Collaborative Proposal: Effects of Mineral Ballast and Particle Sinking Velocity on Organic Carbon Export and Remineralization

合作提案：矿物压载物和颗粒下沉速度对有机碳输出和再矿化的影响

• 批准号: 0424771
• 负责人: Bruce Frost
• 金额: $ 10万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424771&HistoricalAwards=false
• 关键词: Collaborative; Proposal; Effects; Mineral; Ballast

ABSTRACTOCE-0424845Sinking particulate matter is the major vehicle for exporting carbon from the sea surface to the ocean interior. During its transit towards the sea floor, most (usually 90%) of particulate organic carbon (POC) is returned to inorganic form and redistributed in the water column. This redistribution determines the depth profile of dissolved CO2, including its concentration in the surface mixed layer, and hence the rate at which the ocean can absorb CO2 from the atmosphere. Recent modeling studies have shed new light on the mechanisms that are responsible for the shapes of POC profiles. It appears that the presence of mineral ballasts (silicates, carbonates, and dust) may account for most of the variability in POC delivery to the sea floor. The ability to predict the formation and subsequent dissolution of ballasts as particles descend may therefore be critical to predicting quantitatively and mechanistically the global implications of carbon fixation for global climate change. In this project, U.S. researchers at the State University of New York at Stony Brook, the Skidaway Institute of Oceanography, and the University of Washington will continue their work with French and Spanish colleagues on a multi-tracer study of different ballast types, along with their associated organic matter and radioisotopes. The research strategy brings together the power of several disciplines: (i) organic geochemistry for characterizing organic matter in protected and unprotected forms and determining its degradation state; (ii) radiochemistry for assessing processes and time-scales involved in particle dynamics and transport; (iii) zooplankton ecology for assessing radioisotope partitioning and organic biomarker alteration; (iv) microbiology for its role in organic matter decomposition, and (v) modeling and statistical analysis to provide a process-based model of flux from the photic zone to the sea floor. The research team now expects to resolve changes in flux, organic matter and mineral ballast composition, and remineralization length scale through the mid-water depth "twilight zone" of the Mediterranean Sea and possibly the Atlantic Ocean near the Canary Islands.Broader impacts: Our project should contribute to a better mechanistic understanding of the global carbon cycle. If a more sophisticated understanding of the ocean's response to increased levels of carbon dioxide can be developed, then more reasonable choices between political alternatives are possible. The project also features a substantial component for training of graduate students and postdoctoral scholars in the marine sciences. Additionally, the research effort will foster international cooperation, since it is highly dependent on collaborative linkages between American oceanographers and colleagues at the IAEA Marine Environment Laboratory (Monaco), the CNRS Laboratory of Marine Microbiology (Marseille), and the Autonomous University of Barcelona.

Abstractoce-0424845Sink颗粒物是将碳从海面出口到海洋内部的主要工具。在向海底的过渡过程中，大多数（通常为90％）的颗粒有机碳（POC）将返回到无机形式，并在水柱中重新分布。这种重新分布决定了溶解的二氧化碳的深度曲线，包括其在表面混合层中的浓度，因此海洋可以从大气中吸收二氧化碳的速率。最近的建模研究已经对负责POC剖面形状的机制开发了新的启示。看来矿物镇流器（硅酸盐，碳酸盐和灰尘）的存在可能是POC传递到海底的大部分变异性。因此，预测镇流器作为颗粒下降的形成和后续溶解的能力对于定量和机械上预测碳固定对全球气候变化的全球影响至关重要。在该项目中，纽约州立大学斯托尼·布鲁克大学的美国研究人员，斯基达威海洋学研究所和华盛顿大学将继续与法国和西班牙同事一起工作，对不同的镇流器类型的多跟踪研究以及相关的有机物和放射性病。研究策略汇集了几个学科的力量：（i）在受保护和未保护形式中表征有机物的有机地球化学以及确定其降解状态； （ii）评估参与粒子动态和运输的过程和时间尺度的放射化学； （iii）浮游生物生态学用于评估放射性同位素分配和有机生物标志物的改变； （iv）微生物学在有机物分解中的作用，以及（v）建模和统计分析，以提供从光学区域到海底的基于过程的通量模型。 研究小组现在预计，通过地中海海上的中间深度“暮光区”，以及在加那利群岛附近的大西洋影响下，通过中间深度“暮光区”来解决通量，有机物和矿物压载组成的变化，以及我们的项目应对全球碳循环有更好的机械理解。如果可以发展对海洋对二氧化碳含量增加的反应的更复杂的理解，那么政治替代方案之间的更合理选择是可能的。该项目还提供了一个重要组成部分，用于培训海洋科学中的研究生和博士后学者。 此外，研究工作将促进国际合作，因为它高度依赖于IAEA海洋环境实验室（摩纳哥），海洋微生物学（Marseille）和巴塞罗那自治大学的美国海洋环境实验室（Monaco），CNRS海洋环境实验室（Monaco）之间的合作联系。