Low-latitude western boundary currents
Low-latitude western boundary currents (LLWBC) are western boundary currents located between the subtropical gyres, within 20° of the equator. They are important for closing the tropical circulation driven by the equatorial zonal flow, and facilitate inter-ocean transport between the subtropical gyres. They occur in regions of negative (positive) wind stress curl in the southern (northern) hemisphere, and originate at the western bifurcation point of the South or North Equatorial Current. They are typically equatorward (cyclonic) as opposed to sub-tropical western boundary currents, which tend to be poleward (anticyclonic). Some well-known examples include the Mindanao Current (MC) and the (EACC). LLWBCs transport a lot of mass, and bring cooler, saltier, and denser water from the subtropics to the warm, less salty, and less dense waters of the tropics. They are subject to changes in intensity and direction on seasonal and multi-annual timescales because of the annual variance in latitude of the equatorial currents and El Niño-Southern Oscillation. (Wikipedia).
