HR: 16:30h
AN: SA32B-03    [PDF]
TI: On the use of Hough Mode Extensions (HMEs) to fit Tidal Structures From SABER and TIDI Measurements
AU: * Forbes, J M
EM: forbes@colorado.edu
AF: University of Colorado, Aerospace Engineering Sciences UCB 429, Boulder, CO 80309-0429 United States
AU: Svoboda, A
EM: asvoboda@odo.colorado.edu
AF: University of Colorado, Aerospace Engineering Sciences UCB 429, Boulder, CO 80309-0429 United States
AU: Miyahara, S
EM: sbm@geo.kyushu-u.ac.jp
AF: Kyushu University, department of Earth and Planetary Science 6-10-1 Hakozaki, Higashi Ward, Fukuoka, 812-8581 Japan
AU: Miyoshi, Y
EM: miyoshi@geo.kyushu-u.ac.jp
AF: Kyushu University, department of Earth and Planetary Science 6-10-1 Hakozaki, Higashi Ward, Fukuoka, 812-8581 Japan
AB: Hough Mode Extensions (HMEs) are analogs of solutions to Laplace's Tidal Equation (i.e., eigenfunctions corresponding to waves of a specified frequency and zonal wavenmber), except that latitudinal and vertical changes in structure due to dissipation are taken into account. In this study, HMEs are computed using the Global Scale Wave Model (GSWM) with arbitrary forcing. HMEs are global (i.e., pole to pole, surface to 250 km). For a give HME, the relative amplitudes and phases of eastward, northward, and vertical velocity components, as well as temperature, density and geopotential perturbations, are internally consistent and fixed. Herein, the concept of using HMEs to extend globally tidal structures determined from TIMED/TIDI and TIMED/SABER wind and temperature measurements, respectively, is explored by using output from the Kyushu University GCM as proxy data. This also provides a means of ascertaining the merit of the globally-extrapolated fields via comparison with the exact solution. Examples are shown for the westward propagating diurnal tides with zonal wavenumbers s = 1 and s = 2, the eastward diurnal tide with s = 3, and the zonally symmetric (s = 0) diurnal tide using data from 95 km only. Very good agreement is achieved in matching global structures, setting the stage for future applications with observational data. Advantages, caveats and shortcomings of the technique are also explored.
DE: 3332 Mesospheric dynamics
DE: 3369 Thermospheric dynamics (0358)
DE: 3384 Waves and tides
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting