Global Biogeochemical Implications of Oceanic Nitrous Oxide, Oxygen, and Nitrate Deficit Patterns: Model and Data Analysis

摘要作为地球主要温室之一的一氧化二氮（N2O）的大气浓度自全球工业化开始以来一直在增加。增加的原因尚不清楚，但有证据表明，多达50%的大气输入来自海洋。显然需要限制海洋一氧化二氮的来源和通量。在这个项目中，斯克里普斯海洋学研究所和国家大气研究中心的研究人员将对海洋N2O的产生、硝化和反硝化进行模型和数据分析研究。该研究旨在利用最新的表面N2O数据和气体传输方法提供海洋N2O来源的最新估计。本分析将审查海洋来源的大小和分布，特别注意沿海和缺氧区域的重要性。该研究的第二个目标是在全球和区域数据集中探索海洋N2O、O2和营养物质之间的关系。该模拟研究预测的海洋N2O来源将与使用气体传输方法从表面N2O数据估计的结果进行比较。非常规的机制，包括反硝化和N2O生产的缺氧微区下沉的有机物，也将进行测试。生物地球化学/运输模式研究的其他目标包括估计在过去气候条件下海洋一氧化二氮排放可能如何变化，并研究氮和碳的生物地球化学循环之间的联系如何可能导致海洋一氧化二氮和二氧化碳通量的相关变化。

ABSTRACTOCE-00996404The atmospheric concentration of nitrous oxide (N2O), one of the major greenhouses of Earth, has increased since the beginning of global industrialization. The reasons for the increase are not understood, but evidence suggests that as much as 50% the input to the atmosphere derives from the ocean. There is a clear need to constrain the sources and fluxes of marine N2O.In this project researchers at the Scripps Institution of Oceanography and the National Center for Atmospheric research will conduct a model and data analysis study of ocean N2O production, nitrification, and denitrification. The study aims to provide an updated estimate of the ocean N2O source using newly available surface N2O data and gas transfer methods. Both the magnitude and distribution of the ocean source will be examined in this analysis, with particular attention to the importance of coastal and suboxic regions. A second goal of the study is to explore the relationships among ocean N2O, O2 , and nutrients in global and regional data sets. The ocean N2O source predicted by this modeling investigation will be compared to that estimated from surface N2O data using gas transfer methods. Nonconventional mechanisms, including denitrification and N2O production in anoxic microzones of sinking organic matter, will be tested as well. Additional goals of the biogeochemistry/transport model study include estimating how ocean N2O emissions may have changed under past climate conditions and examining how links between the biogeochemical cycles of nitrogen and carbon may lead to correlated variations in ocean N2O and CO2 fluxes.