A Parameter Study of Interactions Between Convective Clouds, the Convective Boundary Layer, and a Forested Surface

Abstract

A numerical model was developed which included cloud parameterizations, a convective boundary layer, solar and longwave radiation, a soil layer and a parameterized forest layer. The model simulated the growth of the convective boundary layer and convective clouds on days when solar heating was primarily responsible for the convection, and meso- or synoptic-scale forcing was weak. The simulations agreed more closely with observations, and were generally more realistic when the parameterized forest layer and interactions between clouds and radiation fluxes were included. Observations and simulations suggest that the model might be able to predict both the onset and general location of regions of cumulonimbus. The simulations also suggest that surface parameters such as soil moisture, forest coverage and transpiration, and surface roughness may affect the formation of convective clouds and rainfall through their effect on boundary-layer growth.