1. Chapter 15 The Atmosphere

2. You breathe out of which layer?

3. The air we breathe and all the weather we see is contained in the lowest 1% of the Earth’s atmosphere.

4. Take a deep breath

5. What is air made out of?

6. Is air strong? Is it matter?

7. Why is our atmosphere important? Why doesn’t it float away

8. Chapter 15 Big Idea
Our atmosphere is critical to all life on Earth. Human actions have a great impact on our atmosphere.

9. Section: Earth’s Atmosphere
Describe the properties of the atmosphere.
Identify the main layers of the atmosphere.
Explain how heat is transferred in the atmosphere

10. The atmosphere is a thin layer of gases surrounding our planet
What is the Atmosphere?
The atmosphere is a thin layer of gases surrounding our planet

11. Why is the ATMOSPHERE important?
Earth’s atmosphere makes life on Earth possible.
Protects us from sun’s rays.
Provides vital gases like oxygen, nitrogen and carbon dioxide.
Keeps temperature comfortable
Allows water to circulate around planet.
Protects us from meteoroids.

12. The Air Around You Weather
Weather is the state of the atmosphere at any one moment.

19. What is it made of? Earth’s Atmosphere is made of: 78 % Nitrogen
21% Oxygen
1% a bunch of others (Argon, Carbon Dioxide, Water Vapor…)

20. Water in the Air
Relative Humidity Amount of water vapor in the air Changes constantly Warm Air = More Moisture Condensation = Clouds

21. Air Pressure The force of a column of air pushing down on an area
Where is air pressure greater, sea level or top of a mountain?

22. As altitude increases air pressure decreases…quickly

23. Barometers
An instrument used to measure air pressure.

24. Changing air pressure is a great indicator of weather changes.

25. Air pressure
Differences in air pressure is going to help us understand:
Wind
Cloud formation
Tornadoes
Almost all weather

26. Four Main Layers of Atmosphere
The four main layers of our atmosphere are classified according to changes in temperature.
Troposphere
Stratosphere
Mesosphere
Thermosphere

29. The Troposphere The Troposphere: Inner most layer (0 to 12km)
Where all weather occurs
The temperature decreases to -60 degrees at top.

30. The Troposphere Clouds, rain, snow and all precipitation occur here.
Air Pressure and Temperature drop quickly in troposphere.

32. Stratosphere Layer above troposphere where atmosphere warms slightly
Ozone layer located there blocks out harmful UV Rays

33. Mesosphere Where meteoroids burn up in atmosphere “Middle Layer”
Temperatures reach -90 degrees Celsius
Where meteoroids burn up in atmosphere

35. Thermosphere “Thermo” means heat
Air is only % as dense as sea level
Air slowly blends into outer space
Hottest layer of atmosphere because energy from the sun strikes it first

37. Heat Transfer in the Troposphere
1) Radiation: The transfer of energy through space, such as heat from the sun to Earth’s atmosphere

38. Heat Transfer in the Troposphere
2) Conduction: The transfer of heat directly between two objects that are in contact

39. Heat Transfer in the Troposphere
3) Convection: The transfer of heat by the movement of currents within a fluid (liquid or gas)

41. The Air Outside Today, Was Somewhere Else Yesterday
Air Masses And Fronts
The Air Outside Today, Was Somewhere Else Yesterday

47. What IS An Air Mass?
An Air Mass is a huge body of air with similar temperature, humidity and pressure.
They sometimes spread over hundreds of square miles.

48. Types of Air Masses There are 4 main types of air masses: 1) Polar
2) Tropical
3) Maritime
4) Continental
Each has unique weather associated with it.

49. 4 Major Air Masses of North America
Maritime Tropical: Warm, Moist Air
Maritime Polar: Cold, Moist Air
Continental Tropical: Warm, Dry Air
Continental Polar: Cold, Dry Air
Where do they originate?

51. What Are Fronts? Fronts are areas where 2 or more air masses collide.
Air with different temperature, humidity and pressure DO NOT MIX WELL.

