A Study of the Abundance of the Atmospheric O2 Mole Fractionin Relationship to the Carbon Cycle and Air-Sea Exchange

大气O2摩尔分数丰度与碳循环和海气交换关系的研究

• 批准号: 8720377
• 负责人: Peter McKinney
• 金额: $ 14.99万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-05-15 至 1990-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8720377&HistoricalAwards=false
• 关键词: Study; Abundance; Atmospheric; O2; Mole

There is scarcely a subject in biogeochemistry which is more fundamental, yet so poorly understood, as the variability in atmospheric oxygen. Oxygen is an essential element to global life cycles and is consumed by fossil fuel-burning and deforestation; yet the changes in the atmospheric oxygen concentration which must reflect these processes have never been detected. The difficulty is simply that the appropriate technology has not been available for measuring the expected variations in oxygen against the large oxygen background of air. Direct measurements of changes in oxygen would substantially improve the framework for studying the global carbon cycle and the perturbations due to human activities. Specifically, measuring the presumed long term rate of decline in oxygen would provide a basis for establishing the net annual global oxidation from which one could construct accurate figures for the net sources and sinks of carbon from fossil fuel burning and biospheric oxidation. This would provide objective constraints on models of oceanic carbon dioxide uptake which are needed to forecast future carbon dioxide levels and future climate. It would also provide a better basis for understanding whether today's elevated carbon dioxide levels are stimulating global net primary production. This project is designed to investigate the atmospheric oxygen and carbon dioxide fraction in air samples gathered from a series of stations around the world. The purpose of those measurements is to correlate seasonal, latitudinal and secular trends in atmospheric carbon dioxide with variations in oxygen. These data will provide insights into changes in global biomass, and in ocean and land biological productivities. Air samples will be taken in glass flasks and oxygen mole fraction will be referenced to compressed air standards using a recently developed interferometric oxygen analyzer. The measurements will be accompanied by systematic studies of oxygen stability in glass flasks and high pressure cylinders. Other work will include a laboratory feasibility study of obtaining cryogenically extracted air samples from the stratosphere for oxygen analysis, which would be of interest for determining recent oxygen depletion.

生物地球化学中几乎没有一个主题，它是大气氧的变异性更为基本，但知之甚少。 氧气是全球生命周期的重要因素，并且被化石燃料燃料和森林砍伐所消耗。然而，从未检测到必须反映这些过程的大气氧浓度的变化。 困难仅仅是没有适当的技术可用于测量对空气中较大的氧气背景的氧气的预期变化。 直接测量氧气变化将大大改善研究全球碳循环和由于人类活动引起的扰动的框架。 具体而言，测量氧气中假定的长期下降速率将为建立净年度全球氧化提供基础，从中可以从化石燃料燃烧和生物圈氧化中为碳的净来源和碳汇集量的准确数字。 这将提供对海洋二氧化碳吸收模型的客观限制，这些模型需要预测未来的二氧化碳水平和未来气候。 这也将为理解当今的二氧化碳水平是否刺激全球净初级生产提供更好的基础。 该项目旨在研究从世界各地的一系列电台收集的空气样品中的大气氧和二氧化碳部分。 这些测量的目的是将大气二氧化碳的季节性，纬度和世俗趋势与氧气变化相关。 这些数据将为全球生物量以及海洋和土地生物学生产力的变化提供见解。 空气样品将在玻璃瓶中采集，使用最近开发的干涉氧分析仪将参考压缩空气标准。 测量结果将伴随着玻璃瓶和高压气缸中氧气稳定性的系统研究。 其他工作将包括一项实验室可行性研究，该研究是从平流层中获取低温提取的空气样品进行氧气分析，这对于确定近期氧气耗尽的含量非常有意义。