Determination of particulate organic carbon sources to the surface mixed layer of the Canada Basin, Arctic Ocean
Determination of particulate organic carbon sources to the surface mixed layer of the Canada Basin, Arctic Ocean
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DOI：
10.1002/2013jc009197
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发表时间：
2014-02
影响因子：
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通讯作者：
K. Brown;F. McLaughlin;P. Tortell;D. Varela;M. Yamamoto‐Kawai;B. Hunt;R. Francois
中科院分区：
文献类型：
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作者：
K. Brown;F. McLaughlin;P. Tortell;D. Varela;M. Yamamoto‐Kawai;B. Hunt;R. Francois
2008年和2009年，对加拿大海盆表层混合层样品中颗粒有机碳（POC）的稳定同位素比以及其他示踪剂进行了分析。在2008年融化季节结束时和2009年冻结期开始时，在各种表面条件下进行了采样，包括开放水域，新形成的季节性冰和多年冰。在这两年中，POC的同位素范围很广（δ 13 C-POC −24.5至−31.1‰），其中同位素贫化最严重的物质通常出现在中央盆地。同位素富集的材料被发现在货架上，符合较高的生物生产和强烈相关的原位碳吸收率。相比之下，在中央海盆近海，δ 13 C-POC分布与叶绿素a或CO2水溶液浓度之间没有显着的关系，表明原位生物生产不是主要的控制。淡水来源的分析表明，海冰融化贡献的POC的表面沃茨在加拿大盆地中部的δ 13 C-POC分布的影响可以忽略不计，而在加拿大盆地中部的表面沃茨中的同位素耗尽的POC来源于外部通过平流输送的河流有机物。我们发现，碱度和大气降水含量可以用来区分POC输入北美和俄罗斯的河流，我们的分析表明，俄罗斯的河流输入的主要来源13 C-贫化有机物的混合层的加拿大盆地中部。
Stable isotope ratios of particulate organic carbon (POC), together with other tracers, were analyzed in samples from the Canada Basin surface mixed layer in 2008 and 2009. Sampling was conducted during the end of the 2008 melt season and at the beginning of the 2009 freezeup under a variety of surface conditions, including open water, newly formed seasonal ice, and multiyear ice. In both years, POC exhibited a wide isotopic range (δ13C-POC −24.5 to −31.1‰), with the most isotopically depleted material generally found in the central basin. Isotopically enriched material was found on the shelves, consistent with higher biological production and strongly correlated with in situ carbon-uptake rates. In contrast, offshore in the central basin, there was no significant relationship between δ13C-POC distributions and either chlorophyll a or aqueous CO2 concentrations, suggesting that in situ biological production was not the dominant control. Analysis of freshwater sources suggested that the sea ice melt contribution of POC to surface waters in the central Canada Basin exerted a negligible influence on δ13C-POC distributions, and instead isotopically depleted POC in the surface waters of the central Canada Basin were sourced externally through advective transport of riverine organic matter. We show that alkalinity and meteoric water content can be used to distinguish POC inputs from North American and Russian rivers and our analysis suggests that Russian river inputs are the predominant source of 13C-depleted organic matter to the mixed layer of the central Canada Basin.