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2.2.3 Forcing for Barotropic Models

The circulation in a barotropic ocean is generally the result of two kinds of ``forcings'': the wind stress at the ocean's surface, and the source--sink mass flows at the basin boundaries. The source flows could be ocean currents that enter the basin due to wind forcing in an adjacent basin, or enter simply to replace mass driven out by the wind or baroclinic pressure gradients in the model basin. Sink flows have similar origins. However, in this first paper on the barotropic circulation we will only consider closed boundaries and confine ourselves to consideration of the wind forcing.

During the model testing stage, we will utilize only steady winds. With a steady wind forcing, the ocean will generally arrive at a steady circulation via a ``spin-up'' process. Steady winds are also customarily used in theoretical studies when one studies the balance of forces and energy conversions, and when one tries to obtain the mean or climatological circulation.