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

越来越多的证据表明，海洋颗粒有机物（OM）受到海底洋流的广泛重新分布，因此在给定沉积位置的物质可能基本上是预老化的，并且远离其形成地点。 OM源和汇在空间和时间上脱钩的过程在大陆边可能特别普遍，在那里颗粒可以沿斜坡横向平流下降，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一致的船上测量将以前所未有的细节建立西部深海边界流及其与墨西哥湾流的相互作用的动态。对于该项目，研究人员将在系泊装置上增加透射计，并收集沉积物、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，使它们能够限制颗粒和有机物的性质、来源、年龄和通量通过横向平流输送，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地区，从而确定其全球意义。 如果这些过程是普遍的，这一发现将有重要的影响，我们对全球碳循环的理解，因为假设的海底“风暴”的运输机制是气候控制。 还可以在沉积记录中确定识别诊断性沉积物和有机质积累模式的能力，并在气候变化的背景下进行明确的解释。

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.