SURFACE CURRENTS

Surface Currents• horizontal• wind-driven• caused by friction between wind and water• wind blows water, but then Coriolis effect affects direction of water movement

Coriolis Effect

Coriolis Effect• wind blows the water, but then water is deflected clockwise or counterclockwise

• results in:gyres – massive circular systems of wind-driven surface currents – similar patterns in Atlantic, Pacific and IndianOceans

main gyres in the world’s ocean

northern hemisphere - clockwisesouthern hemisphere - counterclockwise

WIND PATTERNS

wind patterns and Coriolis effect result in the major currents in

the ocean

Western Boundary Currents• along western edge of ocean basins• strongest currents in oceans• in part due to amplification of Coriolis

effect at higher latitudes• ex: Gulf Stream Current

Eastern Boundary Currents

• along eastern edge of ocean basins• much weaker• ex: Canary Current

western boundary currents arestronger than eastern boundary currents

The Gulf Stream• known for years that currents could

help ships travel faster• Benjamin Franklin had first map of

Gulf StreamCurrent made

The Gulf Stream• western boundary current in North Atlantic• strongest current in ocean• separates cold northern water from warmer water of the Sargasso Sea

TheGulf

StreamCurrent

Eddies• also called warm core rings• break off of currents• can transport tropical organisms to

Long Island waters

howeddiesform