Seasonal and Geographic Variation in Dissolved Carbon Biogeochemistry of Rivers Draining to the Canadian Arctic Ocean and Hudson Bay
Seasonal and Geographic Variation in Dissolved Carbon Biogeochemistry of Rivers Draining to the Canadian Arctic Ocean and Hudson Bay
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DOI：
10.1029/2018jg004659
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Joanna Y. S. Li Yung Lung;S. Tank;C. Spence;Daqing Yang;B. Bonsal;J. McClelland;R. Holmes
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文献类型：
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作者：
Joanna Y. S. Li Yung Lung;S. Tank;C. Spence;Daqing Yang;B. Bonsal;J. McClelland;R. Holmes
河水的化学成分可以用来诊断陆地上的变化，同时在受河流影响的海水的生态和生物地球化学中起决定性作用。尽管如此，人们对加拿大北部大部分地区河流化学的季节性和地理变化知之甚少。在这里，我们使用以前未公布的政府数据评估了流入加拿大北冰洋和哈德逊湾的一系列河流的化学成分。我们关注无机碳和有机碳（碱度和溶解有机碳），使用配对化学和放电测量来评估组分通量。在加拿大北部地区，溶解有机碳的浓度和面积标准化产量差异很大，通常在哈德逊湾低地的河流中溶解有机碳最高，在科迪勒拉和平原地区的河流中碱度最高，在加拿大地盾流域的河流中有机与无机物种的比例最高。主要风化离子的产量表明，碳酸盐风化——其中很大一部分可能是由硫化物氧化驱动的——主导着我们评估的河流的无机碳输送。尽管数据集的覆盖范围相当多样化，但我们发现存在明显的差距，包括缺乏迄今为止许多河流的数据，以及缺乏北极群岛和哈德逊湾东岸的测量数据。因此，我们使用建模方法来推断整个加拿大北极流域的通量。我们的结果与以前的模型之间的区域特定差异加强了对整个加拿大北极地区有针对性的河流水化学测量的需求。
The chemical composition of river water can be used to diagnose change on land, while playing a determining role in the ecology and biogeochemistry of riverine‐influenced ocean waters. Despite this, little is known about the seasonal and geographic variability of riverine chemistry throughout much of the Canadian north. Here we assess the chemical composition of a broad suite of rivers draining to the Canadian Arctic Ocean and Hudson Bay using previously unpublished government data. We focus on inorganic and organic carbon (alkalinity and dissolved organic carbon), using paired chemistry and discharge measurements to assess constituent flux. Concentrations and area‐normalized yields vary substantially across the northern Canadian landscape, with dissolved organic carbon typically highest in rivers draining the Hudson Bay Lowland, alkalinity highest in rivers draining Cordillera and Plains terrains, and the ratio of organic to inorganic species highest in rivers draining the Canadian Shield. Yields of major weathering ions show that carbonate weathering—a notable proportion of which may be driven by sulfide oxidation—dominates inorganic carbon delivery from the rivers we assess. Despite the reasonably diverse coverage of the data set, we find that clear gaps exist, including a lack of data through to the present day for many rivers, and a dearth of measurements from the Arctic Archipelago and eastern shores of Hudson Bay. We therefore use a modeling approach to extrapolate fluxes to the full Canadian Arctic drainage basin. Region‐specific differences between our results and previous models reinforce the need for targeted river water chemistry measures throughout the Canadian Arctic domain.