Dynamic Turbulence Modelling in Large-Eddy Simulations of the Cloud-Topped Atmospheric Boundary Layer

Dynamic Turbulence Modelling in Large-Eddy Simulations of the Cloud-Topped Atmospheric Boundary Layer PDF Author: M. P. Kirkpatrick
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Book Description
The use of large eddy simulation, or LES, to study the atmospheric boundary layer dates back to the early 197Os when Deardorff (1972) used a three-dimensional simulation to determine velocity and temperature scales in the convective boundary layer. In 1974 he applied LES to the problem of mixing layer entrainment (Deardorff 1974) and in 1980 to the cloud-topped boundary layer (Deardorff 1980b). Since that time the LES approach has been applied to atmospheric boundary layer problems by numerous authors.

Dynamic Turbulence Modelling in Large-Eddy Simulations of the Cloud-Topped Atmospheric Boundary Layer

Dynamic Turbulence Modelling in Large-Eddy Simulations of the Cloud-Topped Atmospheric Boundary Layer PDF Author: M. P. Kirkpatrick
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

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Book Description
The use of large eddy simulation, or LES, to study the atmospheric boundary layer dates back to the early 197Os when Deardorff (1972) used a three-dimensional simulation to determine velocity and temperature scales in the convective boundary layer. In 1974 he applied LES to the problem of mixing layer entrainment (Deardorff 1974) and in 1980 to the cloud-topped boundary layer (Deardorff 1980b). Since that time the LES approach has been applied to atmospheric boundary layer problems by numerous authors.

Large-eddy Simulation of Stably Stratified Atmospheric Boundary Layer Turbulence

Large-eddy Simulation of Stably Stratified Atmospheric Boundary Layer Turbulence PDF Author: Sukanta Basu
Publisher:
ISBN:
Category :
Languages : en
Pages : 268

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Book Description


Subgrid-scale Turbulence Modeling for Improved Large-eddy Simulation of the Atmospheric Boundary Layer

Subgrid-scale Turbulence Modeling for Improved Large-eddy Simulation of the Atmospheric Boundary Layer PDF Author: Rica Mae Enriquez
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Large-eddy simulation (LES), as the name suggests, resolves the large eddies in the flow while modeling the effects of smaller motions (turbulence) on those larger eddies. Powerful computers make LES increasingly practical for analyzing a variety of atmospheric behavior in more detail, creating a need for more realistic turbulence models. Advances in describing atmospheric turbulence can impact many disciplines, e.g., weather and climate prediction, wind energy production, ocean dynamics, and, indeed, even computational fluid dynamics itself. Although the turbulence model can significantly affect the accuracy of the LES, simple turbulence models, which are known to be less accurate, are widely used. As an alternative, the Generalized Linear Algebraic Subgrid-Scale (GLASS) model, that actively couples momentum and heat transport, was developed. This model is more complete than conventional LES turbulence models because it accounts for additional transport processes. GLASS includes production, dissipation, pressure redistribution, and buoyancy terms. With the inclusion of an actively coupled turbulent heat flux model, GLASS is applicable to a range of atmospheric stability conditions for the unsaturated atmosphere. LES at various resolutions in a neutrally stratified boundary layer flow indicated that the GLASS model is a more physically complete subgrid-scale turbulence model that provides near-wall anisotropies and yields proper velocity profiles in the logarithmic layer. LES of the moderately convective boundary layer demonstrated that GLASS predicted the evolution of resolved quantities at least as well as the LESs with simple models, while including additional physics. Additional simulations of the stable boundary layer and the transitioning boundary layer highlight that GLASS can be applied to various stability conditions without the need of tuning model coefficients.

Shallow Clouds, Water Vapor, Circulation, and Climate Sensitivity

Shallow Clouds, Water Vapor, Circulation, and Climate Sensitivity PDF Author: Robert Pincus
Publisher: Springer
ISBN: 3319772732
Category : Science
Languages : en
Pages : 396

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Book Description
This volume presents a series of overview articles arising from a workshop exploring the links among shallow clouds, water vapor, circulation, and climate sensitivity. It provides a state-of-the art synthesis of understanding about the coupling of clouds and water vapor to the large-scale circulation. The emphasis is on two phenomena, namely the self-aggregation of deep convection and interactions between low clouds and the large-scale environment, with direct links to the sensitivity of climate to radiative perturbations. Each subject is approached using simulations, observations, and synthesizing theory; particular attention is paid to opportunities offered by new remote-sensing technologies, some still prospective. The collection provides a thorough grounding in topics representing one of the World Climate Research Program’s Grand Challenges. Previously published in Surveys in Geophysics, Volume 38, Issue 6, 2017 The aritcles “Observing Convective Aggregation”, “An Observational View of Relationships Between Moisture Aggregation, Cloud, and Radiative Heating Profiles”, “Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations”, “A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment”, “Low-Cloud Feedbacks from Cloud-Controlling Factors: A Review”, “Mechanisms and Model Diversity of Trade-Wind Shallow Cumulus Cloud Feedbacks: A Review”, “Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere”, “Emerging Technologies and Synergies for Airborne and Space-Based Measurements of Water Vapor Profiles”, “Observational Constraints on Cloud Feedbacks: The Role of Active Satellite Sensors”, and “EUREC4A: A Field Campaign to Elucidate the Couplings Between Clouds, Convection and Circulation” are available as open access articles under a CC BY 4.0 license at link.springer.com.

