ROTATIONAL TEMPERATURES AND PRODUCTION MECHANISMS OF SOME INFRARED RADIATORS IN THE DAYLIT TERRESTRIAL THERMOSPHERE

Daytime line-of-sight rates of production of vibrationally excited CO, CO2(nu(3)), and NO+ and their rotational temperatures are derived for the lower terrestrial thermosphere from the CIRRIS 1A database and co mpared with those calculated by models assuming rotational local therm odynamic equilibrium(LTE). It is found that vibrationally excited CO i s in rotational LTE, although the calculated rate of its production is about 3 times too small. The observed radiance in the 4.3 mu m band o f CO2 is found to be in good agreement with the predictions of the rot ational LTE model SHARC (strategic high altitude radiance code). The l ine-of-sight rotational temperature of this emission is, however, less than that calculated by SHARC, in agreement with earlier non-LTE mode l calculations. The reaction of N-2(+) with O is shown to be the domin ant mechanism for producing NO+ above 140 km; the experimental data ar e consistent with the production of N(D-2) and rotationally and vibrat ionally non-LTE NO+ as the main reaction channel.