Figure 4 . Port Clyde Maine. Cross sectional charts of average summertime daily maximum ozone concentration. The characteristic lifetime of ozone is not known. However, it possible to begin to place bounds on this lifetime.
Sources influence more distant receptors in the predominate direction of transport.
During the summer months, June - August, the characteristic distance of transport is smallest in the Southeast and increases the further north the source region. Figure 6 . New England region. The averaging regions are shown in Figure 3 . The Industrial Midwest with its high stationary source NOx emissions appears to be a common source area for many receptor areas.