Gung Ho Phase 2

工合二期

• 批准号: NE/K006789/1
• 负责人: David Ham
• 金额: $ 37.66万
• 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: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FK006789%2F1
• 关键词: Gung; Ho; Phase

Historically, major improvements in the accuracy of numerical weather forecasts and climate simulations have come from the increased resolution enabled by the exponential growth in computer power. In order to achieve further gains in accuracy through further increases in resolution, it will be necessary to exploit the massively parallel computer architectures that are becoming available. However, current state-of-the-art operational algorithms are not expected to perform well beyond a few thousand processors: the grid structure of the traditional latitude-longitude grid means that interprocessor communication eventually but inevitably becomes a bottleneck.The overall aim of the proposed project is to develop a new, three-dimensional, fully compressible dynamical core suitable for operational global and regional weather and climate prediction, as well as for research use, on massively parallel machines, and to demonstrate its accuracy, efficiency, and scalability. The accuracy should be comparable to that of existing state of the art algorithms. The algorithm must be efficient enough to run in the available operational time slots, and it must scale well on 100,000 to 1000,000 processors.Phase 1 of this project (Feb 2011 - Jan 2013) addressed several of the basic scientific questions that underpin the development, including choice of quasi-uniform horizontal grid, choice of horizontal discretization, choice of transport scheme, time integration scheme, and some of the computer science aspects of the project. Several candidate approaches were tested and evaluated in a simplified two-dimensional fluid system (the Shallow Water Equations), and a small number of promising approaches were identified for further development in Phase 2.Phase 2 of this project will build on the progress made in Phase 1 in order to develop a three-dimensional, fully compressible dynamical core. The work in Phase 2 falls broadly into three work packages:* Vertical aspects. The stability and accuracy of the discretization depends crucially on the choice of vertical coordinate, the choice of thermodynamic variables predicted, and the vertical placement of variables relative to each other (`staggering'). It will also depend on the details of how, for example, the pressure gradient term is evaluated, especially near steep mountains, and how the vertical discretization couples with the horizontal discretization. Building on current understanding, candidate schemes will be formulated and tested.* Code design and development. The code for the three-dimensional dynamical core will be based around a carefully designed software framework. The interface between the numerical discretization and its parallel implementation will be optimized, so that modifications to the former require minimal knowledge of the latter. The software framework will be highly flexible, so that it can easily accommodate future evolution of the dynamical core, such as changes in grid structure.* Testing. The behaviour of complex numerical algorithms can be difficult to predict theoretically, even when individual components are well understood and tested. It will be vital, therefore, to test comprehensively the proposed formulations at the earliest opportunity, and revise if necessary. Early testing will focus on the shallow water formulation arising out of Phase 1 of the project, and on one-dimensional (column) and two-dimensional (vertical slice) prototypes of the vertical formulation. Testing of the three-dimensional formulation will begin as soon as code is available.

从历史上看，数值天气预报和气候模拟的精确度的主要改进来自于计算机能力的指数增长带来的分辨率的提高。为了通过进一步提高分辨率来实现精度的进一步提高，有必要利用正在出现的大规模并行计算机体系结构。然而，当前最先进的运算算法的性能预计不会超过数千个处理器：传统的经纬度网格的网格结构意味着处理器之间的通信最终但不可避免地成为瓶颈。该项目的总体目标是开发一个新的、三维的、完全可压缩的动态核，适合在大规模并行机上进行全球和区域天气气候预测以及研究用途，并证明其准确性、效率和可扩展性。其精确度应与现有最先进的算法相当。该算法必须足够高效，才能在可用的操作时隙中运行，并且必须在100,000到100,000个处理器上很好地扩展。该项目的第一阶段(2011年2月至2013年1月)解决了支撑该开发的几个基本科学问题，包括准均匀水平网格的选择、水平离散化的选择、传输方案的选择、时间整合方案以及该项目的一些计算机科学方面。在简化的二维流体系统(浅水方程)中测试和评估了几种候选方法，并确定了少数有希望的方法在第二阶段进一步开发。该项目的第二阶段将在第一阶段取得进展的基础上，开发一个三维的、完全可压缩的动力核心。第二阶段的工作大致分为三个工作包：*垂直方面。离散化的稳定性和准确性主要取决于垂直坐标的选择、预测的热力学变量的选择以及变量相对于彼此的垂直位置(“令人震惊”)。这也将取决于例如如何计算压力梯度项的细节，特别是在陡峭的山脉附近，以及垂直离散化如何与水平离散化相结合。在现有理解的基础上，将制定和测试候选方案。*代码设计和开发。三维动态核心的代码将基于精心设计的软件框架。数值离散化和并行实施之间的接口将得到优化，因此对前者的修改只需要最少的对后者的了解。软件框架将高度灵活，因此它可以轻松地适应未来动态核心的演变，例如网格结构的变化。*测试。复杂的数值算法的行为在理论上可能很难预测，即使在单个组件得到充分理解和测试的情况下也是如此。因此，至关重要的是尽早全面测试拟议的配方，并在必要时进行修订。早期测试将集中在项目第一阶段产生的浅水配方，以及垂直配方的一维(柱)和二维(垂直切片)原型。一旦代码可用，三维配方的测试将立即开始。

项目成果

Variational formulations of sound-proof models Variational Sound-Proof Models

隔音模型的变分公式 变分隔音模型

• DOI: 10.1002/qj.2260
• 发表时间: 2014
• 期刊: Quarterly Journal of the Royal Meteorological Society
• 影响因子: 8.9
• 作者: Cotter C

Compatible Finite Element Methods for Geophysical Flows - Automation and Implementation Using Firedrake

地球物理流的兼容有限元方法 - 使用 Firedrake 进行自动化和实现

• DOI: 10.1007/978-3-030-23957-2
• 发表时间: 2019
• 作者: Gibson T

A Parallel Edge Orientation Algorithm for Quadrilateral Meshes

四边形网格的平行边方向算法

• DOI: 10.1137/15m1021325
• 发表时间: 2016
• 期刊: SIAM Journal on Scientific Computing
• 影响因子: 3.1
• 作者: Homolya M

The 'recovered space' advection scheme for lowest-order compatible finite element methods

最低阶兼容有限元方法的“恢复空间”平流方案

• DOI: 10.1016/j.jcp.2019.04.013
• 发表时间: 2019
• 期刊: Journal of Computational Physics
• 影响因子: 4.1
• 作者: Bendall T

A solution to the trilemma of the moist Charney-Phillips staggering

潮湿的查尼-菲利普斯令人震惊的三难困境的解决方案

• DOI: 10.1002/qj.4406
• 发表时间: 2022
• 期刊: Quarterly Journal of the Royal Meteorological Society
• 影响因子: 8.9
• 作者: Bendall T