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性营养盐，对浮游植物生产力和常量营养盐的地球化学有很强的控制作用。然而，还有其他关键的微量生物元素（镉，钴，镍和锌），也可能影响南大洋浮游植物生产力的次要方面。这项工作的核心将是调查南大洋铁供应情况下这些生物元素的分布和形态。主要的现场工作将在Polarstern ANTXXIV-3 ZERO&DRAKE期间进行，作为IPY项目GEOTRACES的一部分。在这次航行中，将在海水中铁浓度/生物有效性的梯度上检查Cd、Co、Ni和Zn的形态和分布;范围从沿着本初子午线的开阔海洋区域、威德尔海和德雷克海峡到南极岛屿附近。实验室工作将侧重于南大洋沃茨环境温度下这些元素形态形成的动力学方面。本论文的工作将采用以下最先进的技术进行：（1）竞争性配体交换，通过阴极溶出伏安法检测Co2+，Ni 2+的动力学和形态。(2)阳极溶出伏安法用于测量Cd 2+和Zn 2+的动力学和形态。(3)流动注射化学发光法测定南大洋沃茨中的钴。(4)海水中钴、镍、镉和锌测量用石墨炉原子化标准溶剂萃取法。积累的数据将纳入南大洋痕量金属地球化学综合模型。

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.