Biogeochemical cycles of climate-active gases CH4, N2O and DMS in Arctic and Subarctic Marine Waters

北极和亚北极海水中气候活性气体 CH4、N2O 和 DMS 的生物地球化学循环

• 批准号: RGPIN-2017-03790
• 负责人: Tortell, Philippe
• 金额: $ 2.84万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=687288
• 关键词: Biogeochemical; cycles; climate; active; gases

Arctic and Subarctic marine waters play a large role in controlling the atmospheric concentration of various gases that influence Earth's climate. Methane (CH4) and nitrous oxide (N2O) are potent greenhouse gases acting to warm the planet, while dimethylsulfide (DMS), a trace gas produced by marine microbes, promotes the formation of clouds and atmospheric aerosols that back-scatter incoming solar radiation and act to cool the planet. The concentration and sea-air exchange of these 'climate-active' gases are influenced through the interplay of physical, chemical and biological processes, and sensitive to climate-driven shifts in oceanic conditions. At present, the magnitude of these potential climate-dependent changes is poorly constrained by direct observations. The proposed research program will collect fundamental data on the concentrations and biological / chemical cycles of DMS, CH4 and N2O in surface ocean waters. The principle research objectives are to: 1) quantify the spatial and temporal variability of these gases in Arctic and Subarctic marine waters across a range of oceanographic conditions; and 2) use isotope-labeling experiments to quantify the rates of key production and consumption in the DMS, CH4 and N2O cycles. The results from this work will advance our understanding of potential climate-dependent changes in the oceanic production of these gases over the coming decades. ******Ship-based field surveys will be used to map the concentrations of CH4, N2O and DMS in coastal and offshore waters of the Subarctic Pacific, and in the Canadian Arctic Ocean. Measurements will be conducted using a suite of analytical methods we have developed over the past decade. Isotope labeling experiments will be used to follow the production and consumption of DMS through various pathways, and quantify the cycling of CH4 and N2O through different precursor compounds. The results of the proposed work will provide new mechanistic insight into the factors regulating oceanic CH4, N2O and DMS concentrations, and their potential response to climate-sensitive variables. This, in turn, will be of great relevance to understanding the future evolution of the global climate system. *****

北极和亚北极海水在控制影响地球气候的各种气体的大气浓度中起着重要作用。 甲烷（CH4）和一氧化二氮（N2O）是作用着加热行星的有效温室气体，而二甲基硫化物（DMS）是海洋微生物产生的痕量气体，促进了云层的形成和大气中的气溶胶，后散射的散射剂辐射辐射和使行星冷却。 这些“气候活性”气体的浓度和海水交换受到物理，化学和生物学过程的相互作用的影响，并且对海洋条件下的气候驱动转移敏感。 目前，这些潜在的气候依赖性变化的大小受到直接观察的约束。拟议的研究计划将收集有关表面海水中DMS，CH4和N2O的浓度和生物 /化学周期的基本数据。主要研究目标是：1）在一系列海洋条件下量化这些气体在北极和亚北极海水中这些气体的空间和时间变化； 2）使用同位素标记的实验来量化DMS，CH4和N2O周期中关键产生和消耗的速率。 这项工作的结果将使我们对这些气体海洋生产的潜在气候依赖性变化的理解在未来几十年中。 ******基于船舶的现场调查将用于绘制亚北极太平洋沿海和海上水域以及加拿大北极海洋中CH4，N2O和DM的浓度。 将使用我们在过去十年中开发的一系列分析方法进行测量。 同位素标记实验将用于通过各种途径遵循DMS的生产和消耗，并通过不同的前体化合物量化CH4和N2O的循环。 拟议工作的结果将为调节海洋CH4，N2O和DMS浓度的因素提供新的机械洞察力，以及它们对气候敏感变量的潜在反应。 反过来，这将与理解全球气候系统的未来演变非常相关。 *****