Photostationary state relation

From Glossary of Meteorology

photostationary state relation

A relationship that determines the ratio of the concentrations of nitric oxide, NO, and nitrogen dioxide, NO2, in the troposphere.

In its simplest form, the ratio is controlled by the following chemical reactions, which interconvert NO and NO2 without any change in the ozone concentration:
In the real atmosphere, the ratio is perturbed by the presence of other oxidants (mostly hydroperoxyl and organic peroxyl radicals), which also convert NO to NO2 and lead to net ozone production. The photostationary state relation is also occasionally referred to as the Leighton relationship, after Philip Leighton.

Leighton, P. A. 1961. Photochemistry of Air Pollution. Academic Press, New York.