Collaborative Research: Overturning in the Subpolar North Atlantic Program

合作研究：北大西洋次极地计划的颠覆

• 批准号: 1948198
• 负责人: William Johns
• 金额: $ 228.32万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing 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=1948198&HistoricalAwards=false
• 关键词: Collaborative; Research; Overturning; Subpolar; North

A US-led international effort, Overturning in the Subpolar North Atlantic Program (OSNAP), has provided a continuous record of the full-water column, trans-basin fluxes of heat, mass, and freshwater in the subpolar North Atlantic since 2014, in partnership with the UK, Netherlands, Canada and Germany. Results from the first four years of OSNAP observations have challenged the current understanding of overturning circulation in the subpolar North Atlantic. This grant provides funding for an additional four years of observations in order to deliver to the community a ten-year time series of the meridional overturning, heat and freshwater fluxes in the subpolar basin. Variations in these quantities have been invoked to explain changes in a wide range of physical, chemical and biological parameters in the North Atlantic, Nordic Seas, and Arctic Ocean. Thus, by quantifying Atlantic meridional overturning variability and understanding its drivers, OSNAP is providing a critical first step towards addressing societally-relevant, interdisciplinary questions concerning the melting of Greenland ice and Arctic sea-ice, heat content in the Arctic Ocean, climate of the Nordic Seas, and anthropogenic carbon storage. The researchers will actively engage the broader international communities through four workshops, each targeting a societally relevant theme: 1) ocean biogeochemistry and carbon sequestration; 2) overturning in ocean models; 3) Arctic cryosphere; and 4) Nordic Seas variability. Two new postdocs and one graduate student will be supported in this phase of OSNAP and will benefit from the diversity of methodologies and exposure to the large number of OSNAP international scientists. In addition, approximately 20 graduate students from different US and international institutions will receive field training through participation in OSNAP cruises through 2024.The first four years of data from the OSNAP observing system have shown that the eastern subpolar region, from Greenland to Scotland, dominates the mean meridional mass and heat transport in the subpolar North Atlantic, while more than half of the total meridional freshwater transport occurs across the Labrador basin. Based on the success of the previous work, this project extends the time series and address the following critical questions: 1. What governs overturning variability in the North Atlantic subpolar gyre on intra-seasonal to interannual time scales? 2. What are the sources of freshwater across the OSNAP section and what governs their variability? 3. What are the impacts of the meridional heat and freshwater fluxes in the subpolar gyre? Additional motivation for this next phase of OSNAP is provided by the fundamental advancements in our understanding of subpolar North Atlantic dynamics and variability, that will result from the four main U.S. OSNAP mooring arrays, individually and in combination with other OSNAP observations. Further observations are expected to provide a strong observational basis for a new paradigm of overturning in this region, which will include an understanding of the linkage between dense water formation and overturning - a connection present in climate models, yet unobserved to date. Additionally, this this work will further quantify the structure and transport of the upper and deep ocean boundary currents off the east and west coasts of Greenland and within the Iceland Basin, as well as determine their variability and forcing mechanisms.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.

