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Course rewards. Free statement of participation on completion of these courses. Create your free OpenLearn profile. Course content Course content. The oceans Start this free course now. Free course The oceans. Figure 17 a The Ekman spiral pattern under ideal conditions in the Northern Hemisphere.
Each successive layer of water is deflected to the right. The lengths of the arrows correspond to the strength and direction of the current. The force from the wind is balanced by the Coriolis force.
In the Southern Hemisphere the direction of the spiral and the average motion is reversed. Long description. View larger image. Figure 18 The mean global surface wind pattern in July.
Previous 4. Because the Earth rotates, surface water moves to the right of the wind direction in the Northern Hemisphere and to the left of the wind direction in the Southern Hemisphere due to the Coriolis effect. The speed and direction of the moving water changes with depth. Ocean water at the surface moves at an angle to the wind, and the water under the surface water turns a bit more, and the water below that turns even more.
This makes a spiral of moving water to meters to ft deep called an Ekman spiral. The average direction of all this turning water is about a right angle from the wind direction. This average is Ekman transport. The Ekman spiral and Ekman transport are named for Swedish scientist V. Walfrid Ekman who first described the spiral in To help him make a mathematical model of these movements, Ekman used the observations that Fridtjof Nansen made while frozen into the Arctic sea ice.
An Ekman spiral A is a rotating column of water that forms when water moves at an angle to the wind direction due to the Coriolis Effect. The net effect of the rotating water B is movement at right angle to the wind direction.
The example shown above is for the Northern Hemisphere.
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