U.S. GEOTRACES North Atlantic Section: The chemical speciation of dissolved iron and copper

GEOTRACES是一项新启动的国际海洋学计划，旨在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，并建立对这些分布对不断变化的环境条件的敏感性的理解。2010年，当GEOTRACES游船前往北大西洋盆地时，百慕大海洋科学研究所的一名科学家将重点研究水体中溶解铁（Fe）的有机络合特征。在海洋环境中，铁通常被99%的强有机配体络合，使这些配体成为铁元素生物地球化学循环的重要组成部分。具体目标如下：(1)确定强铁结合有机配体的分布以及强配体与溶解铁浓度之间关系的变异性来源；(2)将船上和实验室的物种形态分析与其他分析人员的分析以及公开的实地数据进行比较；(3)评估风沙沉积对地表水溶解铁结合有机配体浓度变化的明显贡献。至于更广泛的影响，本研究的结果将为未来的建模工作提供急需的现场数据。这项研究的外联部分确实令人印象深刻，包括制作了“我们的海洋世界”的广播片段，突出了这项研究的研究成果，并与高中教师合作制定了包含与该项目相关的动手实验的课程计划。

GEOTRACES is a newly initiated international oceanographic program to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the oceans and to establish an understanding of the sensitivity of these distributions to changing environmental conditions. During the GEOTRACES cruise to the North Atlantic basin in 2010, a scientist from the Bermuda Institute of Ocean Sciences will focus on characterizing the organic complexation of dissolved iron (Fe) in the water column. Iron is typically 99% complexed by strong organic ligands in the marine environment making these ligands a crucial component of the biogeochemical cycling of this element. The specific goals of the proposed work are the following: (1) determine the distributions of strong Fe-binding organic ligands and the sources of variability in the relationship between strong ligand and dissolved Fe concentrations in the proposed hydrographic regions; (2) inter-compare shipboard and laboratory-based speciation analyses with those of other analysts as well as with published field data; and (3) assess any apparent contributions of aeolian deposition to changes in dissolved Fe-binding organic ligand concentrations in surface waters. As regards broader impacts, results from this study would provide much-needed field data for future modeling endeavors. The outreach component of the study was truly impressive and includes the production of an radio segment from 'Our Ocean World' that highlight research finding from this study and the collaboration with high school teachers to develop lesson plans containing both hands-on experiments related to the project.