THE PRODUCTION OF NORTH-ATLANTIC DEEP-WATER - SOURCES, RATES, AND PATHWAYS

Updating an earlier account by Dickson et al., (1990), this paper revi ews the initial development phase of North Atlantic Deep Water (NADW) production from the points where the dense inflows from Nordic seas cr oss the Greenland-Scotland Ridge to the point off south Greenland wher e the buildup of new production appears almost complete. In particular , three long-term current meter arrays totaling 91 instruments and set at approximately 160 km intervals south from the Denmark Strait sill are used to validate earlier short-term arrays by others and, in combi nation with these earlier arrays, to describe the downstream evolution of mean speed, depth and entrainment, the variability of the overflow current in space and time, and the likely contribution of the other t hree main constituents of NADW production at densities greater than si gmatheta = 27.8. From the points of overflow (5.6 Sv) the transport wi thin this range increases by entrainment and confluence with other con tributory streams to around 13.3 Sv at Cape Farewell. While recirculat ing elements prevent us from determining the net southgoing transport, a NADW transport of this order appears consistent with recent estimat es of net abyssal flow passing south through the North and South Atlan tic.