An assessment is made of the ability of current theory to explain the phenomenology of upper atmospheric ozone as revealed by the sizeable body of measurements presenfiy available. The chemistry of ozone in the mesosphere and lower thermosphere is closely coupled to the chemistries of other oxygen/hydrogen-containing species, which must be considered concurrenfiy. To provide insight into the sensitivity of model calculations to the choice of values used for key chemical rate constants and climatological parameters, simple analytical expressions for ozone are derived for those situations when it is in photochemical steady state, the mesosphere during daylight hours and the lower thermosphere throughout the full diurnal period. The model is found to reproduce the detailed Aladdin 74 rocket measurements of ozone from 50 to 95 kin, numerous other measurements of mid-latitude ozone in the lower mesosphere, the secondary maximum in the ozone vertical distribution at the mesopause, and the diurnal variability of ozone seen in the radio measurements of Wilson and Schwartz (1981) and other observations. The agreement with the Aladdin 74 data results from adjusting some key parameters within the uncertainties of laboratory measurements or known natural climatolog/cal variability. The variety of mid-latitude observations can be understood in terms of the estimated variability of environmental factors: diurnal, seasonal, and solar cycles in the solar illumination; the abundance of water vapor; and the details of the thermal profile of the atmosphere. The ozone secondary maximum results from the onset of the coupling between active-hydrogen and active-oxygen chemistry and its observed variability may be a consequence of secular changes in mesopause dynamics. Above ---95 km, ozone observations are consistenfiy higher than model results and cannot be accounted for by the set of reactions currently included in the model.
INTRODUCTIONOzone in the terrestrial atmosphere between the stratopause (--50 km altitude) and the homopause (--100 km altitude), encompassing the mesosphere and lower thermosphere, is a subject worthy of detailed study, because its presence is a key factor in upper atmospheric processes that are of significant importance to human activities and the evolution of the terrestrial ecosystem. As a result of its optical and chemical properties, ozone affects the thermal structure and dynamics of the upper atmosphere [London, 1980] [1971, 1980] has presented the set of reactions important for the hydrogen/oxygen chemistry. The papers by Hunt [1971, 1973] [ 1983] all present model profiles of ozone for part or all of the altitude range between the stratopause and the homopause. As a result of this cumulative work, a general understanding of the key chemical and atmospheric parameters affecting the ozone distribution has developed. Some of these papers present limited comparisons between model distributions and the observations available at the time. Since most of this work appeared, there have been significant ...
