HR: 1340h
AN: SA33A-1062    [Abstracts]
TI: Comparisons of Observational and Model Estimates of Auroral Electron Precipitation
AU: * Solomon, S C
EM: stans@ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307- 3000, United States
AU: Qian, L
EM: lqian@ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307- 3000, United States
AU: Wang, W
EM: wbwang@ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307- 3000, United States
AB: Upper atmosphere numerical models require accurate specification of magnetospheric forcing of the high latitude ionosphere-thermosphere system. This includes both the imposed electric field and the energetic particle precipitation energy flux and distribution. The former has a greater effect on ionosphere/thermosphere changes during geomagnetic storms, but the latter is also crucial because it controls the conductance pattern through which magnetospheric currents flow, alters the chemical composition of the polar regions, and contributes to heating. However, there is little agreement on various estimates of the basic magnitude of auroral energy fluxes. In this paper, we examine several empirical representations of the electron hemispheric power and morphological distribution, compare them to each other, and to magnetospheric MHD model specifications. These are also compared to measurements obtained during selected auroral events. We then apply differing auroral forcing to the NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM) to evaluate the effect on some key observables: global neutral density and auroral nitric oxide. The model estimates are compared to measurements of these quantities to lend some guidance to the process of obtaining appropriate levels of auroral precipitation for coupled model simulations.
DE: 0310 Airglow and aurora
DE: 0355 Thermosphere: composition and chemistry
DE: 0358 Thermosphere: energy deposition (3369)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting