A new source of ozone in the terrestrial upper atmosphere?

The simultaneous measurements of atomic O, O₂, O₃, and N₂ between 90 and 110 km obtained by a rocket-borne mass spectrometer flown during the Aladdin 74 program provide an opportunity to test directly the simple atmospheric chemical model first proposed more than 50 years ago by S. Chapman, which is today the core of the complex chemistry controlling stratospheric O₃. The Aladdin 74 O₃ results are found to be significantly in excess of model abundances computed using the most current values of the key chemical parameters. The calculations may possibly be in error due to uncertainties in these key parameters and/or in the measurement of the related species. However, the extra O₃ may be a consequence of reactions between ground state O₂ and electronically excited O₂ resulting from the recombination of atomic O.