Abstract. In the Arctic, the snowpack forms the major interface between atmospheric and terrestrial mercury (Hg) cycling, a global pollutant. In this study, we investigated Hg dynamics in an interior arctic tundra snowpack in northern Alaska during two snow seasons. Using a snow tower system and soil wells to monitor trace gas exchange of Hg, we observed consistent concentration declines of gaseous elemental Hg (Hg0gas), the volatile form of Hg, from the atmosphere to the snowpack to soils. This indicates a sink of Hg0gas in tundra soils. There was no evidence of photochemical reduction of HgII to Hg0gas in the tundra snowpack, unlike in temperate snowpacks, with the exception of short periods during late winter. We consistently measured low concentrations of both total (Hgtot) and dissolved (Hgdiss) Hg in the tundra snowpack throughout two years (generally
Supplementary material to "Mercury in arctic tundra snowpack: temporal and spatial concentration patterns and trace–gas exchanges"