Improvement of ice cloud modeling capabilities in the Community Radiative Transfer Model

Ice cloud optical property look-up tables (LUTs) used in the current Community Radiative Transfer Model (CRTM) are based on the ice cloud models employed in the Moderate Resolution Imaging Spectroradiometer (MODIS) collection 5 operational retrieval products, which was known to lead to spectral inconsistencies in the ice scattering property retrievals. We solve this problem by implementing an ice cloud model consisting of roughened column aggregates in conjunction with the Gamma size distribution. The improved model has been validated in comparison with vigorous and accurate method (i.e. DISORT). Comparisons are also carried out for the ice cloud scenes simulated by CRTM and those observed from the satellite instruments. The results show that the updated ice cloud property LUTs significantly enhance the modeling capabilities of CRTM under ice cloud conditions.