A Simple Numerical Model for Studying Cloud Formation Process Inthe Tropics : Heated and Cooled Surface Experiments

A simple numerical model for demonstrating local cloud formation processes in the tropics is beingdeveloped. The model equations are derived from the fundamental system of partial differential equations ofcomputational fluid dynamics and the deep convection approximation is used to eliminate sound waves. Themodel domain is two-dimensional with length100 kilometers and height 17.5 kilometers. A non-uniform grid isused with the thinnest layer (100 meters) at the earth's surface and thickest layer (1,300 meters) at the top of thetroposphere. The horizontal cell's width one kilometer. The Arakawa-C grid is used for the leapfrog method andforward Euler method. Experiments to study the effects of heating and cooling at the surface and the deepconvection approximation in moist air are discussed. The deep convection approximation was found to beunsuitable for a model. The model without the deep convection approximation gives processes expected in thereal atmosphere.