GLOBAL MESOSPHERIC TIDAL WINDS OBSERVED BY THE HIGH-RESOLUTION DOPPLER IMAGER ON BOARD THE UPPER-ATMOSPHERE RESEARCH SATELLITE

This paper presents preliminary results of a study of mesospheric and lower thermospheric diurnal tidal winds obtained with the High Resolut ion Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite ( UARS). Zonal averages of the meridional and zonal wind fields are perf ormed at fixed local times. These analyses reveal tidal structures in the mean meridional wind field during the months of February and March 1992. Results are presented for a typical day in February 1992. The o bserved maximum amplitude of meridional wind is approximately 75 m s-1 . The observed vertical wavelength is about 20 km, with amplitudes inc reasing linearly with height. In addition to the tides, the zonal wind field reveals many features of the mesospheric climatological mean zo nal wind.