Ocean currents move vast amounts of water around the globe and play an important role in transporting organisms, nutrients, and pollutants. There are three main types of currents: surface currents driven by wind, thermohaline circulation driven by temperature and salinity differences, and wind-driven upwelling where wind causes deeper water to rise. Surface currents form massive circular gyres in each ocean basin and eddies that transport materials to new areas, while thermohaline circulation drives a global conveyor belt of water movement.

1. OCEAN CURRENTS

2. current mass of water moving from one place to another like a river within the ocean

3. importance: moves drifting organisms from place to place – plankton, disperse young carries eggs and larvae of organisms that have external fertilization brings food, oxygen carries away waste, pollutants

4. three types of currents surface currents thermohaline circulation (currents) wind-driven vertical currents (upwelling)

5. surface currents wind driven currents occur at surface horizontal currents caused by friction between wind and water - wind pushes water

6. surface currents Coriolis effect causes moving objects in northern hemisphere to veer clockwise causes moving objects in southern hemisphere to move counter- clockwise

7. surface currents Coriolis effect

8. surface currents gyre massive circular system of wind-driven surface currents cover whole oceans clockwise in Northern hemisphere counter-clockwise in Southern hemisphere

9. surface currents eddies = warm core rings break off of currents and transport organisms elsewhere

10. thermohaline circulation (currents) causes deep ocean circulation vertical currents temperature and salinity cause water density differences due to density differences, water masses rise and fall

11. thermohaline circulation (currents) ↑ salinity = ↑ density = water mass sinks ↑ temp. = ↓ density = water mass floats

12. thermohaline circulation (currents)

13. thermohaline circulation (currents) when combined with surface currents, results in conveyor belt movement of water around globe

14. wind driven vertical currents = upwelling wind blows, moves water away, causes new water to rise up to replace it