Upper panel, Figure 2a: Contour plot constructed from 8 hour average O₃ passive diffusion sampler data. Locations of sampling sites are indicated by pink triangles. Lower panel, Figure 2b: Contour plot is constructed from 8 hour averaged data from continuous monitors located at the sites marked by pink triangles. The dashed outline rectangle shows the area depicted in the upper panel. Wells are superimposed to aid as geographic markers.