Subarctic rivers of northern Québec (Nunavik, Canada) unveil a potential pathway for waterborne release of greenhouse gases generated through mobilization of organic matter in the large ambient reservoir of permafrost carbon (see e.g. Nordicana D48). In the warming Arctic, this contribution may substantially alter the current parameterization of global carbon balance and the corresponding climate feedbacks. This Nordicana D archive presents the concentrations of dissolved greenhouse gases (methane, carbon dioxide, and nitrous oxide) that were measured in water sampled in the Great Whale River (GWR), Sasapimakwananisikw (SAS) River, the Sheldrake River, and their major tributaries, in summer and winter (GWR). Additional data are presented for dissolved oxygen concentration, temperature, pH, salinity, turbidity, and conductivity. The concentrations of the dissolved greenhouse gases were determined by (1) gas chromatography of gas samples extracted by headspace equilibration in a 2L flask (details in Matveev et al 2019), and (2) direct measurement with methane and carbon dioxide profilers (METS) by Franatech GmbH (details in Matveev et al 2018). The water column values of dissolved oxygen concentration, temperature, pH, salinity, turbidity and conductivity were determined with either Hydrolab DS5, RBR Concerto, and/or YSI EXO2 profilers.
