Advective Controls on Organic Carbon Export and Burial on the Northwest Atlantic Margin

对西北大西洋边缘有机碳输出和埋藏的平流控制

• 批准号: 0425677
• 负责人: Timothy Eglinton
• 金额: $ 70.5万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0425677&HistoricalAwards=false
• 关键词: Advective; Controls; Organic; Carbon; Export

ABSTRACTOCE-0425677A growing body of evidence indicates that oceanic particulate organic matter (OM) is subject to extensive redistribution by bottom currents so that material at a given depositional location may be substantially pre-aged and remote from its site of formation. Processes that impart spatial and temporal decoupling of OM sources and sinks may be particularly prevalent on continental margins where particles can be laterally advected down- and along-slope, and ultimately exported to the ocean interior. Researchers at Woods Hole Oceanographic Institution have pooled their expertise in geochemistry, sedimentology and physical oceanography to document these processes on the N.W. Atlantic margin. Beginning in Spring 2004, an array of moored physical oceanographic instrumentation and coordinated shipboard measurements will establish in the dynamics of the Deep Western Boundary Current and its interactions with the Gulf Stream in unprecedented detail. For this project, the researchers will augment the moorings with transmissometers and collect sediments, sediment trap samples and suspended particles for detailed geochemical, isotopic and mineralogical analyses, permitting them to constrain the nature, provenance, age and fluxes of particles and organic matter transported via lateral advection and to help establish its ultimate depositional fate. A broader impact will be a better ability to identify other areas that may be similarly affected, and hence to establish its global significance. If these processes are widespread, this finding would have important implications for our understanding of the global carbon cycle since the hypothesized transport mechanism of benthic "storms" is climatically controlled. An ability to recognize diagnostic sediment and OM accumulation patterns could also be identified in the sedimentary record and unambiguously interpreted in the context of climate change.

越来越多的证据表明，海洋颗粒有机质（OM）受到海底洋流的广泛再分配，因此在给定沉积位置的物质可能在很大程度上提前老化，并且远离其形成地点。使OM源和汇在空间和时间上解耦的过程在大陆边缘可能特别普遍，在那里颗粒可以沿斜坡向下横向平流，并最终输出到海洋内部。伍兹霍尔海洋研究所的研究人员汇集了他们在地球化学、沉积学和物理海洋学方面的专业知识，记录了西北大西洋边缘的这些过程。从2004年春季开始，一系列系泊的物理海洋学仪器和协调的船上测量将以前所未有的细节建立深西部边界流的动力学及其与墨西哥湾流的相互作用。在这个项目中，研究人员将用透射仪增强系泊装置，收集沉积物、沉积物陷阱样本和悬浮颗粒，进行详细的地球化学、同位素和矿物学分析，使他们能够约束通过横向平流运输的颗粒和有机质的性质、来源、年龄和通量，并帮助确定其最终的沉积命运。更广泛的影响将是更有能力确定可能受到类似影响的其他领域，从而确定其全球意义。如果这些过程广泛存在，这一发现将对我们对全球碳循环的理解产生重要影响，因为底栖生物“风暴”的假设运输机制是由气候控制的。识别诊断性沉积物和OM积累模式的能力也可以在沉积记录中确定，并在气候变化的背景下得到明确的解释。