Trace metal marine geochemistry: speciation and coastal processes

海水中的微量元素既是营养物质，也是海洋过程的示踪物和污染物。它们的生物地球化学循环对碳循环、气候变化、海洋生态系统和环境污染等多个领域的研究具有重要意义。尽管人们认识到微量元素的重要性，但我们利用这些信息的能力受到有关它们的来源、汇、内部循环和海洋中化学形态的不确定性的限制。我的研究重点是确定东北太平洋中选定的微量元素(Al、Ga、Ti、Zr、Hf、Mn、Cu、Cd、Zn、Pb)的分布，在某些情况下，它们的化学形态、评估这些元素的来源、汇和内部循环。目的是评估调节它们分布的物理、化学和生物过程。这包括对某些金属结合配体的表征，这些配体对海洋中的微量元素形态有很大影响。在接下来的几年里，我将重点描述海岸来源和输送过程，包括河流输入、陆架交换、上升流和中尺度涡旋的输送。虽然许多感兴趣的元素都已知有沿海来源，但这些来源的详细来源和规模尚不清楚。虽然河流向该地区的海水和大陆架提供溶解金属和悬浮沉积物，但一些金属通过成岩作用从陆架沉积物中被转移。而涡流可能会将这些金属从沿海地区带到亚北极环流，一个已知初级生产受到铁限制的地区。我建议研究这些来源对东北太平洋选定的痕量金属分布的影响。我还建议研究各种河口和沿海地区以及实验室浮游植物养殖中与金属强结合的有机配体的结构、丰度和分布。

Trace elements in seawater play important roles as nutrients, as tracers of ocean processes, and as contaminants.  Their biogeochemical cycling has implications for research in diverse areas such as the carbon-cycle, climate-change, ocean ecosystems, and environmental contamination.  Despite the recognized importance of trace elements, our ability to use this information is limited by uncertainties concerning their sources, sinks, internal cycling and chemical speciation within the ocean.  My research focuses on determining the distributions of selected trace elements (Al, Ga, Ti, Zr, Hf, Mn, Cu, Cd, Zn, Pb) in the Northeast Pacific, and in some cases their chemical speciation, to assess the sources, sinks, and internal cycling of these elements.  The aim is to evaluate the physical, chemical and biological processes regulating their distributions. This includes characterization of some of the metal-binding ligands which strongly influence trace element speciation in the oceans. Over the next few years I will focus on characterizing coastal sources and transport processes, including fluvial input, shelf exchange, upwelling and transport in mesoscale eddies.  Many of the elements of interest are known to have coastal sources, but the detailed origins and magnitudes of these sources are not known.  Rivers supply dissolved metals and suspended sediments to seawater and the continental shelf in this region, some metals are mobilized from the shelf sediments via diagenetic processes.  Eddies may carry these metals from the coastal region out into the subarctic gyre, an area where primary production is known to be limited by iron.  I propose to look at the effect of these sources on the distribution of selected trace metals in the northeast Pacific.  I also propose to look at the structure, abundance and distribution of the strong metal-binding organic ligands in various estuarine and coastal regimes, as well as in laboratory phytoplankton cultures.