A modeling assessment of the role of reversible scavenging in controlling oceanic dissolved Cu and Zn distributions
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Published version
Author(s)
Little, SH
Vance, D
Siddall, M
Gasson, E
Type
Journal Article
Abstract
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.
Date Issued
2013-08-18
Date Acceptance
2013-07-28
Citation
Global Biogeochemical Cycles, 2013, 27 (3), pp.780-791
ISSN
0886-6236
Publisher
American Geophysical Union (AGU)
Start Page
780
End Page
791
Journal / Book Title
Global Biogeochemical Cycles
Volume
27
Issue
3
Copyright Statement
© 2013 The Authors. Global Biogeochemical Cycles published by Wiley
on behalf of the American Geophysical Union.
This is an open access article under the terms of the Creative Commons
Attribution License, which permits use, distribution and reproduction in any
medium, provided the original work is properly cited.
on behalf of the American Geophysical Union.
This is an open access article under the terms of the Creative Commons
Attribution License, which permits use, distribution and reproduction in any
medium, provided the original work is properly cited.
License URL
Publication Status
Published