Chapter%20Menu

1
Chapter Menu
Chapter Introduction Lesson 1 Earths
Atmosphere Lesson 2 Energy Transfer in the
Atmosphere Lesson 3 Air Currents Lesson 4 Air
Quality Chapter Wrap-Up
2
Chapter Introduction

• How does Earths atmosphere affect life on Earth?

3
Chapter Introduction

• What do you think?

Before you begin, decide if you agree or disagree
with each of these statements. As you view this
presentation, see if you change your mind about
any of the statements.
4
Chapter Introduction
Do you agree or disagree?

• 1. Air is empty space.
• 2. Earths atmosphere is important to living
  organisms.
• 3. All the energy from the Sun reaches Earths
  surface.
• 4. Earth emits energy back into the atmosphere.

5
Chapter Introduction
Do you agree or disagree?

• 5. Uneven heating in different parts of the
  atmosphere creates air circulation patterns.
• 6. Warm air sinks and cold air rises.
• 7. If no humans lived on Earth, there would be no
  air pollution.
• 8. Pollution levels in the air are not measured
  or monitored.

6
Lesson 1 Reading Guide - KC
Earths Atmosphere

• How did Earths atmosphere form?
• What is Earths atmosphere made of?
• What are the layers of the atmosphere?
• How do air pressure and temperature change as
  altitude increases?

7
Lesson 1 Reading Guide - Vocab
Earths Atmosphere

• atmosphere
• water vapor
• troposphere

• stratosphere
• ozone layer
• ionosphere

8
Lesson 1-1
Importance of Earths Atmosphere

• The atmosphere is a thin layer of gases
  surrounding Earth.
• The atmosphere contains the oxygen and water
  necessary for life on Earth.
• The atmosphere provides insulation and helps
  keep temperatures on Earth within a range in
  which living organisms can survive.

9
Lesson 1-1
Importance of Earths Atmosphere (cont.)

• The atmosphere helps protect living organisms
  from some of the Suns harmful rays and
  meteorites.

atmosphere from Greek atmos, means vapor and
Latin sphaera, means sphere
10
Lesson 1-2
Origins of Earths Atmosphere

• Erupting volcanoes emitting hot gases from
  ancient Earths interior surrounded the planet to
  form an atmosphere.
• Ancient Earths atmosphere was thought to be
  water vapor with a little carbon dioxide and
  nitrogen, but not enough oxygen to support life.
• Water vapor is water in gaseous form.

11
Lesson 1-2
Origins of Earths Atmosphere (cont.)

• As Earth and its atmosphere cooled, the water
  vapor condensed into liquid, rain fell, and then
  evaporated from Earths surface for thousands of
  years.
• Eventually water began to accumulate on Earths
  surface, forming oceans.
• Earths first organisms could undergo
  photosynthesis, which changed the atmosphere.

12
Lesson 1-2
Origins of Earths Atmosphere (cont.)

• The organisms removed CO2 from the atmosphere and
  released oxygen into it.
• Eventually the levels of CO2 and oxygen supported
  the development of other organisms.

13
Lesson 1-2
Origins of Earths Atmosphere (cont.)
How did Earths present atmosphere form?
14
Lesson 1-3
Composition of the Atmosphere

• Todays atmosphere is mostly made up of invisible
  gases, including nitrogen, oxygen, and carbon
  dioxide.
• About 78 percent of the atmosphere is nitrogen,
  and about 21 percent is oxygen.
• The amounts of water vapor, carbon dioxide, and
  ozone vary.

15
Lesson 1-3

• Acids in the air are formed when sulfur dioxide
  and nitrous oxide combine with water vapor.

PhotoLink/Getty Images
16
Lesson 1-3
Composition of the Atmosphere (cont.)

• Many tiny solid particles, such as pollen, dust,
  and salt, can enter the atmosphere through
  natural processes.
• Solid particles of ash from volcanic eruptions
  and exhaust soot from cars are also present in
  the atmosphere.

17
Lesson 1-3

• One way solid particles enter the atmosphere is
  from volcanic eruptions.

