Trace gas

The term Trace gas refers to a gas or gases which make up less than 1% by volume of the earth's atmosphere, and therefore includes all gases except nitrogen (78.1%) and oxygen (20.9%). The most abundant trace gas at 0.934% is argon, which is being continually produced by radioactive decay of ⁴⁰K in the earth's rocks. Water vapor also occurs in the atmosphere with highly variable abundance.

Several atmospheric trace gases such as ozone chem|O|3, sulfur dioxide chem|SO|2 and nitrogen oxides chem|NO|x are anthropogenic, chemically reactive factors of air quality at a regional level. Others such as carbon dioxide chem|CO|2 and methane chem|CH|4 are important greenhouse gases [cite journal
author=R.K. Monson & E.A. Holland
year=2001
title=Biospheric trace gas fluxes and their control over tropospheric chemistry
journal=Ann. Rev. Ecol. Sys.
volume=32
pages=547–576
doi=10.1146/annurev.ecolsys.32.081501.114136] and are produced anthropogenically but also by plants, microorganisms and from natural geothermal sources. [cite journal
author=S.J. Hall, P.A. Matson & P.M. Roth
year=1996
title=NO_"X" emissions from soil: Implications for air quality modeling in agricultural regions
journal=Ann. Rev. Energy Env.
volume=21
pages=311–346
doi=10.1146/annurev.energy.21.1.311] [cite journal
author=R.K. Monson
year=2002
title=Volatile organic compound emissions from terrestrial ecosystems: A primary biological control over atmospheric chemistry
journal=Israel J. Chem.
volume=42
pages=29–42
doi=10.1560/0JJC-XQAA-JX0G-FXJG]

References

External links

* [http://www.ace.mmu.ac.uk/eae/Atmosphere/Older/Trace_Gases.html A description of atmospheric trace gases]