Atmosphere Atmosphere Chapter 6

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Atmosphere Atmosphere Chapter 6 Powered By Docstoc
      Chapter 6
 Earth’s Atmosphere
  Importance of the Atmosphere
• Atmosphere: thin
  layer of air that forms
  a protective covering
  around the planet

• Balances heat
  absorbed (from sun)
  and heat released
  (into space)

• Protects us from
  sun’s harmful rays
    What is the atmosphere made up
• Mixture of gases, liquids and
• Extends from earth’s surface to
  outer space
• Gases in the atmosphere
  – 78% : Nitrogen
  – 21% : Oxygen
  – 1% : other gases
     • 0.93%: Argon
     • 0.03%: Carbon Dioxide
     • Vapor, ozone, helium, methane,
      Atmosphere continued
• Solids in the atmosphere:
  – dust, salt, pollen

• Liquids in the atmosphere
  - Small liquid droplets from clouds, volcanic

           - Mount Pinatubo---
Layers of the atmosphere
      Layers of the Atmosphere
• 5 layers, each with own
  unique properties

• Lower layers
  – Troposphere
  – Stratosphere
• Upper layers
  – Mesosphere,
  – Thermosphere
  – Exosphere
• Lowest layer
• Extends up to 10 km
• Temperature decreases as you go up

• Where all weather occurs
• Most of total mass of atmosphere is
  located here (ocean, mountains, people, animals,
  plants etc)

• Layer above troposphere
• 10-50km
• Temperature increases as you go up

• Contains Ozone (O3)
  – Ozone (O3) : gas that absorbs sun’s
  harmful rays (solar radiation)

• Layer above stratosphere
• 50-85km
• Temperature decreases as you go up

• Find meteors here
• Most meteors that enter the atmosphere
  burn up here
• Layer above the mesosphere
• 85km-500km
• Temperature increases as you go up (heated by
  radiation from the sun)

• Thickest layer, known for its high temperatures
• Air is very thin (molecules very spread apart)
• Contains layer-ionosphere (radio waves) and

• Highest layer of the atmosphere (before
• 500 km-1,000km, upper boundary 10,000
  km (6,200 miles)

• Very thin air (molecules extremely far apart)
• Satellites
• Space shuttle orbits
Glossary Words
  • Atmosphere
  • Troposphere
  • Stratosphere
  • Mesosphere
 • Thermosphere
    • Exosphere
   • Ionosphere
   • Water cycle
Energy Transfer in the
  Light energy VS Heat Energy
             Energy from the Sun
• Sun provides most energy on
• Drives ocean and wind
• Allows plants to grow and
  produce food provides
  nutrition to animals

• Sun’s energy can be…
• - reflected back into space by
  clouds, atmosphere and
  Earth’s surface (35%)
• - Absorbed by the atmosphere
  or Earth’s surface (65%)
• Heat- flow from high temperature to low temperature

• 1) Energy from the sun reaches Earth’s surface
• 2) Heat transferred by radiation, conduction,
  convection (distributes the Sun’s heat throughout the
• Energy transferred in
  the form of rays or

• Sun reaches Earth in
  the form of radiant

• Feel the Sun’s heat
  and warmth
• Transfer of energy that
  occurs when molecules bump
  into one another (direct

• Earth’s surface conducts
  energy directly to the
  - As air moves over warm
  land or water, molecules in
  air are heated by conduction
• Transfer of heat by the flow
  of material

• Circulates heat throughout
  the atmosphere

• Cool air sinks, Warm air
  rises Convection current
                      The Water Cycle
• Hydrosphere: describes all water on Earth
• Constant cycling of water within the atmosphere and
  hydrosphere- determines weather patterns and
  climate types

• Water moves from
  – Earth Atmosphere Earth

• Evaporation Condensation Precipitation
                  • 1) Sun- liquid (lakes,
The Water Cycle     streams, oceans) gas

                  • 2) Water vapor cools
                    changes back to a liquid-
                    clouds form

                  • 3) Clouds grow in
                    droplet size and fall to
                    Earth (PRECIPITATION)

                  • 4) RUNOFF precipitation
                    to groundwater back
                    to ocean
Questions from Water Cycle Model
        and Study Cards
• What do you see happening?
• What did the ice do to the water that went into
  the air?
• What happened to the water in the air after it
• Where did the drops of water (rain) go?

• How was the water in our model heated?
• What heats water in the real oceans and lakes?
• What did our lamp represent?
         Atmospheric Pressure
• Pressure= Force/Area (force exerted on a
  surface divided by the total area over which the force is

• Atmospheric Pressure
  – Air (makes up the atmosphere around Earth)
    around you presses on you with tremendous
   Variations in Atmospheric Pressure
• Atmospheric pressure
  changes with altitude

• As altitude increases-
  pressure decreases
  – Fewer air particles are found
    in a given volume

• As altitude decreases 
  pressure increases
  – More air particles are found
    in a given volume
         Balanced Pressure
• Why don’t we feel air pressure?
• Pressure exerted outward by fluids of your
  body balances the pressure exerted by the
  atmosphere on the surface of your body
                              Fluids in her body
                               exert a pressure
                               that BALANCES
• Experiment with a balloon (pg 120)
  – Designed an experiment in which he filled a
    balloon only partially with air. He then had the
    balloon carried to the top of a mountain. As he
    predicted, the balloon expanded while being
    carried up the mountain.
  – The amount of air inside the balloon stayed the
    same, while the air pressure pushing in on it
    from the outside decreased. The particles of
    air inside the balloon were able to spread out
               Air movement
• Uneven heating of Earth’s surface causes some
  areas to be warmer than others.

• Due to Earth’s curve
  – Equator receives more radiation (direct) than North or
    South poles
               Heated Air
• Convection currents
  – Equator: hotter air from suns radiation—less
    dense (rise)---LOW PRESSURE
  – Poles: colder air---more dense (sink)---HIGH
               The Coriolis Effect
• Rotation of the Earth causes
  moving air and water to
  appear to turn to the
  – RIGHT north of the equator
    (northern hemisphere)
  – LEFT south of the equator
    (southern hemisphere)

  Coriolis Effect + uneven heating of
   Earths surface  Distinct wind
   patterns which influence
Global Winds
              • Doldrums :
     – near the equator (low pressure area)
            – Windless, rainy zone
            • Trade Winds:
         – air extending to 30°N & S
                – steady winds
              • Westerlies:
       – 30 °– 60° N&S moves opposite
                   trade wind,
      – responsible for much movement of
            weather in N. Hemisphere
              • Easterlies:
            – Found near the poles
         – north pole-move southwest,
           – south pole- northwest
Jet Streams
     • Narrow belts of strong
       winds that blow near the
       top of the troposphere
       (~8mi high)

     • The polar jet stream
       forms at the boundary of
       cold, dry polar air to the
       north and warmer, more
       moist air to the south.
             Local Wind Systems
• Smaller wind systems affect local weather
• Sea and Land Breezes
   – Convection currents over areas where land meets the
        SEA BREEZE                          LAND BREEZE
 During the day (solar radiation      During the night, (land cools more
 warms the land more than water)      rapidly than water)
 Warm air rises over land, Cool air   Warm air rises over water, cool air
 sinks and moves from water           sinks and moves from land toward
 towards land                         the water
Sea Breeze (Day)
Land Breeze (Night)


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