Abstract (from http://pubs.acs.org/doi/full/10.1021/acs.est.5b02685): Dissolved organic carbon (DOC) plays a fundamental role in the biogeochemistry of glacier ecosystems. However, the specific sources of glacier DOC remain unresolved. To assess the origin and nature of glacier DOC, we collected snow from 10 locations along a transect across the Juneau Icefield, Alaska extending from the coast toward the interior. The Δ14C-DOC of snow varied from −743 to −420‰ showing progressive depletion across the Icefield as δ18O of water became more depleted (R2 = 0.56). Older DOC corresponded to lower DOC concentrations in snow ( R2 = 0.31) and a decrease in percent humic-like fluorescence ( R2 = 0.36), indicating an overall decrease in modern [...]
