Atmospheric chemistry is a multidisciplinary field of research in which the chemistry of the atmosphere is studied. It also involves physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines.

Average composition of dry atmosphere, by volume
Gas	per NASA
Nitrogen	78.084%
Oxygen	20.946%
Argon	0.934%
Minor constituents in ppmv.
Carbon Dioxide	350
Neon	18.18
Helium	5.24
Methane	1.7
Krypton	1.14
Hydrogen	0.55
Water vapor	Highly variable; typically makes up about 1%

Notes: the concentration of CO₂ and CH₄ vary by season and location. Ppmv represents parts per million by volume.
The mean molecular mass of air is 28.97 g/mole.

The composition and chemistry of the atmosphere is of interest to scientists for several reasons, but primarily because of the interactions between the atmosphere and living organisms. These interactions include health effects, stimulation of growth, water and nutrient cycling, and climate change.

Of particular interest in recent literature are subjects such as global ozone concentrations and global warming caused by natural and anthropogenic sources. Other subjects include acid rain, air pollution, and climate change.