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Atmosphere Composition of the atmosphere

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Atmosphere Composition of the atmosphere Powered By Docstoc
					                                                                                  Our atmosphere serves two
                                                                                           purposes:
                                                                            1. Protects life on Earth from the Sun’s
   Atmosphere                                                                  harmful rays.
                                                                            2. Maintains a balance between amounts of
                                                                               heat absorbed from the sun and the
                                                                               amount of heat that escapes back into
           A layer of air that forms a
                                                                               space.
         protective covering around the
                     planet.




Composition of the atmosphere:                                                  The atmosphere is composed of:
                                                                            •   Solids- dust, pollen, salt
                                                                            •   Liquids- water etc.
                                                                            •   Gases-
                                                                            •    Nitrogen (78%) produced from
                                                                                – volcanic eruptions,
                                                                                – dead and decaying plants.
                                                                            • Oxygen (21%)
                                                                                – produced by plants (photosynthesis)




   Atmosphere is composed of 5 layers.
   These layers are based on pressure and temperature,
   which are affected by altitude.

                              Atmosphere




Air Pressure                                        Temperature

-as altitude increases,                           - as altitude increases
 air pressure decreases                            temperature changes
                          Which are effected by




                                Altitude




                                                                                                                        1
              As altitude increases,            As altitude changes, so does the
              air pressure decreases.                     temperature.




 Both air pressure and temperature             • Troposphere: 0 – 16
                                                 km
    are affected by the altitude               • Tropo=turning or
                                                 changing
• As altitude increases, pressure decreases.
  The molecules at the bottom layer            • Weather takes place
                                                 here
  (Troposphere) have more pressure on
  them to force them together than those at    • 90% of the
                                                 atmosphere’s total
  the top layer (Thermosphere).                  mass
• Temperature differences result from the           0°c
                                               • - 6 at the top of the
  way solar energy is absorbed as it moves       troposphere
  down through the layers of the               • As altitude increases,
  atmosphere.                                    temperature
                                                 decreases




                                               • Mesosphere: 50 – 80 km
• Stratosphere: 16 – 50 km
                                               • Meso = middle
• Strato= layer or spreading out               • Temperature decreases
• Jet stream = contains broad,
                                                 as altitude increases.
  fast flowing “rivers of air” called          • Outer mesosphere is the
  jet streams. These jet streams                 coldest part of the
  can change weather patterns                    atmosphere. -93°c at the
  in the troposphere.                            top.
• Upper layer is warmer than                   • Protects Earth’s surface.
  lower due to ozone layer.                      This is where meteoroids
• Ozone layer= O3 (Ozone)                        burn up upon entry into
  absorbs sun’s ultraviolet rays,                the atmosphere:
  so temperature increases. IT                   “shooting stars”.
  is very thin, only 2.5-3.5 mm                • Scientists have recently
  thick. O2 (Oxygen) vs O3
  (Ozone).
                                                 discovered large
                                                 windstorms with winds
• -60°c to 0°c                                   speeds up to 320 km/h in
                                                 this layer.




                                                                                   2
                                • Ionosphere:
• Thermosphere: 80 – 550        • Lower layer of the
  km                              thermosphere composed
                                  primarily of oxygen.
• Thermo = heat
                                • Absorbs x-rays and gamma
• Largest layer, .001             rays, which contribute to the
  percent as dense as the         high temperature and cause
                                  the gas molecules to become
  air at sea level.               electronically charged (ions).
• Temperature increases         • Aurora Borealis/Australis: The
  as altitude increases.          northern and southern lights.
                                  Particles from the sun enter
  Temperatures reach              and strike oxygen and nitrogen
  1700°c.                         particles, causing them to
                                  glow.
• Very hot because energy
                                • The ionosphere can reflect
  coming from the sun             many types of radio waves,
  strikes this layer first.       allowing them to bounce
                                  around the world.
• Energy = heat




• Exosphere: Above 550
  km                                          5 Layers Revisited
• No true end of
  atmosphere. Gas
  molecules simply break
  free of Earth’s gravity and
  disperse.
• Space shuttles, ISS
  (International Space
  Station) and satellites
  orbit the earth in this
  layer. This is how long
  distance calls, satellite
  TV, internet, cell phones,
  etc., reach you.




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