As a precursor to the embedding of a thermal stratification model of the ocean into an Ocean General Circulation Model (OGCM) we have compared the performance of an integral (or bulk) (Kraus-Turner) and a differential (Eddy Diffusion Dimension 1) thermal stratification model for the eastern Indian Ocean. Forced with the Comprehensive Ocean-Atmosphere Data Set (COADS) and Subjectively Estimated Cloudiness in the Australian Region (SECAR) data sets, both models successfully stimulated the annual cycle in sea surface temperature. On the other hand, their predictions of the mixed layer depth differed substantially. Whereas the differential model slightly underestimated the winter mixed layer depth, the winter mixed layer depths calculated by the bulk model were substantially larger than the observed values. An additional analysis of the simulated heat storage cycle of the eastern Indian Ocean with respect to the activity of tropical-extratropical cloudbands in the Australian region has reveaved a strong relationship between these two parameters. The results have shown that a stronger activity of the tropical-extratropical cloudbands coincides with periods of heat transfer oriented from the ocean to the atmosphere.