The past, present and future greenhouse gas (GHG) footprint of lakes: from biogeochemical processes to large scale upscaling

湖泊过去、现在和未来的温室气体 (GHG) 足迹：从生物地球化学过程到大规模升级

• 批准号: RGPIN-2022-04110
• 负责人: Prairie, Yves
• 金额: $ 3.13万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765232
• 关键词: past; present; future; greenhouse; gas

The overarching goal of my NSERC Discovery Grant research program is the development a robust quantitative framework to assess the role of inland waters in landscape carbon and greenhouse gas (GHG) budgets, from local to regional to global. While CO2 is typically the dominant form in which lakes emit carbon to the atmosphere, the higher warming potential of methane (CH4) renders their impact on radiative forcing about co-equal. However, given the more complex nature of the biogeochemical cycling of methane relative to CO2, estimates of the contribution of CH4 to total GHG emissions is much more variable and poorly constrained. The specific objectives of this proposal are focused on methane and aim 1) to test a new model describing sediment CH4 production and its partitioning between ebullitive and diffusive fluxes, 2) to establish the quantitative relationship between sediment CH4 production and other lake characteristics (in particular, trophic status and temperature) on a broad set of lakes, 3) continue the development of a novel coupled physical-biogeochemical model (PB-GHG) and its validation using both a multi-lake and within-lake approaches, 4) apply the PB-GHG model to evaluate by how much the GHG footprint of Canadian lakes has changed over the past 70 years and by how much it is likely to change further under different scenarios of climate change and eutrophication. Together, these projects, combined our previous work, will provide the most comprehensive framework to better predict the dynamics of CH4 in lakes.

我的NSERC发现基金研究项目的总体目标是建立一个强有力的定量框架，以评估内陆水域在从地方到区域到全球的景观碳和温室气体（GHG）预算中的作用。虽然二氧化碳通常是湖泊向大气排放碳的主要形式，但甲烷（CH4）较高的变暖潜势使它们对辐射强迫的影响大致相等。然而，考虑到甲烷相对于二氧化碳的生物地球化学循环更为复杂，对甲烷对温室气体排放总量的贡献的估计更加多变且缺乏约束。本提案的具体目标集中在甲烷上，旨在1)测试描述沉积物CH4生成及其在沸腾通量和扩散通量之间分配的新模型；2)在广泛的湖泊中建立沉积物CH4生成与其他湖泊特征（特别是营养状况和温度）之间的定量关系。3)继续发展一种新的物理-生物地球化学耦合模型（PB-GHG），并使用多湖和湖内方法对其进行验证；4)应用PB-GHG模型评估过去70年来加拿大湖泊温室气体足迹的变化程度，以及在不同气候变化和富营养化情景下可能进一步变化的程度。总之，这些项目，结合我们以前的工作，将提供最全面的框架，以更好地预测湖泊中CH4的动态。