Air is essential for life it self; without it we could survive only a
few minutes. It constitutes immediate physical environment of
living organisms. It is a mixture of various gases like nitrogen,
oxygen and carbon dioxide, and others in traces; along with
water vapor perceptible as humidity and suspended solids in
particulate form.
The atmosphere is layered in to four distinct zones of
contrasting temperature due to differential absorption of solar
energy. The four atmospheric layers are: Troposphere,
stratosphere, mesosphere, and thermosphere. Understanding 2
how these layers differ and what creates them helps us
understand atmospheric function.