Figure 3.
Time series of surface ozone mole fractions at selected GAW stations.
Hourly data from the WDCGG archive were averaged to monthly mean values, months with less than 67% coverage were excluded, and a 12-months running mean was applied with the condition that at least 8 months had valid data. Panel a shows ozone series from the Northern Hemisphere, and panel b shows data from the Southern Hemisphere.
