The objective of this study has been to use data collected during the 1975 Northeast Oxidant Study to determine the cause of high ozone concentrations in the Connecticut River Valley and to develop a method for predicting ozone levels that can be expected in southern New England under various meteorological conditions. During the summer months, the prevailing southwesterly winds place the valley directly downwind of the New York/New Jersey/southwestern Connecticut urban complex (and on some days the Philadelphia and Washington/Baltimore areas). The ozone formed from the urban emissions (i.e., the urban plume) was observed on many case study days to move into Connecticut from the southwest in early afternoon, cross the Connecticut River Valley, and continue into Massachusetts during the evening. In one case an O3-rich air mass was tracked as far north as the coast of Maine. The dimensions of the urban plumes on several days were found to vary from 30-80 miles in width and 100-75 miles in length, seemingly depending on wind speed. Several methods of predicting ozone in southern New England were investigated including regression integrals, simple regression and multiple regressions.

"EPA-600/3-77-041." "May 1977." Includes bibliographical references (pages 89-90).