Activity 5

Prevailing winds develop waves and push them in one predominant direction forming surface ocean currents. This produces strong Equatorial Currents due to the trade winds and mid-latitude Easterly Currents due to the prevailing westerly winds. Surface ocean currents die out just like particle motion associated with wave motion dies out. As a result of the Coriolis force, the Trade winds (tropical easterly winds) push surface water to the west and north while the mid-latitude westerlies push water to the east and south. This forms a dome of water near 30° latitude (on average) between the two wind belts. As the dome builds, it sets up a pressure gradient and water attempts to flow away from the dome. As it flows away, it is deflected by Coriolis force and ends up flowing in the same direction as the prevailing winds on either side of the bulge. As currents flow west under the trade winds, they strike continental barriers. The currents are then deflected mostly northward (southward) in the northern (southern) hemisphere by the Coriolis effect forming Western Boundary Currents. The Gulf Stream in the North Atlantic Ocean is a prime example of this process.

http://earth.usc.edu/~slund/systems/topic4.html

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