Globally Simulated Poynting Flux Into Earth's Ionosphere as a First Step to Simulating Auroral Ion Outflow

HR: 0800h
AN: SA21C-0364 [Abstracts]
TI: Globally Simulated Poynting Flux Into Earth's Ionosphere as a First Step to Simulating Auroral Ion Outflow
AU: * Gagne, J R
EM: John.Gagne@Dartmouth.edu
AF: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755-8000 United States
AU: Lotko, W
EM: William.Lotko@Dartmouth.edu
AF: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755-8000 United States
AU: Murr, D
EM: David.Murr@Dartmouth.edu
AF: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755-8000 United States
AB: The LFM and TING codes numerically calculate and describe the properties of the earth's magnetosphere and ionosphere, respectively. Coupling in the spatial gap between TING and LFM has been implemented electrodynamically, but currently, no mass transfer occurs between the two computational domains and the exclusive source of the magnetospheric plasma population is the solar wind. In reality, some of the magnetosphere's plasma may come from an outflow of heavy ionospheric ions that are energized during geomagnetic storms. One of the primary modes of outflow evidently occurs when the topside ionospheric plasma is energized by magnetic field oscillations in the ultralow frequency range below and up to the oxygen gyrofrequency. These transverse oscillations are carried by AlfvＯ waves that originate in the outer magnetosphere via a dynamo action resulting from the motional electric field of the solar wind plasma. In order to determine the influence of AlfvＯ waves on ion outflow, Poynting flux diagnostics for the inner boundary of the LFM magnetosphere have been developed. Results for the Poynting flux at the magnetosphere's inner boundary are shown to vary greatly with sampling rates, data filtering techniques, and designation of the background magnetic field. Poynting flux statistical studies have been performed using in situ satellite measurements. For example, Keiling et al. used data from the Polar satellite, Gary et al. used data from DE 2, and Korth et al. used data from Iridium and SuperDARN. The purpose of this research is to evaluate the Poynting flux into the ionosphere from LFM. It will be compared with the Poynting flux magnitudes and morphology obtained via satellite and radar measurements by Keiling, Gary, and Korth, in order to quantify the energy available to facilitate auroral ion outflow, and eventually develop a mass transfer coupling module between the LFM and TING simulations. 1. Keiling, A., et al., The Global Morphology of Wave Poynting Flux: Powering the Aurora, Science 299, 383, 2003. 2. Gary, J., et al., Summary of field-aligned Poynting flux observations from DE 2, Geophysical Research Letters 22, 1861, 1995. 3. Korth, H., et al., Intercomparison of ionospheric electrodynamics from the Iridium constellation with global MHD simulations, Journal of Geophysical Research 109, A07303, 2004.
DE: 7843 Numerical simulation studies
DE: 2730 Magnetosphere--inner
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2753 Numerical modeling
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting