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，寒冷的风都从北美的连续吹冷却拉布拉多海的地面水，该水域位于加拿大和格陵兰岛之间。随着海洋冷却，氧气和二氧化碳从大气中混合到一层厚的水中，最终向南蔓延，以填充北大西洋及以后的大量水。这种水质量的存在阻止了北大西洋的任何地方完全没有氧气。拉布拉多海中的垂直混合也将二氧化碳重新分配到深海中，在那里可以保留数百年，从而阻止其对温室效应做出贡献。然而，对海洋吸收气体吸收的过程尚未得到充分理解或量化。鉴于上世纪，在上个世纪，海洋在氧气中的缝制程度更高，同时还吸收了大量的人为二氧化碳，观察气体交换过程对于理解和预测海洋和气候系统的演变至关重要。自2014年以来，对拉布拉多海的循环进行了监测，并从海底延伸到几乎海面的一系列仪器电缆。该项目将气体传感器添加到该阵列中，以调查有关气体交换的费率和过程。通过该项目，学生和博士后将通过富裕的国际合作者网络对跨学科海洋学进行培训。该项目科学家应对提高公共海洋素养的需求，将与罗德岛大学的内部空间中心合作，向合作伙伴高中的教育工作者进行现场直播的互动科学会议，并在三个参与学校的面对面科学咖啡馆进行跟进。赋予Labrador Sea在提供氧化型（O2）和co2 dioxiles（o2）的途径（CO2）的独特作用。对盆地中气体吸收和运输的机械理解是领先的科学优先事项。拉布拉多海水的氧合可防止大西洋中的大规模缺氧在大西洋的任何地方发展，而盆地中的人为二氧化碳存储在全球海洋中最高。在大西洋中，O2和CO2摄取及其可变性与热量流失的动力学相关，而翻倒的循环遍及文献，但从未根据直接观察进行评估。这就是GOHSNAP（北大西洋北大西洋计划的倾覆和水平循环中的气体）解决了这一差距，并且迫切需要更好地了解气体吸收，运输和倾覆圆圈之间的相互作用。具体而言，该计划将提供2年连续的2年记录，以跨巴拉多海南部边界的全面水柱运输的全面水柱运输，利用了美国领导的系泊基础设施，在北大西洋计划（OSNAP）的国际国际推翻。在此阵列上的各个深度上添加了O2传感器，并补充了由自主平台收集的观测值，将允许定量从拉布拉多海出口的O2出口。数据将进一步用于经验对碳​​浓度进行建模并估计碳出口。提议的仪器还将在两个冬季测量混合O2和PCO2，从该冬季计算出空气天然气交换并与Labrador Sea对流内部的类似观察结果进行比较。该奖项反映了NSF的法定任务，并使用该基金会的智力功能和广泛的影响来评估NSF的法定任务，并被认为是珍贵的支持。

项目成果

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

• DOI: 10.5670/oceanog.2021.supplement.02-03
• 发表时间: 2021-12-01
• 期刊: OCEANOGRAPHY
• 影响因子: 2.8
• 作者: Atamanchuk, Dariia;Palter, Jaime;Nicholson, David
• 通讯作者: Nicholson, David