Numerical simulations of the effect of soil moisture and vegetation cover on the development of deep convection

Abstract

A one-dimensional (column) version of a primitive equations model has been used to study the impact of soil moisture and vegetation cover on the development of deep cumulus convection in the absence of dynamical forcing. The model includes parameterizations of radiation, turbulent exchange, deep convection, shallow boundary layer convective clouds, vegetation, and soil temperature and moisture. Vegetation cover was found to promote convection, both by extraction of soil moisture and by shading the soil so that conduction of heat into the soil was reduced (thereby increasing the available energy). The larger values of initial soil moisture were found to delay the onset of precipitation and to increase the precipitation amount. The greatest rainfall amounts were generally predicted to occur for moist, fully vegetated surfaces. -from Authors