Caption title. "May 1988." At head of title: Project summary. Distributed to depository libraries in microfiche. "EPA/600-S3-88-011."

A CUmulus VENTing (CUVENT) cloud module has been developed that calculates the vertical flux of mass from the boundary layer to the cloud layer by an ensemble of nonprecipitating subgrid-scale air mass clouds. This model will be integrated into the Regional Acid Deposition Model (RADM) and will serve to establish the effect of cloud venting for the RADM. In the initial phase of this research project, the basic cloud venting algorithm was established. CUVENT used the cloud model that was established by Ritter and Stedman (1985) to calculate the vertical transport of mass due to the ensemble of nonprecipitating air mass convective clouds. The major effort of the first phase of this research project was to design an optimal parameterization scheme for the cloud model so that it may be incorporated in the RADM. This parameterization scheme used basic meteorological data such as pressure, temperature, humidity, surface heat flux, etc., to predict the convective cloud amount at cloud base and cloud distribution parameters. The various models that made up this scheme were developed using data obtained during the VENTEX field program.