CoDyPhy: Improved Coupling of Dynamics and Physics for understanding and modelling moist convection

CoDyPhy：改进动力学和物理耦合，用于理解和建模湿对流

基本信息

批准号：
NE/N013123/1
负责人：
John Thuburn
金额：
$ 94.11万
依托单位：
UNIVERSITY OF EXETER
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FN013123%2F1
关键词：
CoDyPhy Improved Coupling Dynamics Physics

项目摘要

Moist convection is the term used to describe the vertical transport within clouds whose buoyancy is produced by the latent heat released when water vapour condenses. Moist convection is one of the dominant processes affecting the weather and climate in Earth's atmosphere. However, despite decades of effort, there remain major challenges in representing convective systems in the computer models used for weather and climate prediction. Common errors and biases include an inability to simulate a physically correct equilibrium between convection and radiative cooling, an unrealistic diurnal cycle of convection over ocean and over tropical land, unrealistically fast and weak convectively-coupled large-scale waves in the tropics, spuriously strong intermittency of modelled convection in space and time, and the occurrence of excessively violent `grid point storms' at the scale of the model grid.The proposed project aims to improve our ability to represent moist convection in weather prediction and climate models. This will be achieved through an improved understanding of how convection interacts with the atmospheric circulation on small and large scales, and through the development of a novel way of representing convection in numerical models.The interaction of convection with the atmospheric circulation is extremely complex and poorly understood. It involves many different feedback mechanisms, including large scale dynamics and transport, the atmospheric boundary layer and surface fluxes, and radiative processes. Our work will focus on tropical circulations: the Hadley circulation and InterTropical Convergence Zone, the Walker circulation, and convectively coupled waves. We will improve understanding of these interactions by using a simplified model of the global circulation to carry out carefully controlled hypothesis testing experiments and sensitivity tests. The aim here is not to simulate these circulations as accurately as possible, but to improve understanding by isolating the most important processes, diagnosing mechanisms, and quantifying sensitivities. This modelling work will be complemented by the development of a new theoretical model describing the interaction of convection with the atmospheric boundary layer and the larger scale circulation. This new theoretical model will be applied to understanding the role of the boundary layer in setting the structure of the Walker circulation. A third strand of this work will be to use theory and numerical models to understand the role of the boundary layer in influencing the diurnal cycle of convection.Global weather forecast models and climate models currently use grid resolutions coarser than 10km and of order several 10's of km, respectively. The so-called `dynamical core' of the model predicts the evolution of wind and temperature fields at these resolved scales. Typical convective clouds, however, have a horizontal scale of order 1km. Therefore, such models cannot resolve individual convective clouds. Instead, convection is represented by a subgrid model or `parameterization' scheme that attempts to model the effects of convection on the resolved scales. Here we propose a new approach to representing convection, in which separate wind and temperature fields for non-convecting fluid and convecting fluid are predicted by the dynamical core. We will extend the theoretical understanding of this two-fluid model, we will implement it in a three-dimensional computer model, and we will evaluate its performance in a series of tests of increasing complexity. This new representation of convection has the potential to overcome several long-standing limitations of conventional convection schemes.

湿对流是一个术语，用于描述云内的垂直传输，其浮力是由水蒸气凝结时释放的潜热产生的。湿对流是影响地球大气层天气和气候的主要过程之一。然而，尽管经过数十年的努力，在用于天气和气候预测的计算机模型中表示对流系统仍然存在重大挑战。常见的错误和偏差包括无法模拟对流和辐射冷却之间物理上正确的平衡、海洋和热带陆地上空对流的不切实际的昼夜循环、热带地区不切实际的快速和弱对流耦合大规模波、虚假的强间歇性模型在空间和时间上对流的影响，以及模型网格尺度上过度猛烈的“网格点风暴”的发生。该项目旨在提高我们的能力代表天气预报和气候模型中的潮湿对流。这将通过更好地理解对流如何在小尺度和大尺度上与大气环流相互作用，并开发一种在数值模型中表示对流的新方法来实现。对流与大气环流的相互作用极其复杂且较差明白了。它涉及许多不同的反馈机制，包括大尺度动力学和传输、大气边界层和表面通量以及辐射过程。我们的工作重点是热带环流：哈德利环流和热带辐合带、沃克环流和对流耦合波。我们将通过使用全球循环的简化模型来进行仔细控制的假设检验实验和敏感性测试，以增进对这些相互作用的理解。这里的目的不是尽可能准确地模拟这些循环，而是通过隔离最重要的过程、诊断机制和量化敏感性来提高理解。这项建模工作将得到描述对流与大气边界层和更大规模环流相互作用的新理论模型的开发的补充。这个新的理论模型将用于理解边界层在设定沃克环流结构中的作用。这项工作的第三个部分将是使用理论和数值模型来了解边界层在影响对流昼夜循环中的作用。全球天气预报模型和气候模型目前使用的网格分辨率比 10 公里粗，数量级为几十个公里，分别。该模型所谓的“动力核心”预测了这些解析尺度下风场和温度场的演变。然而，典型的对流云的水平尺度为 1 公里量级。因此，此类模型无法解析单个对流云。相反，对流由子网格模型或“参数化”方案表示，试图对对流对解析尺度的影响进行建模。在这里，我们提出了一种表示对流的新方法，其中动力核心预测非对流流体和对流流体的单独风场和温度场。我们将扩展对这种二流体模型的理论理解，我们将在三维计算机模型中实现它，并且我们将在一系列复杂性不断增加的测试中评估其性能。这种新的对流表示方式有可能克服传统对流方案的几个长期存在的局限性。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Diagnosing Coherent Structures in the Convective Boundary Layer by Optimizing Their Vertical Turbulent Scalar Transfer

通过优化垂直湍流标量传递来诊断对流边界层中的相干结构

DOI：
http://dx.10.1007/s10546-019-00480-1
发表时间：
2019
期刊：
Boundary-Layer Meteorology
影响因子：
4.3
作者：
Efstathiou G
通讯作者：
Efstathiou G

Consistent and flexible thermodynamics in atmospheric models using internal energy as a thermodynamic potential. Part II: Non-equilibrium regime

使用内能作为热力学势的大气模型中一致且灵活的热力学。

DOI：
http://dx.10.1002/qj.4373
发表时间：
2022
期刊：
Quarterly Journal of the Royal Meteorological Society
影响因子：
8.9
作者：
Bowen P
通讯作者：
Bowen P

Characterizing Convection Schemes Using Their Responses to Imposed Tendency Perturbations

利用对流方案对强加趋势扰动的响应来表征对流方案

DOI：
10.1029/2021ms002461
发表时间：
2021-01-15
期刊：
Journal of Advances in Modeling Earth Systems
影响因子：
6.8
作者：
Y. Hwong;S. Song;S. Sherwood;A. Stirling;C. Rio;R. Roehrig;C. L. Daleu;R. Plant;D. Fuchs;P. Maher;L. Touzé‐Peiffer
通讯作者：
L. Touzé‐Peiffer

A Simple Model of a Balanced Boundary Layer Coupled to a Large-Scale Convective Circulation

与大规模对流环流耦合的平衡边界层的简单模型