BIOCOMPLEXITY: High-Precision 13CO2/12CO2 Ratio Measurements Using an Optical Fiber Based Difference Frequency Generation Laser Source

生物复杂性：使用基于光纤的差频产生激光源进行高精度 13CO2/12CO2 比率测量

• 批准号: 0215702
• 负责人: David Carlson
• 金额: $ 124.69万
• 依托单位: University Corporation For Atmospheric Res
• 依托单位国家: 美国
• 项目类别: Cooperative Agreement
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-10-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0215702&HistoricalAwards=false
• 关键词: BIOCOMPLEXITY; Precision; 13CO2; 12CO2; Ratio

This project entails the development, test, validation, and deployment of a mid-infrared laser based gas sensor system for continuous in-situ measurements of the isotopic composition of atmospheric carbon dioxide (13CO2/12CO2 ratio) with a precision equal to or better than 0.1 per mil. A science team from the National Center for Atmospheric Research, Rice University, and the University of Colorado will utilize the latest developments in optical fiber technology, recent advances in difference frequency generation (DFG), and multi-year experience in carbon cycle research. The proposed DFG instrument will employ commercially available telecommunication lasers which operate at room temperature. Such a laser source presents significant advantages over more traditional laser systems for achieving high measurement precision.The instrument will be used to acquire high precision atmospheric measurements of 13CO2/12CO2 ratios - a measurement currently accomplished by a network of flask samples followed by mass spectrometric analysis. These data are crucial for understanding terrestrial and oceanic carbon sinks which requires an understanding of the distribution, contribution, and evolution of regional and local CO2 source and sink processes. High precision continuous measurements are needed to provide broad temporal and spatial coverage, even though the isotopic precision is inferior to the flask method (0.012 per mil) At present there does not exist a robust field-deployable instrument capable of continuous 13CO2/12CO2 measurements with a precision of 0.1 per mil or better with verifiable accuracy.The first phase of this effort will focus on extensive laboratory testing to identify and implement optimal experimental conditions and data acquisition and retrieval routines. The next phase will focus on optimal packaging for field measurements, and this will be followed by an extensive set of side-by-side comparisons with state-of-the-art flask sample/mass spectrometric measurements carried out in the field at the University of Colorado's Niwot Ridge Observatory site. Co-located measurements will be carried out on both the ground and the University of Colorado tower facility. The new continuous measurements will provide the foundation for a long-term database from the Niwot Ridge site as well as the necessary experience to further extend these new measurements to other venues and platforms. This project has potential broad impacts in the area of carbon cycle research. In addition, the new instrument and associated new approaches can be adapted to other new research problems requiring ultra high measurement precision. Moreover, a multifaceted educational program with graduate and undergraduate students, high school students and teachers, will transfer the understanding and use of this new laser and fiber optic technology to a broader scientific community. The students will be introduced to 1) the potential of optical fiber technologies and its applications; 2) an overview of the carbon cycle; and 3) the challenges of, and information content offered by, high precision isotopic ratio measurements of CO2.

该项目需要开发、测试、验证和部署基于中红外激光的气体传感器系统，用于连续原位测量大气二氧化碳的同位素组成（13 CO2/12 CO2比率），精度等于或优于0.1 ‰。来自莱斯大学国家大气研究中心的一个科学小组，科罗拉多大学将利用光纤技术的最新发展、差频发电（DFG）的最新进展以及碳循环研究的多年经验。拟议的DFG仪器将采用在室温下工作的商用电信激光器。这种激光源在实现高测量精度方面比传统激光系统具有显著优势。该仪器将用于获得13 CO2/12 CO2比率的高精度大气测量-目前通过烧瓶样品网络进行测量，然后进行质谱分析。这些数据对于了解陆地和海洋碳汇至关重要，这需要了解区域和本地CO2源和汇过程的分布，贡献和演变。需要高精度连续测量以提供广泛的时间和空间覆盖，尽管同位素精确度不如烧瓶法（0.012每密耳）目前不存在能够连续测量13 CO2/12 CO2测量精度为每密耳0.1或更高，并具有可验证的准确性。这项工作的第一阶段将集中在广泛的实验室测试，确定并实施最佳实验条件和数据采集及检索程序。下一阶段的重点将是最佳的包装实地测量，这将是一个广泛的一套并排比较与国家的最先进的烧瓶样品/质谱测量进行了实地在科罗拉多大学的尼沃特岭天文台网站。将在地面和科罗拉多大学塔设施上进行共址测量。新的连续测量将为尼沃特岭场地的长期数据库提供基础，并为进一步将这些新测量扩展到其他场地和平台提供必要的经验。该项目在碳循环研究领域具有潜在的广泛影响。此外，新仪器和相关的新方法可以适应其他需要超高测量精度的新研究问题。此外，与研究生和本科生，高中生和教师的多方面教育计划将把这种新的激光和光纤技术的理解和使用转移到更广泛的科学界。学生将被介绍到1）光纤技术及其应用的潜力; 2）碳循环的概述;和3）的挑战，并提供信息内容，CO2的高精度同位素比测量。