Numerical Simulation of Deep Tropical Convection Associated with Large-Scale Convergence

Abstract

Abstract A set of four-hour simulations has been carried out to study deep moist convection characteristic of the Global Atmospheric Research Program (GARP) Atlantic Tropical Experiment (GATE). The present model includes warm rain bulk cloud physics and effects associated with a large-scale, time-invariant convergence. The convection took approximately two hours to develop from a random moisture disturbance. The cloud efficiency, in terms of the total water vapor condensed, was near 40%. The heat and moisture budgets and the time–mean vertical fluxes of mass, heat, and moisture were calculated for the last 80 minutes of the simulations. In this study the primary emphasis was placed upon run A, the three-dimensional calculation. For this calculation, the layer centered near 4.0 km was a region of low mean cloudiness but of strong convection. The upward mass flux was strong and upward heat and moisture fluxes had maximum values in this layer. The strongest downward mass flux was due to weak downward velocit...