Cloud properties retrievals from different radiative transfer approaches

Abstract

The amount of solar radiation flux that reaches the Earth’s surface strongly depends on the existence of clouds and consequently on its optical, geometrical and microphysical properties. Hence it is important to be able to estimate the cloud properties. The aim of this work is the estimation of cloud properties obtained from different approaches, two numerical and one analytical cloud radiative transfer model. By the combination of the analytical with a 3D numerical cloud radiative transfer model the top and base cloud shape factors, which characterize the geometrical properties of the cloud borders, are obtained. From the comparison between simulations of global solar irradiance fields at the surface obtained with an 1D numerical radiative transfer model and the global irradiance measurements from a Multi-Filter Rotating Shadow Band Radiometer YES MFRSR-7 installed at the Évora Geophysics Centre (CGE) Observatory, both the cloud cover and the cloud optical depth are obtained for some selected days.