Evidence for an eastward flow along the Central and South American Caribbean Coast

Abstract

Hydrographic transects suggest an eastward flow with a subsurface core along the entire southern boundary of the Caribbean Sea. The transport of the coastal limb of the Panama‐Colombia Gyre (PCG), known as the Panama‐Colombia Countercurrent, decreases toward the east (from ∼6 Sv off Panama), as water is lost into the recirculation of the PCG. Off Panama, the flow is strongest at the surface, but, off Colombia, it is strongest at around 100 m. A portion of the counterflow (∼1 Sv) continues eastward along the Colombian coast as far as the Guajira region (12°N, 72°W), where it submerges to become an undercurrent beneath the coastal upwelling center there. The eastward flow also occurs in the Venezuela Basin, beneath the coastal upwelling region off Cariaco Basin and exits the Caribbean through the Grenada Channel at around 200 m depth. Numerical simulations suggest that this flow, counter to the Caribbean Current, is a semi‐continuous feature along the entire southern boundary of the Caribbean, and that it is associated with offshore cyclonic eddies. It probably constitutes part of the Sverdrup circulation of the Tropical North Atlantic cyclonic cell.