EMPIRICAL-MODEL OF 90-120 KM HORIZONTAL WINDS FROM WIND-IMAGING INTERFEROMETER GREEN LINE MEASUREMENTS IN 1992-1993

An empirical model of horizontal winds is developed based on wind-imag ing interferometer (WINDII) green line observations between 90 and 120 km in 1992-1993. The model includes mean winds, solar diurnal and sem idiurnal tides, and some planetary wave components, as well as annual and semiannual variations in these fields. Its formulation is similar to that of HWM-90 and HWM-93 of Hedin et al. [1991,1996], but greatly modified and extended to use the higher resolution global wind measure ments now available from WINDII. While the technique will only reach f ruition when results can be combined from the wind measurements of sev eral years by the different instruments on the UARS satellite, this in terim, but updated model provides improved representation of the tempo ral and geographic variations of the wind fields compared to the curre nt reference models. The model-generated climatological mean wind, diu rnal tides, and some samples of the entire wind motion fields are pres ented and compared with the WINDII measurements and analysis results o btained from the data sets by different methods to check the consisten cies between the model representations and the observations. This stud y also reveals a dual cell structure in the meridional component of th e diurnal, tides with two amplitude maxima centered around 95 and 102 km near 20 degrees latitude and strongly symmetric about the equator a t equinox. Large interannual variabilities are found to exist in both diurnal wind components with maximum amplitudes of similar to 40 and 5 5 m/s for the zonal and meridional, respectively, at the vernal equino x of 1992.