NET RADIATIVE HEATING AND DIAGNOSTICS OF THE DIABATIC CIRCULATION IN THE 15-110 KM HEIGHT LAYER

The vertical and latitudinal structure of both net radiative heating a nd radiative equilibrium temperature in the 15-1 10 km height region h as been calculated for solstice and equinox conditions. The monthly me an climatological fields' of temperature and chemical constituents alo ng with an accurate radiative algorithm were used. Solar heating due t o O3, O2, CO2 and H2O and infra-red cooling due to CO2, O3, H2O and NO were taken into account. Using the fields of net radiative heating an d climatological data for temperature and the mean zonal wind, the dia batic circulation and eddy zonal accelerations were diagnosed. The int erhemispheric transport regime at the solstice is shown to extend into the lower thermosphere, while at the equinox, the diabatic circulatio n has a more intricate multi-cell structure. The interhemispheric diff erences in the diagnosed fields are found in both winter and spring he mispheres. The distributions of eddy accelerations obtained for solsti ce conditions have two height maxima in the mesosphere and lower therm osphere for each hemisphere.