Operation of A National Ocean Sciences Accelerator Mass Spectrometry Facility at The Woods Hole Oceanographic Institution

美国国家海洋科学加速器质谱仪(NOSAMS)提供各种天然样品类型的最先进的14C(放射性碳)测量，包括海水、地下水、碳酸盐、散装沉积物、土壤和有机碳。天然样品中放射性碳的测量为海洋和地球科学提供了一套独特而强大的工具。5700年的14C半衰期(样品中一半原子衰变所需的时间)可用于测定5万年前的含碳样品的年代，并可用于研究海洋环流和混合的时间尺度、气候变化的时间以及现代碳循环的细节。放射性碳测量用于海洋研究的许多分支，包括物理海洋学、生物地球化学、古海洋学和气候变化。通过NOSAMS的测量，这项研究解决了对社会很重要的问题：其中包括过去和未来的全球气候变化、当地和区域环境影响以及自然资源的开发。除了支持与社会相关的研究外，NOSAMS还将在研究生和博士后研究人员的培训和指导方面发挥重要作用。NOSAMS通过网站和为来访公众举办参观活动，促进公众对放射性碳和相关科学问题的普遍了解。国家海洋科学基金会海洋科学部为国家海洋科学加速器质谱仪(NOSAMS)设施的运行和维护提供基地支持。该设施为海洋界提供自然水平的放射性碳测年服务。放射性碳是气候、碳循环和生物地球化学研究的重要工具。它是一个覆盖了过去50,000年的有用的计时器，它是过去碳循环变化的诊断，它是海洋循环的示踪剂，它是环境中碳流的探测器。因此，放射性碳测量被用于海洋科学研究的许多部门，从古海洋学、物理海洋学、生物地球化学和气候变化科学。目前的环境水平放射性碳测量需要仔细的样品处理，将污染风险和其他实验人工制品降至最低，并使用加速器质谱仪(AMS)系统。因此，拥有和维护一个中央设施，通过进行这种测量并作为专业知识中心，以及维持和促进这种测量的最先进水平，为更广泛的海洋科学界服务是有利的。皮？S建议继续运行五年，同时逐步增加每年分析的样本数，提高测量的准确度和精密度，并向新的方向拓展方法学。他们还计划继续改进和发展新的放射性碳测量能力，并提议扩大向社区提供的服务组合。最近的进展包括开创性的创新技术，如REDICS(溶解无机碳快速提取系统)和斜坡热解系统，这两项技术都使NOSAMS保持了竞争优势。拟议的研究包括在化合物特定和化合物类放射性碳分析方面的新进展，以及将分析扩展到较小的样本。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The National Ocean Sciences Accelerator Mass Spectrometry facility (NOSAMS) offers state of-the-art 14C (radiocarbon) measurements in a wide range of natural sample types, including seawater, groundwater, carbonates, bulk sediments, soils, and organic carbon. Measurements of radiocarbon in natural samples provide a unique and powerful set of tools for ocean and earth science. The 14C half-life (time it takes for half of the atoms in a sample to decay) of 5700 years can be used to date carbon-bearing samples as old as 50,000 years, and to study the time scales of ocean circulation and mixing, the timing of climate changes, and the details of modern carbon cycling. Radiocarbon measurements are used in many branches of ocean research including physical oceanography, biogeochemistry, paleooceanography, and climate change. The research enabled by the NOSAMS measurements addresses questions that are important to society: among them issues of past and future global climate change, local and regional environmental impacts, and the development of natural resources. In addition to supporting socially relevant research, NOSAMS will play an important role in training and mentorship of graduate students and postdoctoral researchers. NOSAMS promotes general public understanding of radiocarbon and related scientific issues through web sites and in hosting tours for the visiting public.The Division of Ocean Sciences at NSF provides base support for the operation and maintenance of the National Ocean Sciences Accelerator Mass Spectrometer (NOSAMS) facility. The facility provides natural level radiocarbon dating services to the oceanographic community. Radiocarbon is an important tool in climate, carbon cycle, and biogeochemical science. It is useful as a chronometer covering the past ~50,000 years, it is a diagnostic of past changes in the carbon cycle, it serves as a tracer of ocean circulation, and it is a probe for carbon flow in the environment. Thus radiocarbon measurements are used in many sectors of ocean science research ranging from paleoceanography, physical oceanography, biogeochemistry, and climate change science. Current environmental level radiocarbon measurements require careful sample processing that minimizes contamination risk and other experimental artifacts, and the use of Accelerator Mass Spectrometry (AMS) systems. Consequently, it is advantageous to have and maintain a central facility that serves the broader ocean sciences community by making such measurements and acting as a center of expertise, as well as sustaining and advancing the state-of-the-art in such measurements. The PI?s propose to continue operations for another five years, while gradually increasing the numbers of samples analyzed each year, improving the accuracy and precision of measurements, and expanding the methodology in new directions. They also plan to continue to improve and develop new radiocarbon measurement capabilities and propose to expand the portfolio of services offered to the community. Recent advances include pioneering innovative techniques such as the REDICS (Rapid Extraction of Dissolved Inorganic Carbon System) and the Ramped Pyrolysis System, both of which allow NOSAMS to maintain its competitive edge. Proposed research includes new inroads into compound specific and compound class radiocarbon analysis, as well as extending analyses to smaller samples.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.