Figure 5From: Associations between ozone and morbidity using the Spatial Synoptic Classification system Ozone distribution of the seven air masses for the 9-year period 1996-2004. (a) Probability (expressed as a percentage) of finding ozone (O3) concentrations above a threshold concentration for a given air mass (P(O3|AM)). (b) Probability (expressed as a percentage) of having a particular air mass present when ozone concentrations are above a threshold concentration (P(AM|O3)).Back to article page