1. Hydrosphere - Unit 3
OCEANS

2. What is density?
Density is MASS
per unit VOLUME

3. Ocean Currents Ocean currents are created by changes in: Temperature
and
Salinity

4. Ocean Temperature The Sun heats the upper layers of water.
First meters of water much warmer due to mixing (distributes the heat).
Deeper waters are much colder, often just around 4°C.

5. Ocean Temperature

6. Ocean water and Density
How do we relate ocean temperature and density?
Cold water is MORE dense, therefore it will sink.
Warm water is LESS dense, therefore it will rise.

7. Density of Ocean Water Affected by temperature.
Higher temperature = lower density
Lower temperature =higher density

8. Density of Ocean Water Affected by salinity.
Low salinity = lower density
Higher salinity = higher density
Low Salinity
High Salinity

9. Video Clips
Ocean Current Salinity Experiment
Ocean Stratification Demo

10. Ocean water exchanges heat in the water with the atmosphere
Thermohaline circulation: a worldwide current system in the ocean.
North American Deep Water (NADW)
the deep portion of the thermohaline circulation
denser, saltier, cool water that sinks
moves deep beneath the surface
Ocean Temperature

12. Types of Ocean Currents
Deep Currents
Caused by differences in:
Temperature
Salinity
Surface currents
Caused by:
Winds
Deflection off of continents
Coriolis Effect

13. Videos
Coriolis Effect Video: (
Difference between Surface and Deep Currents:

14. Gyres
Gyres are large current systems created by global winds and the Earth’s rotation.

15. GYRES

16. Gulf Stream Part of the N. Atlantic Gyre.
Warm water current that moves up the East coast of the US.

17. Pacific Trash Gyre Video

18. Convection Currents
Convection currents are the movement of water due to changes in temperature

19. Convection Currents

20. Mr. Wizard!!!! Convection Currents

21. How does water Keep Its Temperature?
Specific Heat - the amount of heat required to change a mass of a substance by one degree in temperature.
Water has a HIGH specific heat.

22. What does this mean?
It takes a lot of heat to change the temperature of water.
Once water is warmed, it takes a long time for it to lose it’s warmth.

23. What causes COLD water to be brought towards the surface?
As the wind blows water surface water away from the shore, deep cold water is brought up to replace the surface water. This process is called an upwelling.

24. Upwellings
Upwellings bring cold, deep, nutrient-rich water from the bottom.

25. Partners/Groups for OA Lab
Lorin/Irina Liam/Brock
Matthew/Jordan Brendan/Jared/Kevin
Jerrel/Greg Raul/Cameron/Joshua
Michael/Bryan Abigail/Rachael
Brittany/Kallie Alex/Emilio/Brian