Comparison of ozone variations and of its distribution with height over middle latitudes of the two hemispheres

The paper contains a study of the day-to-day, seasonal and latitudinal distribution of ozone over the southern hemisphere in comparison with those observed in the northern hemisphere. It has been observed that there is more ozone over the middle latitudes of the southern hemisphere in summer, autumn and early winter, than in the northern hemisphere, whereas the spring maximum values are more or less the same in both hemispheres, suggesting lesser destruction of ozone from spring to autumn in the southern than in the northern hemisphere. The distribution of ozone with height computed from umkehr observations over Aspendale by method B has been compared with that over Tateno in Japan. The results are discussed in relation to the idea of a poleward flow of air from the lower stratosphere and the neighbourhood of the equatorial tropopause in the southern hemisphere. It is concluded that the mean meridional circulation in the lower stratosphere of the southern hemisphere is weaker than, or at any rate only as vigorous as that in the northern hemisphere in spring.