The photochemical production of ozone in the troposphere

Ozone plays an important and multi-facetted role in the chemistry of the troposphere. Depending on the concentration of nitrogen oxides it can be photochemically produced or destroyed. The net ozone tendency is the residue of large production and destruction terms. State-of-the-art airborne measurements of trace gases over South America and Europe allow a direct determination of the gross ozone tendencies.