Collaborative Research: Enhancing our Understanding of North Atlantic Deep Water Pathways using Nonlinear Dynamics Techniques

合作研究：利用非线性动力学技术增强我们对北大西洋深水路径的理解

• 批准号: 1851097
• 负责人: Francisco Beron-Vera
• 金额: $ 39.96万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1851097&HistoricalAwards=false
• 关键词: Collaborative; Research; Enhancing; our; Understanding

For most of the last century, the equatorward spread of cold water masses from high latitudes in the Labrador and Nordic Seas was expected to be largely contained along the Deep Western Boundary Current in the subpolar and subtropical North Atlantic. Since the turn of this century, observational floats launched within these water masses have defied this expectation. Instead, myriad interior pathways have been revealed across the North Atlantic. Contemporaneously, an inventory of anthropogenic carbon dioxide has shown the subpolar North Atlantic to be the most intense (per unit area) sink of all ocean basins, a characteristic attributable to the deep penetration of newly-formed water masses in that basin. While the deep limb of the Atlantic Meridional Overturning Circulation has long been appreciated as a heat and freshwater reservoir, its role as a carbon reservoir is now apparent. Thus, at a time when the conventional understanding of these deep water mass pathways has been upended, there is a stronger reason than ever to understand the spread and fate of these water masses. Over the past decade, simulated float trajectories have augmented the relatively small number of observational floats in the North Atlantic in order to gain a broader understanding of water mass pathways. However, analyses of the observed and modeled trajectories have largely used conventional methods to ascertain a limited number of flow characteristics. This study will capitalize on recent advances in nonlinear dynamics in order to provide a more comprehensive description and understanding of these water masses and flows limited observations. Thus, by using these tools to unravel deep water pathways, this project will aid our understanding of the North Atlantic as a deep carbon reservoir, and thereby have a significant societal impact. Broader impacts with this proposed work also include the training of a postdoctoral researcher to facilitate an independent research career and the training of a physical oceanography student in the use of nonlinear dynamical tools. This project will address a fundamental question in modern physical oceanography through the use of two complementary tools emerging at the interface of nonlinear dynamics and fluid dynamics. Probabilistic tools will be used to cast new light on the transformation and fate of the deep waters through the construction of Lagrangian geographies that constrain connectivity, residence times within water mass provinces, preferred circulation pathways, transit times along these pathways, and transport across province boundaries. Deterministic tools that have recently proven efficient at extracting persistent transport pathways will also be used to delineate preferred transport pathways, and thus will be used to frame deep water routes. This offers a promising fertilization of nonlinear dynamical tools into a traditional physical oceanographic area of study. Specifically, this work will apply dynamical systems tools to: 1) determine the long-term fate and elucidate the preferred pathways of the deep water masses; 2) ascertain the extent to which potential vorticity conservation or other dynamics constrains these pathways; and 3) identify spatial provinces (domains) that define water mass residence and evaluate exchanges among them. The small, but growing number of observational floats, including those recently recovered from the Overturning in the Subpolar North Atlantic Program (OSNAP), as well as Argo data and simulated float trajectories from ocean general circulation models, will be used in this analysis.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.

在上个世纪的大部分时间里，拉布拉多海和北欧海高纬度冷水团向赤道的扩散预计将在很大程度上被沿着副极地和亚热带北大西洋的深层西边界流所控制。自本世纪之交以来，在这些水体中发射的观测浮标违背了这一期望。相反，无数的内部路径已经在北大西洋被揭示出来。与此同时，一份人类活动产生的二氧化碳清单表明，北大西洋亚极地是所有海洋盆地中（单位面积）最密集的汇，这一特点可归因于该盆地新形成的水团的深度渗透。虽然大西洋经向翻转环流的深支长期以来一直被认为是热量和淡水的储存库，但它作为碳储存库的作用现在已经很明显了。因此，在对这些深水团路径的传统理解被颠覆的时候，有一个比以往任何时候都更强的理由来理解这些水团的传播和命运。在过去十年中，模拟浮子轨迹增加了北大西洋相对较少的观测浮子，以便更广泛地了解水团路径。然而，观察到的和模拟的轨迹的分析主要使用传统的方法来确定有限数量的流动特性。这项研究将利用非线性动力学的最新进展，以提供更全面的描述和了解这些水团和流动有限的观测。因此，通过使用这些工具来解开深水路径，该项目将有助于我们了解北大西洋作为一个深层碳库，从而产生重大的社会影响。这项拟议工作的更广泛影响还包括培训一名博士后研究人员，以促进独立的研究生涯，以及培训一名物理海洋学学生使用非线性动力学工具。该项目将通过使用非线性动力学和流体动力学界面上出现的两种互补工具来解决现代物理海洋学中的一个基本问题。概率工具将被用来投下新的光的改造和命运的深沃茨，通过建设拉格朗日地理约束连接，停留时间内的水团省，首选的流通途径，过境时间沿着这些途径，并跨省界运输。最近被证明在提取持久性迁移途径方面有效的确定性工具也将被用来描绘首选迁移途径，从而将被用来确定深水路线。这为传统的物理海洋学研究领域提供了一个有前途的非线性动力学工具。具体而言，这项工作将应用动力系统工具：1）确定长期的命运，并阐明深水质量的首选路径; 2）确定在何种程度上的潜在涡度守恒或其他动力学约束这些路径;和3）确定空间省（域），定义水团居住和评估它们之间的交换。观测浮标的数量虽小，但越来越多，包括最近从北大西洋副极地翻转计划（OSNAP）中恢复的浮标，以及Argo数据和海洋环流模型模拟的浮标轨迹，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

项目成果

Transition paths of North Atlantic Deep Water

北大西洋深水的过渡路径

• DOI: 10.1175/jtech-d-22-0022.1
• 发表时间: 2022
• 期刊: Journal of Atmospheric and Oceanic Technology
• 影响因子: 2.2
• 作者: Miron, P.;Beron-Vera, F. J.;Olascoaga, M. J.
• 通讯作者: Olascoaga, M. J.

Transition paths of marine debris and the stability of the garbage patches

海洋垃圾迁移路径与垃圾带稳定性

• DOI: 10.1063/5.0030535
• 发表时间: 2021
• 期刊: Chaos: An Interdisciplinary Journal of Nonlinear Science
• 作者: Miron, P.;Beron-Vera, F. J.;Helfmann, L.;Koltai, P.
• 通讯作者: Koltai, P.

Surface Pathways Connecting the South and North Atlantic Oceans

连接南大西洋和北大西洋的地表通道

• DOI: 10.1029/2021gl096646
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Drouin, Kimberley L.;Lozier, M. Susan;Beron‐Vera, Francisco J.;Miron, Philippe;Olascoaga, Maria J.
• 通讯作者: Olascoaga, Maria J.

Sampling-Dependent Transition Paths of Iceland–Scotland Overflow Water

冰岛-苏格兰溢流水的采样相关转变路径

• DOI: 10.1175/jpo-d-22-0172.1
• 发表时间: 2023
• 期刊: Journal of Physical Oceanography
• 影响因子: 3.5
• 作者: Beron-Vera, F. J.;Olascoaga, M. J.;Helfmann, L.;Miron, P.
• 通讯作者: Miron, P.