MRI: Development of an Ultra-High-Precision Gas Mass Spectrometer

MRI：超高精度气体质谱仪的开发

• 批准号: 1920369
• 负责人: Jeffrey Severinghaus
• 金额: $ 112万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1920369&HistoricalAwards=false
• 关键词: MRI; Development; Ultra; Precision; Gas

This Major Research Instrumentation award supports development of a next-generation gas mass spectrometry system with sufficient precision to measure the rate of ocean warming due to fossil fuel burning. The method works by measuring the atmosphere's krypton and xenon abundances over time, which are rising due to the fact that warm water holds less dissolved gas than cold water. These measurements complement the direct ocean temperature observations from floats and ships with a completely independent method, which takes advantage of the well-mixed nature of the atmosphere to track volume-average ocean heat at a single location. Given that 93% of the excess heat from greenhouse gases ends up in the ocean, this approach is a cost-effective way to add confidence to society's knowledge of this crucial planetary vital sign. The gas mass spectrometry system also enables measurement of past atmospheric oxygen concentrations from trapped air in ice cores, which will improve scientific understanding of release of greenhouse gases from soils as they warm. Broader impacts of the work include education of one PhD student, and the research career development of two under-represented minorities who will use the instrument. The inventory of excess ocean heat reflects in a rather direct way the cumulative energy imbalance at the top of the atmosphere due to human radiative forcing. In principle, a better knowledge of ocean heat content over the past half century would narrow the uncertainty on the estimate of sensitivity, which has been at 3+-1.5 degrees C for the last 50 years. Archived air samples taken by the Scripps CO2 program over the past 50 years will be measured for krypton and xenon concentration, using the proposed equipment, to see if it is possible to improve the historical record of ocean heat, and thereby reduce the uncertainty on the sensitivity. The technological strategy is based on purchase of a factory-modified MAT 253 Ultra mass spectrometer, combined with a custom pressure-stabilized inlet system already in use at the Scripps Institution of Oceanography. A parallel conventional inlet system will enable frictionless shared use of the instrument for other purposes, such as gas measurements that require high mass resolution to separate interfering masses from the species of interest, or studies of rare isotopologues and mass-independent fractionation. This proposal will establish a shared-use Facility for Advanced Isotope Geochemistry at Scripps, which will underpin transformative new discoveries and attract young researchers.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.

该重大研究仪器奖支持开发下一代气体质谱系统，该系统具有足够的精度来测量由于化石燃料燃烧而导致的海洋变暖速度。该方法的工作原理是随着时间的推移测量大气中氪和氙的丰度，由于温水比冷水含有更少的溶解气体，这些丰度正在上升。这些测量通过完全独立的方法补充了浮标和船舶的直接海洋温度观测，该方法利用大气的充分混合特性来跟踪单个位置的体积平均海洋热量。鉴于温室气体产生的多余热量有 93% 最终流入海洋，这种方法是一种经济有效的方法，可以增强社会对这一重要地球生命体征的了解。气体质谱系统还能够测量冰芯中滞留空气中过去大气中的氧气浓度，这将提高对土壤变暖时温室气体释放的科学认识。这项工作的更广泛影响包括一名博士生的教育，以及将使用该工具的两个代表性不足的少数群体的研究职业发展。海洋多余热量的存量以相当直接的方式反映了人类辐射强迫导致的大气顶部累积的能量不平衡。原则上，更好地了解过去半个世纪的海洋热含量将缩小敏感性估计的不确定性，过去 50 年的敏感性估计一直在 3+-1.5 摄氏度。斯克里普斯二氧化碳计划过去 50 年来采集的存档空气样本将使用拟议的设备测量氪和氙的浓度，看看是否有可能改善海洋热量的历史记录，从而减少海洋热量的不确定性。敏感性。该技术策略基于购买工厂改装的 MAT 253 Ultra 质谱仪，并结合斯克里普斯海洋学研究所已使用的定制压力稳定入口系统。并行的传统入口系统将使仪器能够无摩擦地共享用于其他目的，例如需要高质量分辨率以将干扰质量与感兴趣的物质分开的气体测量，或稀有同位素体和与质量无关的分馏的研究。该提案将在斯克里普斯建立一个先进同位素地球化学共享设施，这将支持变革性的新发现并吸引年轻的研究人员。该奖项反映了 NSF 的法定使命，并通过利用基金会的智力优势和更广泛的影响进行评估，被认为值得支持审查标准。