1. Surface Currents
Movement of water that flow in the upper part of the ocean’s surface

2. Surface Currents
1. Caused by friction between the ocean and the wind that blows across its surface
2.Created by the prevailing wind system
3. Currents are closely related to the general circulation pattern of the atmosphere
4. Can be localized, seasonal or permanent

3. The major cause of gyres is…
the Coriolis effect – the deflection of currents away from their original as a result of the Earth’s rotation
Northern Hemisphere – deflection to the right
Southern Hemisphere – deflection to the left

4. Gyres

5. Currents and Climate
low latitude currents move to high latitudes – transferring heat from the warm to the cooler areas
High latitude currents move to low latitudes – transferring cooler water to warmer climates
Ocean water movement accounts for ¼ of heat transport on the Earth

6. The Gulf Stream brings warmer water to Great Britain and Northwestern Europe
Causes warmer winters (felt in the middle latitudes)

7. Upwelling Wind induced
The vertical rising of cooler water from deeper layers of the ocean to replace warmer surface water
cooler temperatures brings greater amounts of nutrients and therefore greater amount of fish and other marine life

11. Ocean Water Trends??????
Temperature:
Density:
Salinity:

13. Deep Ocean Circulation
Significant vertical movement
Accounts for the thorough mixing of deep- water masses

14. Density Currents
Dense water sinks and spreads out beneath the ocean’s surface
Increased density caused by:
decrease in temperature
increase in salinity

15. High Latitudes (decrease in temps.)
where most deep currents begin
sea-ice is formed due to cold temps., leaving behind a greater salinity of remaining water, which then sinks
highest density of ocean water found near Antarctica
ocean water sinks and travels the ocean basin for some years

16. Evaporation (increases in salinity)
high temps. - increase evaporation
less water leads to greater salinity of remaining water
remaining water sinks to ocean basin and travels the globe

17. Conveyor Belt – Thermohaline Circulation
warm surface water flows towards the poles
at the poles water temp. drop - salinity increases making it more dense and it sinks

18. sinking water then moves towards the equator on the ocean floor
at the equator the water is cold and deep
deep water eventually upwells to complete the circuit –
influences global climate by warm water releasing heat into the atmosphere

20. Predict:
What would happen if thermohaline circulation were to stop?