EFFECTS OF NON-PHOTOCHEMICAL PROCESSES ON THE MERIDIONAL DISTRIBUTION AND TOTAL AMOUNT OF OZONE IN THE ATMOSPHERE

The photochemical equilibrium distribution of ozone below 41 km. is computed for the solstices and equinoxes from recent rocket observations of the solar ultraviolet energy received at the top of the atmosphere. In this study an attempt is made to investigate the important part played by the mean seasonal transport processes in distributing the ozone below 41 km. in the stratosphere. To make such an investigation it is assumed that a steady state meridional distribution of ozone is produced when photochemical and transport processes are acting together. Relevant theory and numerical procedure to compute such a steady state meridional distribution of ozone have been developed. In order to make a model of the transport processes that is needed for the calculation of the distribution of ozone, theoretical and observational information available at present on the various transport processes present in the stratosphere is reviewed. Further, in the calculations of ozone an attempt is made to combine the mean meridional motions and the large-scale mixing processes within the limits acceptable to the current ideas on these transport processes. The seasonal distribution of total ozone thus computed from the model of the transport processes and with an assumption of steady state conditions shows a satisfactory agreement with the observed seasonal and latitudinal variation of total ozone. The mean annual total ozone variation with latitude deduced from the computed seasonal distribution of total ozone, demonstrates the ability of the method developed here to account for the mean annual total ozone variation with latitude observed in the earth's atmosphere. The model of the transport processes developed in this study to calculate the distribution of ozone in the atmosphere emphasizes the importance of the large-scale eddy diffusion processes. The theoretical and observational findings from the spread of W185 (a radioactive isotope of tungsten introduced into the stratosphere by nuclear explosions) have been very useful in making this model of the transport processes.