SAVI: Collaborative Research: Overturning in the Subpolar North Atlantic - Labrador Basin and Floats

SAVI：合作研究：北大西洋副极地的翻转 - 拉布拉多盆地和浮体

• 批准号: 2017520
• 负责人: Susan Lozier
• 金额: $ 7.3万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2017520&HistoricalAwards=false
• 关键词: SAVI; Collaborative; Research; Overturning; Subpolar

This project is one of two components of a US-led international program, Overturning in the Sub-polar North Atlantic (OSNAP), designed to provide a continuous record of the full-water column, trans-basin fluxes of heat, mass and freshwater in the subpolar North Atlantic. The OSNAP observing system consists of two legs: one extending from southern Labrador to the southwestern tip of Greenland across the mouth of the Labrador Sea (OSNAP West), and the second from the southeastern tip of Greenland to Scotland (OSNAP East). The observing system also includes subsurface floats (OSNAP Floats) in order to trace the pathways of overflow waters in the basin and to assess the connectivity of currents crossing the OSNAP line. The location of the OSNAP East and West legs purposefully melds with a number of long-term observational efforts in the North Atlantic: the Canadian repeat hydrography program in the Labrador Sea; the German Labrador Sea western boundary array at 53°N; the global Ocean Observatories Initiative node to be placed in the southwestern Irminger Sea; the repeat hydrographic sections across the Irminger and Iceland basins; and the Ellett line in the Rockall region. Substantial international collaboration has been garnered for OSNAP, including measurement contributions from the UK, Germany, the Netherlands and Canada. Importantly, this proposed observing system, in conjunction with the RAPID/MOCHA array at 26°N and the European Union NACLIM program at Nordic Seas overflows, will provide the first comprehensive three-dimensional measure of the Atlantic Meridional Overturning Circulation (AMOC) and provide a means to evaluate inter-gyre connectivity in the North Atlantic. This collaborative project will implement the OSNAP West section and the OSNAP Float program. The primary observational components are: (i) a mooring array across the eastern margin of the Labrador Sea, where the subpolar boundary current enters the basin. This array will complement an analogous array across the western margin at the exit point of the Labrador Sea, maintained by institutions in Germany and Canada; (ii) a sequential release of acoustically tracked floats in the lower limb of the AMOC at the OSNAP East and OSNAP West boundary arrays. These floats will be seeded in the two densest components of North Atlantic Deep Water (NADW) over the four-year period of the measurement program (2014-2018).Intellectual Merit: For decades oceanographers have understood the AMOC to be highly susceptible to changes in the production of NADW. However, a number of recent observational and modeling studies have called into question this supposition, as more has been learned about the role of wind forcing in AMOC variability. Thus, the overall goal of this project is to establish an observing system that will determine the role that intermediate and deep water mass formation and basin-scale wind forcing play in the overturning and associated poleward heat transport, assessments that currently have only been theorized and modeled, but not observed.Broader Impact: In January of 2007, the US Joint Subcommittee on Ocean Science and Technology identified the study of the AMOC as one of four near-term priorities in the US Ocean Research Priorities Plan. This proposed work directly addresses that priority via a design of an AMOC observing system in the sub-polar North Atlantic. While a primary motivation for studying AMOC variability comes from its potential impact on the climate system, additional motivation for the measure of the heat, mass and freshwater fluxes in the sub-polar North Atlantic arises from their potential impact on marine biogeochemistry and the cryosphere. There is growing evidence that the ocean has played (and is playing) a role in the reduction of Arctic sea ice and in mass loss from the Greenland Ice Sheet - both of which have been attributed to changes in the poleward heat transport by the ocean. Also, the ocean plays an essential role in the carbon cycle by moderating increasing atmospheric concentrations of CO2 through the sequestration of anthropogenic carbon in the deep ocean. Variability in the AMOC is expected to impact this sequestration. Broader impacts also include the training of five graduate students in seagoing operations and in the processing and analysis of observational data. The graduate students will have an opportunity to collaborate with their international counterparts through virtual meetings and in-person visits and will be mentored by multiple advisors. This research award includes support for a Science Across Virtual Institutes (SAVI) that is co-funded by NSF's Office of International and Integrative Activities.

