1. Warm Up Question
Do you feel more pressure on your body when you are sitting, standing or lying down? Define pressure and explain.
Demonstrations: Towers of Blocks, Tower of Water, Vacuum Pump.

2. Water Pressure Demonstration
Describe what happened indoors.
Describe what happened outdoors.

3. How much water pressure?
A two inch diameter pipe that is ten feet long holds 15 pounds of water. If the area of the pipe is 3 square inches, what is the water pressure?
What is the longest length of pipe we could use and still not have the water come out?

4. Air Pressure and Wind

5. What is air pressure? The force exerted by air molecules
as they collide with a surface
The weight of the atmosphere as it
pushes on Earth’s surface

6. What is air pressure? Air has mass
Gravity pulls these molecules towards Earth giving them weight
The weight of the molecules acting over an area creates air pressure kg

7. What is air pressure?
At sea level the pressure of air pushing down is 14.7 pounds per square inch
The weight on the roof of a typical house is about 2.1 million kg (4.6 million lbs)
Why don’t all of our houses collapse?
Or Why aren’t we all squished?
CHECK THIS OUT!!!
Extreme Atmospheric Pressure

8. What is air pressure?
Air pressure is exerted (pushes) in all directions
An equal force pushing down is balanced by air pushing up

9. What Is Air Pressure? The same thing as gravity
The weight of the atmosphere pushing downward over an area.
A form of pollutant

10. Why Don’t We Get Crushed By The Pressure Of The Atmosphere?
The air is not that heavy
Air pressure is exerted in all directions, and we are in equilibrium
The water in our bodies prevents it

11. Measuring air pressure
The barometer is the instrument used to measure air pressure
2 types of barometers
Mercury
Aneroid
Mercury Barometer

12. Measuring air pressure
As the weight of the air increases, the mercury rises
The pressure of the mercury column must equal the atmospheric pressure at this point, or the mercury will move.

13. Measuring air pressure
As the weight of the air decreases, the mercury lowers

14. Can Barometer

15. Can Barometer

16. Measuring air pressure
The Aneroid barometer
A capsule with most of the air removed changes size as the pressure outside of it increases or decreases
This moves the needle

17. Measuring air pressure
Pressure will be measured in
mm Hg
Inches of Hg
Millibars
Average Pressure at sea level
mb = in. Hg = 14.7 lbs./ in2

18. Why does air pressure change?
3 factors that affect pressure:
Elevation/Altitude (p414)
Temperature (p416)
Humidity (p416)

19. Complete the graphic organizer by filling in the 3 factors that affect pressure. Then create branches explaining how they cause pressure to change.

20. Recall the towers of water demonstration.
Draw a mercury barometer in Fullerton, Cuchamonga, and on top of Mt. Baldy. Show the mercury levels to reflect the air pressure at that altitude.

21. Changes in air pressure
Altitude
(height above sea level)
As the altitude increases pressure decreases
As the altitude decreases pressure increases

22. Changes in air pressure
Altitude Drawing
High Altitude / Low Pressure
Low Altitude / High Pressure

23. Stop Wednesday

24. Changes in air pressure
Humidity
(the amount of water vapor in air)
Water molecules weigh less than O2 or N2
Water vapor replaces these molecules in humid air
As humidity increases, pressure decreases
As humidity decreases, pressure increases
HUMID AIR
DRY AIR

25. Changes in Air Pressure
Humidity Drawing
Low Humidity / High Pressure
High Humidity / Low Pressure

26. Changes in air pressure
Temperature
In warm air the molecules are far apart.
In cool air the molecules are closer together
As air temperature increases, pressure decreases
As air temperature decreases, pressure increases

27. Changes in air pressure
Temperature Drawing
High Temperature / Low Pressure
Low Temperature / High Pressure

28. Let’s Summarize Temperature Altitude Decrease Pressure Increase
Humidity

29. Low Pressure Generally associated with stormy weather.
The air is rising.

30. High Pressure
Generally associated with clear skies.
Air is sinking.

31. Warm Up
Make the following questions into true statements.

32. What does a barometer measure?
Atmospheric pressure
The humidity of the air
Air quality
How much it has rained

33. What affects air pressure?
Altitude
Humidity
Temperature
All of the above

34. Why is water vapor less dense than air?
There is less of it
H2O molecule has less mass than O2 or N2 molecules
It is hotter, so it has less mass

35. Low pressure is usually associated with…
Clear skies
Cold Desert Nights
Earthquakes
Stormy weather and rising air

36. High pressure is usually associated with…
Rain
Tornadoes
Sunny, dry weather with sinking air
Pushy car salesmen

37. Factors Affecting Wind Direction and Speed

38. What makes the wind blow?
Air moves from
HIGH PRESSURE to LOW PRESSURE
This movement of air is WIND

39. What makes the wind blow? (see last page of note packet)
Island Example

40. Sea Breeze- day time

41. Land Breeze- night time

42. Stop -Friday

43. Factors Affecting Wind Direction
Coriolis Effect
Pressure Gradients (differences in pressure HIGH vs LOW)
Friction (resistance)

44. The Coriolis Effect
An object moving over Earth’s surface will curve away from its intended path
This is due to Earth’s rotation
Faster speed at the equator
Slower speed at the poles

45. The Coriolis Effect Coriolis-1.mp4 Guidelines (p419):
objects are deflected to the RIGHT in the Northern Hemisphere and the LEFT in the Southern Hemisphere
The effect (curve) increases as the difference in tangential speed increases
The effect DOES NOT depend on the objects direction
The effect is greater at the poles and less at the equator
Most noticeable of large distances (Not in TOILETS)

