Deciphering the composition and fate of dissolved organic matter in a rapidly changing Arctic Ocean

破译快速变化的北冰洋中溶解有机物的成分和命运

• 批准号: RGPIN-2021-03984
• 负责人: Gueguen, Celine
• 金额: $ 3.72万
• 依托单位: Université de Sherbrooke
• 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=748680
• 关键词: Deciphering; composition; fate; dissolved; organic

Marine dissolved organic matter (DOM) is central to the current and future global carbon cycle, with a reservoir comparable in size to the current atmospheric carbon dioxide reservoir. The fact that the oceans are a huge reservoir of carbon has continued to urge scientists to investigate what DOM is in terms of its source, chemical composition, reactivity and function in marine environments for decades. Marine DOM originates from marine primary production, however only a small fraction is identifiable as common molecules. My research program aims to elucidate the composition and dynamics of dissolved organic matter in marine ecosystems. During the next five years, I plan to continue my research program on the cycling and dynamics of DOM in the highly stratified Arctic's Canada Basin. Specifically, the main objectives will be to: 1)Link fluorescence properties of marine DOM to identifiable molecules. Excitation emission matrix spectroscopy associated with Parallel Factor Analysis (EEM-PARAFAC) has been applied to gain insights about the distribution and dynamics of protein-like and humic-like DOM but there is still a lack of direct evidence linking PARAFAC components to molecularly characterized molecules. Concurrent determination of fluorescence composition, lignin phenol, carbohydrates and amino acids will be used to investigate the relationships between specific fluorescent components and identifiable molecules. 2)Assess the refractory nature of DOM. Mesocosm experiments will be conducted aboard the Canadian Coast Guard icebreaker to assess how the bulk and molecular composition of DOM changes over time, and with changes in bacteria taxonomy. Our research aims to illuminate dark-ocean organic biogeochemistry that is crucial for understanding the cycling of DOM in the global ocean. 3)Investigate the seasonal dynamics of DOM in the Arctic Ocean. High frequency measurements from in situ fluorescent DOM sensors will expand our observations spatially and seasonally. The temporal variability in DOM fluorescence will be related to the change in stratification, biological activities, mineralization and ice cover. This research program will allow to better understand the composition, source and dynamics of DOM in marine waters. The 19 HQP involved in this program would also have the unique opportunity to work in the Canadian Arctic where rapid environmental changes are occurring. The skills and knowledge gained within this project, including cutting edge analytical techniques, arctic experience and intercultural and leadership skills will be invaluable in careers in academia, government or industry.

海洋溶解有机物（DOM）对于当前和未来的全球碳循环至关重要，储层的大小与当前大气二氧化碳储层相当。海洋是碳的巨大储层，这一事实继续敦促科学家在数十年中在海洋环境中研究其来源，化学成分，反应性和功能的dom是什么。海洋多龙起源于海洋初级生产，但是只有一小部分被识别为普通分子。 我的研究计划旨在阐明海洋生态系统中溶解有机物的组成和动态。在接下来的五年中，我计划继续进行有关DOM骑自行车和动态的研究计划，在高度分层的北极加拿大盆地中。具体而言，主要目标是：1）将海洋DOM的荧光特性与可识别分子联系起来。与平行因子分析相关的激发发射矩阵光谱（EEM-PARAFAC）已应用于获得有关蛋白质样和腐殖质状DOM的分布和动力学的见解，但仍然缺乏将Parafac成分与分子表征分子联系起来的直接证据。同时测定荧光组成，木质素苯酚，碳水化合物和氨基酸将用于研究特定的荧光成分与可识别分子之间的关系。 2）评估DOM的难治性。将在加拿大海岸警卫队破冰船上进行中验实验，以评估DOM的散装和分子组成如何随时间变化，并随着细菌分类法的变化而变化。我们的研究旨在阐明黑界有机生物地球化学，这对于了解全球海洋中DOM的循环至关重要。 3）研究北极海洋中DOM的季节动态。来自原位荧光DOM传感器的高频测量将在空间和季节性上扩展我们的观察结果。 DOM荧光的时间变化将与分层，生物活性，矿化和冰盖的变化有关。 该研究计划将允许更好地了解海水中DOM的组成，来源和动态。参与该计划的19 HQP还将有独特的机会在发生快速环境变化的加拿大北极工作。该项目中获得的技能和知识，包括尖端的分析技术，北极经验以及跨文化和领导能力在学术界，政府或工业的职业中都是无价的。