River influences on air-sea exchange of CO2 and carbon system dynamics in Canadian subarctic coastal waters

河流对加拿大亚北极沿海水域二氧化碳海气交换和碳系统动态的影响

• 批准号: RGPIN-2019-06736
• 负责人: Papakyriakou, Timothy
• 金额: $ 2.19万
• 依托单位: University of Manitoba
• 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=753240
• 关键词: River; influences; air; sea; exchange

The Arctic Ocean plays a disproportionally large role in the uptake of atmospheric CO2. This is due in part to the high CO2 solubility in its cold waters, and physical and biological processes associated with an expansive ocean area underlain by continental shelf. The Arctic Ocean is losing sea ice and is freshening through the combination of increased sea melt and river inflow. We are uncertain as to how these changes will impact the ocean's role as a strong CO2 sink. The Arctic Ocean receives an enormous amount of freshwater and carbon (both organic and inorganic) from rivers and the carbon delivery has a very strong influence on regional carbon cycles. This is because much the organic carbon received from rivers is converted to CO2 (CO2 partial pressure, pCO2w) by biological processes.  River water in the marine system also has the tendency to reduce the seawater's pH and increase in the water's solubility for calcium carbonate. It does this because it has a lower total alkalinity (TA), or buffering capacity. As the solubility increases in water, the saturation state (O) for the calcium carbonate decreases. The combination of these processes (lower pH and lower saturation state) leads to ocean acidification (OA). Many organisms produce types of calcium carbonate for shells and skeletons, and if the seawater becomes undersaturated in calcium carbonate, it will be more difficult for the organisms to produce shells, and/or their shells can dissolve. Hence intensifying ocean acidification can negatively impact the marine ecosystem. The underlying thread of my research is to understand the carbon cycle of coastal waters in the Canadian Arctic. The research that I propose has three objectives, namely: (i) Understand how, and the extent to which pCO2w, DIC, TA, and O evolve in estuaries from river to ocean; (ii) Characterize spatial patterns in the air-sea CO2 flux and OA within a shelf sea and understand what physical and biological processes contributed to the observed variability; (iii) Develop parameterizations for pCO2w, DIC, TA that are shown to be suitable for application in biogeochemical models for coastal waters. Research will be conducted in Hudson and James Bay (hereafter HBC), and will involve the sampling of water in rivers, along estuaries and in the adjacent coast ocean. Water samples will be analysed for  water carbon chemistry. The program will provide opportunity for 6 students, 3 PhD, and 3 MSc students. Research associated with my objectives will allow my students and I to quantify the role of rivers on contemporary and future inorganic carbon systems of the HBC, including its CO2 source/sink and status and progression of OA. Because of its potential impacts on marine ecosystem, OA represents a potential threat to food security. Information resulting from this program will be invaluable to federal and provincial policy-makers, as well as territorial and co-management bodies.

北冰洋在吸收大气中的二氧化碳方面发挥着不成比例的巨大作用，部分原因是二氧化碳在其冷水中的溶解度很高，以及与大陆架下方广阔的海洋区域相关的物理和生物过程。由于海洋融化和河流流入的增加，海冰正在消失，我们不确定这些变化将如何影响海洋作为强大的二氧化碳汇的作用。北冰洋吸收了大量的淡水和碳（均为有机物）。来自河流的碳输送对区域碳循环具有非常大的影响，这是因为从河流接收的大部分有机碳通过海洋系统中的生物过程转化为二氧化碳（CO2 分压，pCO2w）。还具有降低海水 pH 值并增加水中碳酸钙溶解度的趋势，因为它的总碱度 (TA) 或缓冲能力随着溶解度的增加而降低。水，碳酸钙的饱和状态 (O) 降低，这些过程的结合（较低的 pH 值和较低的饱和状态）导致海洋酸化 (OA)，许多生物体会产生用于贝壳和骨骼的碳酸钙。海水中的碳酸钙变得不饱和，生物体将更难产生贝壳，并且/或者它们的贝壳会溶解，因此，海洋酸化的加剧会对海洋生态系统产生负面影响。的我提出的研究有三个目标，即：(i) 了解 pCO2w、DIC、TA 和 O 在河口从河流到海洋的演化过程和程度；(ii) 表征空间特征； (iii) 开发 pCO2w、DIC、TA 的参数化，这些参数被证明适用于沿海水域的生物地球化学模型。研究将在哈德逊湾和詹姆斯湾（以下简称 HBC）进行，将对河流、河口和邻近海岸海洋中的水进行采样，以进行水碳化学分析。该项目将为 6 名学生、3 名博士生和 3 名硕士生提供机会，与我的目标相关的研究将使我和我的学生能够量化河流对 HBC 当代和未来无机碳系统的作用，包括其二氧化碳源/汇以及 OA 的状况和进展 由于其对海洋生态系统的潜在影响，因此该计划产生的信息对于联邦和省级决策者以及地区而言非常宝贵。和共同管理机构。