The Atmosphere

1
The Atmosphere
2
Composition of the atmosphere

• 78 Nitrogen, N2
• 21 Oxygen, O2
• 1 tiny amounts of other gases, including
• Carbon dioxide
• Water vapor
• Ozone

3
Layers of the atmosphere

• Troposphere
• closest to earths surface, 10 mi thick
• where weather occurs all living things are
  found
• most affected by pollutants
• Stratosphere
• ends 30 mi above earths surface
• where most of the ozone in the atmosphere is
  found

4
Layers, continued

• Mesosphere
• the middle layer, ends 53 miles above earths
  surface
• the coldest part of the atmosphere
• Thermosphere
• ends 370 mi above earths surface
• where the space shuttle orbits
• thin air ? very low density, molecules far
  apart
• air is very hot ? heated by sun

5
Layers, continued

• Exosphere
• the uppermost layer, ends 6000 mi above earths
  surface
• where the atmosphere and outer space meet!
• Which layer do you think will matter most to us
  in this unit?