Abstract: Marine boundary layer stratus and stratocumulus clouds are of greatimportance for the heat balance of the earth-atmosphere system.Due to be highly variable in time and space,direct measurement of clouds is never sufficiently dense to determine temporal and spatial variability in cloud depth,cloud droplet number,and effective radius from the observations alone,nor can feedback mechanisms be easily quantified solely on the basis offield data.Modeling of stratocumulus has received much attention in the past years.