Collaborative Research: Experimental constraints on marine Fe isotope effects - Biology, ligands, and particles

铁是海洋浮游植物的一种基本微量营养素，在全球碳循环和海洋生态系统中发挥关键作用，需要更好地了解海洋中这种基本微量营养素的来源和汇。铁同位素是近年来发展起来的一种铁地球化学循环示踪剂，新的铁同位素结果表明铁结合配体在溶解铁的同位素分馏过程中起着重要作用。然而，目前，铁溶解或生物铁吸收在海洋溶解铁的同位素分馏中的定量重要性还不为人所知。在这项研究中，来自南卡罗来纳州大学和百慕大海洋科学研究所的研究人员将收集和分析百慕大大西洋时间序列站（BATS）的样本，以便：1）测量天然气溶胶和含氧沉积物中存在天然铁结合配体时铁溶解的速率和同位素分馏; 2）研究浮游植物在生物吸收过程中对铁同位素的分馏作用。这项研究的结果将促进铁同位素的发展，作为一种工具，用于跟踪铁在海洋地球化学循环。更广泛的影响：该项目将提供科学培训和发展的本科生，研究生和博士后学生。研究结果将用于通过网页、外联活动和百慕大海洋科学研究所的公众图尔斯参观，提高公众对海洋地球化学科学的认识。

Iron is an essential micronutrient for marine phytoplankton, which plays a key role in the global carbon cycle and marine ecosystems, and there is a need to better understand the sources and sinks of this essential micronutrient in the oceans. Iron isotopes are a recently developed tracer of iron biogeochemical cycling, and new iron isotope results indicate that iron-binding ligands may play a critical role in the isotopic fractionation of dissolved iron. At present, however, the quantitative importance of iron dissolution or biological iron uptake in the isotopic fractionation of dissolved iron in the oceans is not well-known. In this study, researchers from the University of South Carolina and the Bermuda Institute of Ocean Sciences will collect and analyze samples from the Bermuda Atlantic Time-series Station (BATS) in order to; 1) measure the rate and isotope fractionation of iron dissolution from natural aerosols and oxic sediments in the presence of natural iron-binding ligands, and; 2) examine how phytoplankton fractionate iron isotopes during biological uptake. Results from this study will advance the development of iron isotopes as a tool for tracing iron biogeochemical cycling in the oceans.Broader Impacts: The project will provide scientific training and development to undergraduate, graduate, and postdoctoral students. Results of the study will be used to raise public awareness of biogeochemical science via a webpage, outreach activities, and public tours at the Bermuda Institute of Ocean Sciences.