Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current
Abstract The ocean circulation dynamics can be represented as a high‐dimensional multi‐scale nonlinear system with inhomogenous meanfields and topography. Numerical simulations of the ocean dynamics resolve the large scales of motion on a computational grid, with the unresolved subgrid interactions...
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ftdoajarticles:oai:doaj.org/article:364afdcee9e243d6b1b452fef2bd6428 2023-07-16T03:52:37+02:00 Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current V. Kitsios J. S. Frederiksen T. J. O’Kane 2023-05-01T00:00:00Z https://doi.org/10.1029/2022MS003412 https://doaj.org/article/364afdcee9e243d6b1b452fef2bd6428 EN eng American Geophysical Union (AGU) https://doi.org/10.1029/2022MS003412 https://doaj.org/toc/1942-2466 1942-2466 doi:10.1029/2022MS003412 https://doaj.org/article/364afdcee9e243d6b1b452fef2bd6428 Journal of Advances in Modeling Earth Systems, Vol 15, Iss 5, Pp n/a-n/a (2023) subgrid parameterization stochastic general circulation model climate topography eddies Physical geography GB3-5030 Oceanography GC1-1581 article 2023 ftdoajarticles https://doi.org/10.1029/2022MS003412 2023-06-25T00:36:40Z Abstract The ocean circulation dynamics can be represented as a high‐dimensional multi‐scale nonlinear system with inhomogenous meanfields and topography. Numerical simulations of the ocean dynamics resolve the large scales of motion on a computational grid, with the unresolved subgrid interactions parameterized. These simulations are highly dependent upon the grid resolution, unless the subgrid terms are appropriately parameterized. There are five fundamental classes of subgrid interactions: eddy‐eddy; eddy‐topographic; eddy‐meanfield; meanfield‐meanfield; and meanfield‐topographic. Scale dependent parameterizations representing each of these interaction classes are presented here in oceanic flows for the first time. Subgrid parameterizations are calculated and validated in baroclinic quasi‐geostrophic simulations of idealized Antarctic Circumpolar Current flows with representative mean currents and ocean floor topography. The parameterization coefficients are derived from the coarse grained statistics of high resolution reference simulations in spectral space. Stochastic and deterministic parameterizations are developed for the eddy‐eddy interactions, and deterministic forms for the remaining classes. The kinetic energy spectra and meanfield resulting from large eddy simulations (LES) adopting these coefficients accurately replicate those of the reference simulation. The eddy‐eddy interactions are dominant, but all classes need to be parameterized for best results. For LES where baroclinic instability is explicitly resolved the stochastic variants out‐perform the deterministic ones across all scales. When baroclinic instability is not explicitly resolved, the stochastic variants out‐perform the deterministic cases at the large scales, but introduce some distortions at the smallest resolved scales. This study provides an assessment of the relevant strengths of the subgrid interaction classes in an idealized yet representative ocean. Article in Journal/Newspaper Antarc* Antarctic Directory of Open Access Journals: DOAJ Articles Antarctic Journal of Advances in Modeling Earth Systems 15 5 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
subgrid parameterization stochastic general circulation model climate topography eddies Physical geography GB3-5030 Oceanography GC1-1581 |
spellingShingle |
subgrid parameterization stochastic general circulation model climate topography eddies Physical geography GB3-5030 Oceanography GC1-1581 V. Kitsios J. S. Frederiksen T. J. O’Kane Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current |
topic_facet |
subgrid parameterization stochastic general circulation model climate topography eddies Physical geography GB3-5030 Oceanography GC1-1581 |
description |
Abstract The ocean circulation dynamics can be represented as a high‐dimensional multi‐scale nonlinear system with inhomogenous meanfields and topography. Numerical simulations of the ocean dynamics resolve the large scales of motion on a computational grid, with the unresolved subgrid interactions parameterized. These simulations are highly dependent upon the grid resolution, unless the subgrid terms are appropriately parameterized. There are five fundamental classes of subgrid interactions: eddy‐eddy; eddy‐topographic; eddy‐meanfield; meanfield‐meanfield; and meanfield‐topographic. Scale dependent parameterizations representing each of these interaction classes are presented here in oceanic flows for the first time. Subgrid parameterizations are calculated and validated in baroclinic quasi‐geostrophic simulations of idealized Antarctic Circumpolar Current flows with representative mean currents and ocean floor topography. The parameterization coefficients are derived from the coarse grained statistics of high resolution reference simulations in spectral space. Stochastic and deterministic parameterizations are developed for the eddy‐eddy interactions, and deterministic forms for the remaining classes. The kinetic energy spectra and meanfield resulting from large eddy simulations (LES) adopting these coefficients accurately replicate those of the reference simulation. The eddy‐eddy interactions are dominant, but all classes need to be parameterized for best results. For LES where baroclinic instability is explicitly resolved the stochastic variants out‐perform the deterministic ones across all scales. When baroclinic instability is not explicitly resolved, the stochastic variants out‐perform the deterministic cases at the large scales, but introduce some distortions at the smallest resolved scales. This study provides an assessment of the relevant strengths of the subgrid interaction classes in an idealized yet representative ocean. |
format |
Article in Journal/Newspaper |
author |
V. Kitsios J. S. Frederiksen T. J. O’Kane |
author_facet |
V. Kitsios J. S. Frederiksen T. J. O’Kane |
author_sort |
V. Kitsios |
title |
Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current |
title_short |
Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current |
title_full |
Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current |
title_fullStr |
Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current |
title_full_unstemmed |
Subgrid Parameterization of Eddy, Meanfield and Topographic Interactions in Simulations of an Idealized Antarctic Circumpolar Current |
title_sort |
subgrid parameterization of eddy, meanfield and topographic interactions in simulations of an idealized antarctic circumpolar current |
publisher |
American Geophysical Union (AGU) |
publishDate |
2023 |
url |
https://doi.org/10.1029/2022MS003412 https://doaj.org/article/364afdcee9e243d6b1b452fef2bd6428 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Journal of Advances in Modeling Earth Systems, Vol 15, Iss 5, Pp n/a-n/a (2023) |
op_relation |
https://doi.org/10.1029/2022MS003412 https://doaj.org/toc/1942-2466 1942-2466 doi:10.1029/2022MS003412 https://doaj.org/article/364afdcee9e243d6b1b452fef2bd6428 |
op_doi |
https://doi.org/10.1029/2022MS003412 |
container_title |
Journal of Advances in Modeling Earth Systems |
container_volume |
15 |
container_issue |
5 |
_version_ |
1771546411941232640 |