Wednesday, 11 January 2012

psc quick reference-Atmosphere

  • The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity.

  • Mainly divided into 4 layers

  1. Troposphere
  2. Stratosphere
  3. Mesosphere
  4. Thermosphere


  • The layer of the atmosphere closest to the earth is the troposphere.
  • This layer is where weather occurs.
  • It begins at the surface of the earth and extends out to about 4-12 miles.
  • The temperature of the troposphere decreases with height.
  • This layer is known as the lower atmosphere.


  • Above the troposphere is the stratosphere, which extends to about 30-35 miles above the earth's surface.
  •  Temperature rises within the stratosphere but still remains well below freezing.
  • Ozone layer seen in this layer.
  • Air travel occurs in this layer.


  • From about 35 to 50 miles above the surface of the earth lies the mesosphere, where the air is especially thin and molecules are great distances apart. 
  • Temperatures in the mesosphere reach a low of -184°F (-120°C). The stratosphere and the mesosphere are the middle atmosphere.

Thermosphere :

  • The thermosphere rises several hundred miles above the earth's surface, from 50 miles up to about 400 miles. 
  • Temperature increases with height and can rise to as high as 3,600°F (2000°C). 
  • Nonetheless, the air would feel cold because the hot molecules are so far apart. 
  • This layer is known as the upper atmosphere.
  • Ionosphere is a part of this layer


  • Extending from the top of the thermosphere to 6200 miles (10,000 km) above the earth is the exosphere. 
  • This layer has very few atmospheric molecules, which can escape into space.


No comments:

Post a Comment