Unit 5 - Surface currents

• Oceanic waters heat up due to Solar Radiation, becoming less dense. • Warm, less dense water moves above the cold, denser water and gives off heat to surrounding waters. • As this water cools, it sinks, taking the place of warmer water. • This creates convection currents, which cause the circulation of surface water.

• Narrow, deep, fast • On the western boundaries of ocean basins • Carries water, therefore heat from equator to poles

• Return flow of western boundary currents • Shallower, broader, colder and slower than western boundary currents. • Moves from the poles to the equator. • Driven by westerly winds

• At the equator, called the North and South equatorial currents. • Flow from East to West on each side of the equator, driven by the Easterly Trade Winds • Closes the tops and bottoms of gyres

• Type of transverse urrent. • Seperates the subtropical gyres in each hemisphere • Narrow, Eastward flowing