North Brazil Current Rings Experiment : surface drifter data report, November 1998-June 2000

Abstract

This data report summarzes 45 surface drifter trajectories collected between November 1998 and June 2000 as part of the North Brazil Current (NBC) Rings Experiment. NBC rings have been proposed as one of several important mechanisms for the transport of South Atlantic upper-ocean water across the equatorial-tropical gyre boundary and into the North Atlantic subtropical gyre. Such transport is required to complete the meridional overturning cell in the Atlantic forced by the high-latitude production and southward export of North Atlantic Deep Water. The goal of this program is to obtain, for the first time, comprehensive observations of the NBC retroflection, the NBC ring formation process, and the physical structure and properties of NBC rings as they translate northwestward along the low-latitude western boundary. A total of 45 drifters were deployed. Twenty-four of these looped anticyclonically within the five rings identified during this experiment. Seven of the looping ring drifters entered the Caribbean, while the rest moved northward along the eastern flank of the Lesser Antiles.