Description: The outflow of Leverett Glacier, a large land-terminating glacier of the Greenland Ice Sheet was sampled over the 2015 ablation season. Dissolved organic carbon (DOC) concentrations, dissolved organic matter (DOM) fluorescence, and hydrogeochemical data (e.g. discharge, specific conductivity, pH, and turbidity) were analyzed to assess changing DOM sources over the melt season. DOC concentrations and red-shifted fluorescence suggest terrestrial inputs from overridden soils dominated DOM early season inputs before progressive dilution with increasing discharge. During the outburst period, supraglacial drainage events disrupted the subglacial drainage system and introduced dominant protein-like fluorescence signatures not observed in basal flow. These results suggest that subglacial hydrology and changing water sources influence exported DOC concentration and DOM composition, differentiated through fluorescence characteristics. The outburst and post-outburst periods were characterized by protein-like fluorescence from supraglacial and potentially subglacial microbial sources.

Description: This data set includes hydrographic and pore water and core incubation silicic acid concentration and isotope measurements, sediment Si-HCl and Si-Alk contents and isotope measurements, and pore water nutrient, major, and trace element concentrations measured in the fjords Ameralik Fjord and Nuup Kangerlua (Godhäbsfjord) in southwest Greenland. Data was collected during a research expedition, R/V Tulu 2019, in September 2019, as part of ERC funded (678371) project ICY-LAB (Isotope CYcling in the LABrador Sea) and Royal Society funded (RGF\EA\181036) project Biogeochemical Cycling in Greenlandic Fjords. Temperature and salinity data derived from CTD rosette casts were recorded at station AM10 in Ameralik Fjord and station GF-inlet in Nuup Kangerlua. Fjord water sampling was carried out at 2 stations (AM10 and AM12) in Ameralik Fjord and station GF-inlet in Nuup Kangerlua using Towfish and Niskin bottles for near surface and sub surface samples, respectively. For bottle samples, temperature and salinity were measured using an EXO3 Multiparameter Water Quality Sonde. Fjord sediments were collected by a large bore sediment corer (Aquatic Research Instruments) at station AM10a in Ameralik Fjord and station GF-inlet in Nuup Kangerlua. Pore waters were extracted from the sediment cores using Rhizon samplers and core incubation experiments were carried out following the methodology of Hammond et al. (2004, doi:10.4319/lom.2004.2.146). Sediment reactive silica was leached using a sequential extraction method from Michalopoulos and Aller (2004, doi:10.1016/j.gca.2003.07.018) and Pickering et al. (2020, doi:10.1029/2020GL087877).

Description: This data product contains dissolved and amorphous particulate silicon concentrations and isotopic compositions, and ancillary data (discharge, conductivity, suspended particulate matter, pH, major ion data) for glacial meltwaters collected from two glaciers in Greenland: Leverett Glacier (67 degrees N, 50 degrees W) and Kiattuut Sermiat (61 degrees N, 45 degrees W).

Description: This data product contains dissolved and amorphous particulate silicon concentrations and isotopic compositions, and ancillary data (discharge, conductivity, suspended particulate matter, pH, major ion data) for glacial meltwaters collected from Pan Arctic and Subarctic glacial catchments.

Description: This data product contains dissolved silicon concentrations and isotopic composition, major ion concentrations and discharge for streams in Potter Peninsula, King George Island and Commonwealth Stream, McMurdo Dry Valleys, Antarctica.