A comparison of seasonal thermocline models with observation

Abstract

The aim of this study is to see how well models might predict sea-surface temperature throughout the year, given the inputs of heat and mechanical energy into the ocean. With this in mind, curves relating surface temperature, heat content and potential energy of the top 250 m of ocean are obtained for one of the North Atlantic weather ships. Then comparisons are made with similar curves predicted by a series of simple models. Of those tried, the most satisfactory is a modified version of the model of Kraus and Turner, where a mixed layer is produced by both mechanical and (in the cooling period) convective mixing. In the original model, all the energy made availability by surface cooling was used to deepen the mixed layer. Much better agreement with observation is obtained if this convective stirring is non-penetrative or only slightly penetrative. This is consistent with recent atmospheric observations. Show more