A modeling assessment of the role of reversible scavenging in controlling oceanic dissolved Cu and Zn distributions
A modeling assessment of the role of reversible scavenging in controlling oceanic dissolved Cu and Zn distributions
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DOI：
10.1002/gbc.20073
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发表时间：
2013-09
影响因子：
5.2
通讯作者：
S. Little;Derek Vance;Mark Siddall;Edward Gasson
中科院分区：
文献类型：
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作者：
S. Little;Derek Vance;Mark Siddall;Edward Gasson
控制现代海洋中元素分布的各种过程的平衡，对于了解海洋内部的再循环及其最终向沉积物输出的速率和性质都很重要。在这里，我们试图评估可能的控制铜和锌的垂直剖面。虽然Cu和Zn的浓度都随深度增加，但Cu的增加比Zn更线性，表现出典型的“营养型”特征。这两种元素都是生物必需的，生物吸收和再生经常被认为是控制其垂直分布的一个重要过程。在这项研究中，我们通过一个简单的一维可逆清除模型研究了另一个关键垂直过程的可能重要性，即对沉降颗粒的被动清除。我们发现，尽管没有横向或垂直的水平流，混合，扩散，或生物吸收，我们的可逆清除模型是非常成功的复制溶解铜浓度分布在一系列的地理尺度。我们提供了初步的限制，清除系数为铜的光谱的颗粒类型（碳酸钙，蛋白石，颗粒有机碳，灰尘），同时强调拟合的形状的建模配置文件的示踪剂数据。相反，铜，并重申锌作为一个真正的微量营养素的行为的信念，清除模型是一个穷人匹配的形状海洋锌配置文件。模拟一个单一的垂直过程，同时突出了横向平流在产生高锌浓度在深太平洋的重要性。
The balance of processes that control elemental distributions in the modern oceans is important in understanding both their internal recycling and the rate and nature of their eventual output to sediment. Here we seek to evaluate the likely controls on the vertical profiles of Cu and Zn. Though the concentrations of both Cu and Zn increase with depth, Cu increases in a more linear fashion than Zn, which exhibits a typical “nutrient‐type” profile. Both elements are bioessential, and biological uptake and regeneration has often been cited as an important process in controlling their vertical distribution. In this study, we investigate the likely importance of another key vertical process, that of passive scavenging on sinking particles, via a simple one‐dimensional model of reversible scavenging. We find that, despite the absence of lateral or vertical water advection, mixing, diffusion, or biological uptake, our reversible scavenging model is very successful in replicating dissolved Cu concentration profiles on a range of geographic scales. We provide preliminary constraints on the scavenging coefficients for Cu for a spectrum of particle types (calcium carbonate, opal, particulate organic carbon, and dust) while emphasizing the fit of the shape of the modeled profile to that of the tracer data. In contrast to Cu, and reaffirming the belief that Zn behaves as a true micronutrient, the scavenging model is a poor match to the shape of oceanic Zn profiles. Modeling a single vertical process simultaneously highlights the importance of lateral advection in generating high Zn concentrations in the deep Pacific.