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

美国化学海洋学研究界是该计划的创始成员之一，该计划的任务是“确定控制海洋中关键微量元素和同位素分布的过程和通量，并确定这些分布对不断变化的环境条件的敏感性”(GEOTRACES Science Plan，2006)。在美国，海洋化学家目前正在组织热带南太平洋东部(ETSP)从秘鲁到塔希提岛的地带性样带，作为美国地球物理研究计划的第二次巡航。这一太平洋部分包括一大片区域，其特点是与秘鲁上升流有关的东部边界的初级生产和颗粒出口率高，一个大型氧气极小区是全球固定氮的主要汇，以及东太平洋隆起产生的大型热液羽流。这一特定部分是在2007年和2008年的开放式规划研讨会上选定的，并于2009年由美国地球观测系统指导委员会提出最终建议。这是一个分两个阶段的计划的第一部分，该计划将包括太平洋从塔希提岛到阿拉斯加的经线部分，作为随后的探险。该奖项向来自南加州大学、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，用于管理美国地质调查局的太平洋活动。三位共同领导人将提供特派团领导、基本支助服务和管理结构，以获取被列为国际地球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NSF的支持下，管理团队将(1)计划和协调上述为期52天的太平洋研究巡航；(2)使用传统的CTD/玫瑰花结和GEOTRACES采样系统获取各种有代表性的痕量金属样品；(3)获取常规JGOFS/WOCE质量的水文数据(CTD、透射计、荧光计、氧传感器等)以及盐度、溶解氧(检测下限为1微米)、植物色素、氧化还原示踪剂(如铵和亚硝酸盐)以及微纳摩尔水平的溶解营养物质的离散样本；(4)确保遵守和报告适当的质量保证/质量控制协议，并遵守所有GEOTRACES内部校准协议；(5)编写所有水文类型数据并将其提供给GEOTRACES数据中心(和美国数据中心)；以及(6)协调所有参与调查人员之间的巡航通信，包括编写水文报告/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牢固的合作伙伴关系，这在化学海洋学中是前所未有的。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，在这种情况下是秘鲁。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.