Slowing of Caribbean through-flow

Trends in near-surface currents passing through the southeastern Caribbean are described using ocean reanalysis and a coupled model projection. The decline of Caribbean through-flow is linked with tropical and polar forcing. In the upstream zone, the North Brazil Current shows increasing retroflection as the southern Hadley Cell expands across the equatorial Atlantic. This inhibits northwestward transport next to the Amazon River plume. In the downstream zone, the Labrador Current feeds low saline Arctic waters into the Gulf Stream, inducing an equatorward shift and reduced flow. Evidence is growing for spin-down of the North Atlantic gyre and its feeder currents, that inhibit poleward heat exchange and contribute to climatic shifts. Eastward trends of winds and currents in the equatorial Atlantic is projected to bring a drier climate to the lower Amazon basin and southeastern Caribbean, hence greater salinity with knock-on effects for regional sea temperatures.