Concentration of ozone in surface air over greater Boston

Abstract

Surface ozone concentrations were measured in the Greater Boston area from November, 1964 to December, 1965. Ozone was monitored continuosly using a Mast microcoulombmetric sensor. A chromium trioxide filter was fitted to the air inlet of the sensor in order to remove negatively interfering sulphur dioxide. Daily ozone concentrations near the surface varied from somewhat greater than 10 to less than 1 pphm by volume. The highest concentrations occurred in late spring while the lowest concentrations occurred in the winter. Such a seasonal variation would be expected if the ozone had arrived in the troposphere from the lower stratosphere. The concentration of ozone during the spring and early summer showed a much greater variability from day to day than was exhibited during the fall and winter months.