1. Oceans and Climate Changes

2. Movement of water from one place to another
Ocean Currents
Movement of water from one place to another

3. Surface Currents
Powered by wind
Move upper few 100 meters of seawater

4. Wind forms when air in an area of high pressure moves to an area of lower pressure
Equator’s warm air is pushed up by denser, colder air
The Pole’s cold air, sinks below less dense air

5. Due to the movement of the earth, wind and currents DO NOT move in straight lines

6. The Coriolis Effect – rotation of the Earth causes moving air and water to change direction
To the right north of the equator
To the left south of the equator

8. Gulf Stream Current - Warm
Atlantic Ocean
Brings warm water from the equator up North
Keeps N. American East Coast Waters warm
Keeps Iceland mild and ice-free all year

10. California Current - Cold
Pacific Ocean
Brings waters from North pole down South
Keeps North American West Coast Cool

12. Density Currents More dense water sinks and pushes up less dense water
This moves water around globe

13. What makes Water Dense? Cold Temperature
High Salinity (amount of salt in water)

14. Cold, Salty Water
When water freezes, salts are dissolved and left in unfrozen water
This makes unfrozen water VERY DENSE
When frozen water melts, it is less dense
This causes a change in density and movement of water…DENSITY CURRENTS

15. WHY IS THIS IMPORTANT?

16. It is important because…
If the ice caps where to melt, then we would have a large amount of less dense water
If salinity is reduced, then density currents would WEAKEN or STOP
This would cause major CLIMATE SHIFTS
Change in climate
Change in weather

17. El Nino
An occasional climatic event in which strong Pacific winds WEAKEN or REVERSE

18. Effects of El Nino Ocean temperatures near Peru HEAT UP.
The position and strength of one of the jet streams may be altered, changing wind and precipitation patterns around the world.
Africa and Australia may experience drought

22. The winds blowing across the Pacific are stronger than normal
La Nina
The winds blowing across the Pacific are stronger than normal