Radiational parameterization for the FNWC primitive equation model using data over the oceans for 16 July 1974

Abstract

This study employs a radiational model, with large-scale cloud parameterization in several layers, in order to compute the absorption of solar insolation by the ocean's surface and by atmospheric layers, and to compute the planetary albedo for the FNWC primitive equation model. Solar insolation dispositions were computed on a gridpoint basis using water-vapor mass and cloud amounts. Using emissivity formulas after Sasamori, the long-wave cooling effects were calculated at the earth's surface and over the tropospheric layers, and were found to be dependent upon the cloud parameterization. FNWC data over oceanic gridpoints for 16 July 1974 were used to test two forms of the cloud parameterization. The objective was to determine the parameterization which better verified the radiational balance at the top of the atmosphere as a function of latitude as compared with satellite climatology. The smaller cloud parameterization gave the better verification.