Iron speciation in the eastern tropical South Pacific oxygen minimum zone off Peru
Iron speciation in the eastern tropical South Pacific oxygen minimum zone off Peru
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秘鲁附近热带南太平洋东部最低氧区的铁形态
DOI：
10.4319/lo.2014.59.6.1945
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发表时间：
2014
影响因子：
4.5
通讯作者：
J. Moffett
中科院分区：
文献类型：
--
作者：
J. Vedamati;T. Goepfert;J. Moffett
2005年10月，在秘鲁外大陆架沿沿着三个断面获得了总溶解铁（DFe）、铁（II）和水文参数的垂直剖面图。分别使用鲁米诺化学发光和同位素稀释电感耦合等离子体质谱法（ICP-MS）测定Fe（II）和DFe浓度。目的是研究氧化还原化学，氮循环过程，底部地形以及该地区铁的分布和化学之间的关系。这是迄今为止对该地区铁地球化学最全面的调查。在广阔的北方大陆架上测得了极高的DFe（0.50 -75 nmol L−1），大部分溶解的Fe以Fe（II）的形式存在于氧跃层以下。在秘鲁南部，大陆架较窄，溶解铁浓度低10倍。此外，溶解铁的一小部分是作为Fe（II）在南部，甚至低于氧跃层。在横断面的西端，Fe（II）最大值与深部（即，次级）亚硝酸盐最大值。这表明硝酸盐还原和水体中Fe（II）积累之间的关系。然而，在大陆架，铁（II）也受到底栖生物过程的影响。大的横向梯度溶解铁横跨货架坡折反映铁去除氧化清除，它似乎是合理的，大部分的铁是“被困”通过氧化还原循环的货架上。然而，维护溶解的Fe（II）丝内的二次亚硝酸盐的最大值构成了一个重要的机制，铁运输离岸。
Vertical profiles of total dissolved iron (DFe), Fe(II), and hydrographic parameters were obtained along three transects across the continental shelf off Peru in October 2005. Fe(II) and DFe concentrations were determined using luminol chemiluminescence and isotope dilution inductively coupled plasma mass spectrometry (ICP‐MS), respectively. The objective was to study the relationships among redox chemistry, nitrogen‐cycle processes, bottom topography, and the distribution and chemistry of iron in the region. The results are the most thorough survey to date of Fe geochemistry in this region. Exceedingly high DFe (∼ 50–75 nmol L−1) was measured over the wide northern continental shelf, with most of the dissolved Fe present as Fe(II) below the oxycline. In southern Peru, the shelf is narrower, and dissolved Fe concentrations were 10‐fold lower. Moreover, a smaller fraction of the dissolved Fe was present as Fe(II) in the south, even below the oxycline. At the western ends of the transects, Fe(II) maxima were coincident with deep (i.e., secondary) nitrite maxima. This suggests a relationship between nitrate reduction and Fe(II) accumulation in the water column. However, over the shelf, Fe(II) was also influenced by benthic processes. Large lateral gradients in dissolved Fe across the shelf–slope break reflect Fe removal by oxidative scavenging, and it seems plausible that much of the Fe is “trapped” by redox cycling on the shelf. Nevertheless, the maintenance of dissolved Fe(II) filaments within the secondary nitrite maxima constitutes an important mechanism for Fe transport offshore.
影响因子：
4.5
作者：
A. Noffke;C. Hensen;S. Sommer;F. Scholz;L. Bohlen;T. Mosch;M. Graco;K. Wallmann
通讯作者：
A. Noffke;C. Hensen;S. Sommer;F. Scholz;L. Bohlen;T. Mosch;M. Graco;K. Wallmann
影响因子：
56.9
作者：
Stramma, Lothar;Johnson, Gregory C.;Mohrholz, Volker
通讯作者：
Mohrholz, Volker