Collaborative Research: Management and Implementation of US GEOTRACES Pacific Meridional Transect

GEOTRACES是化学海洋学领域的一项全球努力，美国在其中发挥了重要作用。GEOTRACES计划的目标是了解海洋中许多元素及其同位素的分布。直到最近，这些因素还无法在全球范围内衡量。了解这些元素和同位素的分布将增加对形成其分布的过程以及依赖于这些元素的过程的理解。例如，许多“微量元素”（含量极低的元素）对生命也很重要，它们的存在与否对海洋生态系统的种群数量起着至关重要的作用。该项目将在阿拉斯加和塔希提岛之间的太平洋启动下一个主要的美国GEOTRACES探险。这里的奖励将支持这次探险的所有主要基础设施，包括研究船，采样设备和一些核心海洋学测量。该项目还将支持领导考察和收集样品所需的人员，该项目将支持美国GEOTRACES太平洋子午断面沿着152° W的基本取样操作和基础设施，以支持随后将进行的关于微量元素和同位素地球化学的各种各样的单独科学项目。因此，本管理提案的主要目标是：（1）计划和协调2018年为期60天的研究巡航;（2）使用传统CTD/玫瑰花、GEOTRACES微量元素采样系统和原位泵为各种TEI获取代表性样品;（3）沿着采集常规CTD水文数据以及盐度、溶解氧、藻类色素的离散样本，（4）确保遵守和报告适当的质量保证/质量控制协议，并履行所有GEOTRACES相互校准协议;（5）准备所有水文数据并将其提交给GEOTRACES数据汇编中心（通过美国BCO-DMO数据中心）;（6）协调调查人员之间的所有巡航通信，包括编写水文报告/出版物。该项目还将提供计划进行大规模深海采矿的克拉里昂-克利珀顿断裂带（北纬7.5度至17度，西经155度至115度）的海底当量指数基线测量。环境影响评估正在与采矿业合作进行，但采矿活动对水体中TEI的影响是GEOTRACES社区唯一可以评估的影响。为了支持向广大受众传播科学的努力，调查人员将招募一名对海洋科学和海洋学感兴趣的早期职业自由科学记者参加巡航，并在船上进行公共宣传，摄影和/或录像，以及社交媒体，并向国家媒体提交有关研究的文章。该项目还将支助几名研究生。

GEOTRACES is a global effort in the field of Chemical Oceanography in which the United States plays a major role. The goal of the GEOTRACES program is to understand the distributions of many elements and their isotopes in the ocean. Until quite recently, these elements could not be measured at a global scale. Understanding the distributions of these elements and isotopes will increase the understanding of processes that shape their distributions and also the processes that depend on these elements. For example, many "trace elements" (elements that are present in very low amounts) are also important for life, and their presence or absence can play a vital role in the population of marine ecosystems. This project will launch the next major U.S. GEOTRACES expedition in the Pacific Ocean between Alaska and Tahiti. The award made here would support all of the major infrastructure for this expedition, including the research vessel, the sampling equipment, and some of the core oceanographic measurements. This project will also support the personnel needed to lead the expedition and collect the samples.This project would support the essential sampling operations and infrastructure for the U.S. GEOTRACES Pacific Meridional Transect along 152° W to support a large variety of individual science projects on trace element and isotope (TEI) biogeochemistry that will follow. Thus, the major objectives of this management proposal are: (1) plan and coordinate a 60 day research cruise in 2018; (2) obtain representative samples for a wide variety of TEIs using a conventional CTD/rosette, GEOTRACES Trace Element Sampling Systems, and in situ pumps; (3) acquire conventional CTD hydrographic data along with discrete samples for salinity, dissolved oxygen, algal pigments, 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 data to the GEOTRACES Data Assembly Centre (via the US BCO-DMO data center); and (6) coordinate all cruise communications between investigators, including preparation of a hydrographic report/publication. This project would also provide baseline measurements of TEIs in the Clarion-Clipperton fracture zone (~7.5°N-17°N, ~155°W-115°W) where large-scale deep sea mining is planned. Environmental impact assessments are underway in partnership with the mining industry, but the effect of mining activities on TEIs in the water column is one that could be uniquely assessed by the GEOTRACES community. In support of efforts to communicate the science to a wide audience the investigators will recruit an early career freelance science journalist with interests in marine science and oceanography to participate on the cruise and do public outreach, photography and/or videography, and social media from the ship, as well as to submit articles about the research to national media. The project would also support several graduate students.