1. Ocean Circulation
16.1

2. 16.1 Ocean Circulation
Ocean current is the mass of ocean water that flows from one place to another.
Two types of ocean currents:
Surface currents
Density currents

3. 1. Surface Currents
Surface currents are movements of water that flow horizontally in the upper part of the ocean’s surface.
• How do you think that a surface current develops?

4. Ocean Surface Currents
Gyres = Clockwise rotation north of equator
Gyres = Counter clockwise rotation south of equator
Gyres are huge circular-moving current systems that dominate the surfaces
of the oceans

5. Coriolis Effect
The Coriolis effect is the deflection of currents away from their original course as a result of Earth’s rotation.

6. 2. Density Currents
Density currents are deep water currents that occur below the surface currents.
Density currents move vertically.
Density currents occur in cold, salty water.
Surface currents
Density currents

7. The Composition of Seawater
The Ocean Conveyor Belt moderates earth’s climate.
• When currents from equator move into north and south poles, they transfer heat from warmer to cooler areas on Earth.
• As cold water currents from north and south poles travel toward the equator, they help moderate warm temperatures of adjacent land areas.
Equator
Red = warm water
Blue = cold water

8. The Composition of Seawater
A Conveyor Belt
• In a simplified model, ocean circulation is similar to a conveyor belt that travels from the Atlantic Ocean, through the Indian and Pacific Oceans, and back again.

9. The Composition of Seawater
1. Upwelling is the rise of cold water from deeper layers to replace warmer surface water.
2. Upwelling brings greater concentrations of dissolved nutrients, to the ocean surface.

10. Effects of Upwelling
Makes no sense without caption in book

11. El Nino Normal Year Offshore winds Good fishing El Nino Year Rain
Poor fishing