, W
EM: zengw@uta.edu
AF: Department of Physics, The University of Texas at Arlington, Arlington, TX 76019, United States
AB: Ion measurements by the Thermal Ion Dynamics Experiment(TIDE) on the POLAR spacecraft show that the O⁺ densities in the polar cap near 5000 km altitude display normal and low density (trough) regions. We use the UT Arlington Dynamic Fluid-Kinetic (DyFK) model to model such O⁺ density profiles. Using solar wind parameters and incorporating auroral fountain effects for these events to drive a time-varying high-latitude convection model and auroral processes of soft electron precipitation and wave-driven ion heating, we treat the evolving high-latitude ionospheric plasma transport and associated parameter profiles for several convecting flux tubes in the high-latitude ionosphere-magnetosphere system, incorporating estimated locations of the auroral processes regions from the Ovation auroral oval model. This auroral oval model has as inputs auroral precipitation measurements from DSMP. For the convection patterns thus computed, these flux tubes nominally intersected the POLAR trajectory where the density measurements were made. It is found that, owing chiefly to F- region recombination processes during trajectory segments when the low altitude portions of such flux tubes in darkness, as well as incorporating auroral fountain effects in the auroral region, normal and low trough-like densities at higher altitudes developed along these flux tubes. The modeled densities near 5000 km altitudes will be compared with POLAR/TIDE-measured O⁺ densities for inside and outside of these observed trough regions.
DE: 2423 Ionization processes (7823)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2447 Modeling and forecasting
DE: 2467 Plasma temperature and density
DE: 2475 Polar cap ionosphere
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly