1. Currents

2. Essential Questions What are ocean currents?
What is the purpose / role of ocean currents?
What is the Coriolis Effect?
What are thermohaline currents?
What are the major global gyres?
What are the major currents affecting Atlantic Canada?

3. What are ocean currents?

4. What is a current?
is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as:
breaking waves,
wind,
Coriolis force,
Temperature,
salinity differences, and
tides caused by the gravitational pull of the Moon and the Sun.

5. What is a gyre?
Gyres are any large system of rotating ocean currents, particularly those involved with large wind movements.
Gyres are caused by the Coriolis Effect; planetary vorticity along with horizontal and vertical friction.

6. http://education. nationalgeographic

7. Complete Investigating Ocean Currents Part 1 Lab

8. What is the purpose / role of ocean currents?

9. Purpose… to carry heat from place to place in the Earth system
affects regional climates
they transport creatures around the world and affect the water temperature in ecosystems

10. Anomalies of surface currents
Ocean Eddies
form when a bend in a surface ocean current lengthens and eventually makes a loop, which separates from the main current.
the swirling waters last for at least a few months
Warm water eddies are sparse in marine life because the water does not have many nutrients
Cold water eddies are usually full of nutrients and marine life.
Upwelling
where water from the deep sea travels up to the surface
often happens where wind blows along a coastline
upwelling areas are full of marine life

11. What is the Coriolis Effect?

12. Who discovered the Coriolis Effect?
Gustave-Gaspard Coriolis
in 1835
he was a French engineer-mathematician

14. Coriolis Effect explained…
The rotation of the Earth causes an interesting phenomena on free moving objects on the Earth.
Objects in the Northern Hemisphere are deflected to the right, while objects in the Southern Hemisphere are deflected to the left.
The Coriolis effect, thus tries to force winds to shift towards the right or left. The Coriolis effect can at times cause winds to blow back up the pressure gradient.

15. There are two reasons for this phenomenon:
Why does this happen?
There are two reasons for this phenomenon:
the Earth rotates eastward
the tangential velocity of a point on the Earth is a function of latitude (the velocity is essentially zero at the poles and it attains a maximum value at the Equator)

16. Analogous Example…
Thus, if a cannon were fired northward from a point on the Equator, the projectile would land to the east of its due north path. This variation would occur because the projectile was moving eastward faster at the Equator than was its target farther north.
Similarly, if the weapon were fired toward the Equator from the North Pole, the projectile would again land to the right of its true path. In this case, the target area would have moved eastward before the shell reached it because of its greater eastward velocity. An exactly similar displacement occurs if the projectile is fired in any direction.

17. What does the Coriolis Effect affect?
it affects the rotation of the oceanic currents
it affects prevailing winds and the rotation of storms

18. What are thermohaline currents?

19. “The Sea’s Greatest River”
Complete Investigating Ocean Currents Part 2 after watching the video
6:32mins

20. How does it work?
Thermohaline currents are driven by density differences in the water
density depends on its temperature (thermo) and salinity (haline)
At the earth's poles, when water freezes, the salt doesn't necessarily freeze with it, so a large volume of dense cold, salt water is left behind.
When this dense water sinks to the ocean floor, more water moves in to replace it, creating a current.

21. This current begins with the cold water near the North Pole and heads south between South America and Africa toward Antarctica, partly directed by the landmasses it encounters.
In Antarctica, it gets recharged with more cold water and then splits in two directions -- one section heads to the Indian Ocean and the other to the Pacific Ocean.
As the two sections near the equator, they warm up and rise to the surface as an upwelling.
When they can't go any farther, the two sections loop back to the South Atlantic Ocean and finally back to the North Atlantic Ocean, where the cycle starts again.

23. Interesting details
an underwater current circles the globe with a force 16 times as strong as all the world's rivers combined
moves much more slowly than surface currents -- a few centimeters per second, compared to tens or hundreds of centimeters per second

24. Purpose… It is crucial to the base of the world's food chain
it transports water around the globe, it enriches carbon dioxide-poor, nutrient-depleted surface waters by carrying them through the ocean's deeper layers where those elements are abundant.
nutrients and carbon dioxide from the bottom layers that are distributed through the upper layers enable the growth of algae and seaweed that ultimately support all forms of life
also helps to regulate temperatures.

25. Deep Connections The Endless Voyage Series
Complete the Self test after watching the video
27mins

26. What are the major global gyres?

27. Major gyres North Atlantic Gyre South Atlantic Gyre Indian Ocean Gyre
North Pacific Gyre
South Pacific Gyre

28. North Atlantic Gyre located in the Atlantic Ocean
contains the Sargasso Sea
circulates clockwise
traps man-made ocean debris in the North Atlantic Garbage Patch

29. South Atlantic Gyre
the southern branch of the subtropical gyre in the south Atlantic
circulates counter-clockwise
this current allows Antarctica to maintain its huge ice sheet by keeping warm ocean waters away
is the largest ocean current

30. Indian Ocean Gyre is located in the Indian Ocean
circulates counter-clockwise

31. North Pacific Gyre located in the northern Pacific Ocean
comprises most of the northern Pacific Ocean
circulates clockwise
is the largest ecosystem on our planet
an accumulation of man-made marine debris, known as the Great Pacific Garbage Patch

32. South Pacific Gyre
located south of the equator between South America and Australia
circulates counter-clockwise
is the Earth's biggest system of ocean currents
it is mostly inactive and contains little marine life

34. What are the major currents affecting Atlantic Canada?

35. The currents of the North Atlantic
The Gulf Stream
The North Atlantic Current
The Irminger Current
The Labrador Current
The Greenland Current

38. The Gulf Stream is a powerful, warm, and swift Atlantic ocean current
it originates at the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean
The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland, and the west coast of Europe
is also a significant potential source of renewable power generation

39. The North Atlantic Current
is a powerful warm ocean current
it continues the Gulf Stream northeast.
West of Ireland it splits in two.
one branch (the Canary Current) goes south
the other continues north along the coast of northwestern Europe where it has a considerable warming influence on the climate.

40. The Irminger Current
is a north Atlantic ocean current setting westward off the southwest coast of Iceland

41. The Labrador Current is a cold current in the North Atlantic Ocean
it flows from the Arctic Ocean south along the coast of Labrador and passes around Newfoundland, continuing south along the east coast of Nova Scotia
It meets the warm Gulf Stream at the Grand Banks southeast of Newfoundland and again north of the Outer Banks of North Carolina. The combination of these two currents produces heavy fogs and also created one of the richest fishing grounds in the world.
In spring and early summer, this current transports icebergs from the glaciers of Greenland southwards into the trans-Atlantic shipping lanes.
have a cooling effect on the Canadian Atlantic provinces and coastal New England

42. The Greenland Current
is a weak cold water current that flows to the north along the west coast of Greenland