Inverting for geophysical parameters from IMG radiances

Radiances observed by the Interferometric Monitor for Greenhouse gases sounder have been used to retrieve temperature, water vapor, and ozone profiles. It is shown that the sounder allows one to simultaneously retrieve stable solutions for temperature and water vapor. Once water vapor and temperature have been retrieved, ozone profile may be estimated on the same fine vertical mesh as water vapor and temperature. Comparison among calculated and observed radiances shows good agreement in several parts of the thermal band which is sensed by the sounder. A slight discrepancy is observed in the wing region of the 720-cm^-1 CO₂ Q-branch, whereas the most severe form of disagreement is seen in the 6.7-μm vibrational H ₂O absorption band. Nevertheless, suitable spectral ranges may be identified which yield accurate and stable inversions for temperature, water vapor, and ozone