A REVIEW OF ATMOSPHERIC GRAVITY-WAVES AND TRAVELING IONOSPHERIC DISTURBANCES - 1982-1995

Recent investigations of atmospheric gravity waves (AGW) and travellin g ionospheric disturbances (TID) in the Earth's thermosphere and ionos phere are reviewed. In the past decade, the generation of gravity wave s at high latitudes and their subsequent propagation to low latitudes have been studied by several global model simulations and coordinated observation campaigns such as the Worldwide Atmospheric Gravity-wave S tudy (WAGS), the results are presented in the first part of the review . The second part describes the progress towards understanding the AGW /TID characteristics, It points to the AGW/TID relationship which has been recently revealed with the aid of model-data comparisons and by t he application of new inversion techniques. We describe the morphology and climatology of gravity waves and their ionospheric manifestations , TIDs, from numerous new observations.