Multi-scale modelling of the ocean beneath ice shelves

冰架下海洋的多尺度建模

• 批准号: NE/G018391/1
• 负责人: Matthew Piggott
• 金额: $ 45.05万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FG018391%2F1
• 关键词: Multi; scale; modelling; ocean; beneath

Quantitative prediction of future sea level is currently impossible because we lack an understanding of how the mass balance of the Earth's great ice sheets can be affected by climate change. Chief among the uncertainties are how changes in ocean circulation and/or temperature will influence the thickness and extent of the ice shelves and how the outflow from the ice sheet will change in response. Observations of the ocean under ice shelves are very sparse and difficult to obtain. Hence, numerical modelling has been used to provide insight into the structure and dynamics of the ocean flow in ice shelf cavities, as well as their influence on the larger scale. However, the complexities associated with this application means that models based upon hydrostatic dynamics, uniform mesh resolution and a layered structure in the vertical, may be improved upon. These complexities include the presence of a grounding line where the water column depth goes to zero under ice deep below mean sea level. The importance of this very limited region to the ice shelf above, and the associated grounded ice sheet, is massive but this is exactly the point where conventional models need to make the largest compromises in representing the real world. Also, the shape of the base of the ice shelf, and the steep change at the front between the ice and the open ocean, place important constraints on the ocean dynamics and hence they need to be represented well in a model in a similar manner to sea floor bathymetry. This, along with the representation of critical buoyancy driven processes that may be of small scale, points towards the use of non-uniform resolution in both the horizontal and vertical directions. In this project we will adapt our state-of-the-art numerical model to study the ocean circulation in the cavities beneath floating ice shelves. Unstructured and anisotropic dynamically-adaptive mesh methods in three dimensions will allow simulations with a resolution and geometric flexibility that is greater than has been possible before. Model developments will be benchmarked against earlier model results and validated on a hierarchy of test problems. Real world applications under the Filchner-Ronne and Pine Island Glacier ice shelves will be used to calibrate and validate the model against observational (including new Autosub) data. Highly timely new science will be preformed in these areas, and this project will also be an important step towards the inclusion of ice shelf cavities in global scale ocean models of the future. The final result will be an improved understanding of the physical processes occurring under ice shelves, and a powerful tool that will enable the explicit inclusion of ice shelves in global scale ocean and climate models of the future. This project fits well with NERC strategy. In particular the prediction of the future contribution of the ice sheets to sea level rise is seen as a high priority goal that cuts across the themes of Climate Systems, Earth System Science and Natural Hazards. Development of the next generation climate models is also a priority for the Climate Systems and Technologies themes.

对未来海平面的定量预测目前是不可能的，因为我们缺乏对气候变化如何影响地球大冰盖的质量平衡的理解。主要的不确定性是海洋环流和/或温度的变化将如何影响冰架的厚度和范围，以及冰盖的外流将如何变化。对冰架下海洋的观测非常稀少，难以获得。因此，数值模拟已被用来提供深入了解的结构和动力学的洋流在冰架腔，以及它们的影响，在更大的规模。然而，与这种应用相关的复杂性意味着，基于流体静力学、均匀网格分辨率和垂直分层结构的模型可能会得到改进。这些复杂性包括存在一条接地线，在该接地线处，在平均海平面以下的冰层深处，水柱深度为零。这个非常有限的区域对上面的冰架和相关的接地冰盖的重要性是巨大的，但这正是传统模型需要在代表真实的世界方面做出最大妥协的地方。此外，冰架底部的形状，以及冰与开阔海洋之间前缘的急剧变化，对海洋动力学造成了重要的限制，因此，需要以类似于海底测深的方式，在模型中很好地表示这些情况。这沿着可能是小规模的临界浮力驱动过程的表示，指向在水平和垂直方向上使用非均匀分辨率。在这个项目中，我们将调整我们的国家的最先进的数值模式，以研究海洋环流的空腔下浮冰架。三维非结构化和各向异性动态自适应网格方法将允许模拟具有比以前更大的分辨率和几何灵活性。模型开发将根据早期的模型结果进行基准测试，并在测试问题的层次结构上进行验证。将使用Filchner-Ronne和松岛冰川冰架下的真实的世界应用程序，根据观测（包括新的Autosub）数据校准和验证模型。将在这些领域开展非常及时的新科学研究，这一项目也将是朝着将冰架空洞纳入未来全球尺度海洋模型迈出的重要一步。最终的结果将是对冰架下发生的物理过程的更好理解，以及一个强大的工具，将使冰架明确纳入未来全球尺度的海洋和气候模型。该项目非常符合NERC的战略。特别是，预测冰盖未来对海平面上升的贡献被视为一个高度优先的目标，贯穿气候系统，地球系统科学和自然灾害的主题。开发下一代气候模型也是气候系统和技术主题的优先事项。

项目成果

An implicit wetting and drying approach for non-hydrostatic baroclinic flows in high aspect ratio domains

• DOI: 10.1016/j.advwatres.2017.02.004
• 发表时间: 2013-12
• 期刊: Advances in Water Resources
• 影响因子: 4.7
• 作者: A. Candy

Modeling ice-ocean interaction in ice-shelf crevasses

• DOI: 10.1002/2013jc009208
• 发表时间: 2014-02-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
• 影响因子: 3.6
• 作者: Jordan, James R.;Holland, Paul R.;Kimura, Satoshi
• 通讯作者: Kimura, Satoshi

Towards a fully unstructured ocean model for ice shelf cavity environments: Model development and verification using the Firedrake finite element framework

面向冰架空腔环境的完全非结构化海洋模型：使用 Firedrake 有限元框架进行模型开发和验证

• DOI: 10.1016/j.ocemod.2023.102178
• 发表时间: 2023
• 期刊: Ocean Modelling
• 影响因子: 3.2
• 作者: Scott W

Integration of Geographic Information System frameworks into domain discretisation and meshing processes for geophysical models

将地理信息系统框架集成到地球物理模型的域离散化和网格划分过程中

• DOI: 10.5194/gmdd-7-5993-2014
• 发表时间: 2014
• 作者: Candy A

On the Conditional Frazil Ice Instability in Seawater

• DOI: 10.1175/jpo-d-14-0159.1
• 发表时间: 2015-04
• 期刊: Journal of Physical Oceanography
• 影响因子: 3.5
• 作者: James R. Jordan;S. Kimura;P. Holland;A. Jenkins;M. Piggott