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.

该主要研究仪器奖支持下一代气体质谱系统的开发，该系统具有足够的精度，可以测量由化石燃料燃烧引起的海洋变暖速率。这种方法是通过测量大气中氪和氙的丰度来实现的。由于温水比冷水含有更少的溶解气体，氪和氙的丰度会随着时间的推移而上升。这些测量结果用一种完全独立的方法补充了从浮标和船只上直接观测到的海洋温度，这种方法利用大气的良好混合特性来跟踪单个地点的海洋体积平均热量。考虑到温室气体产生的93%的多余热量最终会进入海洋，这种方法是一种经济有效的方法，可以增加社会对这一至关重要的地球生命迹象的认识的信心。气体质谱分析系统还可以测量冰芯中被困空气中过去的大气氧浓度，这将提高对土壤变暖过程中温室气体释放的科学理解。这项工作的更广泛影响包括一名博士生的教育，以及两个将使用该仪器的代表性不足的少数民族的研究职业发展。过剩海洋热的库存以一种相当直接的方式反映了由于人类辐射强迫而在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年的敏感性一直在3+-1.5摄氏度之间。斯克里普斯二氧化碳项目在过去50年里采集的空气样本档案将被用来测量氪和氙的浓度，使用提议的设备，看看是否有可能改善海洋热的历史记录，从而减少灵敏度的不确定性。该技术策略是基于购买工厂改装的MAT 253 Ultra质谱仪，结合定制的压力稳定进气系统，该系统已经在Scripps海洋学研究所使用。一个平行的传统进气系统将使仪器无摩擦地共享用于其他目的，例如需要高质量分辨率的气体测量，以从感兴趣的物种中分离干扰质量，或稀有同位素和质量无关分馏的研究。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，这将支持革命性的新发现，并吸引年轻的研究人员。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。