Retrieval of mesospheric and lower thermospheric kinetic temperature from measurements of CO2 15 υm earth limb emission under non-LTE conditions

We present a new algorithm for the retrieval of kinetic temperature in the terrestrial mesosphere and lower thermosphere from measurements of CO2 15 μm earth limb emission. Non-local-thermodynamic equilibrium (non-LTE) processes are rigorously included in the new algorithm, necessitated by tile prospect of satellite-based limb radiance measurements to be made from the TIMED/SABER platform in the near future between 15 km and 120 km tangent altitude. The algorithm requires 20 seconds to retrieve temperature to better than 3 K accuracy on a desktop computer, easily enabling its use in operational processing of satellite data. We conclude this letter with a study of the sensitivity of the retrieved temperatures to parameters used in the non-LTE models, including sensitivity to the rate constant for physical quenching of CO2 bending mode vibrations by atomic oxygen.