HR: 15:25h
AN: SA33B-07    [Abstracts]
TI: Seasonal diurnal tidal variation in the mesopause region over Ft. Collins, CO (40.6N, 105W).
AU: * Yuan, T
EM: titus@lamar.colostate.edu
AF: Colorado State University, 200 West Lake Street, Fort Collins, CO 80523-1875 United States
AU: She, C
EM: Joeshe@lamar.colostate.edu
AF: Colorado State University, 200 West Lake Street, Fort Collins, CO 80523-1875 United States
AU: Hagan, M
EM: hagan@hao.ucar.edu
AF: NCAR, 3450 Mitchell Lane , Boulder, CO 80301 United States
AB: Abstract: Based on a first yearlong lidar observation (May 2002 - April 2003) over full diurnal cycles, harmonic analysis, binned bi-monthly, was performed to extract diurnal perturbations of temperature, zonal and meridional winds in the mesopause region over Fort Collins, CO (40.6N, 105W). The results were compared to predictions of the 2000 and 2002 versions of Global Scale Wave Model (GSWM00 and GSWM02) as well as of the 2002 version of Thermosphere, Ionosphere, Mesosphere and Electrodynamics general circulation model (TIME-GCM). The observed diurnal phases are in good agreement with GSWM predictions, except the Nov-Dec period temperature, which shows roughly constant diurnal phase with the altitude. The agreement with TIME-GCM 2002 version predictions, however, is not as good, especially in temperature. As far as the tidal amplitudes comparison, GSWM00 diurnal amplitudes predictions are reasonably close to lidar observations, while GSWM02 diurnal amplitudes calculations, on the other hand, seems to overestimate the observations. In this paper, we focus on diurnal-period perturbations in winter temperature and on the seasonal variation in zonal wind. We discuss winter anomaly using newer data in 2003 and older data in 1998, both collected in winter months. We also compare observed seasonal variation in zonal wind tidal perturbations with those of radar observation from nearby Platteville, CO and with GSWM00 prediction. To the extent feasible, collaborative study with TIMED/SABER and TIMED/TIDI observations will be evaluated.
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3360 Remote sensing
DE: 3384 Waves and tides
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting