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

ABSTRACTOCE-0425677 越来越多的证据表明，海洋颗粒有机物 (OM) 会受到底部水流的广泛重新分布，因此给定沉积位置的物质可能基本上已预先老化并远离其形成地点。 使有机质源和汇在空间和时间上解耦的过程可能在大陆边缘特别普遍，在那里颗粒可以沿斜坡横向平流输送，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，记录了西北地区的这些过程。大西洋边缘。从 2004 年春季开始，一系列系泊物理海洋学仪器和协调一致的船上测量将在西深边界流的动态及其与墨西哥湾流的相互作用中以前所未有的细节建立起来。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，从而限制通过横向平流输送的颗粒和有机物的性质、来源、年龄和通量，并帮助确定其最终沉积命运。 更广泛的影响将是更好地识别可能受到类似影响的其他领域的能力，从而确定其全球重要性。 如果这些过程广泛存在，这一发现将对我们理解全球碳循环产生重要影响，因为假设的海底“风暴”传输机制是受气候控制的。 还可以在沉积记录中识别诊断性沉积物和有机物质积累模式，并在气候变化的背景下进行明确解释。

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.