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

稳定同位素示踪剂在地球科学研究中的使用提供了关于在自然界中运行的过程的特别有价值的信息，无论是在今天还是在古代。使用这些示踪剂的研究已经看到了广泛的应用开发，其中许多应用将地球科学与化学、生物和物理等学科以及工业和医学中的应用科学联系起来。这些应用是在稳定同位素研究人员提出问题之后进行的，因为新的想法和技术已经被开发出来，更精确和更专注的测量开辟了新类型的研究，有时是新的领域。最近这种发展的一个例子涉及对稀有同位素进行多次取代的物种的同位素研究。这些同位素分子或同位素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地质、大气和生物过程研究相关的新信息，并像过去一样，在地球科学的传统界限之内和之外产生影响。这笔赠款支持马里兰大学的一个跨学科团队最近开发了一台最先进的高质量分辨率/高灵敏度同位素比质谱仪(HR/HS-IRMS)，用于测量同位素。所请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，以实施当地控制和改进全球预算的定义，并增加大气负担；(2)使用双取代的分子氧同位素，结合更传统的同位素和浓度数据，限制北冰洋冰破裂时的光合作用生产和氧气的呼吸消耗；(3)新的硫(~(36)S)同位素体系的建立，这将为研究S代谢的生态学和再氧化S循环的作用，包括它与全球海洋碳氧循环的联系提供新的途径。第一个目标将提供必要的关键信息，以便在区域和全球范围内了解甲烷的生物来源和化石来源；第二个目标将有助于理解北极季节性无冰海洋系统的响应；第三个目标将有助于理解S循环的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第一个此类仪器，支持新的大西洋中部研究，这些研究将为马里兰州气候变化计划和区域温室气体倡议(RGGI涉及九个州)提供与政策相关的科学，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，长期目标是30%的外部地球科学用户将利用其能力扩大其科学和社会相关工作。该仪器将在实验室研究中发挥核心作用，促进教与学，包括对当地高中生、本科生和其他机构的来访者进行指导。特别是在马里兰大学，这些活动将扩大代表不足的群体(妇女、非裔美国人、西班牙裔)对地球科学研究的参与。从吸引公众的活动的角度来看，这些仪器将被纳入现有的计划，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大学(UMBC)选择计划、UMD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名参观者来到校园。

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.