SOFAR float Mediterranean outflow experiment data from the first year, 1984-1985

Abstract

In October, 1984, the Woods Hole Oceanographic Institution SOFAR float group began a three-year long field program to observe the low frequency currents in the Canary Basin. The principal scientific goal was to learn how advection and diffusion by these currents determine the shape and amplitude of the Mediterranean salt tongue. Fourteen floats were launched at a depth of 1100 min a cluster centered on 32N, 24W, and seven other floats were launched incoherently along a north/south line from 24N to 37N. At the same time investigators from Scripps Institution of Oceanography and the University of Rhode Island used four other SOFAR floats to tag a submesoscale lens of Mediterranean water. Slightly over twenty years of float trajectories were p reduced during the first year of the experiment. In this report we briefly describe the 1984 field operations and show the first year's SOFAR float data. Perhaps the most striking result is that westward flow within the Mediterranean salt tongue was found to be confined to a rather narrow jet {roughly 150 km in meridional extent) which had a mean speed of roughly 2 em s -l. To the north or south of this jet the mean flow was much weaker and eastward. This suggests that currents associated with the salt tongue itself {rather than the gyre scale circulation) may be most important for determining the salt distribution.