NSF/GEO-NERC: Stirring at the Walls - A Dynamical Boundary Model for the Ocean

NSF/GEO-NERC：墙壁搅拌 - 海洋动态边界模型

• 批准号: 1941963
• 负责人: William Dewar
• 金额: $ 32.79万
• 依托单位: Florida State University
• 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: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1941963&HistoricalAwards=false
• 关键词: NSF; GEO; NERC; Stirring; Walls

Much of ocean circulation variability occurs over time scales of days to months and length scales of 10s to 100s of km, a range known as the 'mesoscale'. These features can feedback on the larger scales of circulation in the ocean (up to 'basin scale' - 6000 km), and are important in determining ocean circulation on interannual to decadal timescales. Yet mesoscale features require much finer grids to represent them in models than basin scale features, so their direct numerical resolution over the entire globe for the long times required in climate simulations is far beyond current computer resources. This project will use a 'Dynamical Boundary Model' (DBM) instead of high resolution grids at model boundaries. This project will first develop a DBM that can be incorporated into existing realistic global climate models. Then performance will be evaluated by comparison to models with high resolution near boundaries. Finally, the project will investigate mixing at boundaries using realistic models with the DBM implementation. The overall collaboration will support a post-doctoral fellow, a graduate student, and an undergraduate from an under-represented demographic. The work has broad social relevance, as success would represent a significant technical step forward in numerical modeling and prediction of global climate. The basic methodology is to split the ocean into separate interacting regions: an outer region that encompasses the general ocean circulation and a narrow boundary layer with different dynamics, referred to as a DBM. Mathematically, this is accomplished by the introduction of a small parameter that measures the ratio of the thin boundary layer thickness to the large horizontal scale of the ocean basin. At smaller scales, the boundary layer equation becomes a nonlinear wave equation allowing coastal waves to break, energy to be dissipated and fluid to mix at the boundary, and feeds back into the interior dynamics. To extend this work to non-idealized geometry, the equations for the boundary layer will be generalized to include coastal curvature and cross-shore depth profiles, and Kelvin waves on vertical walls will be replaced by coastal trapped waves. Once a reliable and rapid method has been derived for the boundary/interior interaction, the DBM will be inserted directly into global climate primitive equation (PE) models. Side-by-side numerical experiments using PE models with dense nested grids to explicitly resolve the boundary layer will be compared with those run at coarser resolution using the DBM. This project is jointly funded by the National Science Foundation's Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with their own country.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.

大部分的海洋环流变化发生在几天到几个月的时间尺度和10秒到100公里的长度尺度上，这一范围被称为“中尺度”。这些功能可以反馈在海洋环流的大尺度（“流域尺度”- 6000公里），并在确定海洋环流的年际到十年的时间尺度上是很重要的。然而，中尺度特征需要比流域尺度特征更精细的网格来在模型中表示它们，因此在气候模拟所需的长时间内，它们在整个地球仪上的直接数值分辨率远远超出了当前的计算机资源。这个项目将使用“动态边界模型”（DBM），而不是模型边界的高分辨率网格。该项目将首先开发一个DBM，可以纳入现有的现实全球气候模型。然后通过与边界附近具有高分辨率的模型进行比较来评估性能。最后，该项目将使用DBM实现的真实模型来研究边界处的混合。整体合作将支持一名博士后研究员，一名研究生和一名来自代表性不足的本科生。这项工作具有广泛的社会意义，因为成功将代表着全球气候数值模拟和预测的重大技术进步。 其基本方法是将海洋分割成相互作用的区域：一个包含一般海洋环流的外部区域和一个具有不同动力学的狭窄边界层，称为DBM。在数学上，这是通过引入一个小参数来实现的，该参数测量薄边界层厚度与海洋盆地的大水平尺度的比率。在较小的尺度上，边界层方程变成非线性波动方程，允许海岸波浪破碎，能量耗散，流体在边界混合，并反馈到内部动力学。为了将这项工作扩展到非理想化的几何形状，边界层的方程将被推广到包括海岸曲率和跨海岸深度剖面，垂直壁上的开尔文波将被海岸捕获波取代。一旦一个可靠的和快速的方法已经得到了边界/内部相互作用，DBM将直接插入到全球气候原始方程（PE）模式。并排数值试验使用PE模式与密集嵌套网格，明确解决边界层将与那些运行在粗糙的分辨率使用DBM进行比较。该项目由国家科学基金会地球科学理事会（NSF/GEO）和联合王国国家环境研究理事会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。一旦成功地共同确定了一个奖项，每个机构都会为与自己国家有关的预算和调查人员提供资金。这个奖项反映了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标准进行评估，被认为值得支持。

项目成果

The decay of a dipolar vortex in a weakly dispersive environment

弱色散环境中偶极涡旋的衰变

• DOI: 10.1017/jfm.2021.298
• 发表时间: 2021
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Johnson, Edward R.;Crowe, Matthew N.
• 通讯作者: Crowe, Matthew N.

Oceanic dipoles in a surface quasi-geostrophic model

表面准地转模型中的海洋偶极子

• DOI: 10.1017/jfm.2023.87
• 发表时间: 2023
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Johnson, E.R.;Crowe, M.N.
• 通讯作者: Crowe, M.N.

CaTSM: A Pseudo‐Spectral Thermodynamically Consistent Model of Compressible Flows

CaTSM：可压缩流的伪谱热力学一致模型

• DOI: 10.1029/2022ms003112
• 发表时间: 2022
• 期刊: Journal of Advances in Modeling Earth Systems
• 影响因子: 6.8
• 作者: Brown, Justin M.;Dewar, William;Radko, Timour
• 通讯作者: Radko, Timour

Diagnosing the Thickness‐Weighted Averaged Eddy‐Mean Flow Interaction From an Eddying North Atlantic Ensemble: The Eliassen‐Palm Flux

• DOI: 10.1029/2021ms002866
• 发表时间: 2022-03
• 期刊: Journal of Advances in Modeling Earth Systems
• 影响因子: 6.8
• 作者: T. Uchida;Q. Jamet;W. Dewar;J. Le Sommer;T. Penduff;D. Balwada

The Moist Quasi-Geostrophic Coupled Model: MQ-GCM 2.0

潮湿准地转耦合模型：MQ-GCM 2.0

• DOI: 10.5194/gmd-15-7449-2022
• 发表时间: 2022
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: Kravtsov, Sergey;Mastilovic, Ilijana;Hogg, Andrew McC.;Dewar, William K.;Blundell, Jeffrey R.
• 通讯作者: Blundell, Jeffrey R.