The ______ lies above the mesopause and is a region in which temperatures increase with height.

The correct answer is thermosphere.

Key Points

• The thermosphere lies above the mesopause and is a region in which temperatures increase with height.
• Thermosphere:
  • In the thermosphere, the temperature rises very rapidly with increasing height.
  • The ionosphere is a part of this layer.
  • It extends between 80-400 km. This layer helps in radio transmission.

Additional Information

• There are a total of five atmospheric layers. These are -
  • Troposphere.
  • Stratosphere.
  • Mesosphere.
  • Thermosphere.
  • Ionosphere: the lowest part of the Thermosphere contains the ionosphere.
  • Exosphere.
• Stratosphere:
  • It lies beyond the troposphere, up to an altitude of 50 km from the earth's surface.
  • The temperature in this layer remains constant for some distance but then rises to reach a level of 0°C at 50 km altitude.
  • This rise is due to the presence of ozone.
  • This layer is almost free from clouds and associated weather phenomena, making conditions most ideal for flying aeroplanes.
• Exosphere:
  • This is the uppermost layer of the atmosphere extending beyond the ionosphere above a height of about 400 km.
  • The air is extremely rarefied and the temperature gradually increases through the layer.
  • Light gases like helium and hydrogen float into space from here.
• Troposphere:
  • It is the lowermost layer of the atmosphere.
  • The layer starts at Earth's surface and extends 8 to 14.5 km high (5 to 9 miles).
  • The troposphere contains dust particles and water vapour.
  • This is the most important layer of the atmosphere because all kinds of weather changes take place only in this layer.
  • The zone dividing troposphere from the stratosphere is known as the tropopause.