C. Sherburne/PhotoLink/Getty Images
18
Lesson 1-3
Composition of the Atmosphere (cont.)

• The most common liquid particles in the
  atmosphere are water droplets.
• Though microscopic in size, water particles are
  visible when they form clouds.
• Other atmospheric liquids include acids that
  result when volcanoes erupt and fossil fuels are
  burned.

19
Lesson 1-3
Composition of the Atmosphere (cont.)

• Acids in the air are formed when sulfur dioxide
  and nitrous oxide combine with water vapor.

What is Earths atmosphere made of?
20
Lesson 1-4
Layers of the Atmosphere

• The atmosphere has several different layers, each
  with its own unique properties.

21
Lesson 1-4
Layers of the Atmosphere (cont.)

• The atmospheric layer closest to Earths surface
  is called the troposphere.
• The troposphere extends from Earths surface to
  altitudes between 8-15 km.
• The temperature of the troposphere decreases as
  you move away from Earth.

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Lesson 1-4
Layers of the Atmosphere (cont.)

• Sunlight passes through the atmosphere, warms
  Earths surface, and the warmth is radiated to
  the troposphere, causing weather.
• The stratosphere is the atmospheric layer
  directly above the troposphere.

23
Lesson 1-4
Layers of the Atmosphere (cont.)

• The stratosphere extends from about 15 km to
  about 50 km above Earths surface.
• The area of the stratosphere with a high
  concentration of ozone is referred to as the
  ozone layer.
• The presence of the ozone layer causes the
  stratospheric temperatures to increase with
  altitude.

24
Lesson 1-4
Layers of the Atmosphere (cont.)

• Ozone has three oxygen atoms and absorbs the
  Suns ultraviolet rays more effectively than
  oxygen.
• Ozone protects Earth from ultraviolet rays that
  can kill plants, animals, and other organisms and
  cause skin cancer in humans.

25
Lesson 1-4
Layers of the Atmosphere (cont.)

• Combined, the mesosphere and thermosphere are
  much thicker than the troposphere and the
  stratosphere, yet only 1 percent of the
  atmospheres gas molecules are found in the
  mesosphere and thermosphere.
• Most meteors burn up in the mesosphere and
  thermosphere instead of striking Earth.

26
Lesson 1-4

• The ionosphere is a region within the mesosphere
  and thermosphere containing ions.
• The ionospheres ions reflect AM radio waves
  transmitted at ground level.

27
Lesson 1-4

• Auroras occur in the ionosphere when ions from
  the Sun strike air molecules, causing them to
  emit vivid colors of light.

Per Breiehagen/Getty Images
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Lesson 1-4
Layers of the Atmosphere (cont.)

• The exosphere is the atmospheric layer farthest
  from Earths surface where pressure and density
  are so low that individual gas molecules rarely
  strike one another.
• The molecules move at incredibly fast speeds
  after absorbing the Suns radiation and can
  escape the pull of gravity and travel into space.

29
Lesson 1-4
Layers of the Atmosphere (cont.)
What are the layers of the atmosphere?
30
Lesson 1-5
Air Pressure and Altitude

• Gravity pulls the atmosphere toward Earth,
  creating air pressure.
• At higher altitudes, the air is less dense and
  air pressure is lower.
• At lower altitudes, the air is denser and air
  pressure is higher.

31
Lesson 1-6
Temperature and Altitude

• Temperature changes in different ways as altitude
  increases in the different layers of the
  atmosphere.
• In the troposphere, temperature decreases as
  altitude increases.
• In the stratosphere, temperature increases as
  altitude increases because of the high
  concentration of ozone.

32
Lesson 1-6
Temperature and Altitude (cont.)

• In the mesosphere, as altitude increases,
  temperature again decreases.
• In the thermosphere and exosphere, temperatures
  increase as altitude increases.

33
Lesson 1-6
34
Lesson 1-6
Temperature and Altitude (cont.)
How does temperature change as altitude increases?
35
Lesson 1 - VS

• Earths atmosphere consists of gases that make
  life possible.

