Direct retrieval of stratospheric CO2 infrared cooling rate profiles from AIRS data

Abstract

We expand upon methods for retrieving thermal infrared cooling rate profiles, originally developed by Liou and Xue (1988) through application to the inversion of the stratospheric cooling rate produced by carbon dioxide (CO2) and a formal description of the associated error budget. Specifically, we infer lower- and mid-stratospheric cooling rates from the CO2 ν2 band on the basis of selected spectral channels and available data from the Atmospheric Infrared Sounder (AIRS). In order to establish the validity of our results, we compare our retrievals to those calculated from a forward radiative transfer program using retrieved temperature data from spectra taken by the Scanning High-Resolution Interferometer Sounder (S-HIS) on two aircraft campaigns: the Mixed-Phase Arctic Cloud Experiment (MPACE) and the Aura Validation Experiment (AVE) both in Fall, 2004. Reasonable and consistent comparisons are illustrated, revealing that spectral radiance data taken by high-resolution infrared sounders can be used to determine the vertical distribution of radiative cooling due to CO2. Copyright 2006 by the American Geophysical Union.