Ocean micronutrient cycles: UK GEOTRACES

海洋微量营养素循环：英国 GEOTRACES

• 批准号: NE/H008713/1
• 负责人: Alex Piotrowski
• 金额: $ 18.21万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH008713%2F1
• 关键词: Ocean; micronutrient; cycles; UK; GEOTRACES

A paradigm developed during the 20th Century that the amount and type of life in the oceans depended to a large degree on the supply to the surface ocean of three nutrients - phosphate, nitrate, and silica (the macronutrients). International research efforts mapped the distribution of these macronutrients in detail and developed a full understanding of how these macronutrients are chemically cycled into, out-of, and within the oceans. Models of ocean biology and the global carbon cycle now incorporate this understanding. In the early 1990s, however, it became clear that this view of ocean nutrients was incomplete. New ability to sample seawater without contaminating it, and to make sensitive measurements, demonstrated that a range of metals, present at low concentrations in seawater, were required by life. Of these 'micronutrients', the most prominent is iron which is now known to be the major limitation on life in large areas of the ocean. Other micronutrients, such as zinc and cobalt, are also essential for critical biological processes. Despite their importance, our knowledge of the chemical cycle of these micronutrients is rudimentary, particularly compared to that of the macronutrients. We know micronutrients enter the ocean in dust, but the size of other inputs (from rivers, alteration of sediments, or from undersea volcanoes) is not known. Even the distribution of these micronutrients in the ocean is poorly known and measurements are sparse, particularly in the deep ocean. To understand controls on life and the carbon cycle in the ocean, there is an urgent need to dramatically improve knowledge of the distribution and cycling of micronutrients. This is the goal of a major new international research programme - GEOTRACES. The programme seeks to develop an understanding of micronutrient cycles as comprehensive as that of the macronutrients, through a series of sections spanning all the ocean basins. This proposal represent the UK contribution to that programme. We will map the concentration of the seven most important micronutrients through the full water column along an east-west section at 40oS in the Atlantic. This ocean is little studied but is an important region for ocean biogeochemical cycles. In the surface at this latitude the ocean is very productive, requiring addition of micronutrients, but the source of these micronutrients is not known. At depth are found three different water masses. The uppermost flows northwards and upwells to the surface at the equator to provide micronutrients to this very productive region, while the middle layer flows southward before upwelling in the Southern Ocean where low iron supply is known to be the primary limitation on life. Understanding micronutrient inputs to these deep water masses is therefore important for life in a much broader region, and will teach us generally about the processes that control cycling of micronutrients into surface and deep waters around the globe. We will study the inputs of micronutrients from four ocean boundaries - from the atmosphere as dust blown from South America; from rivers (the large Plata River); from sediments; and from the active volcanoes found in the mid Atlantic. We will use a variety of tools - including other chemicals that act as tracers of the micronutrients, and computer models - to assess how micronutrients get from their sources into the open ocean. And we will study the relationship between these micronutrients and the nature of the ecosystems that occur in the productive seas of 40oS. This work will rely on co-operation between 10 leading UK institutes, including universities and research centres, and also involves leading scientists from other countries (partially through the GEOTRACES programme). This national and international effort will lead to a significant improvement in our understanding of the cycles of the metals that control the biology and carbon system in the ocean.

