1. Air and Sea Interactions
2012
Discuss with your partner……What is the difference between climate and weather?

2. Ocean Motion Constant Movement, more in some places then others.
Three Factors
Winds
Coriolis Effect
Current

3. Atmosphere Winds are named for the direction in which they blow from.
Convection Current - Moves materials around.
Cells move air in the atmosphere around.

4. Atmospheric Cells
Air movement into the atmosphere and back down.

5. Atmospheric Cells
Tell me as much as you can about each cell type based on what you see on the following slide:
Hadley Cells
Ferrel Cells
Polar Cells

7. Why is it not just one large cell….
What goes up must come down.
The cycle:
Warm air rises…less dense.
Eventually this warm air cools off.
Cool air is more dense and sinks down.

8. Three major connections
Connecting Air Cells
Three major connections

9. Meeting Air Currents – Hadley to Hadley
Intertropical Convergence Zone
Trade winds from both hemispheres converge together.
Gentle Breeze
Doldrums
Wind dies down and ships are stuck in the ITCZ

10. Meeting Air Currents – Hadley to Ferrel
Horse Latitudes – 30˚N and 30˚S
Also called Subtropical High
Winds separating in different directions.
Dry air and high pressure results in weak winds.
Desert areas
Why were they called the horse latitudes?

11. Meeting Air Currents –Ferrel to Polar
Cold air masses from higher latitudes and warmer air masses from lower latitudes
Areas of storm activity

12. Wind Patterns Movement of air across the globe.
Different air flow convergence and divergence gives us our general climate conditions.

13. Wind Patterns
Tell me as much as you can about each wind pattern based on what you see on the following slide:
Trade Winds – Northeasterly and Southeasterly
Westerlies
Easterlies (Polar)

16. Ocean Motion Currents are named by the direction they flow 2 Types:
Surface Currents
Deep Sea Circulation

17. Ocean Vertical Structure
Top Ocean Layer well mixed because of air interactions.
Pycnocline – Area between the mixed layer and deep ocean layer.
Major changes in density and salinity occur here
Increasing density.
Thermocline - Temp Changes
Halocline – Salinity Changes

18. Global Conveyor Belt Overall circulation to transport heat and salt.
Cold salt water is more dense, then the less dense warmer waters. (More oxygen and nutrients in colder water as well)
Flows top to bottom and along the surface.
Begins near Greenland 1000 years to complete a cycle.

20. Coriolis Effect Due to Earth’s rotation.
Shallow layer of the surface water is deflected to the right in the Northern hemisphere and to the left in the Southern hemisphere
At the equator this effect is at zero.

21. What happens UNDER the surface?
Wind bombards the surface ocean
Water starts to move
Coriolis deflection alters its path
What happens UNDER the surface?

22. Ekman Transport (Spiral)
surface layer (1) drags on
the water underneath (2).
layer 2 starts to move. It moves more slowly than layer 1 due to friction.
(smaller yellow arrow)
Coriolis deflection
alters path of layer 2.
Decreases as you move down the water column.

23. Upwelling
As surface waters are pushed offshore, water is drawn from below to replace them.
Good: Upwelling brings up cold, nutrient-rich waters to the surface, which encourage seaweed growth and support blooms of phytoplankton.
Bad: upwelling that moves surface water offshore can potentially move drifting larvae long distances away from their natural habitat
Most common on West Coast

24. About half the world's total fish catch comes from upwelling zones.

25. Downwelling
Where Ekman transport moves surface waters toward the coast, the water piles up and sinks.
The surface layer of warm, nutrient-deficient water thickens as water sinks.
Reduces biological productivity and transports heat, dissolved materials, and surface waters rich in dissolved oxygen to greater depths.

26. Returns oxygen poor water to be recycled

27. Boundary Currents Western Currents Eastern Currents
Gulf Stream, Kuroshio,
East Australia Currents
warm water moving from
equator to pole
narrow: < 100 km wide
deep: down to 2 km
“fast:” 100s of km/day
sharp boundaries defined by
water temperature
Eastern Currents
California, Canary, Peru
Currents
cold water moving from
pole to equator
wide: ~ 1000 km wide
shallow: < 500 m
“slow:” 10s of km/day
diffuse boundaries

29. Wind Tricks
Making a Gyre

30. Gyres Geostrophic Flow
Formed by major currents interacting with each other.
Deflection is piling up water (Coriolis Effect).
Gravity is pulling it down.
The pile is ALWAYS THERE.
These forces must be EQUAL.

31. Sargasso Sea - a mound of water in the Atlantic Ocean

32. Major Gyres (5)

33. Notice how the winds are helping the currents

34. Wind Trick #2
Western Intensification

35. What happens when you push in on a plastic container of water?

36. The container moves first, and water moves a
fraction of a second later.

37. Water sloshes up again the left-hand side, creating a pile

38. As Earth rotates the continents smack into the oceans
Earth’s rotation
The Americas hit the
Atlantic Ocean
Asia, Australia hit the
Pacific Ocean
Sverdrup et al., Introduction to the World’s Oceans, 8th edition, McGraw Hill, Fig. xxx

39. West East Continents crash into the mound of water.
A West to East Cross Section of the mound of water
Continents crash into the mound of water.
The mound is asymmetrical.
This leads to Western Intensification – water piles up on the coast
West
East
North
America 1m
Only ~ 1m high, but that’s enough to create BIG
differences in the currents.

40. West East Western Intensification
A West to East Cross Section of the mound of water
West
East
North
America
Gravity is trying to pull this down and out to flatten the ocean.
The flow is constricted on the WEST side and spread out on the EAST
Think about constricting flow out of a garden hose by covering half
the opening with your thumb. The constricted flow moves FASTER.

41. East West Western Intensification Gulf Stream (Flowing into screen)
Narrow and fast
East
West
Canary Current
(Flowing OUT of screen)
diffuse, slow
North
America
Think about constricting flow out of a garden hose by covering half
the opening with your thumb. The constricted flow moves FASTER.
WHY?
SAME AMOUNT of water forced to move through smaller opening

42. The Southern Oscillation
Pattern of reversing surface air pressure between the eastern and western tropical pacific

43. El Nino Spanish for “The Christ Child”…why?
Unusually warm ocean temperatures
Results:
Major rainfall, flooding, across the southern US and in Peru.
Drought in the West Pacific, can cause devastating brush fires in Australia.

44. Normal vs. Nino

45. La Nina unusually cold ocean temperatures
Eastern Pacific is cooler than usual, and the cool water extends farther westward than is usual
Wetter than normal conditions across the Pacific Northwest
Dryer and warmer than normal conditions across much of the southern tier.

46. Normal vs. Nina

47. Definition
Characteristics
Word
Made by
name
Example
Picture

48. When you feel you are finished, you will switch with someone that has a different word as yourself.
You will add 1 thing to it and then write at the bottom
Checked by your name.