Vertical structure of atmosphere is divided into five different layers with different atmospheric characteristics particularly with respect to the climate variables like temperature and density. These are Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere.

Troposphere

• Lowest layer of atmosphere. It has an average height of 13 km but can vary from 8 km at the poles to 18-20 km at the equator. 
• This layer is thickest at Equator due to strong convection currents that carry heat upward. 
• Temperature in the Troposphere decreases at a rate of 1ºC per every 165m of height.
• It is where we find the air which we breathe and the weather phenomena such as rainfall, fog, and hailstorms occurs. It makes troposphere crucial for biological life and activity on earth. 
• The Troposphere is separated from the Stratosphere by the Tropopause, a zone with a relatively constant temperature.
• The air temperature at tropopause is about minus 80ºC over the equator and minus 45ºC over the poles.

Stratosphere

• The stratosphere indeed extends upward from the tropopause. It extends up to a height of 50 km. 
• It accounts for about 10 percent of the total molecular mass of the atmosphere.
• One important feature of the stratosphere is that it contains the ozone layer. This layer absorbs harmful ultra-violet radiation from the Sun and shields life on the earth from intense and harmful forms of energy from the Sun. 
• This layer is almost free from clouds and associated weather phenomenon, making conditions most ideal for flying aeroplanes. 

Mesosphere

• The mesosphere layer extends above the stratosphere up to the height of 80 km. 
• The average temperature in this layer decreases with height. 
• Meteorites burn up in this layer on entering from the space. 
• The upper limit of mesosphere is called mesopause. In this region, during the summer nights over high latitudes, noctilucent clouds (night shining clouds) are observed.

Thermosphere

• The thermosphere layer extends above the mesopause, and the lower portion of this layer is predominantly composed of nitrogen, molecular oxygen and atomic oxygen. 
• In thermosphere temperature rises very rapidly with increasing height, mainly due to the absorption of ultra-violet radiation by the molecular oxygen and atomic oxygen. 
• Ionosphere is a part of this layer. This layer helps in radio transmission as it contains electrically charged particles known as ions and the radio waves transmitted from the earth are reflected back to the earth by this layer.

Exosphere

• The upper most layer of the atmosphere is called the exosphere. This layer has very thin air. 
• Light gases like helium and hydrogen float into the space from here.