1. Brainstorm It is a scientific fact that the Earth heats unevenly.
What evidence can you give to support this idea?
What factors do you think cause the Earth to heat unevenly?

2. Evidence?
Seasons!
If the sun were to heat the Earth evenly, there would be very little change in temperature over the course of the year.

3. 4 Factors that Cause the Earth to Heat Unevenly:
Earth is spherical (light from a single source won’t strike a sphere evenly)
Earth’s axis of rotation is tilted 23.5 degrees
Distance between Earth and sun varies with time of year
Earth’s orbit isn’t circular, it’s slightly elliptical (more heat when closer to sun)

4. Video Clip
As you watch the 6 minute clip, answer the following question:
How does the ocean influence weather and climate?

5. How is the ocean a driving force for weather and climate?
The ocean stores more heat than the atmosphere
el Niño and la Niña
Changes in water temp affect humidity in the air which steers storms in certain directions
Warm water from the Gulf is carried in the Gulf stream causing areas in Europe to be warmer
Hurricanes

6. Map Activity
Accurately draw and label the Equator, Tropic of Cancer and Tropic of Capricorn on your map.

7. Directions Cont’d
In pencil, draw and label the 7 major ocean currents indicating direction of the current
West Wind Drift (a.k.a. the Antarctic Circumpolar Current)
East Wind Drift (Antarctic Coastal Current/Antarctic Subpolar current)
North Equatorial Current
South Equatorial Current
Peru Current
Kuroshio Current
Gulf Stream

8. Directions Cont’d
Using a hot color and a cold color, indicate on the map (by tracing over your pencil lines) whether each current is a warm water current, cold water current, or contains both

9. Currents of the World

10. Fact vs. Fiction: What does Finding Nemo teach us about ocean currents?

11. What is a current? The “motion of the ocean”
A steady flow of water within a larger body of water
Surface currents and deep currents

12. Why are Currents Important?
Moderate climates
Mix nutrients and add oxygen
Transportation (larvae, nekton, boats, etc.)

13. Based on Your Map: How Do Ocean Currents Differ?
Direction of flow
Relative Temperature
Velocity

14. Demonstration Surface Currents Materials Plate 400mL of Water Cinnamon
Sand
Straw

15. How do the following 3 Factors Drive Ocean Currents?
1. The rise and fall of the tides
2. Wind
3. Thermohaline circulation

16. 1. The rise and fall of the tides
Tides create a current (called “tidal currents”) in the oceans, near the shore, and in bays and estuaries along the coast.
They are the only type of currents that change in a very regular pattern and can be predicted for future dates.

17. 2. Wind Winds drive currents that are at or near the ocean's surface.
Measured in meters per second or in knots
1 knot = 1.85 kilometers per hour or 1.15 miles per hour
Locally - winds drive currents near coastal areas
Globally – winds drive currents across the open ocean

18. 3. Thermohaline Circulation (aka Global Ocean Conveyor Belt)
A process driven by differences in water density due to temperature (thermo) and salinity (haline) variations in different parts of the ocean.
Can be deep or shallow
Move much slower than tidal or surface currents.

19. Surface Currents

20. Video Clip Bob Ballard Analogy

21. What is the Coriolis Effect?
The tendency for wind-driven surface currents to deflect to the right in the N. Hemisphere and to the left in the S. Hemisphere
Caused by the
Earth’s rotation
*Video Clip

22. What is a Gyre?
The circular flow of currents in an ocean basin due to the Coriolis effect