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A dynamically adaptive wavelet method for the shallow water equations on the sphere: towards heterogeneous multi-scale climate models. Kevlahan, Nicholas
Description
This talk presents a dynamically adaptive wavelet method for the shallow water equations on the staggered hexagonal C-grid on the sphere. The adaptive grid hierarchy is a dyadic subdivision of the icosahedron, which is optimized to ensure good geometric properties. Distinct biorthogonal second generation wavelet transforms are developed for the pressure and the velocity, together with compatible restriction operators to ensures discrete mass conservation and no numerical generation of vorticity. Coastlines are introduced by a new volume penalization method of the shallow water equations which ensure inertia-gravity waves are reflected physically, and that no-slip boundary conditions are imposed for the horizontal velocity. The code is fully parallelized using mpi, and we demonstrate good weak parallel scaling to at least 1000 processors. The efficiency and accuracy of the method are verified by applying it to a tsunami-type inertia-gravity wave with full topography, to wind-driven gyre flow and to homogeneous rotating turbulence. Even in the unfavourable case of homogeneous turbulence significant savings in the number of degrees of freedom are achieved by the adaptivity. This project is an initial step towards developing a full dynamically adaptive climate model. I will also discuss some outstanding issues in sub-grid parameterization of multiphysics processes (e.g. unresolved turbulence, cloud formation, precipitation, effect of topography).
Item Metadata
Title |
A dynamically adaptive wavelet method for the shallow water equations on the sphere: towards heterogeneous multi-scale climate models.
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Creator | |
Publisher |
Banff International Research Station for Mathematical Innovation and Discovery
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Date Issued |
2016-06-07T09:20
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Description |
This talk presents a dynamically adaptive wavelet method for the
shallow water equations on the staggered hexagonal C-grid on the
sphere. The adaptive grid hierarchy is a dyadic subdivision of the
icosahedron, which is optimized to ensure good geometric properties.
Distinct biorthogonal second generation wavelet transforms are
developed for the pressure and the velocity, together with compatible
restriction operators to ensures discrete mass conservation and no
numerical generation of vorticity. Coastlines are introduced by a new
volume penalization method of the shallow water equations which ensure
inertia-gravity waves are reflected physically, and that no-slip
boundary conditions are imposed for the horizontal velocity. The code
is fully parallelized using mpi, and we demonstrate good weak parallel
scaling to at least 1000 processors. The efficiency and accuracy of
the method are verified by applying it to a tsunami-type
inertia-gravity wave with full topography, to wind-driven gyre flow
and to homogeneous rotating turbulence. Even in the unfavourable case
of homogeneous turbulence significant savings in the number of degrees
of freedom are achieved by the adaptivity.
This project is an initial step towards developing a full dynamically
adaptive climate model. I will also discuss some outstanding issues
in sub-grid parameterization of multiphysics processes (e.g.
unresolved turbulence, cloud formation, precipitation, effect of
topography).
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Extent |
56 minutes
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Subject | |
Type | |
File Format |
video/mp4
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Language |
eng
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Notes |
Author affiliation: McMaster University
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Series | |
Date Available |
2017-01-27
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Provider |
Vancouver : University of British Columbia Library
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Rights |
Attribution-NonCommercial-NoDerivatives 4.0 International
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DOI |
10.14288/1.0340112
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URI | |
Affiliation | |
Peer Review Status |
Unreviewed
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Scholarly Level |
Faculty
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Rights URI | |
Aggregated Source Repository |
DSpace
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Rights
Attribution-NonCommercial-NoDerivatives 4.0 International