Gulf of Maine intermediate water

Abstract

The thermohaline dynamics of the Gulf of Maine are analyzed from the two year, eight cruise, data set of Colton, Marak, Nickerson, and Stoddard (1968). Six water masses are described: the Maine Surface Water, Maine Intermediate Water, and the Maine Bottom Water as interior water masses; and the Scotian Shelf Water, the Slope Water, and the Georges Bank Water as exterior water masses. Particular attention is given to the formation and disposition of the Maine Intermediate Water. Salt balance, T-S volume, and T-S drift analyses are used to provide transport and mixing estimates for the year 1966. The Slope Water entered at depth through the Northeast Channel at a rate of 2600 km/sup 3//yr; while the Scotian Shelf Water entered the surface and intermediate layers, mostly during winter intrusions, at a rate of 5200 km/sup 3//yr. The surface and intermediate layers exported a total of 7900 km/sup 3//yr in a 3:5 ratio, respectively. The Maine Intermediate Water tends to collect over the Wilkinson Basin during the stratified season, to exit via the Great South Channel during early spring, and to exit via the Northeast Channel during spring and summer. Comparisons are made between the estimated winter heat loss of 280more » Ly/d and the observed heat losses of 230 Ly/d (surface layers) and 360 Ly/d (surface and intermediate layers). A limit for the Scotian Shelf Water contribution is about -70 Ly/d. It is concluded that the Maine Intermediate Water is produced locally and that it is exported in significant quantities.« less