Collaborative Research: GEOTRACES Pacific Section: The Geochemistry of Size-fractionated Suspended Particles Collected by In-situ Filtration

颗粒在微量元素和同位素（TEI）的循环和分布中起着重要作用。例如，清除颗粒和通过颗粒出口去除颗粒是许多tei的主要汇。然而，影响TEI清除的空间范围和时间变异性的驱动因素在很大程度上仍然未知。美国GEOTRACES位于秘鲁和塔希提岛之间的东太平洋带状样带将跨越三个生物地球化学重要区域，为研究人员限制未知的颗粒清除奠定了基础。来自伍兹霍尔海洋研究所和明尼苏达大学双城分校的科学家们将讨论粒子形成的位置、粒子-溶解物种的相互作用、主要粒子相以及粒子相在运输过程中的演变等基本问题。在颗粒相方面，研究人员将测量颗粒有机碳（POC）、碳酸钙、蛋白石、岩性和氢氧化物，以及覆盖三个不同区域的颗粒大小的微量元素组成：大的横向生产力梯度，秘鲁海岸的主要缺氧区，以及来自南东太平洋隆起的世界闻名的热液羽流。此外，由于先前的结果表明颗粒类型影响清除，研究人员将专门测量酸浸出的微量金属、颗粒浓度和主要颗粒组成。这些综合测量将使他们能够理清热液颗粒、底栖星云状层和清除tei的高生产力边际的相对重要性。巡航样带也将提供独特的机会来研究远离喷口场的热液颗粒中铁和POC的形态，以及聚集和POC涂层对TEI分配的影响。至于更广泛的影响，研究人员计划创建一个关于海洋中颗粒微量金属的教育模块，这将成为由毕格罗海洋科学实验室的本杰明·特宁博士与缅因州大学海洋科学教育卓越中心合作开发的五部分GEOTRACES网络研讨会系列的一部分。伍兹霍尔海洋研究所的一名研究生和明尼苏达大学双城分校的一名研究生将作为该项目的一部分得到支持和培训。此外，作为伍兹霍尔多元化倡议教育合作项目的一部分，一名本科生将在夏季参加这项研究。

Particles play essential roles in the cycling and distribution of trace elements and isotopes (TEI). For instance scavenging onto particles and removal by particle export is a major sink for many TEIs. However the driving factors affecting the spatial extent and temporal variability of TEI scavenging remain largely unknown. The U.S. GEOTRACES East Pacific Zonal Transect between Peru and Tahiti will cross three biogeochemically important areas, setting the stage for researchers to constrain unknowns surrounding particle scavenging. Scientists from Woods Hole Oceanographic Institution and University of Minnesota-Twin Cities will address fundamental questions on the location of particle formation, particle-dissolved species interactions, dominant particle phases, and the evolution of particle phases during transport. As regards particle phases, the researchers will measure particulate organic carbon (POC), calcium carbonate, opal, lithogenics, and oxyhydroxides, as well as the trace element compositions of size fractionated particles covering three distinct zones: large lateral productivity gradients, a major oxygen deficient zone off the coast of Peru, and a world renowned hydrothermal plume emanating from the southern East Pacific Rise. Furthermore, since previous results suggest particle type affects scavenging, investigators will specifically measure acid-leachable trace metals, particle concentration, and major particle composition. These combined measurements will allow them to disentangle the relative importance of hydrothermal particles, benthic nepheloid layers, and high productivity margins for scavenging of TEIs. The cruise transect will also offer unique opportunities to examine the speciation of Fe and POC in hydrothermal particles away from the vent field and the effects of aggregation and POC coatings on TEI partitioning. As regards broader impacts, the researchers plan to create an educational module on particulate trace metals in the ocean which would become part of a five part GEOTRACES webinar series developed by Dr. Benjamin Twining at the Bigelow Laboratory for Ocean Sciences in collaboration with the Center for Ocean Sciences Education Excellence-Ocean Systems at the University of Maine. One graduate student from Woods Hole Oceanographic Institution and one graduate student from the University of Minnesota, Twin Cities, would be supported and trained as part of this project. In addition, an undergraduate student would participate in the research during the summer month as part of the Woods Hole Diversity Initiative Partnership in Education program.