Measurement of Atmospheric He/N2 (Helium to Nitrogen) Ratio as a Tracer of Stratospheric-Tropospheric Exchange

测量大气 He/N2（氦气与氮气）比率作为平流层-对流层交换的示踪剂

• 批准号: 1940361
• 负责人: Ralph Keeling
• 金额: $ 52.88万
• 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: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-11-15 至 2023-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1940361&HistoricalAwards=false
• 关键词: Measurement; Atmospheric; He; N2; Helium

This project supports the development of new instrumentation to measure very precisely the ratio of the concentration of helium (He) to nitrogen (N2) in the atmosphere. Measurements of this ratio will be used to evaluate the exchange of atmospheric constituents between the stratosphere (the layer of the atmosphere just above the troposphere) and the troposphere, the lowest portion of the atmosphere closest to the Earth's surface. Better understanding of stratospheric-tropospheric exchange (STE) is important for increasing general knowledge about the atmosphere and improving models that predict weather and climate.The newly developed instrumentation will be used to: (1) measure long-term trends in He/N2 as recorded in the Scripps Institute of Oceanography archive of high pressure gas cylinders of air that extends back to the 1970s; (2) conduct real-time measurements of He/N2 for a period spanning one year at La Jolla, where stratospheric influences are expected in association with Santa Anna wind events; and (3) test new methods to allow He/N2 ratios to be measured in flask samples. Modeling studies will be used to assess the expected stratospheric influences on the He/N2 ratio. This project is expected to provide the first estimates of seasonal and synoptic variations in the He/N2 ratio. This effort will also improve the ability of Ar/N2 measurements to serve as a constraint on ocean warming. The new technique will be used to advance the understanding of stratospheric circulation and the resulting implications for tropospheric chemistry, and ultimately, by assessing the sources of these compounds, to attain a better understanding of the effects of human activities on the atmosphere.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.

该项目支持开发新的仪器，以非常精确地测量大气中氦（He）与氮（N2）的浓度比。对这一比率的测量将用于评价平流层（对流层上方的大气层）和对流层（最接近地球表面的大气层最低部分）之间的大气成分交换。更好地了解平流层-对流层交换（STE）对于增加大气的一般知识和改进天气和气候预测模型是重要的。新开发的仪器将用于：（1）测量斯克里普斯海洋学研究所高压气瓶空气档案中记录的He/N2的长期趋势，该档案可以追溯到20世纪70年代;（2）在拉霍亚进行为期一年的He/N2实时测量，预计平流层的影响与圣安娜风事件有关;（3）测试新方法，以便在烧瓶样品中测量He/N2比率。模拟研究将用于评估平流层对He/N2比率的预期影响。预计该项目将提供He/N2比值季节和天气变化的初步估计。这一努力还将提高Ar/N2测量的能力，以限制海洋变暖。这项新技术将被用于推进对平流层环流及其对对流层化学的影响的理解，并最终通过评估这些化合物的来源，该奖项反映了NSF的法定使命，并被认为值得通过利用基金会的知识价值和更广泛的影响审查进行评估来支持的搜索.

项目成果

Increasing atmospheric helium due to fossil fuel exploitation

由于化石燃料的开采，大气中的氦气不断增加

• DOI: 10.1038/s41561-022-00932-3
• 发表时间: 2022
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Birner, Benjamin;Severinghaus, Jeffrey;Paplawsky, Bill;Keeling, Ralph F.
• 通讯作者: Keeling, Ralph F.

Short-term variability of atmospheric helium revealed through a cryo-enrichment method

通过低温浓缩方法揭示大气氦的短期变化

• DOI: 10.5194/amt-16-1551-2023
• 发表时间: 2023
• 期刊: Atmospheric Measurement Techniques
• 影响因子: 3.8
• 作者: Birner, Benjamin;Morgan, Eric;Keeling, Ralph F.
• 通讯作者: Keeling, Ralph F.

A method for resolving changes in atmospheric He ∕ N₂ as an indicator of fossil fuel extraction and stratospheric circulation

一种解决大气 He-N₂ 变化的方法，作为化石燃料提取和平流层环流的指标

• DOI: 10.5194/amt-14-2515-2021
• 发表时间: 2021
• 期刊: Atmospheric Measurement Techniques
• 影响因子: 3.8
• 作者: Birner, Benjamin;Paplawsky, William;Severinghaus, Jeffrey;Keeling, Ralph F.
• 通讯作者: Keeling, Ralph F.