Collaborative Research: US GEOTRACES Pacific Section-Shipboard Al, Mn and Fe

2013年GEOTRACES东太平洋分区样带考察航行将从秘鲁沿海的高产上升流区经过南太平洋亚热带环流的分层贫营养沃茨，前往塔希提岛。 将遇到一系列来自秘鲁边缘的地下贫氧水和沉积物，以及东太平洋海隆南纬15度的热液喷口。 来自华盛顿大学和Old自治领大学的科学家计划分析海水样本中溶解和完全溶解的铝（Al），锰（Mn）和铁（Fe）。 来自上层水柱（1000米深）的样品中溶解的铝、锰和铁将在船上进行分析，以确保收集的样品以及来自EPR西部热液羽流深度的样品未受污染。 船上的分析将通过对来自所有深度的水柱样本进行岸上分析以及对总溶解铝、锰和铁的分析得到补充，这将补充其他GEOTRACES调查人员对颗粒金属进行的直接分析。 研究结果将用于验证以下关于海洋中Al、Mn和Fe的来源和循环的假设：（1）当风成输入相对恒定时，表层沃茨中溶解态Al浓度随生物生产力的变化而变化;（2）溶解态Al，Mn，而东太平洋最低含氧区次表层沃茨中的Fe是通过再悬浮和再活动从大陆边缘侧向输送的结果;以及（3）在东太平洋海隆脊顶附近的中性浮力羽流中，溶解的Fe和Al将遇到具有保守行为的环境水平值。至于更广泛的影响，研究结果将通过讲座、互联网和新闻稿向公众传播。 华盛顿大学的一名研究生和一名本科生将作为该项目的一部分得到支助和培训。

The 2013 GEOTRACES Eastern Pacific Zonal transect cruise will transit from the highly productive coastal upwelling region off Peru to the stratified oligotrophic waters of the South Pacific subtropical gyre on its way to Tahiti. A range of subsurface oxygen depleted water and sedimentary inputs from the Peru margin will be encountered, as well as hydrothermal vents at 15°S on the East Pacific Rise (EPR). Scientists from the University of Washington and Old Dominion University plan to analyze seawater samples for dissolved and total-dissolvable aluminum (Al), manganese (Mn), and iron (Fe) in water column samples. The dissolved Al, Mn, and Fe in samples from the upper water column (1000 m depth) will be analyzed onboard to ensure samples being collected are uncontaminated, as well as samples from west of the EPR at hydrothermal plume depths. The shipboard analyses will be augmented by shore-based analyses of water column samples from all depths, as well as analyses of total-dissolvable Al, Mn, and Fe, which will complement the direct analyses of particulate metals undertaken by other GEOTRACES investigators. Results will be used to test the following hypotheses concerning the sources and cycling of Al, Mn and Fe in the ocean: (1) when Aeolian inputs are relatively constant, dissolved Al concentrations in surface waters vary as a function of biological production; (2) concentration maxima of dissolved Al, Mn, and Fe in subsurface waters of the Eastern Pacific oxygen minimum zone are the result of lateral transport from the continental margin by means of resuspension and remobilization; and (3) values about ambient levels with conservative behavior will be encountered in the neutrally buoyant plume about the East Pacific Rise ridge crest for dissolved Fe and Al. As regards broader impacts, results from the study would be disseminated to the public via lectures, the internet, and press releases. One graduate and one undergraduate student from the University of Washington would be supported and trained as part of this project.