A study of satellite observations of ozone and stratospheric temperatures during 1970-1971

Abstract

An account is given of the comparison between ozone observations by the Nimbus 4 backscatter ultraviolet instrument and stratospheric radiances measured by satellite infrared spectrometer (Sirs) for the period April 1970 to April 1971. Zonal means of total ozone and stratospheric radiances (temperatures) in the middle and high latitudes display annual cycles. A strong increase of ozone and temperatures is, however, observed at the northern high latitudes during the stratospheric warming of January 1971, ozone increases being very rapid after mid-October 1970. 2-mbar temperatures are derived by using Sirs radiances, and their analysis includes the comparison with 2-mbar mixing ratio of ozone for the months of October 1970 and January 1971. Results of comparison reveal remarkable asymmetries between northern and southern hemispheres. Distribution of satellite-measured global and hemispheric ozone is compared with the distribution derived by ground-based observation of total ozone and depicts differences in the southern hemisphere. There is a good correlation between global ozone and global Sirs radiances, both showing a steep fall in February 1971. Satellite observations demonstrate a decrease in global ozone in April 1971 as compared to April 1970. The eddy variations of Sirs radiances show a close correspondence with meridional structure of total ozone. Evidence is presented of strong coupling between planetary wave and zonal flow oscillations.