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LAYERS OF THE EARTH’S ATMOSPHERE

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Layers of the Earth’s Atmosphere�From top to Bottom

  • Exosphere
  • Thermosphere
  • Mesopause
  • Mesosphere
  • Stratopause
  • Stratosphere
  • Tropopause
  • Troposphere

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TROPOSPHERE

  • Lowest and thinnest layer
    • 16 km (6 miles) at equator, 8 km at poles
  • 90% of the atmosphere’s mass
  • Temperature decreases with altitude
    • 6°C per kilometer
    • Top of troposphere averages
    • –50°C
  • Where weather occurs
  • Boundary between the troposphere, and the stratosphere is called the tropopause

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STRATOSPHERE

  • Extends from 10 km to 50 km above the ground (30 miles)
  • Less dense (less water vapor)
  • Temperature increases with altitude
  • Almost no weather occurrence
  • Contains high level of ozone

> ozone layer

  • Upper boundary is called stratopause

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MESOSPHERE

  • Extends to almost

80 km high (50 miles)

  • Gases are less dense.
  • Temperature decreases as altitude increases.
    • Gases in this layer absorb very little UV radiation.

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THERMOSPHERE

  • above the mesosphere and extends to almost 600 km (375 miles) high
  • temperature increases with altitude
  • readily absorbs solar radiation
  • Temperature can go as high as 1,500 °C
  • reflects radio waves

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EXOSPHERE

  • the interface between Earth and space
  • atoms and molecules can escape to space

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How to remember them?

  • The Stupid Monkeys Tattled on Elephants
  • Typical, Super Mario’s Time Expired!
  • The Smart Man Takes the Elevator
            • Exosphere
          • Thermosphere
        • Mesosphere
      • Stratosphere
    • Troposphere

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Just add Oxygen?

  • Earth was formed about 4.6 Billion years ago.
  • The first half of Earth's history was devoid of oxygen, but it was far from lifeless.
  • Most scientists believe the amount of atmospheric oxygen was insignificant up until about 2.4 billion years ago when the Great Oxidation Event (GOE) occurred.

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  • This seemingly sudden jump in oxygen levels was almost certainly due to cyanobacteria – photosynthesizing microbes that exhale oxygen.
  • When and how the oxygen-exhalers appeared is uncertain, due to the fact that the GOE was a complicated crossroads of global freezing, mineral upheavals and the flourishing of new species.
  • Oxygen was continued to be released into the atmosphere until it made up 20.9 percent of the atmosphere.

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