46. The Coriolis Effect
Let’s Draw!

47. Low Pressure Generally associated with stormy weather.
The air is rising.

48. Pressure Gradients Pressure gradient:
A difference in pressure from one place to another
Remember wind blows from HIGH to LOW
The stronger the gradient the faster the wind
The faster the wind the more curve from the Coriolis Effect

49. Friction Friction between the air and the ground slows wind.
The higher above the surface the faster the wind will blow
The higher above the surface the more curve due to Coriolis

50. Friction
Little friction in the upper troposphere allows a jet stream to form moving air from west to east.
The jet stream supplies energy to storms and directs the path of weather across the United States
Affects airplanes as they travel coast to coast

51. Jet Stream

52. Warm Up Questions

53. What are the 3 factors that affect air pressure?
Altitude, Humidity, and Temperature
Coriolis, Pressure, Gradients, and Frction
Sunlight, Convection, and Friction

54. How does a pressure gradient affect the speed of wind?
The stronger the gradient, the weaker the wind
The stronger the gradient, the stronger the wind
It does not effect the speed

55. How does friction affect wind speed?
Objects or rough surfaces cause a drag on the wind
Friction makes the wind faster
Friction creates wind

56. What are the 3 factors that affect wind direction?
Altitude, Humidity, and Temperature
Altitude, Humidity, and Coriolis Effect
Coriolis Effect, Pressure Gradient, and Friction

57. Why does the Coriolis Effect cause wind to deflect?
The wind was already curving; the Coriolis Effect only effects airplanes
The spinning of the Earth causes the path to curve

58. Convergence- show with your hands

59. Tuesday Feb 7, 2012

60. Wed. Feb 8,
2012

62. If winds blow from high to low pressure, won’t they eventually stop?
Global and Local Winds
If winds blow from high to low pressure, won’t they eventually stop?

63. Thermal Convection on a rotating Earth.

66. Thermal Convection on a nonrotating Earth.

67. Trade Winds

68. Doldrums

70. Global Winds
Global winds show the general direction the air is flowing throughout the globe.
Refer to your worksheet for these winds
The winds are named according to where the wind comes from or originates
Ex. What would the name of this wind be?

73. Thermal Convection on a rotating Earth.

75. Stop to Complete “Global Winds” page.

76. Global Winds Climate Zones due to global winds:
Areas of low pressure are characterized by rising air, precipitation = Rainforest (0°, 60°)
Areas of high pressure are characterized by sinking air, dry air = Deserts (30°, 90°)
** Add these areas to your worksheet

78. Warm Up
Matching. For each of the following, choose either high pressure or low pressure.
Low Pressure
Rising Hot, Humid Air at the Equator
Sinking Dry Hot air at 30 degrees latitude
High Pressure
Rising, Cool, Humid Air the 60 degrees latitude
Low Pressure
Sinking, Dry, Very Cold Air at the Poles
High Pressure

79. Draw a large circle to represent Earth
Label the equator. Draw horizontal lines at 30 and 60 degrees latitude

80. 3-Cell Model of Earth’s Winds
Label the high and low pressure belts of the Earth using the previously established reasons.
Sketch in arrows to represent the prevailing winds according the Coriolis Effect. Curve right in the Northern Hemisphere, curve left in the Southern Hemisphere
Label in the ITCZ, Doldrums, Deserts/Horse Latitudes, Temperate Forests, Trade Winds, Prevailing Southwesterly Winds. See 19.3

82. Continental and Local Winds
These winds can go opposite the expected global winds due to changes in local conditions:
Continental Winds
Monsoon
Local Winds
Sea breeze
Land breeze
Santa Ana Winds

83. Micromonsoon Daytime

84. Micromonsoon Nightime

85. Why would the ITCZ shift with the seasons?

89. Monsoon Wedding

91. Monsoon
A Monsoon is a seasonal change in winds.
Ex. India, North America

92. Santa Ana Winds
Occur in Southern California in the late fall/early winter
A high pressure forms as the desert regions
As the air sinks it is compressed and usually warms.

93. Santa Ana Winds
This creates an offshore wind (blows towards the ocean)
The air is very dry and often wildfires are a result of this wind

94. Where will you find areas of high pressure on Earth?
North and South Pole Only
0 and 60 Degrees Latitude
30 and 90 Degrees Latitude
Over the Ocean

95. Where will you find areas of low pressure on Earth?
North and South Pole Only
0 and 60 Degrees Latitude
30 and 90 Degrees Latitude
Over the Ocean

96. What Creates Santa Ana Winds?
High Pressure Over Land and Low Pressure Over Ocean
Low Pressure Over Land and High Pressure Over Ocean
Politicians In Santa Ana

97. Label the Pressure and Wind Belts
Label the Pressure and Wind Belts. Label Tropical Forests, Deserts, Temperate Forests.
Falling Cold, Dry Air
Humid Rising Air
Falling Dry Air
ITCZ Hot and Humid

99. Group Items
1 7,8,9
2 10,11
3 14,15
4 4,5,6
5 12,13
6 16,17
7 18,19,20
8 1,2,3
9 21,22,23

100. Group Numbers
Hint for 7- see page Draw answer on board.
Be prepared to sketch on whiteboard on the map.
Draw #11 on the whiteboard
Same as group 2.
Draw the concept map on the whiteboard
8 1-6