PhotoLink/Getty Images
36
Lesson 1 - VS

• Layers of the atmosphere include the troposphere,
  the stratosphere, the mesosphere, the
  thermosphere, and the exosphere.

Per Breiehagen/Getty Images
37
Lesson 1 - VS

• The ozone layer is the area in the stratosphere
  with a high concentration of ozone.

38
Lesson 1 LR1
Where did hot gases that created Earths
atmosphere come from?
A. the Sun B. erupting volcanoes C. the
air D. the ocean
39
Lesson 1 LR2
What is about 78 percent of Earths atmosphere
made of?
A. nitrogen B. oxygen C. ozone D. carbon dioxide
40
Lesson 1 LR3
What is the region within the mesosphere and
thermosphere containing ions?
A. exosphere B. stratosphere C. ozone
layer D. ionosphere
41
Lesson 1 - Now
Do you agree or disagree?

• 1. Air is empty space.
• 2. Earths atmosphere is important to living
  organisms.

42
Lesson 2 Reading Guide - KC
Energy Transfer in the Atmosphere

• How does energy transfer from the Sun to Earth
  and the atmosphere?
• How are air circulation patterns within the
  atmosphere created?

43
Lesson 2 Reading Guide - Vocab
Energy Transfer in the Atmosphere

• radiation
• conduction
• convection

• stability
• temperature inversion

44
Lesson 2-1
Energy from the Sun

• Radiation is the transfer of energy by
  electromagnetic waves.
• Ninety-nine percent of the radiation from the Sun
  consists of visible light, ultraviolet light, and
  infrared radiation.
• The majority of sunlight is visible light that
  passes through the atmosphere to Earths surface,
  where it is converted to heat.

45
Lesson 2-1
Energy from the Sun (cont.)

• The wavelengths of ultraviolet (UV) light and
  infrared radiation (IR) are just beyond the range
  of visibility to human eyes.
• UV light is harmful to human skin and IR can be
  sensed as thermal energy or warmth.
• As energy from the Sun is absorbed by Earth, it
  is radiated back as IR.

46
Lesson 2-2
Energy on Earth

• As Suns radiation passes through the atmosphere,
  some of it is absorbed and some of it is
  reflected back into space.

reflect Science Use to return light, heat, sound,
etc., after it strikes a surface Common Use to
think quietly and calmly
47
Lesson 2-2
Energy on Earth (cont.)

• Gases and particles in the atmosphere absorb
  about 20 percent of incoming solar radiation.
• Oxygen, ozone, and water vapor all absorb
  incoming ultraviolet radiation.
• Water and carbon dioxide in the troposphere
  absorb some infrared radiation from the Sun.

48
Lesson 2-2
Energy on Earth (cont.)

• About 30 percent of incoming radiation is
  reflected into space.
• Bright surfaces, especially clouds, reflect
  incoming radiation, and some is reflected at
  Earths surface.
• Earths surface only receives and absorbs about
  50 percent of incoming solar radiation.

49
Lesson 2-3
Radiation Balance

• The amount of radiation Earth receives from the
  Sun is the same as the amount Earth radiates into
  the atmosphere.
• This radiation balance maintains an overall
  temperature on Earth.

50
Lesson 2-4
The Greenhouse Effect

• Some of the gases in the atmosphere, called
  greenhouse gases, act like the glass of a
  greenhouse, allowing sunlight to pass through but
  preventing some of Earths IR energy from
  escaping.
• When gases in Earths atmosphere direct radiation
  back toward Earths surface, this warms Earths
  atmosphere more than normal, creating a heat
  surplus.

51
Lesson 2-4
The Greenhouse Effect (cont.)

• The gases that trap IR best are water vapor,
  carbon dioxide, and methane.

52
Lesson 2-5
Thermal Energy Transfer

• Conduction occurs when the atmosphere touches
  Earth.
• Conduction is the transfer of thermal energy by
  collisions between particles of matter.
• Thermal energy always moves from an object with a
  higher temperature to an object with a lower
  temperature.

53
Lesson 2-5
Thermal Energy Transfer (cont.)
conduction from Latin conducere, means to bring
together
54
Lesson 2-5

• Energy is transferred through conduction,
  convection, and radiation.

