Variations in the Oxygen/Nitrogen Ratios of Air: Implications for the Global Carbon Cycle

该项目利用测量的O2/N2（氧/氮）和Ar/N2（氩/氮）比率来提高对碳循环相关过程的理解。 O2/N2测量提供了陆地生物圈和海洋封存CO2（二氧化碳）的信息，有助于了解海洋肥力以及海洋环流和海洋地球化学通量之间的相互作用。 Ar/N2测量提供了关于海洋上部热含量、海洋上部混合和通风、气体交换率和大气示踪剂输送的信息。 这些信息有助于限制物理海洋模型所需的上层海洋生物地球化学和碳交换。 大气混合过程也受到这些观测的约束，这些观测可以导致旨在根据大气CO2分布来表征大气CO2源和汇的逆模型的改进。 因此，将把这两种比率的测量结合起来，作为研究碳循环的重要工具，在现有的测量点（巴罗、萨摩亚、阿姆斯特丹岛、格里姆角、麦考瑞和Syowa）和美国国家海洋和大气管理局的研究船（Ka'imimoana）上安装自动采样器。 将增加两个额外的测量点（Sable Island和Bermuda），并将开始准备量化横跨美国大陆的O2/N2梯度。 这些测量与Ralph Keeling的测量相似，但基于不同的分析方法，其中一些重叠的站点和一些互补的站点。 与Keeling小组的详细相互比较将是这项研究的一个持续部分，这项研究的成果将包括由于对陆地生物圈和海洋碳固存的理解有所提高而获得的最新人为碳平衡。 观测量的季节周期和纬向梯度将有助于更好地了解海洋生物过程和上层海洋动力学以及大气迁移现象，这项研究将提供关于人类活动因化石燃料燃烧和生物圈变化而对全球碳循环产生的影响的重要信息。 这些信息可用于许多领域，包括地球系统各组成部分之间的耦合以应对全球气候变化，预测与特定排放情景相关的环境后果，评估可能的缓解努力，并作为政策决定的科学依据的一部分。 作为这项工作的一部分，两名博士后研究员将接受培训。

This project makes use of measured O2/N2 (oxygen/nitrogen) and Ar/N2 (argon/nitrogen) ratios to improve understanding of processes related to the carbon cycle. The O2/N2 measurements provide information on sequestration of CO2 (carbon dioxide) by the terrestrial biosphere and the ocean, and aid in the understanding of ocean fertility and interaction between oceanic circulation and biogeochemical fluxes. The Ar/N2 measurements provide information on upper ocean heat content, upper ocean mixing and ventilation, gas exchange rates, and atmospheric tracer transport. This information helps to constrain upper ocean biogeochemistry and carbon exchange needed for physical ocean models. Atmospheric mixing processes are also constrained by these observations that can lead to improvement in inverse models aimed at characterizing atmospheric CO2 sources and sinks based on atmospheric CO2 distributions. Therefore, the combination of the two ratio measurements will be deployed as important tools for studying the carbon cycle.This will be accomplished by placing automated samplers at a number of existing measurement sites (Barrow, Samoa, Amsterdam Island, Cape Grim, Macquarie, and Syowa), and aboard a NOAA research vessel (Ka'imimoana). Two additional measurement sites will be added (Sable Island and Bermuda), and preparations will begin to quantify the O2/N2 gradient across the continental United States. These measurements are similar to those of Ralph Keeling, but are based on different analytical methodology, with some overlapping sites and some complementary ones. Detailed intercomparison exercises with Keeling's group will be an ongoing part of this study.Products of this research will include an updated anthropogenic carbon balance available because of improved understanding of terrestrial biosphere and ocean carbon sequestration. The seasonal cycles and meridional gradients of the observed quantities will provide improved understanding of oceanic biological processes and upper ocean dynamics, as well as atmospheric transport phenomena.This study will provide important information on anthropogenic influences on the global carbon cycles due to fossil fuel combustion and changes in the biosphere. This information can be used in a number of arenas including coupling between components of the Earth system in response to global climate change, predicting environmental consequences associated with given emission scenarios, assessing possible mitigation efforts, and as part of a scientific basis for policy decisions. Two post-doctoral fellows will receive training as part of this work.