Compositional layering of the Atmosphere
The atmosphere can be divided into two spheres on the basis of its chemical composition occurring with height i.e. (1) Homosphere. (2) Hereto sphere.
In the lower region up to the height of 88 km the various gases are thoroughly mixed and are homogenous by the process of turbulent mixing, and diffusion. This sphere is called as Homosphere. Herein the presence of gases is governed by the diffusion and the composition remains normally.
In hydrosphere gaseous composition changes and various gases form separate compositional layering individually.
Satellite data have shown the presence of different chemosphere in follows:
Nitrogen and oxygen
From 88 to 115 km
Automatic oxygen layer
From 115 to 965 km
From 965 to 2400 km
From 2400 to 10,000 km
The distribution of the gases is governed by the earth’s gravitational field. Thus heavier gases sink downward while the lighter gases like hydrogen remain at higher altitude.