Clouds exhibit dramatic variabilities at spatial scales smaller than typical grid cells of large scale models used to study climate and weather. These unsolved cloud fluctuations are potentially important for parameterizations of both cloud radiative effects and cloud microphysical processes. It is now well accepted that neglect of cloud subscale variability can seriously bias model estimates of radiative energy budget in the Earth-atmosphere system.

The effects of cloud horizontal inhomogeneity on the radiative energy budget have been extensively studied for a single cloud layer. By contrast, little attention has been given to the radiative transfer in the multi-layer clouds with horizontal inhomogeneities. This study will focus on effects of cloud horizontal inhomogeneities in multi-layer clouds on radiative energy budget.