'Next Generation' unstructured mesh ocean global circulation modelling.

“下一代”非结构化网格海洋全球环流建模。

• 批准号: NE/C521028/2
• 负责人: Christopher Pain
• 金额: $ 40.06万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FC521028%2F2
• 关键词: Next; Generation; unstructured; mesh; ocean

We will build a next generation ocean global circulation model that is more accurate and has more detailed resolution than existing models. This model will be capable of resolving flows simultaneously on global, basin, regional, and process scales. It will be able to change numerical detail in response to both the structure of the modelled flows and user-defined preferences of regions and structures of specific importance. We shall use the model to carry out ocean research which is not possible with existing models. Despite significant advances over the past decade, numerical ocean global circulation models (OGCMs) are based on essentially the same finite-difference methods employed in the earliest ocean models developed in the 1 960s. Meanwhile, unstructured finite element/volume methods have been deployed to great effect in engineering applications and offer several major advantages for ocean modelling. These include the abilities to: conform accurately to complex basin geometries; focus resolution where it is most needed in response to the evolving flow or regional importance; move the mesh in response to error norms and maintain vertical density structures; incorporate various natural boundary conditions in a straightforward manner; and to make rigorous statements about model errors and numerical convergence. The ability of an unstructured mesh ocean model to change resolution smoothly and dynamically in response to changing ocean dynamics can be viewed as the 'ultimate in grid nesting', but avoiding the various difficulties inherent in matching different dynamical regimes at nest boundaries. Although unstructured mesh modelling has long been a goal of many oceanographers, attempts to apply such methods to model the global circulation have failed due to challenges in treating the Coriolis and buoyancy terms accurately and stably on unstructured meshes. Over the past few years important solutions to this problem have been developed (many by us) and incorporated into the Imperial College Ocean Model (ICOM). This model has the best available parallel mesh adaptivity methods, a suite of options for spatial derivatives (such as high-resolution methods for density/tracer advection), novel and robust treatments of balance, optimised bathymetry and coastline geometries and new large eddy mesh adaptive turbulence models. ICOM will form the foundation of the OGCM built by the proposed consortium. The drivers for it are twofold: (a) a new research tool is a necessity as 'standard' finite-difference codes become harder to tweak to improve their accuracy; and (b) there are significant science problems where the disparity between length scales requires the application of new modelling techniques such as ours (e.g. flow through sills and down slopes, eddies, convection within gyres, etc). These methods have the potential to revolutionise the way in which ocean modelling is done, and thus to secure the long-term future of UK Ocean Modelling at the forefront of the field. The next generation ocean model, with its ability to efficiently resolve a wide range of scales, will have numerous applications to the NERC and wider communities. For ocean modellers, it offers the opportunity to efficiently resolve both basin scale circulation and small-scale processes such as boundary currents, through- and overflows and geostrophic eddies. For Earth system and climate modellers, it offers the opportunity to focus resolution in regions of particular importance, such as boundary currents and overflows, without increasing the computational cost above that of a conventional coarse-resolution model. With a wide range of applications in oceanography, climate change, flood defence, pollution and contaminant dispersal, sustainability of water quality and fisheries, the development of such a model is extremely desirable.

我们将建立一个比现有模式更精确、分辨率更详细的新一代海洋全球环流模式。该模型将能够同时解决全球、流域、区域和过程尺度上的流动问题。它将能够根据模拟流动的结构以及用户定义的区域和具有特定重要性的结构的偏好来改变数字细节。我们将使用该模型进行海洋研究，这是现有模型无法实现的。尽管在过去十年中取得了重大进展，但数值海洋全球环流模型(OGCM)基本上是基于20世纪60年代开发的最早海洋模型中使用的有限差分方法。同时，非结构有限元/体积方法已经在工程应用中取得了很大的效果，并为海洋模拟提供了几个主要的优点。这些能力包括：准确地符合复杂的盆地几何形状；根据不断变化的流动或区域重要性，在最需要的地方进行聚焦分辨率；根据误差规范移动网格并保持垂直密度结构；以直接的方式合并各种自然边界条件；以及就模型误差和数值收敛做出严格的声明。非结构网格海洋模式能够顺畅地、动态地改变分辨率，以响应不断变化的海洋动力学，这可以被视为网格嵌套的终极能力，但避免了在嵌套边界匹配不同动力学区域所固有的各种困难。尽管非结构网格模拟长期以来一直是许多海洋学家的目标，但由于在非结构网格上准确和稳定地处理科里奥利项和浮力项的挑战，应用这种方法来模拟全球环流的尝试失败了。在过去的几年里，已经制定了这个问题的重要解决方案(其中许多是由我们提出的)，并将其纳入帝国理工学院海洋模型。该模型具有现有最好的并行网格自适应方法，一套空间导数选项(如高分辨率密度/示踪平流方法)，新的和稳健的平衡处理，优化的水深和海岸线几何形状，以及新的大涡网格自适应湍流模型。国际博协将成为拟议财团建立的OGCM的基础。它的驱动因素有两个：(A)新的研究工具是必要的，因为“标准”有限差分代码变得更难调整以提高其精度；以及(B)存在重大的科学问题，其中长度尺度之间的差异需要应用诸如我们的新的建模技术(例如，流经基床和下坡的流动、旋涡、回旋内的对流等)。这些方法有可能彻底改变海洋模拟的方式，从而确保英国海洋模拟的长期未来处于该领域的前沿。下一代海洋模式具有有效分辨大范围尺度的能力，将在NERC和更广泛的社区中有许多应用。对于海洋模型者来说，它提供了有效解决盆地尺度环流和小尺度过程的机会，如边界流、贯通和溢流以及地转涡。对于地球系统和气候模型，它提供了将分辨率集中在特别重要的区域，如边界流和溢流的机会，而不会增加比传统的粗分辨率模型更高的计算成本。由于在海洋学、气候变化、防洪、污染和污染物扩散、水质可持续性和渔业方面有着广泛的应用，开发这样的模型是非常可取的。

项目成果

Spud 1.0: generalising and automating the user interfaces of scientific computer models

Spud 1.0：科学计算机模型的用户界面的通用化和自动化

• DOI: 10.5194/gmdd-1-125-2008
• 发表时间: 2008
• 作者: Ham D

A new computational framework for multi-scale ocean modelling based on adapting unstructured meshes

• DOI: 10.1002/fld.1663
• 发表时间: 2008-03-20
• 期刊: INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
• 影响因子: 1.8
• 作者: Piggott, M. D.;Gorman, G. J.;Wells, M. R.
• 通讯作者: Wells, M. R.

Tidal circulation in an ancient epicontinental sea: The Early Jurassic Laurasian Seaway

古代陆表海的潮汐环流：早侏罗世劳亚海道

• DOI: 10.1130/g31496.1
• 发表时间: 2011
• 期刊: Geology
• 影响因子: 5.8
• 作者: Mitchell A

Simulated spatially dependent transient kinetics analysis of the Oak Ridge Y12 plant criticality excursion

Oak Ridge Y12 发电厂临界偏移的模拟空间相关瞬态动力学分析

• DOI: 10.1016/j.pnucene.2012.09.006
• 发表时间: 2013
• 期刊: Progress in Nuclear Energy
• 影响因子: 2.7
• 作者: Buchan A