Do interactions between vertically and horizontally transported particles measurably affect particle composition and flux to the sediments? A mechanistic approach.

垂直和水平输送颗粒之间的相互作用是否会显着影响沉积物的颗粒组成和通量？

• 批准号: 1061128
• 负责人: David Black
• 金额: $ 159.71万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1061128&HistoricalAwards=false
• 关键词: Do; interactions; between; vertically; horizontally

The export of many elements from the surface ocean to the deep sea is mediated by the flux of sinking particles; for example, sinking particles account for 50-80% of the vertical transport of organic carbon through the mesopelagic zone. Heterotrophic remineralization of particulate organic carbon (POC) in the open ocean is usually very efficient, as 90% of the POC produced in surface waters is returned to inorganic form in the euphotic zone or during transit through the upper water column. However, a small fraction of the organic matter produced in surface waters survives transit to the deep ocean or seafloor. Similarly, the flux and composition of inorganic material also vary during transport to the sea floor. Perhaps the most obvious example of such modification is the dissolution of carbonate and biogenic silica as they sink through the water column. However, the flux and composition of particulate organic and inorganic matter that reaches the deep sea and sediments depend not just on their source in the surface waters, but also on alteration, supplementation, and selective removal that occurs during vertical transit. In some regions, particularly near margins, lateral transport can also be extensive. Exchange between sinking material and suspended particles or dissolved organic matter via aggregation/disaggregation and solution/dissolution can also influence composition. In this project, a research team at the State University of New York at Stony Brook set out to develop a better mechanistic understanding of the ocean?s role in the global carbon cycle and the factors that influence the sedimentary record. Their work is developed around five interrelated hypotheses revolving around the themes of remineralization and exchange as particles sink to the sea floor, potential horizontal influences on sinking particles, and how vertical and horizontal transport potentially influence the interpretation of the sediment record. They will apply some of the tools developed during the recent MedFlux program to produce better quantitative models of sinking fluxes by incorporating explicit consideration of ballast minerals (including celestite and barite) and to define better the interactions among particles as they sink. They will also compare results of inorganic, organic and radiochemical analyses of particles sampled by traps and pumps with those of bottom sediments at our proposed site on the Bermuda Rise. While this is a modern process study, it is expected to have significant paleoceanographic implications. Quantifying the relative vertical and horizontal fluxes of key paleoceanographic proxies in combination with characterization of the seasonal fluxes will greatly enhance our understanding of the existing sediment record at the Bermuda Rise, and improve the quality of future reconstructions as well as lead to more robust interpretations from other sites with significant lateral input. Broader Impacts. The diversity of backgrounds represented by the PIs (organic geochemistry, radiochemistry, palaeoceanography, modeling) offers unique opportunities to train the next generation of marine scientists. Four graduate students will be involved in this project. All will receive training at sea, in the laboratory, and in modern data analysis. In addition to graduate students, a postdoctoral scholar will be involved in the present project at no additional cost to NSF. The PIs also participate in outreach activities that will include presentations of research results to lay persons and other community groups.

从地面海洋到深海的许多元素的出口是由下沉颗粒的通量介导的。例如，下沉的颗粒占有机碳通过中质区的垂直运输的50-80％。在开阔的海洋中，颗粒有机碳（POC）的异养先生化通常非常有效，因为在地表水中产生的POC的90％返回到兴奋区中的无机形式，或者在通过上水柱过渡过程中。但是，地表水中产生的有机物的一小部分幸存到深海或海底。同样，在运输到海底时，无机材料的通量和组成也有所不同。这种修饰的最明显的例子也许是碳酸盐和生物二氧化硅通过水柱的溶解。但是，到达深海和沉积物的颗粒有机和无机物质的通量和组成不仅取决于其在地表水中的来源，还取决于垂直传输期间发生的改变，补充和选择性去除。在某些地区，尤其是边缘附近，横向运输也可能是广泛的。通过聚集/分解和溶液/溶解在下沉材料和悬浮颗粒或溶解有机物之间的交换也会影响组成。在这个项目中，斯托尼·布鲁克（Stony Brook）纽约州立大学的一个研究团队着手对全球碳循环中的海洋作用以及影响沉积记录的因素有更好的理解。他们的工作是在五个相互关联的假设中发展的，这些假设围绕着回忆性的主题和交换为颗粒沉入海底，潜在的水平影响对下沉颗粒的潜在影响以及垂直和水平运输如何潜在地影响沉积物记录的解释。他们将应用在最近的MEDFLUX程序中开发的一些工具，以通过合并镇流器矿物质（包括Celestite和barite）的明确考虑，并在下沉时更好地定义粒子之间的相互作用，从而产生更好的下沉通量模型。他们还将比较我们在百慕大升高的拟议地点，对陷阱和泵采样的颗粒的无机，有机和放射化学分析的结果。虽然这是一项现代过程研究，但预计它将具有显着的古文学含义。结合季节性通量的特征，量化关键古环志代理的相对垂直和水平通量将大大增强我们对百慕大升高时现有沉积物记录的理解，并提高未来重建的质量，并导致其他站点的更强大的解释和重大输入。更广泛的影响。 PIS代表的背景多样性（有机地球化学，放射化学，古生物学，建模）为培训下一代海洋科学家提供了独特的机会。四名研究生将参与该项目。所有人都将在海上，实验室和现代数据分析中接受培训。除研究生外，博士后学者还将参与本项目，而NSF不需要额外费用。 PI还参加了外展活动，其中将包括向外行人和其他社区团体的研究结果的介绍。