HR: 1340h
AN: SA33A-1065    [Abstracts]
TI: Effects of high-latitude ionospheric electric field variability on global thermospheric Joule heating and mechanical energy transfer rate
AU: * Matsuo, T
EM: tomoko.matsuo@noaa.gov
AF: CU-Boulder, CIRES, Boulder, CO 80309, United States
AU: * Matsuo, T
EM: tomoko.matsuo@noaa.gov
AF: NOAA/NWS/SEC, W/NP9, 325 Broadway, Boulder, CO 80305, United States
AU: * Matsuo, T
EM: tomoko.matsuo@noaa.gov
AF: NCAR/HAO, PO BOX 3000, Boulder, CO 80307, United States
AU: Richmond, A D
EM: richmond@ucar.edu
AF: NCAR/HAO, PO BOX 3000, Boulder, CO 80307, United States
AB: Effects of high-latitude ionospheric electric field variability on the estimation of Joule heating and mechanical energy transfer rate are investigated by incorporating realistic spatial and temporal characteristics of electric field variability derived from observations into the forcing of a thermosphere and ionosphere electrodynamics general circulation model. First, the characteristics of sub-grid scale variability are examined from a spectral analysis of Dynamic Explorer-2 (DE-2) plasma drift measurements. The analysis reveals that the sub-grid scale electric field varies with magnetic altitude, magnetic local time, interplanetary magnetic field, and season in a manner distinct from that of the resolved-scale electric field and of the climatological electric field. Second, the spatial-temporal structure of resolved-scale electric fields are characterized from various electromagnetic observations taken during the storm period of January 10-11, 1997, using a space-time separable covariance model derived from the DE-2 observations. Finally, the modeling results show that the estimated amount of Joule heating in the thermosphere is significantly altered by taking into account the electric field variability and its space-time structure.
DE: 2411 Electric fields (2712)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting