Explicit and Parameterized Realizations of Convective Cloud Systems in TOGA COARE

Abstract Convection and cloud processes are examined in a hierarchy of two-dimensional numerical realizations of cloud systems observed during the 19–26 December 1992 period of the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment. The hierarchy consists of cloud-resolving simulations at a 2-km resolution, and two sets of 15-km resolution simulations; one attempts to treat convection explicitly and the other parameterizes convection using the Kain–Fritsch scheme. The Kain–Fritsch parameterization shows reasonable results but shortcomings are found in comparison with the cloud-resolving model. (i) The entraining plumes in the parameterization excessively overshoot the tropopause, which produces a cold bias mostly through adiabatic cooling. The attendant moisture detrainment overproduces cirrus cloud. (ii) Because parameterized downdrafts detrain at the lowest level they generate a surface cold bias. (iii) The scheme fails to represent the trimodal convection (cumulonimbus reachi...

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