Effects of Inhomogeneous Cloud Properties on 2-D Longwave Radiative Transfer

Clouds have a profound influence on radiative fluxes, for both solar and infrared radiation. Inhomogeneous clouds, in particular, have complex effects on fluxes and can be challenging to parameterize. Killen and Ellingson (1994) showed the importance of cloud geometry and spatial distribution on infrared fluxes, while Takara and Ellingson (1996) emphasized the necessity of modeling both cloud geometry and scattering to obtain accurate longwave fluxes. Both these studies point to the need for a thorough understanding of the radiative effects of inhomogeneous clouds. This study used the Spherical Harmonics Discrete Ordinate Method (SHDOM) radiative transfer model with three sets of large eddy simulation (LES) output to explore the effects of inhomogeneous clouds on infrared fluxes, including the errors produced by common approximations compared to a full solution.