Circulation in the eastern North Atlantic

Basin-wide geostrophic shear profiles have been computed for several latitudes in the eastern Atlantic between 32 and 53N. The absolute velocity on each section has been chosen so that the transport satisfies the Sverdrup relation. It is concluded that the wind-driven currents are not confined to the upper thermocline but extend to great depth. The inferred large-scale circulation south of 48N is slow (order 1 cm/s) at all levels and around 1000 m depth the meridional flow is near zero. Thus, there is very little N-S flow through the saline Mediterranean plume. Above 850 m a south-going drift develops between 48 and 30N which is fed by flow crossing the mid-Atlantic ridge from west to east principally south of 40N. Between 1200 m and 3500 m depth, water enters from the north and crosses the mid-Atlantic ridge from east to west with a flux approximately uniform with latitude. Both agreement and disagreement with other studies is noted.