A diagnostic calculation of the general circulation of the atlantic ocean

Abstract

The general circulation of the Atlantic Ocean is calculated from the low Rossby number equations of motions where all frictional terms except surface wind stress are neglected. Climatological sea surface wind stress, temperature, and salinity, and bottom topography are inputs to the calculation. Total transport is calculated by integrating the vertically integrated equations of motion along contours of constant planetary potential vorticity, f/ H, where f is the Coriolis parameter and H is the local depth. The integration begins on the eastern boundary of the ocean where the total transport is assumed to be zero. Results are also obtained for three transport components; Ekman transport, thermohaline transport, and bottom velocity transport. Despite the rather crude 1° × 1° calculation grid, the results show considerable detail, particularly in the higher latitude Atlantic Ocean. The calculations yield about a 25 × 10 6 m 3 s −1 transport through the Straits of Florida increasing to a maximum Gulf Stream transport of about 90; about 25 × 10 6 m 3 s −1 of this is entrained flow from a Southwestward, nearly barotropic flow along the Middle Atlantic Bight continental slope. Unlike the wind-driven, constant depth, Sverdrup transport result, total transport streamlines are closed in the western boundary without need of bottom or lateral friction in the governing equations.