Trace metal marine geochemistry: speciation and coastal processes

海水中的微量元素作为营养物、海洋过程的示踪剂和污染物发挥着重要作用。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不同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海洋中微量元素来源、汇、内部循环和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，以及在某些情况下它们的化学形态，以评估这些元素的来源，汇和内部循环。目的是评价调节其分布的物理、化学和生物过程。这包括一些金属结合配体的特征，这些配体强烈影响海洋中微量元素的形成。在接下来的几年里，我将重点研究沿海来源和运输过程的特征，包括河流输入、陆架交换、上升流和中尺度涡旋的运输。许多令人感兴趣的元素已知有沿海来源，但这些来源的详细来源和大小尚不清楚。河流向海水和陆架提供溶解金属和悬浮沉积物，部分金属通过成岩作用从陆架沉积物中运移。涡流可能会将这些金属从沿海地区带到亚北极环流中，而该地区的初级生产已知受到铁的限制。我建议研究这些来源对东北太平洋中选定的微量金属分布的影响。我还建议在不同的河口和沿海地区以及实验室浮游植物培养中研究强金属结合有机配体的结构、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.