Flamand, Aude; Lapierre, Jean-François; Biehler, Antoine; Whalen, Dustin; Chaillou, Gwénaëlle: Geochemical data collected in a coastal permafrost environment in the Beaufort sea area [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.960986 (dataset in review)

More than 55 samples of permafrost meltwater, beach groundwater, seawater, lake water and massive ice were collected along the coastal area of the Beaufort Sea to characterize the origin and the fate of the newly mobilized dissolved organic matter (DOM) released by thawing permafrost in the continent-sea continuum. The samples were collected, during the summer of 2019 and 2021, from several coastal bluffs transects up to 1-2 km from the shoreline. Permafrost meltwater was collected from ponds on permafrost slumps, beach groundwater was pumped from the ground (~50 cm deep) in the intertidal zone, seawater was pumped in the bay in front of coastal bluffs, lake water was collected in a lake close to the study site and massive ice was collected under the active layer and thawed at ambient temperature. Furthermore, incubation experiments of permafrost meltwater, beach groundwater and seawater samples, in presence of excess iron oxides, were done to better understand the ability of reactive iron oxides to control the mobility and export of permafrost-derived DOM to the coastal ocean. Physicochemical parameters (pH, salinity, oxygen saturation, and temperature) as well as dissolved organic carbon (DOC) and total dissolved iron concentrations were measured for most of the samples. Optical analyses were performed using a spectrophotometer and a spectrofluorometer to measure the chromophoric fraction of DOM at different wavelengths (CDOM254, CDOM350, CDOM375), the SUVA (Specific Ultraviolet Absorbance), BIX (Biological index), FI (Fluorescence Index), HIX (Humification index) and SR (Slope Ratio). Additionally, a PARAFAC model was built and three major optical components (C1: high molecular weight humic-like terrestrial, C2: low molecular weights tyrosine protein-like microbial and C3: low molecular weight humic-like terrestrial) were extracted and identified based on the literature. This data was collected as part of the International Permafrost Research Program, Nunataryuk.