A Coupled Dynamical-Radiational Model of Stratocumulus

A model dealing with interactions between the air and low stratiform clouds is presented based on the mixed-Layer model Lilly (1968) pioneered and on Deardorff’s three dimensional numerical model results. Its main new aspects lie in 1) consideration of the natures of both the atmosphere and cloud; 2) a new entrainment velocity scheme with few arbitrary assumptions; 3) transition from one-mixed layer to two-mixed layer model; and 4) parameterization of radiation and precipitation calculations.The model results for radiation, moisture, and heat turbulent fluxes turn out to be in good agreement with those calculated or observed by Kawa (1988). Nicholls (1984), and Schmets et al. (1981) in California, the North Sea, and the North Atlantic, respectively.Basically, this paper furnishes the theoretical basis for a model to address questions concerning the time-evolu-tion of thermodynamical profiles both in cloud and out of cloud. The applications of this model will be in a separate paper.