PARAMETERIZATION OF THE 15 MU-M CO2 BAND COOLING IN THE MIDDLE ATMOSPHERE (15-115 KM)

A new parameterization of the 15 mum CO2 band radiative cooling rate in the middle Earth atmosphere for both LTE (local thermodynamic equilibrium) and non-LTE layers is presented. It includes the parameterization of AKMAEV and SHVED [(1982) J. atmos. terr. Phys. 44, 9931 for the 35-70 km layer, which is modified to account for the line overlapping in the band for the 15-35 km layer and for non-LTE effects in the 70-80 km layer. In the non-LTE layer above 80 km a simple recurrence relation between the cooling rates for two neighboring altitude levels is used. For any temperature profile, which has no micro- or meso-scale structure, the absolute error of the parameterization in the 15-80 km layer does not exceed 0.5 K day-1. In the non-LTE 80-115 km layer the error depends on the value of the rate constant for the de-excitation of CO2(01(1)0) by collisions with atomic oxygen O, not exceeding, however, 0.07, 0.4 and 4 K day-1 for values of this constant equal to 5 x 10(5), 5 x 10(6) and 5 x 10(7) s-1 atm-1, respectively.