Interpretation of satellite measurements of the outgoing nonequilibrium IR radiation in the CO2 15-μm band:: 2.: Processing the CRISTA experimental data

A method of a combined retrieval of the vertical profiles of atmospheric parameters from satellite measurements of IR limb radiation under non-local thermodynamic equilibrium (non-LTE) conditions is used to interpret the CRISTA experimental data (15-mum spectral region). The profiles of temperature in the mesosphere and lower thermosphere are obtained. Accounting for non-LTE conditions has enabled the retrieval of temperature profiles up to a height of 120 km. A satisfactory agreement between the temperature profiles retrieved by a remote-sensing method and those obtained independently by the method of failing spheres is demonstrated, and the reasons for the observed discrepancies are analyzed. It is shown that disregarding non-LTE conditions can be responsible for errors of 30 K in determining the temperature starting at heights of about 75 km. The retrieved temperature profiles are compared to climatological data. It is found that the satellite experimental information about the thermal structure of the atmosphere and lower thermosphere is in good agreement with the climatological data. The following characteristic features of the thermal structure are noted: a low and cold summer mesopause, a high and warm winter mesopause, large-amplitude mesospheric inversions (to 50 K) at different heights, and the presence of wave structures. In the mesopause region, the minimum temperature variations (9-12 K) were observed at heights of 75 and 100 km, and the maximum ones (30 K), at heights of 87.5 km.