1. Earth’s Changing Atmosphere
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Earth’s Changing Atmosphere
the BIG idea
Earth’s atmosphere is a blanket of gases that supports and protects life.
15.1
Earth’s atmosphere supports life.
15.2
The Sun supplies the atmosphere’s energy.
15.3
Gases in the atmosphere absorb radiation.
15.4
Human activities affect the atmosphere.
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2. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
Air pressure as you move in the atmosphere.
Just as air pressure with altitude, so does the density of air.
atmosphere
altitude
density
cycle
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3. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
The atmosphere is a thin layer surrounding Earth. Gases in the atmosphere provide substances essential for living things.
atmosphere
altitude
Gases of Earth's Atmosphere
density
cycle
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4. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
Three of the most important cycles that affect the atmosphere are the water cycle, the carbon cycle, and the nitrogen cycle.
The Water Cycle Different forms of water (H2O) cycle between Earth's surface and the atmosphere. For example,
• Liquid water from oceans and lakes evaporates into gas and enters the atmosphere (plants can also release water vapor from their leaves called transpiration).
• Water vapor condenses on small particles in the atmosphere until they become too heavy.
• Precipitation
atmosphere
altitude
density
cycle
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5. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
The Carbon Cycle Carbon dioxide (CO2) and oxygen (O2) gases constantly circulate, or cycle, among plants, animals, and the atmosphere. For example,
• Animals inhale air, use some of its oxygen, and exhale air that has less oxygen but more carbon dioxide and water
• Plants take in carbon dioxide and release oxygen as they make food in the process of photosynthesis
Another photo of the carbon cycle.
atmosphere
altitude
density
cycle
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6. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
The Nitrogen Cycle Different forms of nitrogen cycle among the atmosphere, the soil, and living organisms. For example,
• Tiny organisms remove nitrogen gas (N2) from the air and transform it into other chemicals, which then enter the soil
• Plants and animals use solids and liquids that contain nitrogen, which returns to the soil when the organisms die and decay
• The soil slowly releases nitrogen back into the air as nitrogen gas
atmosphere
altitude
density
cycle
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7. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
When sudden events occur, it takes time before the atmosphere is able to restore balance.
• Volcanic Eruptions Volcanoes
-shoot gases and huge amounts of ash up -gases can produce a haze that may affect the air for many months and lower temperatures worldwide.
atmosphere
altitude
density
cycle
• Forest Fires
- the carbon from trees combines with oxygen making carbon dioxide
- wood ash also enters the atmosphere.
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8. Earth’s atmosphere supports life.
15.1
Earth’s atmosphere supports life.
• Dust Storms
-Wind, water, or drought can loosen soil. -Powerful windstorms may then raise clouds of this eroded soil adding huge amounts of particles to the air for a time.
atmosphere
altitude
density
cycle
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9. The Sun supplies the atmosphere’s energy.
15.2
The Sun supplies the atmosphere’s energy.
The Sun supplies the atmosphere's energy.
radiation
70% = 50% absorbed by the Earth’s surface + 20% absorbed by clouds and the atmosphere
conduction
convection
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10. The Sun supplies the atmosphere’s energy.
15.2
The Sun supplies the atmosphere’s energy.
Energy from the Sun moves through Earth's atmosphere in three ways.visualization example
radiation
conduction
Transfer of Energy
Radiation, conduction, and convection move energy from place to place.
convection
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11. 15.2
radiation
conduction
convection
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12. The Sun supplies the atmosphere’s energy.
15.2
The Sun supplies the atmosphere’s energy.
Density and temperature change with altitude. The layers, from top to bottom, are
radiation
conduction
• thermosphere: The last layer before outer space.
temperature increases as you rise.
convection
• mesosphere: air is thin (less than 0.1%)
most meteors burn up here
temperature decreases as you rise
You can use the word parts to help you recall the temperature layers.
tropo–"turning"
strato–"spreading out"
meso–"middle"
thermo–"heat"
• stratosphere: clear, dry layer
ozone
temperature increases as you rise
• troposphere a: contains about 80% of the total mass of the atmosphere almost all of the water vapor temperature decreases as you rise
Vocab flip cards:
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13. Gases in the atmosphere absorb radiation.
