Dissolved organic matter characteristics from Greenlandic proglacial rivers and non-glacial streams, Greenland, 2017-2018

Riverine input of terrestrial dissolved organic matter (DOM) is an important part of the marine carbon cycle and drives net atmospheric carbon dioxide (CO2) production in coastal zones. DOM exports likely shift over glacial-interglacial timescales as ice sheets retreat but are not directly recorded in the geologic record. However, modern analogs such as Greenland may be used to constrain the magnitudes and drivers of changes. We compare DOM quantity and quality in Greenland between during the spring (2017), summer (2018) and fall (2017) melt seasons between two rivers directly draining the Greenland Ice Sheet (proglacial rivers) and four streams draining deglaciated catchments that are disconnected from the ice (nonglacial streams). This dataset includes dissolved organic carbon concentrations (DOC) and colored dissolved organic matter (CDOM) characteristics analyzed with spectroscopic (UV (ultraviolet) absorbance and fluorescence) measurements. We present DOM quantity and quality streams draining two proglacial watersheds that are located near the towns of Kangerlussuaq (Watson River; WR) and Narsarsuaq (Kiagtut Sermiat; KS), and four deglaciated watersheds in western Greenland near Kangerlussuaq (Lake Helen; LH) and Sisimiut (Sisimiut 1 and Sisimiut 3; S1 and S3) and southern Greenland (Quornup Kua). We measured UV absorption indices (SUVA (specific ultraviolet absorbance) -254) and slope ratio (Sr) and fluorescence characteristics through the generation of excitation-emission matrices (EEMs).