Evidence of abyssal eddies in the Brazil Basin.

International audienceWe report evidence of two deep cyclonic and two deep anticyclonic submesoscale eddies from World Oceanographic Circulation Experiment hydrographic casts made in the Brazil Basin. We infer that three of these were likely formed in or near the Deep Western Boundary Current (DWBC) of North Atlantic Deep Water (NADW), and thus had traveled eastward after formation. These eddies appear to be a new way for transporting NADW away from the DWBC to the ocean interior. One of the apparent cyclonic eddies appeared to be laterally in contact with one of the anticyclonic eddies. About 10 days later an attempt was made to resample the apparent eddies that had been in contact. These observations, although limited, are interpreted to indicate that they survived the encounter, that the cyclonic eddy had now moved to be beneath the anticyclonic one with each being somewhat thinner, and that they produced a new anticyclonic eddy by partially merging. Deep float observations [ Hogg and Owens, 1999 ] partially support the second inference