55
Lesson 2-5
Thermal Energy Transfer (cont.)

• The transfer of thermal energy by the movement of
  matter from one place to another is called
  convection.
• As molecules of air close to Earths surface are
  heated by conduction, they spread apart, becoming
  less dense.
• Less dense air rises, transferring thermal energy
  to higher altitudes.

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Lesson 2-5
Thermal Energy Transfer (cont.)

• Latent heat is exchanged when water changes from
  one phase to another.
• Water is the only substance that can exist as a
  solid, a liquid, and a gas at the temperature
  ranges on Earth.
• Latent heat energy is transferred from Earths
  surface to the atmosphere.

57
Lesson 2-5

• Water releases or absorbs heat energy during
  phase changes.

58
Lesson 2-5
Thermal Energy Transfer (cont.)
How does energy transfer from the Sun to Earth
and the atmosphere?
59
Lesson 2-6
Circulating Air

• Air is constantly moving and circulating.
• On a hot day, air that is heated becomes less
  dense, creating a pressure difference.
• Cool, denser air pushes the warm air out of the
  way and the warm air is replaced by the more
  dense air.
• The warm air is often pushed upward.

60
Lesson 2-6
Circulating Air (cont.)

• Warmer, rising air is always accompanied by
  cooler, sinking air.
• Circulating air affects weather and climate
  around the world.

How are air circulation patterns within the
atmosphere created?
61
Lesson 2-6
Circulating Air (cont.)

• Stability describes whether circulating air
  motions will be strong or weak.
• When air is unstable, circulating motions are
  strong, and during stable conditions, circulating
  motions are weak.
• During unstable conditions, ground-level air is
  much warmer than higher-altitude air.

62
Lesson 2-6
Circulating Air (cont.)

• As warm air rises rapidly in the atmosphere, it
  cools to form large, tall clouds.
• Latent heat, released as water vapor, changes
  from a gas to a liquid, adds to the instability,
  and produces a thunderstorm.
• A temperature inversion occurs in the troposphere
  when temperature increases as altitude increases.

63
Lesson 2-6
Circulating Air (cont.)

• During a temperature inversion, a layer of cooler
  air is trapped by a layer of warmer air above it.

64
Lesson 2 - VS

• Not all radiation from the Sun reaches Earths
  surface.
• Thermal energy transfer in the atmosphere
  occurs through radiation, conduction, and
  convection.

65
Lesson 2 - VS

• Temperature inversions prevent air from mixing
  and can trap pollution in the air close to
  Earths surface.

66
Lesson 2 LR1
The transfer of thermal energy by the movement of
matter from one place to another is called what?
A. latent heat B. conduction C. convection D. the
greenhouse effect
67
Lesson 2 LR2
When air is unstable, circulating motions can
usually be described how?
A. strong B. weak C. absent D. warm
68
Lesson 2 LR3
Which is exchanged when water changes from one
phase to another?
A. water vapor B. convection C. latent
heat D. cool air
69
Lesson 2 - Now
Do you agree or disagree?
3. All of the energy from the Sun reaches Earths
surface. 4. Earth emits energy back into the
atmosphere.
70
Lesson 3 Reading Guide - KC
Air Currents

• How does uneven heating of Earths surface result
  in air movement?
• How are air currents on Earth affected by Earths
  spin?
• What are the main wind belts on Earth?

71
Lesson 3 Reading Guide - Vocab
Air Currents

• wind
• trade winds
• westerlies
• polar easterlies

• jet stream
• sea breeze
• land breeze

72
Lesson 3-1
Global Winds

• Wind patterns can be global or local.
• There are great wind belts that circle the globe,
  and the energy that causes this massive movement
  of air originates at the Sun.
• Not all areas of Earth receive the same amount of
  energy from the Sun.

73
Lesson 3-1
Global Winds (cont.)

• The differences in pressure between areas with
  low temperatures and high temperatures create
  wind.
• Wind is the movement of air from areas of high
  pressure to areas of low pressure.

