1. OCEAN CURRENTS

2. What is a Current ? mass of water moving from one place to another
like a river within the ocean

3. Why are Currents Important? moves drifting organisms from
place to place – plankton,
disperse young
carries eggs and larvae of
organisms that have external
fertilization
brings food, oxygen
carries away waste,
pollutants

4. Three Types of Currents
surface currents
thermohaline circulation (currents)
wind-driven vertical currents (upwelling)

5. Surface Currents wind driven currents occur at surface
horizontal currents
caused by friction between wind
and water - wind pushes water

6. Surface Currents Coriolis effect causes moving objects
in northern hemisphere
to veer clockwise
in southern hemisphere
to move counter-
clockwise

7. Surface Currents
Coriolis effect 7

8. Specific Surface Currents:
Gyre -
massive circular system of wind-driven
surface currents
cover whole oceans
clockwise in
Northern hemisphere
counter-clockwise
in Southern
hemisphere

9. Specific Surface Currents:
Eddies = warm core rings
break off of currents and transport organisms elsewhere

10. Thermohaline Circulation (currents)
causes deep ocean circulation
vertical currents
temperature and salinity cause water density differences
due to density differences, water masses rise and fall

11. Thermohaline Circulation (currents)
↑ salinity = ↑ density = water mass sinks
↑ temp. = ↓ density = water mass floats

12. Thermohaline Circulation (currents)12

13. Thermohaline Circulation (currents)
when combined with surface currents, results in conveyor belt movement of water around globe

14. Upwelling (Wind Driven Vertical Currents)
wind blows, moves water away, causes new water to rise up to replace it

15. How does the Ocean Affect the Weather?
OCEAN-ATMOSPHERE INTERACTION
How does the Ocean Affect the Weather?

16. OCEAN-ATMOSPHERE INTERACTION
- Water, gases, and energy are exchanged between the ocean and atmosphere

17. OCEAN-ATMOSPHERE INTERACTION
This Exchange:
- Moderates the surface temperatures of the ocean
- Shapes the Earth’s weather and climate
- Generates most of the ocean’s waves

18. How are Weather and Climate Different?
WEATHER is the state of the atmosphere at a specific place and time
CLIMATE is the long-term (30 year) average of weather in an area
Both weather and climate are affected by the ocean

19. Ocean’s Effect on Local Weather
                                                                                                                                                                                
Ever Notice???
The weather inland is different than the weather closer to the coast.
WHY???

20. WINTER 41 54 50 43
Water is warmer than land during winter. The ocean warms the cities right along the coast. 52

21. SUMMER
101 91 87 98
Water is cooler than the land during summer. Now the oceans cools the coastal cities. 89

22. Why is there almost always a breeze at the beach?
Coastal Breezes
Why is there almost always a breeze at the beach?
- The land and water heat at different rates
- Land heats and cools faster than the water

23. Afternoon Breezes are onshore
Clouds Form
Cool air sinks to fill in the space
Afternoon Showers
Warmer temperatures cause air to rise
Onshore Breeze
Cooler Ocean
Warmer Land

24. Evening Breezes are offshore
Cool air sinks to fill in the space
Warmer temperatures cause air to rise
Offshore Breeze
Warmer Ocean
Cooler Land