Water samples from rivers in the Canadian Arctic Archipelago, 2014

The investigators will target seven rivers for sampling. River sampling will occur during different flow regimes, but will emphasize sample collection during the spring freshet, the time of year when terrestrial runoff from local Canadian Arctic Archipelago (CAA) rivers maximally impacts coastal waters. Estuarine sampling will include both horizontal and vertical profiles. The data will be synthesized and interpreted using mixing models and regression analyses, and compared with data for the Mackenzie and Yukon Rivers, which have historically been considered "typical" for North American runoff to the Arctic. Acceleration of glacial melt and the hydrologic cycle in a warmer world will likely increase local inputs of freshwater to the CAA. Because many such changes may already be underway, it is important to establish a baseline by which future changes can be compared. The proposed research has implications regarding the variability and magnitude of freshwater export from the Arctic and subarctic oceans to the North Atlantic, and the findings will help fill significant gaps in the knowledge of CAA river geochemistry and the Arctic freshwater cycle.

研究团队将选定七条河流作为采样对象开展野外工作。采样将覆盖不同水流情势时段，但重点聚焦于春季融汛期间——此时当地加拿大北极群岛（Canadian Arctic Archipelago, CAA）河流的陆地径流对沿岸水域的影响达到全年峰值。河口采样将涵盖水平剖面与垂直剖面两种采样方案。本研究将采用混合模型与回归分析对采集到的数据进行综合处理与解析，并与马更些河、育空河的相关监测数据进行对比；这两条河流历来被视为北美北极径流的典型代表。在全球变暖的背景下，冰川消融速率加快与水文循环加速，可能会增加加拿大北极群岛本地河流向周边海域输送的淡水通量。鉴于此类气候变化或已悄然发生，建立可供未来变化对比参照的基准数据体系至关重要。本研究将有助于揭示北极与亚北极海洋向北大西洋输出的淡水通量及其变异性，其研究成果将填补加拿大北极群岛河流地球化学与北极淡水循环领域现有认知的重大空白。