74
Lesson 3-1
Global Winds (cont.)
How does uneven heating of Earths surface result
in air movement?
75
Lesson 3-2
Global Wind Belts

• Three cells in each hemisphere move air through
  the atmosphere.

76
Lesson 3-2
Global Wind Belts (cont.)

• In the first cell, hot air at the equator moves
  to the top of the troposphere then moves toward
  the poles until it cools and moves back to
  Earths surface near the 30 latitude.

77
Lesson 3-2
Global Wind Belts (cont.)

• The second cell, between 30 and 60 latitude, is
  not a convection cell because its motion is
  driven by the other two cells.

78
Lesson 3-2
Global Wind Belts (cont.)

• The third cell, at the highest latitudes, is
  also a convection cell. Air from the poles moves
  toward the equator along Earths surface, and
  warmer air is pushed upward by the cooler air
  near the 60 latitude.

79
Lesson 3-2
Global Wind Belts (cont.)

• The three cells exist in both the Northern and
  Southern Hemispheres.
• Most of the air in this convection cell returns
  to the equator near Earths surface.

80
Lesson 3-2
Global Wind Belts (cont.)

• The Coriolis effect occurs when the rotation of
  Earth causes moving air and water to move to the
  right in the Northern Hemisphere and to the left
  in the Southern Hemisphere.
• The contrast between high and low pressure and
  the Coriolis effect creates distinct wind
  patterns, called prevailing winds.

81
Lesson 3-2
Global Wind Belts (cont.)
How are air currents on Earth affected by Earths
spin?
82
Lesson 3-2
Global Wind Belts (cont.)

• The trade winds are steady winds that flow from
  east to west between 30N latitude and 30S
  latitudes.
• The prevailing westerlies are steady winds that
  flow from west to east between latitudes 30N and
  60N, and 30S and 60S.

83
Lesson 3-2
Global Wind Belts (cont.)

• The polar easterlies are cold winds that blow
  from the east to the west near the North Pole and
  the South Pole.

What are the main wind belts on Earth?
84
Lesson 3-2
Global Wind Belts (cont.)

• Located near the top of the troposphere is a
  narrow band of high winds called the jet stream.
• Jet streams influence weather as they move cold
  air from the poles toward the tropics and warm
  air from the tropics toward the poles.

85
Lesson 3-3
Local Winds

• Local winds occur whenever air pressure is
  different from one location to another.
• A sea breeze is wind that blows from the sea to
  the land due to local temperature and pressure
  differences.
• A land breeze is a wind that blows from the land
  to the sea due to local temperature and pressure
  differences.

86
Lesson 3-3

• Sea breezes and land breezes are created as part
  of a large reversible convection current.

87
Lesson 3 - VS

• Wind is created by pressure differences between
  one location and another.
• Prevailing winds in the global wind belts are
  the trade winds, the westerlies, and the polar
  easterlies.

88
Lesson 3 - VS

• Sea breezes and land breezes are examples of
  local winds.

89
Lesson 3 LR1
What does the difference in pressure between
areas with low temperatures and those with high
temperatures create?
A. wind B. low pressure C. stability D. the
Coriolis effect
90
Lesson 3 LR2
What term refers to steady winds that flow from
east to west between 30N latitude and 30S
latitudes?
A. prevailing westerlies B. jet streams C. polar
easterlies D. trade winds
91
Lesson 3 LR3
Which type of global winds move cold air from the
poles toward the tropics and warm air from the
tropics toward the poles?
A. trade winds B. jet streams C. prevailing
westerlies D. polar easterlies
92
Lesson 3 - Now
Do you agree or disagree?
5. Uneven heating in different parts of the
atmosphere creates air circulation
patterns. 6. Warm air sinks and cold air rises.
93
Lesson 4 Reading Guide - KC
Air Quality

• How do humans impact air quality?
• Why do humans monitor air quality standards?

94
Lesson 4 Reading Guide - Vocab
Air Quality

• air pollution
• acid precipitation
• photochemical smog
• particulate matter

95
Lesson 4-1
Sources of Air Pollution

• The contamination of air by harmful substances
  including gases and smoke is called air
  pollution.
• Point-source pollution is pollution that comes
  from an identifiable source such as large
  factories.
• An example of natural point-source pollution is
  an erupting volcano.

