Modeling and characterization of cloud dynamics

Abstract

A phenomenological model for cloud dynamics is proposed, which consists of the successive operations of the physical processes: buoyancy, diffusion, viscosity, adiabatic expansion, fall of a droplet by gravity, descent flow dragged by the falling droplet, and advection. Through extensive simulations, the phases corresponding to stratus, cumulus, stratocumulus, and cumulonimbus are found by changing the ground temperature and the moisture of the air. They are characterized by order parameters such as the cluster number, perimeter-to-area ratio of a cloud, and Kolmogorov-Sinai entropy. Though our model is simple and constructive, it may shed some light on the true nature of clouds. © 1997 American Physical Society.