DIAGNOSTICS OF THE DIABATIC CIRCULATION AND ZONAL ACCELERATION IN THE MIDDLE ATMOSPHERE

The altitude-latitude distributions of zonal acceleration for solstice and equinox conditions have been calculated basing on diagnostic equations set for the height range 15 - 110 km. The solar heating due to O3, O2, CO2, H2O and infrared cooling due to CO2, O3, H2O and NO were used for calculation of net radiative heating in the middle atmosphere. The breakdown of local thermodynamic equilibrium of CO2 vibrational states was taken into account. The recent climatologic model CIRA-86 was used for diagnostics of meridional circulation and zonal forcing per unit mass. The distributions of eddy accelerations obtained for solstice conditions have two maxima in the mesosphere/lower thermosphere for each hemisphere and are in good agreement with results of 3-D numerical modeling accounting for influence of internal gravity waves.