Application of a 3D delta-Eddington radiative transfer model tocalculation of solar heating and photolysis rates in a stratocumulus cloudlayer,

摘要

Abstract: A number of problems of aerosol/cloud and radiation/cloud interactions, as well as cloud chemistry, related to climate change study, which could be addressed with 3-D cloud structure models which incorporate a detailed `inventory' of physical processes. Also, cloud remote sensing problems can be sensitive to the 3-D structure of clouds. Those problems motivate us to develop a 3-D Large Eddy Simulation model with explicit description of cloud microphysical processes. The model output contains fields of aerosol and drop size distributions, among other output parameters. Some results of recent model runs are presented. In order to study a 3-D radiance response of the system we derive a `two-stream' approximation of radiative transfer for a 3-D inhomogeneous medium based on a 3-D delta- Eddington method. The basic equations of the method are derived and the solution method is outlined. Relevance of the model to investigation of arctic stratus layers is discussed. !21