Particle Transport and Carbon Export over the Northwest Atlantic Margin

“这项奖励是根据2009年美国复苏和再投资法案（公法111-5）资助的。”在这个项目中，伍兹霍尔海洋研究所（WHOI）的研究人员试图解决关于新英格兰大陆边缘有机碳运输的两个主要问题。他们的第一个问题是中间网羽层与底栖网羽层对有机碳运输的相对重要性。他们的第二个问题集中在评估年际变化对粒子输运的重要性。研究人员将在西北大西洋边缘收集沉淀和悬浮颗粒，他们将利用新的和已建立的物质运输示踪剂来解决他们的主要研究问题。他们对粒子动力学的评估将与现有的沿着科德角和百慕大之间的海洋部分（“W线”）的水文观测计划相结合。该计划侧重于该地区的物理特征，并为碳动力学研究提供了伴随的框架。这项工作对全球碳循环的重要性在于，大陆边缘通常保持较高的生物产量，并且是物理动态环境。生物产生的碳的一个潜在命运是，它可能被出口到深海，但出口的碳量通常没有很好的定义。在西北大西洋边缘，大规模洋流有可能成为有机碳向海洋内部扩散的重要机制。在之前的一个研究项目中，研究人员假设颗粒有机碳的横向运输是通过深西部边界流（DWBC）维持的底部nepheloid层（BNL）进行的。虽然他们的研究支持DWBC运输大量有机碳的观点，但他们的观察也表明，来自大陆架斜坡断裂和中大西洋湾上斜坡的中间nepheloid层（inl）也可能是碳输出的重要载体。更广泛的影响：由世界卫生组织的物理海洋学家发起的W线计划，涉及其他机构的合作伙伴，已经建立了一个网站，开展以本节为中心的活动。研究人员正在将他们的生物地球化学通量数据上传到这个网站，并打算建立一个与海洋和碳生物地球化学（OCB）项目办公室网站的链接。此外，这些研究人员打算继续从沉积物陷阱计划中获取等量的材料，并将这些材料提供给研究界的其他成员。除了与W线项目的协同作用外，研究人员还设想，从他们的项目中产生的样本和数据将为该地区的其他研究提供重要的背景，特别是那些探索水团运动的示踪剂，或寻求理解元素边界交换和清除过程的研究。该研究将为麻省理工学院/WHOI联合项目学生David Griffith提供研究生支持。预计该学生将与dr。Eglinton和Charette将获得有机地球化学和放射化学方法方面的经验，并将参加计划中的几次研究巡航。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."In this project researchers at the Woods Hole Oceanographic Institute (WHOI) seek to address two primary questions regarding the transport of organic carbon over the New England continental margin. Their first question addresses the relative importance of intermediate nepheloid layers versus benthic nepheloid layers for organic carbon transport. Their second question focuses on assessing the importance of interannual variability on particle transport. The researchers will collect both settling and suspended particles along the NW Atlantic ocean margin, and they will utilize both novel and established tracers of material transport to address their primary research questions. Their assessments of particle dynamics will be coupled to an existing hydrographic observation program along an ocean section between Cape Cod and Bermuda ('Line W'). This program is focused on the physical characteristics of the region, and provides an accompanying framework for the study of carbon dynamics. The importance of the work to global carbon cycling lies in the fact that continental margins generally maintain high biological production and are physically dynamic environments. One potential fate of the biologically produced carbon is that it may be exported to the deep ocean, yet the magnitude of that exported carbon is generally not well defined. Over the Northwest Atlantic margin, large-scale currents have the potential to be an important dispersal mechanism for organic carbon to the ocean interior. In a prior research project, the investigators hypothesized that the lateral transport of particulate organic carbon occurs via a bottom nepheloid layer (BNL) maintained by the Deep Western Boundary Current (DWBC). Although their research supports the notion that the DWBC transports a significant amount of organic carbon, their observations also indicate that intermediate nepheloid layers (INLs) emanating from the shelf-slope break and upper slope of the Mid Atlantic Bight may also be important vectors for carbon export. Broader Impacts: The Line W program initiated by physical oceanographers at WHOI and involving partners at other institutions, has established a website for activities centered on this section. The researchers are in the process of uploading their biogeochemical flux data onto this website and intend to develop a link to the Ocean and Carbon Biogeochemistry (OCB) Project Office website. In addition, these researchers intend to continue to archive aliquots of materials from the sediment trap program, and make these available to other members of the research community. In addition to their synergy with the Line W program, the researchers envision that the samples and data emanating from their project will provide important context for other studies in this region, particularly those exploring tracers of water mass movement, or seeking to understand elemental boundary exchange and scavenging processes. The research will provide graduate student support for MIT/WHOI Joint Program student, David Griffith. It is anticipated that this student will work closely with Drs. Eglinton and Charette, gaining experience in both organic geochemical and radiochemical methods and will participate in several of the planned research cruises.