Abstract : The contract has supported an extensive programme of atmospheric and ionospheric modelling, aimed at examining Atmospheric Structure and Variability, using the CRAY XMP-48 and the CRAY 2S machines. A technique of forcing tidal and other natural atmospheric fluctuations at the lower boundary of the present version of the 3-dimensional, time-dependent global thermosphere-ionosphere model has been developed. Also, a series of numerical studies have been carried out into the modelled response of the thermosphere during a series of geomagnetic storms in 1981 and 1982, observed by the Dynamics Explorer-2 spacecraft. Further studies have concentrated on using these models for studies of thermosphere - ionosphere coupling, atmospheric density, lower atmospheric tides, participation in the analysis and interpretation of empirical data obtained during the 'Lower Thermosphere Coupling Study', the mid- and low- latitude ionospheric effects of geomagnetic storms, and for studies of the solar activity and geomagnetic activity causes of variations of lower thermospheric atomic oxygen and nitric oxide densities. Keywords: Atmospheric density, Atmospheric tides, Ionosphere-thermosphere coupling, Geomagnetic storm effects, Atomic oxygen, Nitric oxide, Great Britain.