Subinertial variability across and around the Greenland-Scotland Ridge and its impacts on the ocean circulation

格陵兰-苏格兰海岭及其周围的亚惯性变率及其对海洋环流的影响

• 批准号: 2148838
• 负责人: Thomas Haine
• 金额: $ 28.96万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148838&HistoricalAwards=false
• 关键词: Subinertial; variability; across; around; Greenland

This project will examine Greenland-Scotland Ridge (GSR) circulation, where northward-flowing warm and saline surface currents meet southward-flowing dense overflows and Arctic outflows, to quantify the relative importance of subinertial variability (with periods of days to tens of days) compared to the time-average flow in a series of high-resolution realistic numerical model simulations. The work will quantify the impact of subinertial variability on (1) cross-ridge volume transports to and from the deep ocean basins on either side of the GSR; (2) cross-frontal water mass exchange; and (3) cross-shelfbreak volume transport on and off the shallow continental shelves. The first GSR-wide estimates of volume, heat, and salt fluxes across continental shelfbreaks along the ridge (the Greenland, Iceland, Faroe, and Scottish shelves) will be provided, including their spatial and temporal variability. Project outcomes will provide fundamental understanding of the nature and importance of GSR variability, which plays a key role in the global climate system and inform potential observing strategies. Further broader impacts include support of an early-career female PI and train an undergraduate student to gain practical research experience. Hypotheses that subinertial variability exceeds seasonal and superinertial variability in channels, along the GSR, and around the Iceland and the Faroes (excepting tides close to coastal margins) and that it may dominate the time-mean flow in some places on the GSR will be tested by addressing several objectives. These include characterizing subinertial current, sea surface height and isopycnal displacement variability; quantifying how such variability impacts the cross-ridge volume transport; characterizing the spatial structures and scales associated with high-transport events, and how water mass properties are modified due to cross-frontal heat and salt fluxes; and quantifying how subinertial variability impacts the cross-shelfbreak volume transport. Based on these findings, an observational strategy will be recommended to capture the subinertial variability where it is important to the mean flow. Tools to be used include three existing one-year-long hydrostatic simulations from regional ocean-sea ice configurations of the Massachusetts Institute of Technology general circulation model (MITgcm), which have been shown to realistically represent the regional ocean properties and dynamics. An offline particle tracking tool for Lagrangian analyses (developed by the PIs) will be used, which employs a trapezoidal solver with a predictor-corrector scheme, and uses the full four-dimensional velocity fields to calculate particle trajectories. Publicly-available data sets will be used for a model-data comparison. Goals are to quantify the realism of the numerical simulations and estimate bias, and to elucidate the complementary information in sparse, intermittent observations and inaccurate simulations. Products to be used include hydrographic profiles, mooring timeseries, glider datasets , and gridded and along-track altimetry data products. If quality-controlled high resolution satellite altimetry from the planned Surface Water and Ocean Topography (SWOT) mission are released within the duration of this project, they will also be utilized.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.

该项目将检查格陵兰 - 苏格兰山脊（GSR）循环，在该循环中，向南流动的温暖和盐水表面电流与向南流动的浓密溢出和北极流出相比，以量化与一系列高固定型现实模型相比，量化亚文化变异性（与几天之间的时期与数天之间的时期与数天之间）相对的相对重要性。这项工作将量化亚守则变异性对（1）跨托体积的影响，从GSR两侧的深海盆地往返（1）。 （2）跨额外的水质量交换； （3）跨货架销售在浅陆上货架上的跨货架量运输。将提供沿山脊（格陵兰，冰岛，法罗和苏格兰货架）跨大陆货架破裂的首个GSR范围估计，包括它们的空间和时间变化。项目成果将提供对GSR变异性的性质和重要性的基本理解，该变异性在全球气候系统中起着关键作用，并为潜在的观察策略提供了信息。进一步的更广泛的影响包括支持早期女性PI和培训本科生以获得实践研究经验。假设近乎范围的可变性超过了通道，沿GSR以及冰岛和法鲁斯周围的季节性和超级差异性（除了接近沿海边缘的潮汐除外），并且可以通过解决多个目标来测试GSR上某些地方的时间平流。其中包括表征下电流，海面高度和等距位移变异性；量化这种可变性如何影响交叉跨距离运输；表征与高传输事件相关的空间结构和尺度，以及如何由于跨额外的热量和盐通量而改变水质量；并量化下部变异性如何影响跨货架量的运输。基于这些发现，将建议采用观察策略来捕获对平均流量很重要的次允许变异性。要使用的工具包括来自马萨诸塞州理工学院一般循环模型（MITGCM）的三年一年的一年静水压模拟（MITGCM），这些模拟已被证明在现实地代表了区域海洋性能和动态。将使用用于拉格朗日分析的离线粒子跟踪工具（由PIS开发），该工具采用了带有预测器 - 校正方案的梯形求解器，并使用完整的四维速度场来计算粒子轨迹。公共可用数据集将用于模型数据比较。目标是量化数值模拟的现实主义并估计偏见，并阐明稀疏，间歇性观察和不准确的模拟中的互补信息。要使用的产品包括水文剖面，系泊时间，滑翔机数据集以及网格及沿Track Altimetry数据产品。如果在该项目的期限内发布了计划中的地表水和海洋地形（SWOT）任务的质量控制的高分辨率卫星高度测定，也将被利用。该奖项反映了NSF的法定任务，并认为通过基金会的知识分子和更广泛的影响审查Criteria，它被认为是值得通过评估的支持。

项目成果

Interaction of a Kelvin wave with one or two hydraulically controlled sill flows in idealized simulations

理想模拟中开尔文波与一个或两个液压控制的基台流的相互作用

• 发表时间: 2024
• 期刊: Ocean Sciences Meeting
• 作者: Oceane Richet, Renske Gelderloos