Ozone Deficit Problem

Attempts to predict the stratospheric ozone concentration date back to the 1930's. Photochemical models are used to predict the concentration of ozone in the atmosphere, however photochemical models systematically underestimate the observed stratospheric ozone abundances. The discrepancy is particularly puzzling because at altitudes from about 35-80km ozone is in a photochemical steady state and the ozone abundance is thought to be controlled by a relatively small number of chemical reactions.

The ozone deficit problem could be explained if another ozone formation channel could be found, which could account for the additional ozone concentration measured.

It has been proposed that if the O₂ produced in the photodissociation of ozone were sufficiently vibrationally excited to react with ground state O₂ to form an ozone molecule and an oxygen atom, then this sequence of reactions might provide the required ozone formation channel. O₂ in a sufficiently excited vibrational state has been observed as a result of the photodissociation of ozone.