Chemical constituents in the air and snow at Dye 3, Greenland—I. Seasonal variations

• Published in: Atmospheric Environment. Part A. General Topics
• Main Authors: Davidson, C, Jaffrezo, J L, Mosher, B W, Dibb, Jack E., Borys, R D, Bodhaine, B A, Rasmussen, R A, Boutron, C F, Gorlach, U, Cachier, H, Ducret, J, Colin, J.-L., Heidam, N Z, Kemp, K, Hillamo, R
• Format: Text
• Language: unknown
• Published: University of New Hampshire Scholars' Repository 1993
• Subjects: DGASP; Greenland; aerosols; sulfate; MSA; trace metals; radionuclides; CO; CH4; chlorofluorocarbons; particle size; wet deposition; dry deposition; Atmospheric Sciences; Arctic; Dye 3; Dye-3
• Online Access: https://scholars.unh.edu/earthsci_facpub/83; https://doi.org/10.1016/0960-1686(93)90304-H

Chemical constituent concentrations in air and snow from the Dye 3 Gas and Aerosol Sampling Program show distinct seasonal patterns. These patterns are different from those observed at sea-level sites throughout the Arctic. Airborne SO42− and several trace metals ofcrustal and anthropogenic origin show strong peaks in the spring, mostly in April. Some species also have secondary maxima in the fall. The spring peaks are attributed to transport over the Pole from Eurasian sources, as well as transport from eastern North America and western Europe. The fall peaks are attributed primarily to transport from North America, and less frequent transport from Europe. Airborne 7Be and 210Pb show strong peaks in both spring and fall, suggesting that vertical atmospheric mixing is favored during these two seasons. Several other airborne constituents peak at other times. For example, Na peaks in winter due to transport of seaspray from storms in ice-free oceanic areas, while MSA peaks in summer due to biogenic production in the oceans nearby. Many trace gases such as freons and other chlorine-containing species show roughly uniform concentrations throughout the year. CO and CH4 show weak peaks in February–March. Concentrations of chemical constituents in fresh snow at Dye 3 also show distinct seasonal patterns. SO42− and several trace metals show springtime maxima, consistent with the aerosol data. Na shows a winter maximum and MSA shows a summer maximum in the snow, also consistent with the aerosols. 7Be and 210Pb in the snow do not show any strong variation with season. Similarly, soot and total carbon in snow do not show strong variation. When used with dry deposition models, these air and snow concentration data suggest that dry deposition of submicron aerosol species has relatively minor influence on constituent levels in the snowpack at Dye 3 compared to wet deposition inputs (including scavenging by fog); crustal aerosol, on the other hand, may have a more significant input by dry deposition. Overall, the results ...