自2014年以来，由美国领导的国际努力--在亚极地北大西洋计划(OSNAP)中颠覆--与英国、荷兰、加拿大和德国合作，提供了亚极地北大西洋全水柱、跨盆地热通量、质量通量和淡水通量的连续记录。OSNAP头四年的观测结果挑战了目前对北大西洋次极地环流颠倒的理解。这笔赠款为另外四年的观测提供资金，以便向社区提供亚极地盆地经向翻转、热量和淡水通量的十年时间序列。这些数量的变化被用来解释北大西洋、北欧海和北冰洋一系列物理、化学和生物参数的变化。因此，通过对大西洋经向翻转变率进行量化并了解其驱动因素，南大西洋气候行动方案正在为解决格陵兰冰和北冰洋海冰融化、北冰洋的热含量、北欧海的气候和人为碳储存等具有社会意义的跨学科问题迈出关键的第一步。研究人员将通过四个研讨会积极参与更广泛的国际社会，每个研讨会都针对一个具有社会意义的主题：1)海洋生物地球化学和碳封存；2)海洋模型的颠覆；3)北极冰冻圈；以及4)北欧海洋的多变性。两名新的博士后和一名研究生将在OSNAP的这一阶段得到支持，并将受益于方法的多样性和接触到OSNAP的大量国际科学家。此外，来自不同美国和国际机构的约20名研究生将通过参加到2024年的OSNAP巡航接受实地培训。OSNAP观测系统的头四年数据显示，从格陵兰到苏格兰的东部亚极区主导着北极区北大西洋的平均经向质量和热量输送，而超过一半的经向淡水输送发生在拉布拉多盆地。在前人工作的基础上，本项目扩展了时间序列，并解决了以下关键问题：1.在季节内到年际时间尺度上，是什么控制了北大西洋亚极涡旋的倾覆变化？2.OSNAP断面的淡水来源是什么，是什么控制了它们的变化？3.亚极涡旋中经向热量和淡水通量的影响是什么？OSNAP下一阶段的其他动力来自于我们对北大西洋亚极动态和可变性的基本了解的进步，这些进步将来自美国四个主要的OSnap系泊阵列，分别和与OSNAP的其他观测相结合。进一步的观测预计将为该区域新的倾覆模式提供强有力的观测基础，其中将包括了解密水形成和倾覆之间的联系--气候模型中存在这种联系，但迄今尚未观察到这种联系。此外，这项工作将进一步量化格陵兰东西海岸和冰岛盆地内上层和深海边界流的结构和输送，并确定它们的可变性和强迫机制。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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

Climate-Relevant Ocean Transport Measurements in the Atlantic and Arctic Oceans

大西洋和北冰洋与气候相关的海洋运输测量

• DOI: 10.5670/oceanog.2021.supplement.02-04
• 发表时间: 2021
• 期刊: Oceanography
• 影响因子: 2.8
• 作者: Berx, Barbara;Volkov, Denis;Baehr, Johanna;Baringer, Molly;Brandt, Peter;Burmeister, Kristin;Cunningham, Stuart;de Jong, Marieke;de Steur, Laura;Dong, Shenfu
• 通讯作者: Dong, Shenfu

Circulation and overturning in the eastern North Atlantic subpolar gyre

北大西洋东部副极地环流的环流和翻转

• DOI: 10.1016/j.pocean.2022.102884
• 发表时间: 2022
• 期刊: Progress in Oceanography
• 影响因子: 4.1
• 作者: Koman, G.;Johns, W.E.;Houk, A.;Houpert, L.;Li, F.
• 通讯作者: Li, F.

Transport and Evolution of the East Reykjanes Ridge Current

东雷克雅内斯海岭洋流的输送和演化

• DOI: 10.1029/2020jc016377
• 发表时间: 2020
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Koman, G.;Johns, W. E.;Houk, A.
• 通讯作者: Houk, A.

Rapid Freshening of Iceland Scotland Overflow Water Driven by Entrainment of a Major Upper Ocean Salinity Anomaly

受上层海洋盐度异常影响，冰岛苏格兰溢流水迅速清新

• DOI: 10.1029/2021gl094396
• 发表时间: 2021
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Devana, Manish S.;Johns, William E.;Houk, Adam;Zou, Sijia
• 通讯作者: Zou, Sijia

Moored Observations of the Iceland‐Scotland Overflow Plume Along the Eastern Flank of the Reykjanes Ridge

沿雷克雅内斯山脊东侧停泊的冰岛-苏格兰溢流羽流观测

• DOI: 10.1029/2021jc017524
• 发表时间: 2021
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Johns, W. E.;Devana, M.;Houk, A.;Zou, S.
• 通讯作者: Zou, S.