Chemical speciation of iron in the euphotic zone along the Kuroshio Current
Chemical speciation of iron in the euphotic zone along the Kuroshio Current
复制标题
DOI：
10.1016/j.marchem.2021.103966
复制
发表时间：
2021-06
期刊：
影响因子：
3
通讯作者：
Mitsuhide Sato;J. Nishioka;Kazuyuki Maki;S. Takeda
中科院分区：
文献类型：
--
作者：
Mitsuhide Sato;J. Nishioka;Kazuyuki Maki;S. Takeda
通过从台湾东海岸到相模湾的四次横断面调查，阐明了黑潮及其邻近水域中溶解铁（DFe）和有机铁结合配体（LFe）的分布。与邻近水域相比，黑潮地表水的特点是盐度高、DFe 浓度低、LFe 浓度高、腐殖质类物质荧光低。黑潮邻近海域可分为东海水域和沿岸水域两类。东海海水是在冲绳海槽附近发现的，其特征是 DFe 浓度垂直梯度陡峭，几乎与表层混合层内黑潮中的浓度一样低，但在混合层以下达到约 0.5 nM。在日本南部海岸观察到沿海水域，其 DFe 浓度在整个上层 200 m 范围内都很高。黑潮水中 LFe 的浓度在 10 米深度处明显高于较深层。这表明类腐殖质物质是 LFein 河口和深水的主要成分，但在黑潮表层水中发挥的作用相对较小。与沿海水域混合可以通过两种方式增加黑潮地表水中生物可利用的无机铁离子的浓度，即增加 DFe 浓度和降低 LFe 浓度。
The distributions of dissolved iron (DFe) and organic iron-binding ligands (LFe) in the Kuroshio Current and its neighboring waters were elucidated from four cross-sectional surveys from the eastern coast of Taiwan to Sagami Bay. The Kuroshio surface water was characterized by a high salinity, low concentration of DFe, high concentration of LFe, and low fluorescence of humic-like substances, in comparison to the neighboring waters. The neighboring waters of the Kuroshio can be categorized into two types: the East China Sea water and coastal water. The East China Sea water was found near the Okinawa Trough, and characterized by a steep vertical gradient of DFe concentration, almost as low as that in the Kuroshio within the surface mixed layer, but reached ~0.5 nM below the mixed layer. Coastal water was observed on the southern coast of Japan, and its DFe concentration was high throughout the upper 200 m. The concentration of LFein the Kuroshio water was significantly higher at 10-m depth than in the deeper layers. This suggests that humic-like substances, which are a major component of LFein estuarine and deep waters, play a relatively minor role in the Kuroshio surface waters. Mixing with coastal waters can increase the concentration of bioavailable inorganic ferric ions in the Kuroshio surface water in two ways, by increasing the DFe concentration and decreasing the LFeconcentration.