Western Boundary Undercurrent

The Western Boundary Undercurrent is a deep ocean current that flows southward along the western edge of the North Atlantic Ocean. It is part of the larger thermohaline circulation, which is driven by differences in water temperature and salinity. This current is formed primarily from North Atlantic Deep Water (NADW), which sinks in the Greenland and Norwegian seas. The NADW then flows southward, pressed against the western side of the Atlantic, and eventually spreads into the Indian and Pacific oceans.1

The thermohaline circulation is a slow but significant process that extends to the seafloor and influences global ocean patterns. It contrasts with wind-driven circulation, which is more vigorous and confined to the surface layer. The Western Boundary Undercurrent plays a role in ventilating the Atlantic Ocean and is a key component of the global ocean's heat and nutrient distribution.12