This proposal is for continuation of thermospheric tidal studies being conducted with NCAR Thermosphere/Ionosphere General Circular Model. This work directly addresses two goals of the NSF CEDAR program; detailed understanding of the low thermosphere global dynamics and mesosphere/thermosphere coupling. There have been advances in tidal studies. Key developments are; 1) the parameterization of the waves excited in the lower atmosphere in the thermosphere models to better represent the coupling between the lower and upper atmosphere; 2) the inclusion of both the upward propagating diurnal and semidiurnal waves in the thermospheric models; 3) the self-consistent ionosphere/thermosphere coupling in models; 4) the availability of simulation of simultaneous observations of thermospheric winds and temperatures for the first time from loe, mid and high latitude stations. Such data sets are invaluable for testing theoretical tidal models. The research proposed has two main emphasis: 1) the provision of model simulations in support of campaigns; and 2) the continuation of theoretical tidal studies. The main topics of interest for the latter are: monthly simulations of the thermospheric tides during the solar cycles minimum and maximum; the effects of geomagnetic activity on the thermosphere, including the zonal mean/tide/gravity wave interaction; the effects of diurnal tides on the thermosphere/ionosphere; and the latitude atmosphere/ionosphere. Investigation may be extended to the vertical velocities, the terdiurnal and quatradiurnal tides, the midnight temperatures anomaly, and the possible derivation of tidal information from the descent of sporadic E and F1 layer.
