GEOTRACES Arctic Section: Collaborative Research: Biogeochemical cycling of particulate trace elements in the western Arctic basin

作为这一项目的一部分，两名研究人员将参加2015年美国GEOTRACES北极考察，测定北冰洋水柱中不同悬浮颗粒的微量元素组成，以确定这些颗粒的来源和清除能力。 与国际GEOTRACES计划中的其他多国倡议一样，美国北极考察的目标是确定控制海洋中关键微量元素和同位素分布的过程和量化通量，并确定这些分布对环境条件变化的敏感性。一些微量元素是生命所必需的，另一些是已知的生物毒素，还有一些是重要的，因为它们可以用作海洋中各种物理，化学和生物过程的示踪剂。这支微量元素科学家团队将专注于颗粒微量元素的测量，这将使科学家能够更好地估计颗粒金属对北冰洋的来源，并更好地了解它们对生物过程的贡献。该项目还将为本科生、K-12教师和公众提供教育机会。颗粒微量元素分布、源、汇和循环预计将受到北极物理、生物、人为和地球化学过程的控制。此外，许多微量元素是海洋浮游植物必需的营养元素，在海洋初级生产力中起着关键作用。然而，很少有综合海洋学研究进行了专门调查这些关系在这一地区，尽管北极的不断变化的条件和全球意义。该项目将通过测量通过水柱收集的大量颗粒和沉积物以及上层水柱浮游植物中的微粒微量元素浓度，大大促进对北冰洋海盆若干微量元素完整地球化学循环的了解。这些测量将使科学家能够限制来自河流、冰架和冰的颗粒元素的输入，并评估通过被动清除和生物吸收去除溶解的微量元素的情况。

As part of this project, two investigators will participate in the 2015 U.S. GEOTRACES Arctic expedition to determine the trace element composition of different suspended particles in the water column of the Arctic Ocean to identify the sources and scavenging capabilities of these particles. In common with other multinational initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. Some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. This team of trace element scientists will focus on the measurement of particulate trace elements, which will enable scientists to better estimate the sources of particulate metals to the Arctic Ocean and to better understand their contribution to biological processes. This project will also provide educational opportunities for undergraduate students, K-12 teachers, and the general public.Particulate trace element distributions, sources, sinks and cycling are predicted to be controlled by physical, biological, anthropogenic and geochemical processes in the Arctic. Furthermore, many trace elements are required nutrients for marine phytoplankton, playing a key role in oceanic primary productivity. However, few integrated oceanographic studies have been conducted to specifically investigate these relationships in this region, despite the changing conditions and global significance of the Arctic. This project will significantly advance understanding of the complete geochemical cycles of a number of trace elements in the Arctic Ocean basin by measuring the concentrations of particulate trace elements in bulk particles collected through the water column and in sediments, as well as in phytoplankton from the upper water column. These measurements will enable scientists to constrain the inputs of particulate elements from rivers, shelves and ice, and to assess the removal of dissolved trace elements via passive scavenging and biological uptake.