HR: 17:15h
AN: SA24A-06    [Abstracts]
TI: Three-Dimensional Simulation of High-Latitude Ionospheric Neutral and Ion Outflows During Magnetic Storm Conditions, and Northward Turnings of the Interplanetary Magnetic Field
AU: * Gardner, L C
EM: lgardner@cc.usu.edu
AF: Utah State University, Center for Atmospheric and Space Sciences 4405 Old Main Hill, Logan, UT 84322 United States
AU: Schunk, R W
EM: robert.schunk@usu.edu
AF: Utah State University, Center for Atmospheric and Space Sciences 4405 Old Main Hill, Logan, UT 84322 United States
AB: Ion outflow from high-latitudes occurs along geomagnetic field lines that are connected to the interplanetary magnetic field (IMF) and is associated with thermal ions of ionospheric origin. The horizontal motion of ions in the polar wind depends on the high-latitude convection electric fields, and their field-aligned outflow dynamics are modified by the heat input due to precipitating electrons in the auroral zone. Charge exchange occurs between ions in the polar wind and the neutral thermal and geocoronal atoms in the upper atmosphere of the Earth, producing neutral stream particles. A new three-dimensional high-latitude model of the neutral and ion polar winds has been developed which takes into account convection, which controls the horizontal motion of ion polar wind particles, and heating due to precipitating electrons, which heats the neutrals and ions in the auroral zone. The neutral polar wind originates when charge exchange reactions occur between the ions of the ion polar wind and the background thermal and geocoronal neutral atoms, producing neutral stream particles moving in the direction of the parent ion in the charge exchange reaction. Three-dimensional simulations have been conducted for both magnetic storm conditions, and for northward turnings of the IMF, which show large fluxes in both the horizontal and vertical directions, with a fixed observer noting neutral polar wind particles moving in all directions. The neutral polar wind tends to follow the convecting ions, thus showing anti-sunward flows during times of a southward IMF conditions, and sunward flow during times of northward IMF conditions, with a strong dependence on the time-history of neutral flow characteristics at high-latitudes.
DE: 2437 Ionospheric dynamics
DE: 2753 Numerical modeling
DE: 2776 Polar cap phenomena
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005