Aspects of the parametrization of organized convection: contrasting cloud‐resolving model and single‐column model realizations

Abstract

AbstractCloud‐resolving model (CRM) simulations of organized tropical convection observed in the Tropical Ocean/Global Atmosphere Coupled Ocean–Atmosphere Response Experiment are used to evaluate versions of the European Centre for Medium‐Range Weather Forecasts convection and cloud schemes in single‐column model simulations. Emphasis is placed upon the ability of the convection scheme to represent ‘convective‐scale’ processes with typically mode‐1 heating structures through the troposphere, together with a cloud scheme representing the ‘stratiform (mesoscale) component’ with upper‐level heating and low‐level cooling due to the evaporation of precipitation. While diagnosis of convective and stratiform precipitation is sensitive to the sampling criteria applied to the CRM, vertical structures of the mass and heat budgets are robust. Using diagnostics from the CRM simulations as a guide, revisions to the convection and cloud schemes are suggested in order to enable the parametrization to represent the two scales. The study suggests that a mass‐flux convection scheme linked via detrainment to a prognostic treatment of cloud can represent organized convection, provided that the upward motion in the upper‐level stratiform cloud is considered. Copyright © 2002 Royal Meteorological Society