Diurnal and Seasonal Patterns of Particulate Sulfur and Sulfuric Acid in St. Louis, July 1977-June 1978

摘要

Continuous measurements of particulate sulfur and sulfuric acid were taken in St. Louis over a one year period using the in-situ thermal analysis-flame photometric method. These measurements were used to calculate average diurnal patterns for each quarter of the year, and also the seasonal pattern for one year. Enhanced formation of particulate sulfur during the daytime hours of spring and summer is indicated by an afternoon concentration increase of about 20%. The diurnal patterns of aerosol acidity and charge (a bulk measure of 0.01-0.1 micrometers particles) also support the notion. Particulate sulfur and light scattering coefficient exhibited moderate seasonal variation. For the third quarter, particulate sulfur concentration was higher than the annual mean by 40% and light scattering coefficient was higher by 25%.