Towards a Next generation Ocean Model in the Gung-Ho frame form: 2D test cases (G-Ocean:2D)

以 Gung-Ho 框架形式迈向下一代海洋模型：2D 测试用例 (G-Ocean:2D)

• 批准号: NE/L01209X/1
• 负责人: Mike Ashworth
• 金额: $ 9.26万
• 依托单位: Science and Technology Facilities Council
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FL01209X%2F1
• 关键词: Towards; Next; generation; Ocean; Model

This project aims to develop and test a new a software approach to coding ocean models that can exploit the next generation of computer architectures. Ocean models form a vital component of the climate models that produce future climate projections, for example, for the Inter Governmental Panel on Climate Change. They are also important tools for exploring all aspects of the marine environment from coastal to shelf sea and global scales. The use of ocean models relies on national computer facilities that are among the fastest computers in the world. Computer power tends to approximately double every two years, and as these facilities improve then so does the potential for ocean models to provide more accurate simulations, with benefits for climate and weather forecasting, as well as our understanding of the marine environment. However, increases in computer power are now occurring primarily through increased parallelism, with more computer corers per chip and more chips per computer. Hence to exploit increases in computer power we must develop models that can exploit as many different forms of parallelism as possible. While there are many ways of achieving this, they are generally at the expense of the easy of the development of the model, until we might expected only a computer science expert to be able to develop the ocean model - an unreasonable expectation. One of the particular ways oceans scientists would want to use this increase in computer power is by targeting horizontal resolution where the scientific understanding dictates or where it is particularly important for the application.A solution to the computational issue has been identified in an on-going project to develop a new atmospheric model for the UK Met Office (GungHo) to meet many of the same challenges and opportunities identified here. The proposed solution is to separate the model computer code into layers, each requiring different expertise to develop, and so isolate the natural scientist from the complexities of the computer science aspects. While oceans and the atmosphere show many similarities in their physics, they are some important differences, notably the large changes in depth for the ocean and present of land giving complex boundaries and also implying the oceans do not cover the whole globe as the atmosphere does. This naturally leads to ocean modellers not necessarily making the same choices, as in the atmospheric model. Hence, the aim of this project is to apply the 'layered approach' to a simple ocean case to prove the concepts:1. That the computational framework under development in Gung-Ho is sufficiently flexible to accommodate the natural choices of grids and solution approaches for ocean models2. That, when coded within this framework, conventional modelling approaches can perform at least as well as the existing models in terms of their efficiency and scalability, and also have benefits of ease of use and development when highly optimisedThis work will provide a first view of how an ocean model built and designed in the GungHo framework is likely to perform. The tools built here will allow us to explore ocean model design and help answer the question: Are the approaches being developed for GungHo appropriate for the ocean? Or will alternatives be needed? The long term impact of this work is potentially very far reaching. The vision is that this is the first step on the route to an ocean model that runs efficiently on hundreds of thousands to millions of computational cores and has flexibility to change resolution as the science or user interest dictates, but is also readily usable by oceanographers of many disciplines. Realising this vision would represent a step change in Earth System Modelling and Regional System Modelling capability that would be truly world leading.

该项目旨在开发和测试一种新的软件方法来编码海洋模型，该方法可以利用下一代计算机架构。海洋模型是气候模型的重要组成部分，例如为政府间气候变化专门委员会提供未来气候预测。它们也是探索从沿海到陆架海以及全球范围内海洋环境各个方面的重要工具。海洋模型的使用依赖于世界上最快的计算机之一的国家计算机设施。计算机能力大约每两年就会增加一倍，随着这些设施的改进，海洋模型提供更准确模拟的潜力也随之增加，这有利于气候和天气预报以及我们对海洋环境的了解。然而，计算机能力的提高现在主要是通过增加并行性来实现的，每个芯片上有更多的计算机核心器，每台计算机上有更多的芯片。因此，为了利用计算机能力的增强，我们必须开发能够利用尽可能多的不同形式并行性的模型。虽然实现这一目标的方法有很多，但它们通常是以牺牲模型开发的容易性为代价的，直到我们可能期望只有计算机科学专家才能开发海洋模型——这是一个不合理的期望。海洋科学家希望利用计算机能力增强的特殊方式之一是针对科学理解所规定的水平分辨率或对应用特别重要的水平分辨率。在正在进行的一项研究中，已经确定了计算问题的解决方案。项目旨在为英国气象局 (GungHo) 开发新的大气模型，以应对此处确定的许多相同的挑战和机遇。所提出的解决方案是将模型计算机代码分成几层，每层都需要不同的专业知识来开发，从而将自然科学家与计算机科学方面的复杂性隔离开来。虽然海洋和大气在物理上表现出许多相似之处，但它们也存在一些重要的区别，特别是海洋深度的巨大变化和陆地的存在，给出了复杂的边界，也意味着海洋并不像大气那样覆盖整个地球。这自然会导致海洋建模者不一定会做出与大气模型相同的选择。因此，该项目的目的是将“分层方法”应用于一个简单的海洋案例来证明以下概念：1． Gung-Ho 正在开发的计算框架足够灵活，可以适应海洋模型的网格和解决方法的自然选择2。也就是说，当在此框架内进行编码时，传统的建模方法在效率和可扩展性方面至少可以与现有模型一样执行，并且在高度优化时还具有易于使用和开发的优点这项工作将提供如何在 GungHo 框架中构建和设计的海洋模型可能会发挥作用。这里构建的工具将使我们能够探索海洋模型设计并帮助回答以下问题：为 GungHo 开发的方法是否适合海洋？或者是否需要替代方案？这项工作的长期影响可能非常深远。我们的愿景是，这是建立海洋模型的第一步，该模型可以在数十万到数百万个计算核心上高效运行，并且可以根据科学或用户兴趣灵活地改变分辨率，而且也可以很容易地被海洋学家使用。许多学科。实现这一愿景将代表地球系统建模和区域系统建模能力的重大变革，真正达到世界领先水平。

项目成果

Towards Performance Portability in GungHo and GOcean

在 GungHo 和 GOcean 中实现性能可移植性

• 发表时间: 2015
• 作者: Ashworth; M.
• 通讯作者: M.

Towards Compiler-Agnostic Performance in Finite-Difference Codes

实现有限差分代码中与编译器无关的性能

• 发表时间: 2015
• 作者: Porter; AR
• 通讯作者: AR

Evaluating the Scalability of Stencil Codes at Scale

大规模评估模板代码的可扩展性

• 发表时间: 2015
• 作者: Modani; M
• 通讯作者: M