Cirrus cloud optical and microphysical properties determined from AIRS infrared spectra

[1] We developed an efficient thermal infrared radiative transfer model on the basis of the delta-four-stream approximation to facilitate high-spectral-resolution remote sensing applications under cirrus cloudy conditions in the Atmospheric Infrared Sounder (AIRS) data. Numerical experiments demonstrated that sensitivity in the 800-1130 cm 1 thermal infrared window spectral region is sufficiently distinct for the inference of cirrus optical depth and ice crystal mean effective size and shape factor. We analyzed 312 nighttime cirrus pixels in twoAIRS granules over ARMTWP sites and applied the radiative transfer model to these cases to determine cirrus optical depth and ice crystal mean effective size, based on a look-up table approach. The retrieval program has been evaluated through an error budget analysis and validation effort by comparing AIRS-retrieved results with those determined from ground-based millimeter-wave cloud radar data at ARM TWP sites, for five AIRS pixels that were collocated and coincident with ground-based measurements. Citation: Yue, Q., and K. N. Liou (2009), Cirrus cloud optical and microphysical properties determined from AIRS infrared spectra, Geophys. Res. Lett., 36, L05810, doi:10.1029/2008GL036502.