15.3
Gases in the atmosphere absorb radiation.
Gases can absorb and give off radiation.
ultraviolet radiation
-The atmosphere can affect light in four ways.
1. It can absorb light
2. reflect it
3. let it pass through
4. Air can also emit, or give off, light
infrared radiation
ozone
greenhouse effect
greenhouse gas
Although air does not emit much visible light, certain gases absorb and emit radiation that is similar to visible light.
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14. Gases in the atmosphere absorb radiation.
15.3
Gases in the atmosphere absorb radiation.
The ozone layer protects life from harmful radiation when the ozone molecules in the stratosphere absorb harmful ultraviolet radiation.
ultraviolet radiation
infrared radiation
ozone
greenhouse effect
greenhouse gas
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15. Gases in the atmosphere absorb radiation.
15.3
Gases in the atmosphere absorb radiation.
Greenhouse gases in the troposphere keep Earth warm by absorbing and emitting infrared radiation.
ultraviolet radiation
infrared radiation
ozone
greenhouse effect
greenhouse gas
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16. Gases in the atmosphere absorb radiation.
15.3
Gases in the atmosphere absorb radiation.
ultraviolet radiation
infrared radiation
ozone
greenhouse effect
greenhouse gas
VISUALIZATION
See how the greenhouse effect works.
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17. Human activities affect the atmosphere.
15.4
Human activities affect the atmosphere.
Human activities have added different types of pollution and ozone-destroying chemicals to the atmosphere.
air pollution
particulate
fossil fuel
Natural Sources
• dust, pollen, soil, salt
• volcanoes and forest fires:
gases and particles
Human Activities
• fossil fuels: gases and particles
• unburned fuels: smog
• manufacturing: gases and particles
• tractors/construction equipment:
dust and soil
• farming: fertilizers and pesticides
smog
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18. Human activities affect the atmosphere.
15.4
Human activities affect the atmosphere.
Human activities put chlorine and other ozone-destroying chemicals in the stratosphere that break down our ozone.
air pollution
particulate
fossil fuel
smog
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19. Human activities affect the atmosphere.
15.4
Human activities affect the atmosphere.
The amounts of greenhouse gases have been increasing and global temperatures are rising.
air pollution
particulate
fossil fuel
smog
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20. Human activities affect the atmosphere.
15.4
Human activities affect the atmosphere.
What is global warming? Do you believe it is happening? How can we make a difference?
air pollution
particulate
fossil fuel
smog
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21. 15.1 Earth’s atmosphere supports life.
I. Earth’s atmosphere supports life.
atmosphere
A. The atmosphere makes life on Earth possible.
altitude
1. Characteristics of the Atmosphere
density
2. Materials in the Atmosphere
cycle
B. Natural processes modify the atmosphere.
1. Ongoing Processes
2. Sudden Changes
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KEY CONCEPT
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22. 15.2 The Sun supplies the atmosphere’s energy.
II. The Sun supplies the atmosphere’s energy.
radiation
A. Energy from the Sun heats the atmosphere.
conduction
B. The atmosphere moves energy.
convection
C. The atmosphere has temperature layers.
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KEY CONCEPT
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23. 15.3 Gases in the atmosphere absorb radiation.
III. Gases in the atmosphere absorb radiation.
ultraviolet radiation
A. Gases can absorb and give off radiation.
infrared radiation
B. The ozone layer protects life from harmful radiation.
ozone
greenhouse effect
C. The greenhouse effect keeps Earth warm.
greenhouse gas
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KEY CONCEPT
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24. 15.4 Human activities affect the atmosphere.
IV. Human activities affect the atmosphere.
air pollution
A. Human activity can cause air pollution.
particulate
1. Types of Pollution
fossil fuel
2. Effects of Pollution
smog
3. Controlling Pollution
B. Human activities are increasing greenhouse
gases.
1. Sources of Greenhouse Gases
2. Global Warming
3. Reducing Greenhouse Gases
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C. Human activities produce chemicals that destroy the ozone layer.
KEY CONCEPT
SUMMARY

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