C. Sherburne/PhotoLink/Getty Images
96
Lesson 4-1
Sources of Air Pollution (cont.)

• Nonpoint-source pollution is pollution that comes
  from a wide-spread area, such as a large city.
• Some bacteria found in swamps and marshes are
  examples of natural sources of nonpoint-source
  pollution.

97
Lesson 4-1
Sources of Air Pollution (cont.)
Compare point-source and nonpoint-source
pollution.
98
Lesson 4-2
Causes and Effects of Air Pollution

• Acid precipitation occurs when sulfur dioxide and
  nitrogen oxides combine with moisture in the
  atmosphere and create acids that fall as
  precipitation.
• Acid precipitation can be in the form of rain,
  snow, and fog.
• It affects the chemistry of water in lakes and
  rivers and can harm organisms living in the water.

99
Lesson 4-2
Causes and Effects of Air Pollution (cont.)

• Natural sources of sulfur dioxide include
  volcanoes and marshes.
• The most common sources of sulfur dioxide and
  nitrogen oxides are automobile exhausts and
  factory and power plant smoke.
• Photochemical smog is air pollution that forms
  from the interaction between chemicals in the air
  and sunlight.

100
Lesson 4-2
Causes and Effects of Air Pollution (cont.)

• Smog forms when nitrogen dioxide, released in
  gasoline engine exhaust, reacts with sunlight.
• A series of chemical reactions produces ozone and
  other compounds that form smog.
• Ground-level ozone is the main component of smog.

101
Lesson 4-2
Causes and Effects of Air Pollution (cont.)
How do humans impact air quality?
102
Lesson 4-3
Particulate Pollution

• Particulate matter is a mixture of dust, acids,
  and other chemicals that can be hazardous to
  human health.
• Particulate matter in the atmosphere absorbs and
  scatters sunlight, which can create haze.

103
Lesson 4-3
Particulate Pollution (cont.)
particulate from Latin particularis, means of a
part
104
Lesson 4-4
Movement of Air Pollution

• Because air carries pollution with it, some wind
  patterns cause more pollution problems than
  others.
• Weak winds or no wind prevents pollution from
  mixing with the surrounding air, which can create
  high pollution levels and dangerous conditions.

105
Lesson 4-5

• At night, cool air sinks down the mountain sides,
  trapping pollution in the valley below.

106
Lesson 4-5
Maintaining Healthful Air Quality

• Preserving the quality of Earths atmosphere
  requires the cooperation of government officials,
  scientists, and the public.
• The Clean Air Act gives the U.S. government the
  power to set air quality standards which protect
  humans, animals, crops, and buildings from the
  harmful effects of air pollution.

107
Lesson 4-5
Maintaining Healthful Air Quality (cont.)

• Pollution levels are continuously monitored by
  hundreds of instruments in all major U.S. cities.

108
Lesson 4-6
Air Quality Trends

• Air quality in U.S. cities has improved over the
  last several decades.
• Ground-level ozone has not decreased much,
  however, because as the number of cars on the
  road increases, air quality standards have not
  kept up with all pollutant levels.

109
Lesson 4-6

• Pollution emissions have declined, even though
  the population is increasing.

110
Lesson 4-6
Air Quality Trends (cont.)

• The air inside homes and other buildings can be
  as much as 50 times more polluted than outdoor
  air and can impact human health much more than
  outdoor air quality.
• Indoor air pollution can come from tobacco smoke,
  cleaning products, pesticides, fireplaces, and
  radonan odorless gas given off by some soil and
  rocks.

111
Lesson 4-6
Air Quality Trends (cont.)
Why do humans monitor air quality standards?
112
Lesson 4 - VS

• Air pollution comes from point sources, such as
  factories, and nonpoint sources, such as
  automobiles.
• Photochemical smog contains ozone, which can
  damage tissues in plants and animals.

