HR: 17:30h
AN: SA34A-07    [Abstracts]
TI: Gravity wave influence on the global structure of the diurnal tide in the mesosphere and lower thermosphere
AU: * Ortland, D A
EM: ortland@nwra.com
AF: NorthWest Research Associates, 14508 NE 20th St, Bellevue, WA 98007
AU: Alexander, M J
SA34A-07 AF: Colorado Research Associates, 3380 Mitchell Lane, Boulder, CO 80301
AU: Killeen, T L
SA34A-07 AF: NCAR/HAO, 3450 Mitchell Lane, Boulder, Co 80301
AU: Solomon, S C
SA34A-07 AF: NCAR/HAO, 3450 Mitchell Lane, Boulder, Co 80301
AU: Skinner, W
SA34A-07 AF: University of Michigan, 2455 Hayward St. , Ann Arbor, MI 48109
AU: Wu, Q
SA34A-07 AF: NCAR/HAO, 3450 Mitchell Lane, Boulder, Co 80301
AU: Niciejewski, R J
SA34A-07 AF: NCAR/HAO, 3450 Mitchell Lane, Boulder, Co 80301
AU: Mertens, C J
SA34A-07 AF: NASA Langley Research Center, 21 Langley Blvd., MS401B, Hampton, VA 23681
AU: Russell, J M
SA34A-07 AF: Hampton University, Dept. of Physics, Hampton, VA 23668
AB: Observations of the diurnal tide from TIMED instruments TIDI and SABER show that the vertical wavelength of the tide is significantly shorter than what is predicted by tidal theory. We show that the observed vertical structure of the tide can be accounted for by including gravity wave interaction in a mechanistic model of the tide. The model tide structure is rather sensitive to the gravity wave source spectrum, and by comparing the model to observations we can place constraints on the shape and magnitude of this spectrum, and put bounds on the eddy diffusive force that acts on the tide. These constraints will be valuable for the poorly constrained parameterizations of gravity wave forcing commonly applied in global models. Our results have led to significant improvements in the fit of a data assimilation model we have developed that recovers tide and mean flow structure from TIMED data, and shows that any procedure for assimilating mesosphere data into a global model must correctly initialize the dynamical forcing as well as the dynamical fields.
DE: 3315 Data assimilation
DE: 3332 Mesospheric dynamics
DE: 3333 Model calibration (1846)
DE: 3389 Tides and planetary waves
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005