Fig. 3: Seasonal variations of climatological zonal Means (Dobson unit or 10-3 cm-STP) and linear decreasing relative Trends (%/decade) of total O3 amount as derived from the TOMS raw measurements (top) and the analyzed data (bottom) during 1979-1991. The contour interval is 20 units for the means, and 2 for the trends. Trends of O3 relative decreases greater than 6 units are shaded.