On the Application of the Optimum Statistical Inversion Technique to the Evaluation of Umkehr Observations

Abstract

The optimum statistical inversion technique is applied to the evaluation of Umkehr observations from Arosa (46.5N, 9.4E), Aspendale (38.0S, 145.IE) and Tallahassee (30.2N, 84.2W). A Priori statistical information on the vertical ozone distribution is obtained from 511 balloon-sounding profiles at Boulder (40.0N, 105.1W). These latter data are also used to develop a regression method for obtaining a first guess at the O₂ distribution, using total O₂ as the independent variable. The ozone profiles inferred from the statistical method, when compared with concurrent direct measurements, display a significant improvement over profiles derived by the method in use at the World Ozone Data Center, Most of this improvement is attributable to the better first guess based on the total O₂ regression. It is concluded that the utility of Umkehr observations is mainly restricted to estimation of the high-level O₂ distribution above the main O₂ maximum. For inferences about the ozone distribution at and below the maximum, effort should be directed toward regression techniques using total ozone as the independent variable.