OPERATION OF A NATIONAL OCEAN SCIENCES ACCELERATOR MASS SPECTROMETRY FACILITY AT THE WOODS HOLE OCEANOGRAPHIC INSTITUTION

国家科学基金会海洋科学司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。该设施将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，以及保持和推进这种测量的最新水平，为更广泛的海洋科学界服务是有利的。在过去的十多年里，提交给NOSAMS的样品一直在稳步增长。目前，该机构每年分析约7,900个样本，其中1,000个样本用于气候变异性和可预测性(CLIVAR)计划，6,900个样本用于其他客户(约270名不同研究人员每年提交550-600批样本)。通过网络门户网站输入样品提交信息，使用强大、可扩展和安全的数据库管理系统跟踪样品处理和分析的所有阶段，客户可以通过网络安全和方便地获取样品处理状态和分析结果。皮？S建议继续运营5年，同时逐步增加每年分析的样品数量，提高测量的准确度和精密度，并向新的方向扩展方法学；皮？S建议继续改进和发展新的放射性碳测量能力，并建议扩大为社区提供的服务组合。最近的进展包括对碳酸盐进行高精度的放射性碳测量，以及开发一种独特的用于连续流动AMS的气体接受离子源(GIS-CFAMS)，它可以耦合到各种不同的界面，从而产生了新的测量能力。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。广泛的影响：由NOSAMS的测量实现的研究解决了对社会重要的问题：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。

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 will provide 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.Over the past decade and more, there has been a steady growth in sample submissions to NOSAMS. Presently the facility analyzes about 7,900 samples per year, 1,000 for the Climate Variability and Predictability (CLIVAR) program and 6,900 for other clients (550-600 batch submissions annually from ~270 different investigators). Sample submission information is entered through a web portal, samples are tracked through all stages of processing and analysis using a robust, scalable, and secure database management system, and clients have secure and convenient access to sample processing status and analytical results through the web. 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.The PI?s propose 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 high precision radiocarbon measurements on carbonates, and the development of a unique gas-accepting ion source for continuous flow AMS (GIS-CFAMS) which can be coupled to a variety of different interfaces, leading to new measurement capabilities. Proposed research includes new inroads into compound specific and compound class radiocarbon analysis, as well as extending analyses to smaller samples.Broader Impacts: 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.