该项目是由美国领导的国际计划的两个组成部分之一，该计划在北大西洋亚极点（OSNAP）中推翻，旨在提供全水柱的连续记录，北大西洋亚北大西洋中的热量，质量和淡水的跨层盆地通量。 OSNAP观察者系统由两条腿组成：一条从拉布拉多南部延伸到西南绿地，穿过拉布拉多海（Osnap West）的河口，第二个从格陵兰岛的东南端到苏格兰（Osnap East）。观察系统还包括地下浮子（OSNAP浮子），以追踪盆地中溢流水的途径，并评估越过OSNAP线的电流的连通性。 OSNAP东腿和西腿的位置与北大西洋上的许多长期观察工作有目的地融合：拉布拉多海的加拿大重复水文计划；德国拉布拉多海边边界阵列在53°N；全球海洋天文台倡议节点将放置在西南irminger海中；横跨Irminger和Iceland Basses的重复水文部分；还有洛克（Rockall）地区的埃莱特（Ellett）线。大量国际合作已获得OSNAP，包括来自英国，德国，荷兰和加拿大的测量贡献。重要的是，该提议的观察系统以及26°N的快速/摩卡阵列以及北欧海洋溢出的欧盟Naclim计划将提供首个对大西洋子午线倾覆循环（AMOC）的三维综合测量（AMOC），并提供了评估北部Atlyantic Inter-Gyer inter-gy neter-Gyer nelltictic nellative nellativalitive的手段。该协作项目将实施OSNAP WEST部分和OSNAP Float程序。主要的观测成分是：（i）横跨拉布拉多海的东边边缘的系泊阵列，该子极边界电流进入盆地。该阵列将补充由德国和加拿大机构维护的拉布拉多海出口处的西部边缘的类似阵列； （ii）在OSNAP东部和OSNAP西边界阵列的AMOC下肢的声学轨道浮子的顺序释放。这些浮子将在北大西洋深水（NADW）的两个年度测量计划（2014- 2018年）的两个最密集的组成部分中播种。IntlectualFulit：数十年来，海洋学家了解AMOC对NADW生产的变化非常敏感。但是，许多最近的观察和建模研究都提出了质疑，因为有关风力强迫在AMOC变异性中的作用的更多信息。这一点，该项目的总体目标是建立一个观察系统，该观察系统将确定中间和深水质量形成和盆地尺度的强力强迫在推翻和相关的极发热传输中发挥作用，目前只对其进行了理论和建模的评估，但尚未对其进行建模，但尚未观察到。公路影响：2007年1月，对海洋科学的一项研究，在2007年1月的研究中，该研究的一项是AMS COMPART的一项，即在海洋中的一项研究，该研究是在海洋中的一项，即在海洋中的一项研究，该研究是在海洋中的一项研究，该研究是在海洋中的一项，即在海洋中遇到的一项，以下方面的一项是涉及海洋科学的一项。优先计划。这项拟议的工作直接解决了通过在北大西洋亚极点观察系统设计的优先级。虽然研究AMOC变异性的主要动机来自其对气候系统的潜在影响，但北大西洋亚极点中的热，质量和淡水通量的额外动机源于其对海洋生物地球化学和冰冻圈的潜在影响。越来越多的证据表明，海洋在减少北极海冰和格陵兰冰盖的大规模损失中发挥了作用（并且正在发挥作用），这两者都归因于海洋极热传输的变化。此外，海洋通过在深海中人为碳的隔离来调节二氧化碳浓度的增加，在碳循环中起着至关重要的作用。预计AMOC的变异性会影响此隔离。更广泛的影响还包括对五名研究生进行海上运营的培训以及观察数据的处理和分析。研究生将有机会通过虚拟会议和面对面的访问与国际同行合作，并将由多个顾问考虑。该研究奖包括对NSF国际和综合活动办公室共同资助的虚拟机构（SAVI）科学的支持。