Dissolved methane, carbon dioxide and limnological data from subarctic rivers, northern Québec, Canada

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.加拿大魁北克北部（努纳维克地区）的亚北极河流，揭示了一条潜在的水传温室气体释放路径：该路径通过大规模永久冻土碳（permafrost carbon）库中的有机质活化过程实现（例如参见Nordicana D48）。在持续变暖的北极区域，这一碳通量贡献或显著改变当前全球碳平衡的参数化方案及其对应的气候反馈。本Nordicana D数据集档案收录了夏季与冬季采集的大鲸河（Great Whale River, GWR）、萨萨皮马夸尼西斯克河（Sasapimakwananisikw, SAS）、谢尔德雷克河及其主要支流的水样中溶解态温室气体（dissolved greenhouse gases）浓度数据，具体包括甲烷、二氧化碳与一氧化二氮。此外还提供了溶解氧浓度、水温、pH值、盐度、浊度与电导率的配套测量数据。溶解态温室气体浓度通过两种方法测定：(1) 采用2L烧瓶顶空平衡法（headspace equilibration）提取气体样品后进行气相色谱（gas chromatography）分析（详细方法参见Matveev等人2019年的研究）；(2) 使用Franatech GmbH公司生产的甲烷与二氧化碳剖面仪（METS）开展直接测量（详细方法参见Matveev等人2018年的研究）。溶解氧浓度、水温、pH值、盐度、浊度及电导率的水柱剖面值通过Hydrolab DS5、RBR Concerto以及/或YSI EXO2剖面仪测定。