The sensitivity of spectral resolution far-infrared radiances to the microphysical and optical properties of ice clouds

The sensitivity of the high-spectral resolution radiances in the far-infrared region (100 to 700 cm^-1) to the microphysical and optical properties of ice clouds is investigated. A combination of the discrete ordinates radiative transfer model for dealing with multiple scattering and a line-by-line model for computing the monochromatic atmospheric molecular absorption is utilized to simulate the infrared radiative spectrum at the top of the atmosphere with a resolution of 0.2 cm^-1. Sensitivity of the far-infrared radiances to ice crystal shape, ice cloud optical thickness, effective sizes, cloud-top height, and cloud geometrical thickness is studied in detail. The sensitivity study reveals that the high-spectral resolution far-infrared radiances can be potentially useful for inferring the microphysical and optical properties of ice clouds.