Atmospheric structure variations: Modelling of atmospheric structure, 70 - 130 km

Theory and numerical analysis of data were applied to a number of leading problems of atmospheric structure in the upper mesosphere/lower thermosphere during the three years of this project. Three investigations occupied the first 18 months and concerned: (1) diurnal and semidiurnal tidal dissipation of momentum and energy in the upper atmosphere, (2) the modelling of O distribution from 85 km to the turbopause and (3) an empirical model for solar cycle changes in mesospheric structure. During the second part of the project, attention was concentrated on: (4) atmospheric modelling of the intermediate region (70 to 130 km) between given models for the lower (up to 70 km) region and the upper (above 130 km) region. A preliminary report of this work, to the extent that it might meet the needs of a new COSPAR reference atmosphere, was presented at the 1986 COSPAR meeting and a detailed report of the theory and analyses was subsequently completed.