This grants supports the comprehensive data base of lower thermospheric measurements of winds, temperatures, densities, and composition from satellites, rockets, and ground-based radar and optical instruments. These data will be used to develop and test an empirical model of global lower thermospheric diurnal and semidiurnal tidal oscillations from 85 to 150 km. Analysis of the data set will include formation of climatological averages at different geographic locations based on solar cycle and geomagnetic activity where appropriate. Fourier decomposition of the climatological averages will yield diurnal and semidiurnal components at selected altitudes, and finally decomposition of the Fourier component as a function of latitude will allow amplitudes, and phase of the contributing Hough function tidal modes to be determined. Climatological averages and model Hough function amplitudes and phases will be assembled in convenient format for distribution to interested scientists. The resulting model representations of lower thermospheric diurnal and semidiurnal tides will be used in several scientific investigations. Climatological tidal oscillations will be compared with the results of previous theoretical and semiempirical models. Other studies will include investigation of the electrodynamic forcing of the ionosphere arising from the deduced global lower-thermosphere tides and a term analysis of the tidal momentum forcing in the lower thermosphere utilizing the National Center for Atmosphere Research (NCAR) Thermosphere Ionosphere General Circulation Model (TIGCM) and its diagnostic processors. *** '
