Collaborative Research: Gases in the Overturning and Horizontal circulation of the Subpolar North Atlantic Program (GOHSNAP)

合作研究：副极地北大西洋计划翻转和水平环流中的气体（GOHSNAP）

• 批准号: 1947567
• 负责人: David Nicholson
• 金额: $ 28.38万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-15 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1947567&HistoricalAwards=false
• 关键词: Collaborative; Research; Gases; Overturning; Horizontal

Every winter, frigid winds blowing eastward from the North American continent cool the surface waters of the Labrador Sea, which is situated between Canada and Greenland. As the ocean cools, oxygen and carbon dioxide are mixed from the atmosphere into a thick layer of water that ultimately spreads southward to fill a large volume of the North Atlantic and beyond. The presence of this water mass prevents the North Atlantic anywhere from becoming completely devoid of oxygen. Vertical mixing in the Labrador Sea also redistributes carbon dioxide into the deep ocean, where it can remain for hundreds of years, preventing it from contributing to the greenhouse effect. Yet, the processes governing the uptake of gases by the ocean are not well understood or quantified. Given that, over the last century, the ocean has become steadily more depleted in oxygen while also absorbing a large fraction of anthropogenic carbon dioxide, observing gas exchange processes is essential for understanding and predicting the evolution of the ocean and climate system. The circulation of the Labrador Sea has been monitored since 2014 with an array of instrumented cables extending from the seafloor to nearly the ocean surface. This project adds gas sensors to this array to investigate the rates and processes governing gas exchange. Through this project, a student and postdoc will be trained in interdisciplinary oceanography with a rich network of international collaborators. Responding to the need to increase public ocean literacy, the project scientists will work with University of Rhode Island’s Inner Space Center to broadcast live, interactive science sessions to educators at partner high schools and will follow-up with in-person science cafés at three participating schools.Given the unique role of the Labrador Sea in providing a pathway for oxygen (O2) and carbon dioxide (CO2) to enter the intermediate depths of the ocean, a quantification and mechanistic understanding of the gas uptake and transport in the basin is a leading scientific priority. Oxygenation of Labrador Sea water prevents large-scale hypoxia from developing anywhere in the Atlantic Ocean and anthropogenic CO2 storage in the basin is the highest in the global ocean. The assumption that, in the Atlantic Ocean, O2 and CO2 uptake and their variability are tied to the dynamics of heat loss and the overturning circulation pervades the literature but has never been evaluated on the basis of direct observations. Thus, GOHSNAP (Gases in the Overturning and Horizontal circulation of the Subpolar North Atlantic Program) addresses this gap and the urgent need to better understand interactions between gas uptake, transport, and the overturning circulation. Specifically, this program will provide a continuous 2-year record of the trans-basin, full water column transport of O2 across the southern boundary of the Labrador Sea, leveraging the mooring infrastructure of the US-lead, international Overturning in the Subpolar North Atlantic Program (OSNAP). The addition of O2 sensors at various depths on this array, supplemented by observations collected by autonomous platforms will allow for the quantification of O2 export from the Labrador Sea. The data will further be used to empirically model carbon concentrations and estimate carbon export. Proposed instruments will also measure the mixed layer O2 and pCO2 for two winters, from which air-sea gas exchange will be calculated and compared against analogous observations in the convective interior of the Labrador Sea.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

每年冬天，从北美大陆向东吹来的寒风都会使位于加拿大和格陵兰岛之间的拉布拉多海的表层海水冷却。随着海洋变冷，氧气和二氧化碳从大气中混合成一层厚厚的水层。最终向南扩散，充满了北大西洋及其以外的大部分地区。这种水团的存在可以防止北大西洋任何地方完全缺乏氧气，拉布拉多海的垂直混合也可以将二氧化碳重新分配到深处。它可以在海洋中停留数百年，从而避免造成温室效应。然而，鉴于在上个世纪，海洋吸收气体的过程尚未得到充分了解或量化。氧气变得更加贫乏，同时还吸收了大量人为二氧化碳，观察气体交换过程对于了解和预测海洋和气候系统的演变至关重要 自 2014 年以来，人们一直在通过一系列监测拉布拉多海的环流。仪表化的该项目将气体传感器添加到该阵列中，以研究控制气体交换的速率和过程。通过该项目，学生和博士后将在丰富的国际合作者网络中接受跨学科海洋学的培训。为了满足提高公众海洋素养的需要，该项目的科学家将与罗德岛大学内太空中心合作，向合作伙伴高中的教育工作者直播互动科学课程，并将在三个参与项目的科学咖啡馆进行后续活动。学校。鉴于拉布拉多海在为氧气 (O2) 和二氧化碳 (CO2) 进入海洋中层深度提供通道方面发挥着独特作用，对盆地内气体吸收和输送的量化和机械理解是一项领先的科学优先事项拉布拉多海水的氧化可以防止大西洋任何地方发生大规模缺氧，并且该盆地的人为二氧化碳储存量是全球海洋中最高的。它们的变化与热损失的动态有关，翻转环流遍布文献，但从未根据直接观测进行评估，因此，GOHSNAP（北大西洋副极地翻转和水平环流中的气体）解决了这个问题。具体来说，该计划将提供跨越南部边界的跨盆地、全水柱输送的连续 2 年记录。拉布拉多海，利用美国主导的国际北大西洋次极翻转计划（OSNAP）的系泊基础设施，在该阵列的不同深度添加氧气传感器，并辅以自主平台收集的观测数据，将允许拉布拉多海 O2 输出的量化 该数据将进一步用于实证模拟碳浓度并估计碳输出，拟议的仪器还将测量两个冬季的混合层 O2 和 pCO2。将计算海气气体交换，并与拉布拉多海对流内部的类似观测结果进行比较。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Linking Oxygen and Carbon Uptake with the Meridional Overturning Circulation Using a Transport Mooring Array

使用运输系泊阵列将氧气和碳吸收与经向翻转循环联系起来

• DOI: 10.5670/oceanog.2021.supplement.02-03
• 发表时间: 2022-01
• 期刊: Oceanography
• 影响因子: 2.8
• 作者: Atamanchuk, Dariia;Palter, Jaime;Palevsky, Hilary;Le Bras, Isabela;Koelling, Jannes;Nicholson, David
• 通讯作者: Nicholson, David