I' Structure and Characteristics of the Atmosphere

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I. Structure and Characteristics of the
Atmosphere
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A. Early atmosphere

• Created from gases released from volcanoes
  outgassing.
• Mostly water vapor, nitrogen, and carbon dioxide.
• Oxygen was not part of atmosphere until a long
  time later
• The presence of newly formed green algae and
  plants released oxygen into the atmosphere.

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B. Composition of Atmosphere

• Mostly made of nitrogen and oxygen
• Nitrogen 78
• Oxygen 21
• A few other gases are present in small amounts.

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C. 4 Layers

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere

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D. Troposphere

• Closest layer and the layer we live in!
• Clouds, wind, rain, and snow
• Densest
• Why?
• Temperature decreases as altitude increases
• Temperature stops decreasing tropopause

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E. Stratosphere

• 2nd layer
• Oxygen (O2)-deficient no H20 vapor
• Temperature increases as altitude increases
• Why does it get hotter?
• ozone layer upper stratosphere
• What does ozone protect us from?
• What is molecular formula for ozone?
• Temperature stops increasing at - stratopause

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Atmospheric layers video
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F. Mesosphere

• 3rd layer
• Temperature decreases as altitude increases
• No gases that absorb the suns radiation.
• Coldest layer -80C

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G. Thermosphere

• Temperature increases as altitude increases
• Oxygen and nitrogen in this layer absorb suns
  radiation
• Hottest layer 980C
• Convert to Farhenheit
• Tf 32 9/5 Tc
• Tf 32 9/5 (980)
• Tf ? 1796 F
• Outer portion exosphere

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H. Ionosphere

• Electrically charged ions solar radiation
• What is ion?
• Positively charged ion?
• Upper mesosphere and lower thermosphere
• Helpful in radio communication

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Air Pressure

• Atmospheric pressure pressure due to weight of
  atmosphere
• Sea level- 14.7 pounds per square inch.
• 3. The more air above you, the greater the air
  pressure.
• a. Higher air pressure in Valley, than in the
  mountains.
• Mercury barometer

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Air Pressure video
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III. Human Influence on Atmosphere

• Clorofluorocarbons (CFCs) destroy ozone
  molecules.
• Already a hole in ozone near south pole.
• Ozone is getting thinner.
• Excess carbon dioxide leads to greenhouse effect
• Transportation vehicles responsible for ½ of
  pollutants in air.
• Suns radiation trapped global warming
• What effect can global warming have on
  environment?

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Ozone video
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• Solar radiation
• Some radiation is reflected by clouds
• Pollution from cars and factories release carbon
  dioxide.
• Heat is released towards atmosphere. Some
  escapes, some is trapped by greenhouse gases.

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Review Video