52. Types of Fronts There are four types of front: 1) Cold Front
2) Warm Front
3) Stationary Front
4) Occluded Front

53. Cold Fronts
Cold Fronts occur where cold air runs into slowly moving warm air.
Cold air being more dense pushes warm air up. Warm moist rising air can cause clouds and storms.

54. Cold Fronts

55. Warm Fronts
Warm Fronts occur where a warm air mass collides with a slower moving cold air mass.
Because warm air is less dense, it rides above the cold air.

56. Warm Fronts
Warm Fronts move more slowly than cold fronts so weather changes occur more slowly.
In winter they often bring snow.

57. Warm Fronts

59. Section: Pollution of The Atmosphere
What are the main sources of air pollution?
Describe how smog forms
Explain what a temperature inversion is and how it can make are pollution worse.
TERMS: primary and secondary air pollution, catalytic converter, ZEVs, smog, temperature inversion

60. What Causes Air Pollution?
Air pollution is harmful substances in the air
To plants, animals and other organisms
Impact ecosystem functions
WHAT SHOULD BE IN THE AIR?

61. Some Natural Most Human Made
Can you think of other human made AND natural sources of air pollution?

62. Primary vs. Secondary Primary pollutant: put directly in the air
(soot from smoke)
Secondary forms when primary pollutant react with other pollutants
(Smog)

63. Primary vs. Secondary

64. Primary vs. Secondary

65. Sources of Air Pollution
Main Sources of Air Pollution
Burning fossil fuels in cars and at power plants (coal, oil and natural gas)
Urban areas vehicles and industry
Mobile vs. Stationary Sources

66. What can you learn from this graph?

67. Human Made vs. Natural

68. History of Air Pollution
Not a new problem
Why do you think world air-quality today is a bigger problem?

69. History of Air Pollution
Not a “new” problem, but scale has changed during industrial revol.
London “smog” killed 2,000 in 1880, 1,000 in 1911 and between 4,000 and 12,000 in 1952
1948 Donora PA 6,000 sick
1963 NYC 300 killed

70. http://airnow.gov/ Today’s U.S. Air Quality
U.S. Government Web Site With Up To Minute Air Quality Data From Monitors Across the country
U.S. EPA Air Quality Data: Tons of data regarding air quality across the U.S.
EPA report on air trends in U.S.

71. Smog (Smoky – Fog) Smog Secondary Pollutant in many urban areas
Forms from chemical reaction
Vehicle exhaust
Needs sunlight and warm temperatures
OZONE

72. Smog Smog Levels Are Influenced By: Local climate Topography
Population Density
Amount of industry
Transportation
Huge Problem in cities …WHY?

73. Smog: Why care? Smog Impacts: Breathing Problems
Coughing, Eye Irritation
Aggravates asthma, heart problems
Speeds up aging of lung tissue
Damage plants
Reduce Visibility

74. Smog and Temperature Inversion
Normally as you go up in the troposphere what happens to temperature?
Temperature Inversion occurs when a warmer layer forms above a cooler layer
Traps air near ground

75. Temperature Inversion

76. Helena Montana

77. Clean Air Act U.S. Law Passed Congress in 1963 and strengthened 1990
Has been huge success

78. Since the Clean Air Act was first enacted in 1963, emissions of the worst pollutants in the U.S. have decreased by 57%.

79. Clean Air Act
Cars today are about 95% cleaner running

80. Zero-Emission Vehicles (ZEV)
Have no tailpipe emissions

81. Chevy Volt 2010: will travel 30 miles on a battery before gas engine kicks in
Nissan Leaf travels about 100 miles before needing to be charged again

82. Clean Air Act Requires industries to clean up smokestack emissions
Requires Scrubbers

83. Scrubbers

84. Section Review What are the main sources of air pollution?
Describe how smog forms
Explain what a temperature inversion is and how it can make are pollution worse.
TERMS: primary and secondary air pollution, catalytic converter, ZEVs, smog, temperature inversion

86. What will be the future?