MRI: Acquisition of a High Mass Resolution/High Sensitivity Isotope Ratio Mass Spectrometer For Earth Sciences

在地球科学研究中使用稳定同位素示踪剂提供了关于今天和古代在自然界中运作的过程的特别有价值的信息。使用这些示踪剂的研究已经看到了广泛的应用发展，其中许多是地球科学与化学、生物学、物理学以及工业和医学应用科学等学科的桥梁。随着新思想和新技术的发展，更精确和更精细的测量开辟了新的研究类型，有时是新的领域，这些应用程序是在稳定同位素研究人员提出的问题之后提出的。这种发展的一个最近的例子涉及用稀有同位素的多次取代研究物种的同位素。这些同位素分子或同位素学可以用来询问远远超出现有稳定同位素技术所能研究的问题，这些新方法有望提供与研究地质、大气和生物过程相关的新信息，并且像过去一样，在地球科学的传统范围内和之外都有影响。这笔拨款支持购买最新开发的最先进的高质量分辨率/高灵敏度同位素比质谱仪（HR/HS-IRMS），该质谱仪由马里兰大学的一个跨学科科学家团队设计，用于测量同位素。所要求的仪器将支持三个一级科学目标：(1)确定大西洋中部国家甲烷的来源、通量和组成，以实施地方控制和改进全球预算的定义，并增加大气负担；(2)利用分子氧的双取代同位素与更传统的同位素和浓度数据相结合，限制北极海洋冰破裂时的光合作用产生和呼吸消耗的氧气；(3)建立新的硫（36S）同位素系统，为研究硫代谢生态学和再氧化S循环的作用，包括其与全球海洋碳和氧循环的联系提供了新的途径。第一个目标将提供在区域和全球范围内了解甲烷生物源与化石源所需的关键信息；第二个目标将有助于了解北极季节性无冰海洋系统的响应，第三个目标将有助于了解s循环过程及其与现代和古代系统中其他元素循环的联系。该仪器将是美国东海岸的首个此类仪器，支持新的大西洋中部研究，为马里兰州气候变化计划和区域温室气体倡议（RGGI涉及9个州）提供政策相关科学，并对全球范围内的甲烷循环产生更广泛的影响。该仪器将支持整个大学系统的广泛研究活动，其长期目标是30%的外部地球科学用户将利用其能力扩展其科学和社会相关工作。该仪器将促进教学和学习，在实验室研究中发挥核心作用，包括指导当地高中学生、本科生和来自其他机构的访客。特别是在马里兰大学，这些活动将扩大代表性不足的群体（妇女、非洲裔美国人、西班牙裔）对地球科学研究的参与。从公众参与活动的角度来看，这些仪器将被纳入现有的项目，包括史密森学会国家航空航天博物馆青年计划、马里兰大学巴尔的摩县（UMBC）选择计划、马里兰大学新生创新和研究体验（FIRE）计划，以及马里兰日开放日，届时约有75,000名游客来到校园。

The use of stable isotope tracers in Earth Science research has provided particularly valuable information about processes that operate in nature, both today and in the ancient past. Studies using these tracers have seen a wide array of applications develop with many that bridge Earth science with disciplines such as chemistry, biology, and physics as well as applied science in industry and medicine. The applications have followed questions raised by stable isotope researchers as new ideas and technology have been developed where more precise and more finely focused measurements open up new types of studies, sometimes new fields. A recent example of such a development relates to the study isotopic of species with multiple substitutions of rare isotopes. These isotopic molecules or isotopologues can be used to interrogate questions well beyond those that can be studied with existing stable isotope techniques, and these new approaches promise to provide novel information relevant to study of geological, atmospheric, and biologic processes, and as in the past, to have implications within as well as beyond the traditional limits of Earth science. This grant supports acquisition of a recently developed state-of-the-art High Mass Resolution/High Sensitivity Isotope Ratio Mass Spectrometer (HR/HS-IRMS) designed for measurements of isotopologues by a cross disciplinary team of University of Maryland scientists. The requested instrument will support three, first-order scientific objectives: (1) identification of the sources, fluxes, and composition of mid-Atlantic States methane for implementing local controls and improved definition of the global budget and increasing atmospheric burden; (2) use of the doubly substituted isotopologues of molecular oxygen in combination with more traditional isotopic and concentration data for constraint of photosynthetic production and respiration consumption of oxygen at the time of ice breakup in the arctic oceans; and (3) development of a new isotopic system for sulfur (36S) that will provide new ways to study the ecology of the S metabolisms and the role of reoxidative S-cycling, including its connections to the global oceanic cycles of carbon and oxygen. The first objective will provide key information needed to understand the biogenic vs. fossil sources of methane on a regional and global scale; the second objective will contribute to understanding of the response of seasonally ice free marine systems in the Arctic, and the third objective will contribute to understanding the processes of S-cycling and their linkages to other element cycles in modern and ancient systems. The instrumentation will be the first of its kind on the east coast of the United States, supporting new mid-Atlantic research that will provide policy relevant science for the Maryland Climate Change Plan and the Regional Greenhouse Gas Initiative (RGGI involves nine states), as well as wider implications for methane cycling on the global scale. The instrumentation will support a wide range of research activities across the university system with a long-term goal of 30% external Earth Science users who will draw on its capabilities to extend its scientific and societally-relevant work. The instrumentation will promote teaching and learning with a central role in laboratory research that include mentoring of students from local high schools, undergraduate students, and visitors from other institutions. At the University of Maryland in particular, these activities will broaden the participation of under-represented groups, (women, African American, Hispanic) in Earth Science research. From the standpoint of activities that engage the public, the instrumentation will be incorporated into existing programs, including the Smithsonian Institution National Air and Space Museum Youth Program, the University of Maryland Baltimore County (UMBC) Choice Program, the UMD Freshman Innovation and Research Experience (FIRE) Program, as well as the Maryland Day open house when ~75,000 visitors come to campus.