The first 2 years of backscattered ultraviolet (BUV) ozone data from the Nimbus 4 spacecraft have been processed to a more refined level. The seasonal variations of total ozone for the period April 1970 to April 1972 are described using daily means for 10 ¿ latitude zones and a time-latitude cross section. In addition, the BUV data are compared with analyzed Dobson data and with infrared interferometer spectrometer data also obtained from the Nimbus 4 spacecraft. A harmonic analysis was performed on the daily zonal means. Amplitudes, days of peak ozone values, and percentage of variance have been computed or the annual and semiannual waves and for higher harmonics of an annual period for the 2 years. Asymmetries are found in the annual waves in the two hemispheres, with a subtle interannual difference which may be due to changes in the general circulation. A significant semiannual component is detected in the tropics for the first year. This component appears to result from influences of the annual waves in the two hemispheres. A search for shorter periods using the harmonic analysis revealed no periodicity whose amplitude was higher than the noise level.