Human and natural activities displace tiny soil, salt, and ash particles as suspended aerosols,

as well as sulfur and nitrogen oxides, and hydrocarbons as pollutants.

Gravity pulls gases toward earth's surface, and the whole column of gases weighs 14.7 psi at sea level, a pressure of 1013.25 mb or 29.92 in.Hg .

The amount of force exerted Over an area of surface is called Air pressure!

Air Density is The number of air Molecules in a given Space (volume)