The influence of Fe on the distribution and kinetic speciation of Zn, Cd, Co and Ni in the Southern Ocean

铁是南大洋的关键限制营养物质，对浮游植物生产力和大量营养素生物地球化学有很强的控制作用。然而，还有其他关键的痕量生物元素(Cd、Co、Ni和Zn)也可能影响南大洋浮游植物生产力的次级方面。这项工作的核心将是在南大洋铁可获得性的背景下调查这些生物元素的分布和形态。作为IPY项目GEOTRACES的一部分，主要的实地工作将在Polarstein ANTXXIV-3 ZERO&DRAKE期间进行。在这次巡航期间，将研究Cd、Co、Ni和Zn在海水中铁浓度/生物有效性的梯度；范围从沿本初子午线的开阔海域、韦德尔海和德雷克航道以及南极岛屿附近。实验室工作将侧重于在南大洋水域发现的环境温度下这些元素形态形成的动力学方面。拟议的工作将使用最先进的技术进行：(1)竞争配体交换，阴极溶出伏安法检测，用于测量Co2+，Ni2+的动力学和形态。(2)阳极溶出伏安法测定Cd~(2+)、Zn~(2+)动力学和形态。(3)流动注射化学发光法测定南大洋水域中的钴。(4)海水中钴、镍、镉、锌的标准溶剂萃取-石墨炉原子化测定方法。积累的数据将纳入南大洋痕量金属生物地球化学综合模型。

Iron is the key limiting nutrient in the Southern Ocean and has a strong control on phytoplankton productivity and macronutrient biogeochemistry. However there are other key trace bio-elements (Cd, Co, Ni and Zn) which also may influence secondary aspects of phytoplankton productivity in the Southern Ocean. Central to this work will be investigations into the distribution and speciation of these bio-elements in the context of iron availability in the Southern Ocean. The principal field work will be carried out during Polarstern ANTXXIV-3 ZERO&DRAKE as part of the IPY project GEOTRACES. During this cruise the speciation and distribution of Cd, Co, Ni and Zn will be examined across gradients of iron concentration/bioavailabilty in seawater; ranging from an open ocean region along the prime meridian, the Weddell Sea and Drake Passage and near to Antarctic islands. Laboratory work will focus on kinetic aspects of the speciation of these elements at the ambient temperatures found in Southern Ocean waters. The proposed work will be performed using state of the art techniques: (1) Competitive ligand exchange with detection by cathodic stripping voltammetry for the measurement of Co2+, Ni2+ kinetics and speciation. (2) Anodic stripping voltammetry for the measurement of Cd2+ and Zn2+ kinetics and speciation. (3) Flow injection analysis with chemiluminescence detection for the measurement of Co in Southern Ocean waters. (4) Standard solvent extraction methods with graphite furnace atomisation for the measurement of Co, Ni, Cd and Zn in seawater. The accumulated data will be incorporated into a comprehensive model for trace metal biogeochemistry in the Southern Ocean.