Climate and Ocean Currents

1. Climate and Ocean Currents • Surface Current: Wind driven • Sub-surface current (deep ocean current): Density driven • Currents equalize global temperatures • Currents control climate • Currents provide nutrients to marine organisms

2. Open-Ocean Wind driven Surface Current

3. Ekman Effect

4. Ekman Spiral Ekman transport The integrated water mass transport is at the right angle, 90 degree, to the wind direction, known as Ekman transport. Ekman layer Ekman layer

5. Ocean Gyres

6. Geostrophic Currents

7. Equatorial Upwelling

8. Coastal Upwelling and Downwelling

9. Gulf Stream

10. Arctic Ocean Arctic Ocean Barents Sea Westward intensification Harald Sverdrup Henry Stommel

11. Westward intensification

12. Oceanic eddies Land + _ Warm- and Cold-Core Rings

13. Ocean Circulation

14. Ocean Currents And Climate August February

15. Deep ocean circulation heating cooling Upper surface water increases its density either directly by cooling or indirectly when ice freezes out to eject salt, and thus, increasing the density of the remaining water.

16. Deep water formation a. North Atlantic Deep Water (NADW) Source: Norwegian sea, Greenland Sea Labrador Sea b. Mediterranean Deep Water (MIW) Source: Mediterranean Sea d. Pacific Intermediate Water (PIW) Sources: Bering Sea c. Antarctic Bottom Water (AABW) Sources: Margins of Antarctic continent, Wedell Sea, Ross Sea Greenland Sea Norwegian Sea Labrador Sea Mediterranean Sea Wedell Sea Ross Sea

17. Global Oceanic Conveyor Belt NADW AADW Schematic diagram of the global ocean circulation pathway known as ‘conveyer’ belt due to its northward transport at the ocean surface, and southward return flow in the abyss in the Atlantic. The ocean circulation system is a slow, 3-D pattern of flow involving the surface and deep oceans around the world.

18. Ocean Circulation