First 236U data from the Arctic Ocean and use of 236U/238U and 129I/236U as a new dual tracer
First 236U data from the Arctic Ocean and use of 236U/238U and 129I/236U as a new dual tracer
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DOI：
10.1016/j.epsl.2016.02.020
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发表时间：
2016-04-15
影响因子：
5.3
通讯作者：
Christl, M.
中科院分区：
文献类型：
--
作者：
Casacuberta, N.;Masque, P.;Christl, M.
介绍了北冰洋（AO）水柱中U-236/U-238的第一个数据集，显示了迄今为止在公海报告的最广泛的比率范围，从（5 +/- 5）到（3840 +/- 260）x 10（-12）。在2011-2012年的两次GEOTRACES考察期间收集了表面样品和深度剖面，并分析了U-236和I-129的浓度，目的是调查U-236/U-238和I-129/U-236的组合是否可以用作AO的新海洋学工具。结果表明，U-236/U-238和I-129/U-236原子比的分布与AO中不同的水质量相一致。上层水柱中的高U-236/U-238和I-129/U-236比值（分别> 2000 x 10（-12）和>200）说明大西洋沃茨（AW）渗透到AO中。较低的值被发现在太平洋沃茨（PW）和深水沃茨的AO。河流似乎是U-236在时间和空间上受到限制的第三个人为来源，但需要更多的数据来证实这一点。在一个简单的混合模型中，U-236/U-238和I-129/U-236的组合揭示了美亚盆地深层和底层沃茨中天然背景沃茨（核时代前）的高贡献（>99%），表明表观水团更新时间>1000年。尽管美亚海盆深水沃茨的表观年龄相对较高，但这项工作显示了在北冰洋使用双示踪剂方法作为新的海洋学工具的潜力。(C)2016爱思唯尔B. V.保留所有权利。
The first dataset of U-236/U-238 in the water column of the Arctic Ocean (AO) is presented and shows the widest range of ratios reported so far in the open ocean, from (5 +/- 5) to (3840 +/- 260) x 10(-12). Surface samples and depth profiles were collected during two GEOTRACES expeditions in 2011-2012 and analyzed for the concentrations of U-236 and I-129, with the aim of investigating whether the combination of U-236/U-238 and I-129/U-236 can be used as a new oceanographic tool in the AO. Results show that the distributions of the U-236/U-238 and I-129/U-236 atomic ratios are consistent with the different water masses in the AO. High U-236/U-238 and I-129/U-236 ratios in the upper water column (> 2000 x 10(-12) and >200, respectively) illustrate the penetration of Atlantic waters (AW) into the AO. Lower values were found in Pacific waters (PW) and deep waters of the AO. Rivers seem to represent a temporally and spatially constrained third anthropogenic source of U-236 but more data are needed to confirm this. In a simple mixing model, the combination of U-236/U-238 and I-129/U-236 reveals a high contribution (>99%) of natural background waters (pre-nuclear era) in the deep and bottom waters of the Amerasian basin, indicating an apparent water mass renewal time of >1000 years. Despite the relatively high apparent age of the Amerasian Basin deep waters, this work shows the potential of using the dual-tracer approach as a new oceanographic tool in the Arctic Ocean. (C) 2016 Elsevier B.V. All rights reserved.