Collaborative Research: Suspended particle geochemistry along the US GEOTRACES Eastern Pacific Zonal Transect, from high productivity ocean margin to deep sea hydrothermal plume

在2013年GEOTRACES东太平洋巡航期间，将遇到各种各样的海洋环境，从秘鲁附近的高生产力/高颗粒通量水域到秘鲁-智利氧气最低带，东太平洋隆起的热液柱，最后到塔希提岛周围一些最少营养的水域。罗格斯大学（Rutgers University）和伍兹霍尔海洋研究所（Woods Hole Oceanographic Institution）的科学家们将从同样的GO-Flo瓶子中取样悬浮颗粒，这些瓶子将用于取样整个样带的溶解微量金属及其同位素（TEIs）。将对悬浮物样品进行42种元素的分析，包括颗粒反应性稀土元素。此外，将在每个水柱取样站收集岩心顶部沉积物，并分析其总体成分（即有机碳、蛋白石、生物碳酸盐和岩石成分的相对%含量）和悬浮颗粒中要分析的42种元素。本研究的结果将通过解决三个关键问题来评估悬浮颗粒在整个东太平洋TEIs生物地球化学循环中的作用：(1)上层海洋浮游植物和非生物颗粒对TEIs的吸收如何驱动悬浮颗粒组成沿着从高生产力秘鲁边缘到少营养海洋内部的实质性梯度穿过更深的水柱？(2)上层海洋沿样带变化对沉积物（古）记录的传递忠实程度如何？(3)在产生秘鲁-智利OMZ观测到的溶解和颗粒TEIs分布时，垂直再循环与侧向平流的相对影响是什么？(4)岩心顶部沉积物中是否保留了OMZ活动的特征特征？(5)热液柱中TEI吸收/进入自生颗粒的主导因素是什么？岩心顶部沉积物的持续吸收在多大程度上增强了这些过程？(6)海底排放对全球TEI预算的净影响是什么？至于更广泛的影响，罗格斯大学的科学家正在与海洋科学教育卓越网络海洋世界中心（COSEE-NOW）的教育主任合作，通过邀请教师和高中生参加有关气候和海洋科学的研讨会和演讲，为MARE（海洋活动、资源和教育）项目做出贡献。在COSEE-NOW的帮助下，他还计划在太平洋巡航和随后的实验室分析工作期间制作教育视频剪辑，以教育他们使用地球化学来了解海洋是如何运作的。两位科学家还计划为罗格斯大学科学家教授的海洋学导论课程开发一个名为“粒子、金属和碳”的教学模块。作为该项目的一部分，罗格斯大学的一名博士后将得到支持和培训。

During the 2013 GEOTRACES Eastern Pacific cruise a diverse range of oceanic environments will be encountered from the high productivity/high particle flux waters off Peru to the Peru-Chile oxygen minimum zone, the hydrothermal plume of the East Pacific Rise, and finally to some of the most oligotrophic waters around Tahiti. Scientists from Rutgers University and Woods Hole Oceanographic Institution will sample suspended particulates from the same GO-Flo bottles that will be used to sample dissolved trace metals and their isotopes (TEIs) across this entire transect. The suspended matter samples will be analyzed for 42 elements, including the particle-reactive rare earth elements. In addition, core-top sediments will be collected at every water-column sampling station and analyzed for both bulk composition (i.e., relative % content of organic carbon, opal, biogenic carbonate and lithogenic components) and the same 42 elements to be analyzed in the suspended particulates. Results from this study will be used to assess the role of suspended particulates in the biogeochemical cycling of TEIs across the Eastern Pacific by addressing three key sets of questions: (1) How does uptake of TEIs into phytoplankton and non-living particles in the upper ocean drive the suspended particulate composition through the deeper water column, along the substantial gradient from the high productivity Peru margin to the oligotrophic ocean interior?; (2) How faithfully is the along-transect variability in the upper ocean transmitted to the sediment (paleo) record?; (3) What are the relative influences of vertical recycling versus lateral advection in generating the distributions of dissolved and particulate TEIs observed in the Peru-Chile OMZ?; (4) Is there a characteristic signature of OMZ activity that is preserved in core-top sediments?; (5) What dominates TEI uptake onto/into authigenic particles in hydrothermal plumes and to what extent are these processes augmented by continuing uptake in core-top sediments?; and (6) What is the net effect from submarine venting on global TEI budgets?As regards broader impacts, the scientist from Rutgers University is collaborating with the Education Director of the Centers for Ocean Science Education Excellence Networked Ocean World (COSEE-NOW) to contribute to the MARE (Marine Activities, Resources, and Education) program by inviting teachers and high school students to workshops and presentations on climate and ocean sciences. With the help of COSEE-NOW, he also plans to create educational video clips during the Pacific cruise and the subsequent laboratory based analytical work to educate them on the use of geochemistry to understand how the ocean works. Both scientists also plan to develop a teaching module entitled "Particles, Metals, and Carbon" for an Introduction to Oceanography class taught by the Rutgers scientist. One postdoc from Rutgers University would be supported and trained as part of this project.