HR: 09:10h
AN: SA41A-05 INVITED     [Abstracts]
TI: Modeling the Response of the Neutral Atmosphere During Geomagnetic Storms
AU: * Fuller-Rowell, T
EM: tim.fuller-rowell@noaa.gov
AF: CIRES University of Colorado and NOAA Space Environment Center, 325 Broadway, Boulder, CO 80305
AB: Neutral wind dynamics provides the conduit for many of the processes in the upper atmosphere during geomagnetic storms. Following localized impulsive injections of energy at high latitudes, mainly in the form of Joule heating, a cascade of actions follows. Thermal expansion increases density and generates horizontal pressure gradients. The pressure field is 'transmitted' globally to all latitudes through the action of gravity wave propagation. The wind field is highly varying as the waves 'slosh' back and forth across the equator and between the hemispheres. The new circulation evolves consistent with new pressure distribution driven by the balance between solar radiation and storm heat sources at high latitudes. Divergent winds drive vertical winds across pressure levels creating changes in neutral composition, the O/N2 ratio, which can subsequently be transported by both background and storm induced horizontal winds. Neutral winds and composition changes control a significant component of the ionospheric response either directly through collisional transport or changes in loss rates, or indirectly through transport by the disturbance dynamo electric fields.
DE: 0355 Thermosphere: composition and chemistry
DE: 0358 Thermosphere: energy deposition (3369)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2441 Ionospheric storms (7949)
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005