The Atmosphere
Introduction to the Atmosphere
The atmosphere is a layer of gas and suspended solids extending from the Earth's surface up many thousands of miles, becoming increasingly thinner with distance but always held by the Earth's gravitational pull.
The atmosphere surrounds the Earth and holds the air we breathe; it protects us from outer space; and holds moisture (clouds), gases, and tiny particles. In short, the atmosphere is the protective bubble in which we live.
This protective bubble consists of several gases (listed in the table below), with the top four making up 99.998% of all gases. Of the dry composition of the atmosphere, nitrogen by far is the most common. Nitrogen dilutes oxygen and prevents rapid burning at the Earth's surface. Living things need it to make proteins.
Oxygen is used by all living things and is essential for respiration. It is also necessary for combustion (burning). Argon is used in light bulbs, in double-pane windows, and to preserve museum objects such as the original Declaration of Independence and Constitution. Plants use carbon dioxide to make oxygen. Carbon dioxide also acts as a blanket that prevents the escape of heat into outer space.
The exact amounts of each gas vary slightly from day to day. The NOAA Global Monitoring Lab updates trends in the 4 main Greenhouse Gases in the atmosphere daily.
https://www.noaa.gov/jetstream/atmosphere
