Collaborative Research: Arctic time series measurements of atmospheric O2/N2 ratio, CO2 concentration, and CO2 isotopes in relation to changing carbon cycling and biogeochemistry

该项目通过在三个北极地点收集的烧瓶支持对大气二氧化碳（CO2）和相关物种（如氧气）的长期测量。这些测量包括几种关键大气微量气体的最长连续地球化学记录，并与了解北纬高纬度地区的气候变化和陆地和海洋生态系统的相关变化直接相关。二氧化碳不仅是一种关键的温室气体，而且它的变化是陆地生态系统（如苔原和森林）光合作用和呼吸作用的诊断指标，而陆地生态系统支持北极生态系统的食物网和健康。对大气物种的相关测量，如O2和CO2的同位素，补充并扩展了这一知识库。先前对大气二氧化碳的测量清楚地表明，高纬度地区的碳循环发生了巨大的变化。未来几十年可能会发生更大的变化，仅靠模型无法让我们了解这些结果。因此，大气测量是观测系统的一个关键要素，它将使人们了解这些系统变化的速度和方向。该项目不仅继续进行长期的烧瓶测量，而且还通过安装在阿拉斯加Utqiagvik的原位仪器启动了新的大气测量。该项目支持在阿拉斯加的冷湾和乌特基亚维克以及埃尔斯米尔岛的警戒站收集烧瓶。这些烧瓶将被送回斯克里普斯海洋学研究所，在那里它们将被分析二氧化碳浓度、二氧化碳的稳定同位素以及O2/N2和Ar/N2的比率。该项目还将支持阿拉斯加Utqiagvik现场O2/N2分析仪系统的安装和运行。这个新装置将使研究与附近楚科奇海、波弗特海和白令海的O2交换成为可能，这是基于解析区域来源的短期信号的能力。为了加强这些数据收集工作，该项目将支持数据分析，以检测和量化所测大气微量气体的长期变化，并特别关注季节周期的变化。此外，它将支持在乌特基亚维克观测到的O2变化与最先进的数值模式模拟的预期变化估计之间进行比较。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。

This project supports the continuation of long-term measurements of atmospheric carbon dioxide (CO2) and related species such as oxygen (O2) via flasks collected at three Arctic sites. These measurements comprise the longest continuous geochemical records of several key atmospheric trace gases and have direct relevance for understanding climate changes and related changes in land and ocean ecosystems at high northern latitudes. CO2 not only is a critical greenhouse gas but its variations are diagnostic of photosynthesis and respiration of land ecosystems, such as tundra and forests, which support the food-web and health of Arctic ecosystems. Related measurements of atmospheric species, such as O2 and the isotopes of CO2, complement and expand this knowledge base. Previous measurements of atmospheric CO2 reveal clearly that dramatic changes have occurred in the cycling of carbon at high latitudes. Larger changes are likely to occur in the decades ahead and models alone cannot inform our understanding of those outcomes. Hence, atmospheric measurements comprise a key element of an observing system that will allow understanding of how fast and in what respect these systems are changing. This project not only continues long-term flask measurements but also initiates new atmospheric measurements through in situ instrumentation to be installed at Utqiagvik, Alaska. This project supports flask collections at Cold Bay and Utqiagvik, Alaska, and at Alert Station on Ellesmere Island. The flasks will be returned to the Scripps Institution of Oceanography where they will be analyzed for CO2 concentration, the stable isotopes of CO2, and the O2/N2 and Ar/N2 ratios. The project will also support the installation and operation of an in situ O2/N2 analyzer system at Utqiagvik, Alaska. This new installation will enable the study of O2 exchanges with the nearby Chukchi, Beaufort, and Bering Seas based on the ability to resolve short-term signals of regional origin. Augmenting these data collection efforts, this project will support data analysis to detect and quantify long-term changes in the measured atmospheric trace gases, with a particular focus on changes in seasonal cycles. In addition, it will support comparisons between the observed variations in O2 at Utqiagvik with estimates of the expected variations simulated in state-of-the art numerical models.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.