The Atmospheric Boundary Layer

The Atmospheric Boundary Layer PDF Author: J. R. Garratt
Publisher: Cambridge University Press
ISBN: 9780521467452
Category : Mathematics
Languages : en
Pages : 340

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Book Description
The book gives a comprehensive and lucid account of the science of the atmospheric boundary layer (ABL). There is an emphasis on the application of the ABL to numerical modelling of the climate. The book comprises nine chapters, several appendices (data tables, information sources, physical constants) and an extensive reference list. Chapter 1 serves as an introduction, with chapters 2 and 3 dealing with the development of mean and turbulence equations, and the many scaling laws and theories that are the cornerstone of any serious ABL treatment. Modelling of the ABL is crucially dependent for its realism on the surface boundary conditions, and chapters 4 and 5 deal with aerodynamic and energy considerations, with attention to both dry and wet land surfaces and sea. The structure of the clear-sky, thermally stratified ABL is treated in chapter 6, including the convective and stable cases over homogeneous land, the marine ABL and the internal boundary layer at the coastline. Chapter 7 then extends the discussion to the cloudy ABL. This is seen as particularly relevant, since the extensive stratocumulus regions over the subtropical oceans and stratus regions over the Arctic are now identified as key players in the climate system. Finally, chapters 8 and 9 bring much of the book's material together in a discussion of appropriate ABL and surface parameterization schemes in general circulation models of the atmosphere that are being used for climate simulation.

Large-Eddy Simulations of Turbulence

Large-Eddy Simulations of Turbulence PDF Author: M. Lesieur
Publisher: Cambridge University Press
ISBN: 9780521781244
Category : Mathematics
Languages : en
Pages : 240

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Book Description
Large-Eddy Simulations of Turbulence is a reference for LES, direct numerical simulation and Reynolds-averaged Navier-Stokes simulation.

Structure of the Atmospheric Boundary Layer

Structure of the Atmospheric Boundary Layer PDF Author: Zbigniew Sorbjan
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 344

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Book Description


Storm and Cloud Dynamics

Storm and Cloud Dynamics PDF Author: William R. Cotton
Publisher: Academic Press
ISBN: 0080916651
Category : Science
Languages : en
Pages : 826

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Book Description
Storm and Cloud Dynamics focuses on the dynamics of clouds and of precipitating mesoscale meteorological systems. Clouds and precipitating mesoscale systems represent some of the most important and scientifically exciting weather systems in the world. These are the systems that produce torrential rains, severe winds including downburst and tornadoes, hail, thunder and lightning, and major snow storms. Forecasting such storms represents a major challenge since they are too small to be adequately resolved by conventional observing networks and numerical prediction models. - Provides a complete treatment of clouds integrating the analysis of air motions with cloud structure, microphysics, and precipitation mechanics - Describes and explains the basic types of clouds and cloud systems that occur in the atmosphere-fog, stratus, stratocumulus, altocumulus, altostratus, cirrus, thunderstorms, tornadoes, waterspouts, orographically induced clouds, mesoscale convection complexes, hurricanes, fronts, and extratropical cyclones - Summarizes the fundamentals, both observational and theoretical, of atmospheric dynamics, thermodynamics, cloud microphysics, and radar meteorology, allowing each type of cloud to be examined in depth - Integrates the latest field observations, numerical model simulations, and theory - Supplies a theoretical treatment suitable for the advanced undergraduate or graduate level, as well as post-graduate

Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows PDF Author: P. Sagaut
Publisher: Springer Science & Business Media
ISBN: 3662046954
Category : Science
Languages : en
Pages : 437

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Book Description
First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Modeling Complex Turbulent Flows

Modeling Complex Turbulent Flows PDF Author: Manuel D. Salas
Publisher: Springer Science & Business Media
ISBN: 9401147248
Category : Science
Languages : en
Pages : 385

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Book Description
Turbulence modeling both addresses a fundamental problem in physics, 'the last great unsolved problem of classical physics,' and has far-reaching importance in the solution of difficult practical problems from aeronautical engineering to dynamic meteorology. However, the growth of supercom puter facilities has recently caused an apparent shift in the focus of tur bulence research from modeling to direct numerical simulation (DNS) and large eddy simulation (LES). This shift in emphasis comes at a time when claims are being made in the world around us that scientific analysis itself will shortly be transformed or replaced by a more powerful 'paradigm' based on massive computations and sophisticated visualization. Although this viewpoint has not lacked ar ticulate and influential advocates, these claims can at best only be judged premature. After all, as one computational researcher lamented, 'the com puter only does what I tell it to do, and not what I want it to do. ' In turbulence research, the initial speculation that computational meth ods would replace not only model-based computations but even experimen tal measurements, have not come close to fulfillment. It is becoming clear that computational methods and model development are equal partners in turbulence research: DNS and LES remain valuable tools for suggesting and validating models, while turbulence models continue to be the preferred tool for practical computations. We believed that a symposium which would reaffirm the practical and scientific importance of turbulence modeling was both necessary and timely.