Computer programs that solve the equations of fluid motion and thermodynamics for the ocean are known as ocean models. They range from idealized process models to global general circulation models that couple with the atmosphere and ice for climate simulation.

Models divide the ocean into a three-dimensional grid and step forward in time, calculating velocity, temperature, salinity, and often biogeochemical tracers. Resolution determines which features can be represented explicitly; eddies, for example, require grid spacing of roughly 10 kilometers or finer. Subgrid-scale processes such as mixing are parameterized.

Ocean models are used to interpret observations, test hypotheses, forecast seasonal conditions, and project the ocean’s response to greenhouse-gas forcing. They are evaluated against satellite data, Argo profiles, and ship measurements. Continuous improvement in resolution, physics, and data assimilation has made models indispensable tools in both research and operational oceanography.

A global model run at high resolution still requires major supercomputing resources and careful validation.