COMPARISON OF LINE-BY-LINE AND CURTIS MATRIX CALCULATIONS FOR THE VIBRATIONAL TEMPERATURES AND RADIATIVE COOLING OF THE CO2 15-MU-M BANDS IN THE MIDDLE-ATMOSPHERE AND UPPER-ATMOSPHERE

A comparison of the iterative line-by-line RAD, and the inverse modifi ed Curtis matrix (MCM) non-LTE models has been undertaken with the pur pose of studying the effect of radiative transfer algorithms on the no n-LTE populations of the CO2(v(2)) levels and on the 15 mu m radiative cooling rates produced by the bands originating from them. The compar ison has been carried out for a large range of model input parameters which include CO2 strong and weak 15 mu m bands, extreme atmospheric t emperature structures, a large altitude interval (40-160 km), and extr eme values for kinetic parameters. A good general agreement for the po pulations and cooling rates for all bands and conditions is found. The model differences for the vibrational temperatures and cooling rates are generally smaller than 2 K and 0.5 K/day, respectively. This resul t is in contrast with the large differences found when compared with s ome previous non-LTE models.