HR: 1400h
AN: SA33A-07    [Abstracts]
TI: Analysis of the Steady-State Eddy Available Energy Budget in the High-Latitude Lower Thermosphere
AU: * Richmond, A D
EM: richmond@ucar.edu
AF: NCAR High Altitude Observatory, PO Box 3000, Boulder, CO 80305, United States
AU: Kwak, Y
EM: yskwak@ucar.edu
AF: NCAR High Altitude Observatory, PO Box 3000, Boulder, CO 80305, United States
AU: Roble, R G
EM: roble@ucar.edu
AF: NCAR High Altitude Observatory, PO Box 3000, Boulder, CO 80305, United States
AB: Only part of the energy of the thermospheric gas is available for driving dynamics. This eddy available energy (EAE) is composed of an eddy kinetic energy (EKE) and an eddy available potential energy (EAPE). In the high-latitude thermosphere EKE is generated primarily where the ion-drag force associated with plasma convection accelerates the neutral gas, and is destroyed primarily where the ion-drag force opposes the wind. EAPE is generated primarily where Joule heat is deposited in regions of elevated temperatures, and destroyed where the heat is deposited in regions of reduced temperatures. We have evaluated the budgets of EAE production, transport, and loss under steady-state forcing of the high-latitude lower thermosphere, using the NCAR Thermosphere-Ionosphere-Electrodynamics General-Circulation Model. In general, ion-drag forcing is a larger contributor to both the production and destruction (depending on location) of EAE than is Joule heating for steady-state conditions, although Joule heating can play a more significant role for impulsive forcing. Transport of EAE by horizontal and vertical winds is a significant component of the EAE budget. Conversion of EAPE to EKE, and of EKE to EAPE, constitutes an important part of the budgets of these two components of EAE.
DE: 0358 Thermosphere: energy deposition (3369)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 3369 Thermospheric dynamics (0358)
SC: SPA-Aeronomy [SA]
MN: 2007 Joint Assembly