Collaborative Research: Management and Implementation of US GEOTRACES Eastern Pacific Zonal Transect

国际GEOTRACES计划（www.geotraces.org）的使命是“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，并建立这些分布对不断变化的环境条件的敏感性”（GEOTRACES科学计划，2006年），美国化学海洋学研究界是该计划的创始成员之一。在美国，海洋化学家目前正在组织从秘鲁到塔希提岛的热带南太平洋东部（ETSP）的区域样带，作为美国geotraces计划的第二次巡航。该太平洋部分包括与秘鲁上升流相关的东部边界具有高初级生产速率和颗粒输出速率的大面积区域，一个大型氧气最小带，是全球固定氮的主要汇，以及一个来自东太平洋隆起的大型热液羽流。这一特殊区域是2007年和2008年开放规划研讨会的结果，并由美国地质轨迹指导委员会于2009年提出最终建议。这是一个分两阶段计划的第一部分，接下来的探险将包括从塔希提岛到阿拉斯加的太平洋经向部分。该奖项为来自南加州大学、老道明大学和伍兹霍尔海洋研究所的一组科学家提供资金，用于管理美国地质足迹太平洋运动。三个共同领导将提供任务领导、基本支持服务和管理结构，以获取作为国际GEOTRACES科学计划核心参数的微量元素和同位素样本，以及参与调查人员所需的水文和营养数据。在美国国家科学基金会的支持下，管理团队将(1)计划和协调上述52天的太平洋研究巡航；(2)使用传统的CTD/玫瑰花和GEOTRACES采样系统获得各种感兴趣的痕量金属的代表性样品；(3)获取常规JGOFS/ woce质量的水文数据（CTD、透射仪、荧光仪、氧传感器等）以及盐度、溶解氧（检测限为1 μ m）、植物色素、氧化还原示踪剂（如铵和亚硝酸盐）和微纳级溶解营养物质的离散样本；(4)确保遵循和报告适当的QA/QC协议，并履行所有GEOTRACES Intercalibration协议；(5)准备并向GEOTRACES数据中心（以及美国数据中心）提供所有水文类型数据；(6)协调所有参与调查人员之间的巡航通信，包括准备水文报告/出版物。更广泛的影响：该项目是一个国际合作计划的一部分，该计划在相互校准和实施阶段建立了强有力的伙伴关系，这在化学海洋学领域是前所未有的。这些集体任务的科学成果将提高我们理解如何解释海洋化学成分的能力，并解释气候变化将如何影响海洋化学。伙伴关系包括对在研究领域有重叠利益的发展中国家的基础设施的贡献，在这个案例中是秘鲁。该项目有很强的教育成分，许多博士生在该项目中进行论文研究。

The mission of the International GEOTRACES Program (www.geotraces.org), of which the U.S. chemical oceanography research community is a founding member, is "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" (GEOTRACES Science Plan, 2006). In the United States, ocean chemists are currently in the process of organizing a zonal transect in the eastern tropical South Pacific (ETSP) from Peru to Tahiti as the second cruise of the U.S.GEOTRACES Program. This Pacific section includes a large area characterized by high rates of primary production and particle export in the eastern boundary associated with the Peru Upwelling, a large oxygen minimum zone that is a major global sink for fixed nitrogen, and a large hydrothermal plume arising from the East Pacific Rise. This particular section was selected as a result of open planning workshops in 2007 and 2008, with a final recommendation made by the U.S.GEOTRACES Steering Committee in 2009. It is the first part of a two-stage plan that will include a meridional section of the Pacific from Tahiti to Alaska as a subsequent expedition. This award provides funding for management of the U.S.GEOTRACES Pacific campaign to a team of scientists from the University of Southern California, Old Dominion University, and the Woods Hole Oceanographic Institution. The three co-leaders will provide mission leadership, essential support services, and management structure for acquiring the trace elements and isotopes samples listed as core parameters in the International GEOTRACES Science Plan, plus hydrographic and nutrient data needed by participating investigators. With this support from NSF, the management team will (1) plan and coordinate the 52-day Pacific research cruise described above; (2) obtain representative samples for a wide variety of trace metals of interest using conventional CTD/rosette and GEOTRACES Sampling Systems; (3) acquire conventional JGOFS/WOCE-quality hydrographic data (CTD, transmissometer, fluorometer, oxygen sensor, etc) along with discrete samples for salinity, dissolved oxygen (to 1 uM detection limits), plant pigments, redox tracers such as ammonium and nitrite, and dissolved nutrients at micro- and nanomolar levels; (4) ensure that proper QA/QC protocols are followed and reported, as well as fulfilling all GEOTRACES Intercalibration protocols; (5) prepare and deliver all hydrographic-type data to the GEOTRACES Data Center (and US data centers); and (6) coordinate cruise communications between all participating investigators, including preparation of a hydrographic report/publication. Broader Impacts: The project is part of an international collaborative program that has forged strong partnerships in the intercalibration and implementation phases that are unprecedented in chemical oceanography. The science product of these collective missions will enhance our ability to understand how to interpret the chemical composition of the ocean, and interpret how climate change will affect ocean chemistry. Partnerships include contributions to the infrastructure of developing nations with overlapping interests in the study area, in this case Peru. There is a strong educational component to the program, with many Ph.D. students carrying out thesis research within the program.