Surface Pathways Connecting the South and North Atlantic Oceans

The North Brazil Current (NBC) is considered a bottleneck in the South Atlantic, responsible for carrying upper-ocean waters into the North Atlantic. This work explores the surface pathways connecting the NBC and 26 degrees N in the North Atlantic. To identify said pathways, we use observational trajectories from surface drifters in conjunction with transition path theory applied on a Markov chain. The pathways are computed as ensembles of paths transitioning directly between the NBC and 26 degrees N. Our results suggest that there are two dominant surface pathways: The first is the traditional pathway through the Caribbean Sea and Gulf of Mexico, carrying waters to the Florida Current, while the second is a direct route east of the Caribbean supplying waters to the Antilles Current and basin interior. The latter is composed of multiple pathways that are collectively more probable than the traditional pathway.