Lowest layer of the atmosphere is:

The correct answer is Troposphere.

Important Points

• The air is a mixture of several gases and it encompasses the earth from all sides.
• The air surrounding the earth is called the atmosphere.

Key Points

• The troposphere is the lowermost layer of the atmosphere.
• The height of this layer is about 18 km on the equator and 8 km on the poles.
• The thickness of the troposphere is greatest at the equator because heat us transported to great heights by strong convectional currents.
• All phenomena of climate and weather, which physically affects the man, takes place with in this layer.
• The temperature decreases with increasing height of the atmosphere.
• It decreases at the rate of 1 degree Celsius for every 165 m of height.
  • This is called Normal Lapse Rate.
• The zone separating the troposphere from the stratosphere is known as the tropopause.
  • The air temperature at the tropopause is about – 80 degree Celsius over the equator and about – 45 degree Celsius over the poles.
  • The temperature here is almost constant.