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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716368
• 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 () 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 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CO2方面发挥着巨大的作用。这部分是由于二氧化碳在其寒冷的沃茨中的高溶解度，以及与大陆架下面的广阔海洋区域有关的物理和生物过程。北冰洋正在失去海冰，并通过增加海水融化和河流流入的结合而变得清新。我们不确定这些变化将如何影响海洋作为一个强大的二氧化碳汇的作用。北冰洋从河流中接收了大量的淡水和碳（有机和无机），碳的输送对区域碳循环有很大的影响。这是因为从河流中接收的大部分有机碳通过生物过程转化为CO2（CO2分压，pCO 2 w）。 海洋系统中的河水也有降低海水pH值和增加碳酸钙在水中溶解度的趋势。这是因为它具有较低的总碱度（TA）或缓冲能力。随着在水中的溶解度增加，碳酸钙的饱和状态（）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）。许多生物体产生用于壳和骨骼的碳酸钙类型，并且如果海水中碳酸钙变得不饱和，则生物体将更难以产生壳，和/或它们的壳可以溶解。因此，海洋酸化加剧会对海洋生态系统产生负面影响。 我研究的基本思路是了解加拿大北极地区沿海沃茨的碳循环。 我建议的研究有三个目标，即： (i)了解pCO 2 w、DIC、TA和从河流到海洋的河口的演变方式和程度; (ii)描述陆棚海海气CO2通量和OA的空间模式，并了解哪些物理和生物过程导致了观察到的变异性;（iii）开发pCO 2 w、DIC、TA的参数化，这些参数化被证明适合应用于沿海水域的生物地球化学模型。沃茨。 研究将在哈德逊和詹姆斯湾（以下简称哈得逊湾）进行，并将包括对河流、沿着河口和邻近海岸的海水进行取样。 将对水样进行水碳化学分析。 该计划将为6名学生，3名博士和3名硕士学生提供机会。 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CO2源/汇以及OA的现状和进展。由于其对海洋生态系统的潜在影响，有机农业对粮食安全构成潜在威胁。该方案产生的信息对联邦和省级决策者以及地区和共同管理机构都是非常宝贵的。