WINTERTIME CONCENTRATIONS AND SINKS OF ATMOSPHERIC PARTICULATE CARBON AT A RURAL LOCATION IN NORTHERN MICHIGAN

Particulate elemental carbon, organic carbon, and SO//4**2** minus wintertime atmospheric concentrations were determined at a rural site in northern Michigan during two winters. Examination of the concentrations, based on both surface-wind direction and backward-trajectory analysis, indicated that concentrations were significantly influenced by the long-range transport of pollutants. Measurements of the wet- and dry-deposition rates of elemental carbon showed that it is removed primarily by wet deposition at this site. The dry deposition velocity of elemental carbon to a snow surface averaged less than 0. 2 cm s** minus **1 during most of the study, but was considerably higher for one period during which it appeared to be influenced by large particles from local sources. A comparison of the scavenging ratios of SO//4**2** minus and elemental carbon suggests that elemental carbon can be transported long distances and, thus, may degrade visibility and have other effects over wide regions.