The Diurnal Variations of Ozone at Different Altitudes on a Rural Mountain in the Eastern United States

Because O/sub 3/ has been mentioned as a possible contributor to the decline of forests at high altitudes in Europe and in the U.S., it is important to understand the diurnal behavior of ozone at higher altitudes. The data collected in this study, conducted on a 550-m mountain near the common border of New Jersey, New York, and Pennsylvania, show that daily maximum ozone concentrations and mid-day concentrations are similar at different altitudes but the ozone dosages increase with height. The lower the site, the more time the site is below the nocturnal inversion layer where the ozone is rapidly depleted. A site located at 500 m received an average ozone dose 32 percent greater than at the 300-m level and 72 percent greater than at the 140-m level.