Comparison of Monte Carlo Calculations with Observations of Light Scattering in Finite Clouds

Abstract

Abstract Two experimental data sets have been compared with calculations of solar radiation scattered by finite cumulus clouds. The first approach was to observe the radiation exiting the sides of cumulus clouds from 0.8 to 3.0 km in vertical thickness as a function of azimuth angle relative to the sun. Results indicated that small scale feature in the clouds are not accounted for by a cubic model, but observations averaged over the cloud side are well represented by the model. Observations and model computed relative radiances yield a correlation coefficient of 0.91. The second approach was to observe cloud-to-cloud radiative interaction in the laboratory using rayon clouds to simulate optically thick cumulus clouds. These observations also agree well with theoretical predictions. The results of the two experiments confirm that the Monte Carlo model simulations are compatible with calculations for finite clouds. They also give confidence to the use of physical models such as rayon in exploring radiative ...