Abstract This paper presents an analysis of the diurnal variation of tropical oceanic convection and its associated energy cycle as simulated by an anelastic cumulus ensemble model. The model includes subgrid turbulence, cloud microphysics, and radiative transfer processes. In two experiments designed to simulate the diurnal cycles in large-scale disturbed (A1) and undisturbed conditions (A4) over the tropical western Pacific warm pool, the model produces diurnal variations that are in general agreement with observations. In A1, a time-independent SST and mean ascending motion are prescribed in the model. The model generates a diurnal cycle with positive (negative) rainfall anomalies during the night (day), and the maximum (minimum) rainfall near 0200 (1300–1400) local time. In A4, a diurnally varying SST is prescribed in the model and the domain-averaged vertical velocity is constrained to be zero. The simulated diurnal variations still have a nocturnal rainfall maximum but with a weaker magnitude and a ...
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