Unexpected Source and Transport of Iron from the Deep Peru Margin
Unexpected Source and Transport of Iron from the Deep Peru Margin
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秘鲁深部边缘铁的意外来源和运输
DOI：
10.1021/acsearthspacechem.0c00066
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发表时间：
2020
影响因子：
3.4
通讯作者：
Buck, Kristen N.
中科院分区：
文献类型：
--
作者：
Lam, Phoebe J.;Heller, Maija I.;Lerner, Paul E.;Moffett, James W.;Buck, Kristen N.
铁是海洋中最重要的微量营养素，但其来源和汇到海洋的性质和数量受到很少的限制。在这里，我们通过综合美国地理轨迹GP16东热带太平洋带状断面(EPZT)在秘鲁边缘附近巡航的观测结果，评估我们对边缘环境中铁源和铁汇的理解。GP16观测显示，沿边缘的溶解铁(DFE)浓度升高，但在富氧水域的斜坡深度(1000-3000米)，而不是在缺氧水域的陆架深度(100-300米)，DFE的羽流向西较大。我们研究了对这一意外观察的潜在解释。来自GP16的多种示踪剂表明，在斜坡深度，沉积物再悬浮是重要的，这将导致DFE的底栖生物通量高于先前测量的通量。DFE在陆架羽流和斜坡羽流向海洋内部的表观持久性和穿透性方面的差异可能是由于陆架DFE比斜坡DFE的移除速度更快所致。来自陆架的DFE几乎完全以DFE(II)形式存在，而来自斜坡的DFE几乎完全以DFE(III)形式存在。虽然底栖生物DFE(II)扩散到缺氧的上覆水中，但仍然存在DFE(II)的氧化，DFE(II)沉淀成颗粒状的Fe(III)。相反，斜坡羽流似乎以稳定的DFE(III)形式持续存在。我们假设，具有中等有机碳向沉积物输送和浅层氧渗透的沉积物孔隙水是水体中持久性DFE的特别好来源。
Iron is the most important micronutrient in the ocean, but the nature and magnitude of its sources and sinks to the ocean are poorly constrained. Here we assess our understanding of the sources and sinks of iron in margin environments by synthesizing observations from the U.S. GEOTRACES GP16 Eastern Tropical Pacific Zonal Transect (EPZT) cruise near the Peru margin. GP16 observations showed elevated dissolved iron (dFe) concentrations along the margin, but a larger westward plume of dFe at slope depths (1000–3000 m) in oxygenated waters, rather than at shelf depths (100–300 m) in oxygen deficient waters. We examine the potential explanations for this unexpected observation. Multiple tracers from GP16 suggest that sediment resuspension was important at slope depths, which would lead to enhanced benthic flux of dFe above what was previously measured. The difference in the apparent persistence and penetration of shelf versus slope plumes of dFe into the interior of the ocean likely results from faster removal rates of the shelf dFe compared to slope dFe. The dFe sourced from the shelf was almost entirely in the dFe(II) form, whereas dFe sourced from the slope was almost entirely in the dFe(III) form. Although benthic dFe(II) diffuses into oxygen deficient overlying waters, there is still oxidation of dFe(II), which precipitates to particulate Fe(III). In contrast, the slope plume appears to persist in a stabilized dFe(III) form. We hypothesize that sediment porewaters with moderate organic carbon delivery to sediments and shallow oxygen penetration are especially good sources of persistent dFe to the water column.
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南太平洋热带东部的生物颗粒通量和底栖再矿化
DOI：
--
发表时间：
2015
期刊：
影响因子：
--
作者：
W. Berelson;W. Haskell;M. Prokopenko;A. Knapp;D. Hammond;N. Rollins;D. Capone
通讯作者：
D. Capone
影响因子：
4.9
作者：
T. Wagener;C. Guieu;N. Leblond
通讯作者：
T. Wagener;C. Guieu;N. Leblond
影响因子：
3
作者：
V. Sanial;L. Kipp;P. Henderson;P. Beek;J. Reyss;D. Hammond;N. Hawco;M. Saito;J. Resing;P. Sedwick;W. Moore;M. Charette
通讯作者：
V. Sanial;L. Kipp;P. Henderson;P. Beek;J. Reyss;D. Hammond;N. Hawco;M. Saito;J. Resing;P. Sedwick;W. Moore;M. Charette
与南美洲西部贫氧水相关的中间粒子最大值
DOI：
--
发表时间：
1980
期刊：
影响因子：
--
作者：
H. Pak;L. Codispoti;J. Zaneveld
通讯作者：
J. Zaneveld
影响因子：
4.5
作者：
D. Ohnemus;S. Rauschenberg;G. Cutter;J. Fitzsimmons;R. Sherrell;B. Twining
通讯作者：
D. Ohnemus;S. Rauschenberg;G. Cutter;J. Fitzsimmons;R. Sherrell;B. Twining