You are here:
OXYGEN ISOTOPES IN ATMOSPHERIC SULFATES, SULFUR DIOXIDE, AND WATER VAPORS FIELD MEASUREMENTS, JULY 1975
Citation:
Holt, B., M. Bouchard, P. Cunningham, A. Engelkemeir, AND E. Nielsen. OXYGEN ISOTOPES IN ATMOSPHERIC SULFATES, SULFUR DIOXIDE, AND WATER VAPORS FIELD MEASUREMENTS, JULY 1975. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-78/045.
Description:
Oxygen isotope ratios were determined for atmospheric samples of sulfate aerosols, sulfur dioxide, and water vapor collected simultaneously during a six-day period in July, 1975, at St. Louis, MO; Auburn, IL; and Glasgow, IL. The collection sites were located about 100km apart. Concerted variations in isotopic and concentration results were found for the three sites, demonstrating an apparent regional impact on the quality and quantity of particulate sulfate in the atmosphere. At all three sites, the oxygen-18 enrichments in suspended sulfates clearly varied inversely with sulfate concentration. This variation suggests that sulfates in cleaner air may have a different origin than sulfates in more polluted air masses. Samples collected during a period of local thunderstorm activity showed an abrupt increase in the oxygen-18 composition of particulate sulfate, but little effect on the isotopic composition of ambient water vapor. The lack of positive correlation between oxygen-18 variations in aerosol sulfate and oxygen-18 variations in water vapor suggests that the aerosol sulfate was not formed predominantly from the ambient water in the air masses from which it was sampled.