C. Sherburne/PhotoLink/Getty Images
113
Lesson 4 LR1
What is pollution that comes from a wide-spread
area, such as a large city?
A. smog B. haze C. nonpoint-source
pollution D. point-source pollution
114
Lesson 4 LR2
Which is a mixture of dust, acids, and other
chemicals that can be hazardous to human health?
A. photochemical smog B. acid precipitation C. sul
fur dioxide D. particulate matter
115
Lesson 4 LR3
What describes what has happened to air quality
in U.S. cities over the last several decades?
A. it has declined dramatically B. it has
declined slightly C. it has improved D. it has
remained the same
116
Lesson 4 - Now
Do you agree or disagree?
7. If no humans lived on Earth, there would be no
air pollution. 8. Pollution levels in the air are
not measured or monitored.
117
Chapter Review Menu
Key Concept Summary Interactive Concept
Map Chapter Review Standardized Test Practice
118
The BIG Idea

• The gases in Earths atmosphere help sustain life
  on Earth and regulate the cycling of thermal
  energy among Earths systems.

119
Key Concepts 1
Lesson 1 Earths Atmosphere

• Earths atmosphere formed as Earth cooled and
  chemical and biological processes took place.
• Earths atmosphere consists of nitrogen, oxygen,
  and a small amount of other gases, such as CO2
  and water vapor.
• The atmospheric layers are the troposphere, the
  stratosphere, the mesosphere, the thermosphere,
  and the exosphere.
• Air pressure decreases as altitude increases.
  Temperature either increases or decreases as
  altitude increases, depending on the layer of
  atmosphere.

PhotoLink/Getty Images
120
Key Concepts 2
Lesson 2 Energy Transfer in the Atmosphere

• The Suns energy is transferred to Earths
  surface and the atmosphere through radiation,
  conduction, convection, and latent heat.
• Air circulation patterns are created by
  convection currents.

121
Key Concepts 3
Lesson 3 Air Currents

• Uneven heating of Earths surface creates
  pressure differences. Wind is the movement of air
  from areas of high pressure to areas of low
  pressure.
• Air currents curve to the right or to the left
  due to the Coriolis effect.
• The main wind belts on Earth are the trade
  winds, the westerlies, and the polar easterlies.

122
Key Concepts 4
Lesson 4 Air Quality

• Some human activities release pollution into the
  air.
• Air quality standards are monitored for the
  health of organisms and to determine if
  anti-pollution efforts are successful.

C. Sherburne/PhotoLink/Getty Images
123
Chapter Review MC1
Which is the atmospheric layer directly above the
troposphere?
A. stratosphere B. ionosphere C. exosphere D. atmo
sphere
124
Chapter Review MC2
Which describes the air at higher altitudes?
A. more dense B. hot C. layered D. less dense
125
Chapter Review MC3
Which term refers to the transfer of thermal
energy by collisions between particles of matter?
A. conduction B. convection C. radiation D. circu
lation
126
Chapter Review MC4
The contamination of air by harmful substances
including gases and smoke is called what?
A. photochemical smog B. particulate
matter C. air pollution D. ground-level ozone
127
Chapter Review MC5
Which describes air pollution that forms from
interaction between chemicals in the air and
sunlight?
A. acid rain B. photochemical smog C. particulate
matter D. nonpoint-source pollution
128
Chapter Review STP1
Which term refers to water in gaseous form?
A. ozone B. nitrogen C. acid D. water vapor
129
Chapter Review STP2
Which term describes the thin layer of gases
surrounding Earth?
A. ozone layer B. atmosphere C. troposphere D. st
ratosphere
130
Chapter Review STP3
The transfer of energy by electromagnetic waves
is called what?
A. convection B. conduction C. radiation D. circul
ation
131
Chapter Review STP4
Which term refers to the movement of air from
areas of high pressure to areas of low pressure?
A. temperature inversion B. stability C. air
pollution D. wind
132
Chapter Review STP5
Which describes air pollution that comes from an
identifiable source such as large factories?
A. point-source air pollution B. nonpoint-source
air pollution C. photochemical smog D. acid
precipitation