在20世纪发展出一种范式，即海洋中生命的数量和类型在很大程度上取决于海洋表层三种营养物质的供应--磷酸盐、硝酸盐和二氧化硅（常量营养素）。国际研究工作详细绘制了这些宏量营养素的分布图，并充分了解了这些宏量营养素如何在海洋内外进行化学循环。海洋生物学和全球碳循环的模型现在已经纳入了这一认识。然而，在20世纪90年代初，人们清楚地认识到，这种海洋养分的观点是不完整的。在不污染海水的情况下对海水进行取样并进行灵敏测量的新能力表明，海水中存在的低浓度金属是生命所必需的。在这些“微量营养素”中，最突出的是铁，现在已知铁是海洋大面积生命的主要限制。其他微量营养素，如锌和钴，也是重要的生物过程所必需的。尽管它们很重要，但我们对这些微量营养素的化学循环的了解是基本的，特别是与常量营养素相比。我们知道微量营养素以尘埃的形式进入海洋，但其他输入（来自河流，沉积物的改变或海底火山）的大小尚不清楚。甚至这些微量营养素在海洋中的分布也知之甚少，测量数据也很少，特别是在深海。为了了解对海洋生命和碳循环的控制，迫切需要大幅提高对微量营养素分布和循环的了解。这是一个新的重大国际研究方案- GEOTRACES的目标。该方案力求通过跨越所有海洋盆地的一系列部分，使人们对微量营养素循环有与对常量营养素一样全面的了解。这项建议是联合王国对该方案的贡献。我们将绘制大西洋40 ° S东西向部分的完整水柱中七种最重要的微量营养素的浓度。该洋是海洋地球化学循环的重要研究区，研究较少。在这个纬度的表面，海洋是非常有生产力的，需要添加微量营养素，但这些微量营养素的来源是未知的。在深处发现了三个不同的水团。最上层向北流动，并上升到赤道的表面，为这个非常多产的地区提供微量营养素，而中间层在南大洋上升之前向南流动，那里的低铁供应被认为是生命的主要限制。因此，了解微量营养素进入这些深水区对更广泛区域的生命非常重要，并将使我们了解控制微量营养素进入地球仪周围表层和深层沃茨的循环过程。我们将研究来自四个海洋边界的微量营养素的输入-从大气中吹来的灰尘从南美洲;从河流（大普拉塔河）;从沉积物;和从发现在大西洋中部的活火山。我们将使用各种工具-包括其他作为微量营养素示踪剂的化学物质和计算机模型-来评估微量营养素如何从其来源进入公海。我们将研究这些微量营养素与40 ° S多产海域生态系统性质之间的关系。这项工作将依赖于英国10个主要研究机构（包括大学和研究中心）之间的合作，并涉及其他国家的领先科学家（部分通过GEOTRACES计划）。这项国家和国际努力将大大提高我们对控制海洋生物和碳系统的金属循环的理解。

项目成果

Isotopic fractionation of carbon during uptake by phytoplankton across the South Atlantic subtropical convergence

南大西洋副热带辐合浮游植物吸收过程中碳的同位素分馏

• DOI: 10.5194/bg-2019-162
• 发表时间: 2019
• 作者: Tuerena R

Reversible scavenging and advection - Resolving the neodymium paradox in the South Atlantic

可逆扫气和平流 - 解决南大西洋的钕悖论

• DOI: 10.17863/cam.78018
• 发表时间: 2021
• 作者: Wang R

Reversible scavenging and advection – Resolving the neodymium paradox in the South Atlantic

可逆清除和平流 — 解决南大西洋的钕悖论

• DOI: 10.1016/j.gca.2021.09.015
• 发表时间: 2021
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: Wang, Ruixue;Clegg, Josephine A.;Scott, Peter M.;Larkin, Christina S.;Deng, Feifei;Thomas, Alexander L.;Zheng, Xin-Yuan;Piotrowski, Alexander M.
• 通讯作者: Piotrowski, Alexander M.

The large-scale evolution of neodymium isotopic composition in the global modern and Holocene ocean revealed from seawater and archive data

• DOI: 10.1016/j.chemgeo.2017.03.018
• 发表时间: 2017-05-10
• 期刊: CHEMICAL GEOLOGY
• 影响因子: 3.9
• 作者: Tachikawa, Kazuyo;Arsouze, Thomas;Waelbroeck, Claire
• 通讯作者: Waelbroeck, Claire

GEOTRACES intercalibration of neodymium isotopes and rare earth element concentrations in seawater and suspended particles. Part 1: reproducibility of results for the international intercomparison

• DOI: 10.4319/lom.2012.10.234
• 发表时间: 2012-04
• 期刊: Limnology and Oceanography: Methods
• 作者: T. van de Flierdt;K. Pahnke;H. Amakawa;P. Andersson;C. Basak;B. Coles;C. Colin;K. Crocket;M. Frank;N. Frank;S. Goldstein;Vineet Goswami;B. Haley;E. Hathorne;S. Hemming;G. Henderson;C. Jeandel;K. Jones;K. Kreissig;F. Lacan;M. Lambelet;E. Martin;D. Newkirk;H. Obata;L. Pena;A. Piotrowski;C. Pradoux;H. Scher;H. Schöberg;Sunil Kumar Singh;T. Stichel;H. Tazoe;D. Vance;Jingjing Yang