Collaborative Research: A Coordinate-Free Framework for Improving Eddy Parameterizations

协作研究：改进涡流参数化的无坐标框架

• 批准号: 2220291
• 负责人: Jonathan Lilly
• 金额: $ 33.48万
• 依托单位: Planetary Science Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220291&HistoricalAwards=false
• 关键词: Collaborative; Research; Coordinate; Free; Framework

This project is to create and apply a new theoretical framework for developing and assessing parameterizations of eddy transport in numerical models. The framework constitutes a set of principles linking physical meaning to parameterization form, including extant as well as yet-unformulated variations. This work will provide an avenue for the cross-evaluation of existing or proposed parameterizations from first principles. Two significant software packages that will result from this work are (i) symbolic algebra software for implementing eddy parameterizations in an arbitary model coordinate system and choice of discretization, and (ii) numerical code for error diagnostics in model implementation.The Explicit, Stochastic, Coordinate-independent (ESC) framework will incorporate: (i) explicit and rigorous definitions for filtering and averaging operations; (ii) a flexible approach to stochastic modeling that relaxes the unrealistic constraints implicit in existing parameterizations on eddy path smoothness and dependence on local conditions; and (iii) the use of coordinate-independent representations to express the physical essence of parameterizations free from choice of model geometry. This work will clarify the link between parameterization forms and conserved properties (energy, enstrophy, etc.); speed the identification and assessment of discretization errors in multiple model systems; uniquely identify the advective and diffusive components of parameterized fluxes across implementations; and account for the impact of the observed range of high-frequency trajectory behavior on parameterization structure.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.

该项目将创建并应用一个新的理论框架来开发和评估数值模型中涡流传输的参数化。该框架构成了一组将物理含义与参数化形式联系起来的原则，包括现存和尚未形成的变化。这项工作将为对第一原则的现有或拟议参数化的​​交叉评估提供途径。这项工作将产生的两个重要的软件包是（i）符号代数软件，用于在arbitary模型坐标系统中实现涡流参数化和离散化选择，以及（ii）在模型实现中错误诊断的数值代码。显式，随机，坐标不依赖于坐标的框架（ESCERDICTISTIND（ESC）的框架都将符合操作： （ii）一种灵活的方法进行随机建模的方法，它放松了对涡流平滑度和对局部条件的依赖性的参数化的不切实际约束； （iii）使用与坐标无关的表示表达无需选择模型几何形状的参数化的物理本质。这项工作将阐明参数化形式与保守特性（能量，endrophy等）之间的联系；加快多个模型系统中离散错误的识别和评估；独特地确定跨实现参数化通量的对流和扩散的组成部分；并说明了观察到的高频轨迹行为对参数化结构的影响。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响来通过评估来支持的。