The upper atmosphere of Mars cools by radiative emission from vibrationally-excited CO2. There are several vibrational states that contribute to the emission profile, and the low-lying excited states can be populated by a wide variety of V-V and V-T energy exchange processes in addition to solar pumping.  Efficient collisional energy transfer mechanisms involving CO2 can have a significant influence on the energy balance of the Martian atmosphere.  The present effort focuses on laboratory measurement of the rate coefficients for collisional self-quenching of CO2 in the eight lowest-lying vibrational states.  The goal of the work is to reduce uncertainty in the current literature rate parameters and aid in the development of more accurate non-local thermodynamic equilibrium models for the upper atmosphere of Mars.  A typical pump-probe approach is used; the rate of collisional quenching is measured by monitoring the populations of various rovibrational states of CO2 via transient infrared absorption spectroscopy following a temperature perturbation. The current status of the project will be reported.

Laboratory measurement of CO<sub>2</sub> quenching rates for Martian atmospheric non-LTE models

248th National Meeting (2014)

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Laboratory measurement of CO2 quenching rates for Martian atmospheric non-LTE models

Laboratory measurement of CO₂ quenching rates for Martian atmospheric non-LTE models