HR: 16:15h
AN: SA14A-02    [Abstracts]
TI: Estimating the Upper Atmospheric Forcing through Observing and Modelling the Thermospheric Response
AU: * Minter, C F
EM: Cliff.Minter@NOAA.gov
AF: University of Colorado, NOAA/SEC R/SEC 325 Broadway, Boulder, CO 80305 United States
AU: Fuller-Rowell, T J
EM: Tim.Fuller-Rowell@NOAA.gov
AF: University of Colorado, NOAA/SEC R/SEC 325 Broadway, Boulder, CO 80305 United States
AU: Codrescu, M V
EM: Mihail.Codrescu@NOAA.gov
AF: University of Colorado, NOAA/SEC R/SEC 325 Broadway, Boulder, CO 80305 United States
AB: A data assimilation system for specifying the thermospheric composition and denity has been developed over the last several years. Although the drivers of the upper atmosphere are well understood, quantifying the thermospheric forcing still remains a primary error source in the data assimilation system during geomagnetic storm periods. Correctly modelling the high latitude forcing requires knowledge of the spatial and temporal variations of the convection electric field and the auroral precipitation. At best, the globally averaged Joule heating is known only within a factor or two. At a given location, this uncertainty can rise to a factor of ten. However, since the solar heating at low latitudes and the magnetospheric sources at high latitudes control the magnitude and spatial distribution of the global circulation, these strongly affect the neutral composition and density structure. Observations of the change in the neutral density and composition structure consequently provide an additional information source in specifying the upper atmospheric driver. The enhanced driver specification may, in turn, improve the thermospheric specification in the data assimilation scheme.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 0355 Thermosphere--composition and chemistry
DE: 0358 Thermosphere--energy deposition
DE: 0394 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting