The atmosphere

The atmosphere

DEFINITION
1. Layer of gases that surrounds the Earth
ORIGIN
1. 4.4 BY
  1. Gases escaped from deep inside
  2. Hydrogen & Helium
  3. Blew away by solar wind
2. Primitive atmosphere
  1. Volcanic gases
  2. Thanks to magnetic field
3. 3.5 BY
  1. Photosynthetic bacteria produced Oxygen
COMPOSITION
1. Primitive atmosphere
  1. Volcanic gases
    1. Carbon dioxide
    2. Chlorine & Sulphur oxides
    3. Small amounts: nitrogen & argon
2. Today
  1. Oxigen 21%
  2. Nitrogen 78%
  3. Trace gases 1%
    1. Argon 0.9%
    2. Carbon dioxide
    3. Other gases 0.06%
      1. Methane Chorine & Sulphur oxides Ozone
STRUCTURE
1. Troposphere
  1. Lowest layer Closest to Earth
  2. 90% mass
  3. To -55ºC
  4. Weather
  5. Tropopause 10-15 km
2. Stratosphere
  1. Very stable vertically
  2. 10-50km
  3. Planes
  4. Strong horizontal winds
  5. Contains Ozonosphere
  6. Stratopause
3. Mesosphere
  1. 50-80km
  2. Temperature reaches -100ºC
  3. Mesopause
4. Ionosphere
  1. Outer layer
  2. At 500 km meets outer space
  3. Less and less air
  4. Higher temperatures
FUNCTIONS
1. Provides to living things:
  1. Oxygen to breath
  2. Carbon dioxide used in photosynthesis
  3. Nitrogen used by some bacteria
  4. Filter against solar radiation
  5. Regulation of global temperature
2. Other functions
  1. Winds
    1. Distribute solar energy
    2. Change landscape through erosion, transport and sedimentation
  2. Changes/breaks rocks
    1. Through chemical reactions
    2. Through temperature variations
CHARACTERISTICS
1. Atmospheric pressure
  1. Weight of air
  2. Depends on altitude & temperature
  3. Measured with a barometer
2. Air movement
  1. Wind
    1. Mass of air that moves
    2. Caused by atmospheric pressure differences
  2. Air mass
    1. Large volume of air with similar properties
    2. Fronts
      1. Boundary between masses
      2. Warm front
      3. Cold front
    3. Areas
      1. High pressure area
        Air fails & moves away in all directions
      2. Low pressure area
        Air enters from all directions & rises
3. Precipitation
  1. Any form of water that falls to Earth
  2. At very low temperatures: Snow or hail
4. Weather
  1. Conditions of the atmosphere in a specific area at a particular time
5. Air pollution
  1. Air quality: state of air at a given time
  2. Pollutants
    1. Substances that affect negativity air quality
    2. Examples
      1. Carbon monoxide
        Causes suffocation
      2. Sulphur & nitrogen oxides
        Irritant & Acid rain
      3. Soot
        Particles, enter lungs & blood, causing serious damage
    3. Solid, liquid or gas
  3. Problems
    1. Global warming
      1. Carbon dioxide
        Human activities
        Increases Acumulates
        Green house effect
        Traps heat energy emitted by Earth
        Natural component of air
    2. Hole in the ozone layer
      1. CFC gases
        Produced by industry
        If they reach stratosphere, destroy ozone
6. Clouds
  1. Water droplets
    1. Very light
    2. Air rises
7. Climate
  1. Average atmosphere conditions in a specific area over a long period of time
  2. Meteologists
    1. Study average daily values over a long period:
      1. Temperature
      2. Precipitation
    2. Create climographs
8. Favorable actions

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	Criado por Mónica Garrido mais de 5 anos atrás