Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models
Advancing the representation of uncertainties in ocean general circulation numerical models is required for several applications, ranging from data assimilation to climate monitoring and extended-range prediction systems. The atmospheric forcing represents one of the main uncertainty sources in nume...
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2023
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ftdoajarticles:oai:doaj.org/article:1193439d710a44a9a9e3bd1ed7335231 2023-05-15T15:13:28+02:00 Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models Andrea Storto Chunxue Yang 2023-03-01T00:00:00Z https://doi.org/10.3389/fmars.2023.1155803 https://doaj.org/article/1193439d710a44a9a9e3bd1ed7335231 EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2023.1155803/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2023.1155803 https://doaj.org/article/1193439d710a44a9a9e3bd1ed7335231 Frontiers in Marine Science, Vol 10 (2023) air-sea fluxes ensemble generation stochastic physics bulk formulas ocean simulations Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2023 ftdoajarticles https://doi.org/10.3389/fmars.2023.1155803 2023-03-26T01:36:23Z Advancing the representation of uncertainties in ocean general circulation numerical models is required for several applications, ranging from data assimilation to climate monitoring and extended-range prediction systems. The atmospheric forcing represents one of the main uncertainty sources in numerical ocean models. Here, we formulate and revise different approaches to perturb the air-sea fluxes used within the atmospheric boundary conditions. In particular, perturbation of the fluxes is performed either through i) stochastic modulation of the air-sea transfer coefficients; ii) stochastic modulation of the air-sea flux tendencies; iii) coarse-graining of stochastic sub-grid computation of the fluxes; or iv) multiple bulk formulas. The schemes are implemented and tested in the NEMO4 ocean model, implemented at an eddy-permitting resolution on a domain covering the North Atlantic and Arctic oceans and the Mediterranean Sea. A series of 22-year 4-member ensemble experiments with different stochastic schemes are performed and analyzed for the period 2000-2021, and results are compared in terms of the ensemble mean and, when applicable, ensemble spread of the principal oceanic diagnostics. Results indicate that the schemes, in general, can significantly improve some verification skill scores (e.g. against drifter current speed, SST analyses, and hydrographic profiles) and, in some cases, enhance the mesoscale activity and weaken the large-scale circulation. The response, however, is different depending on the specific scheme, whose choice thus depends on the target application, as detailed in the paper. These findings foster the adoption of these schemes in both extended-range operational ocean forecasts and coupled long-range climate prediction systems, where the boundary conditions perturbations may contribute to performance increases. Article in Journal/Newspaper Arctic North Atlantic Directory of Open Access Journals: DOAJ Articles Arctic Frontiers in Marine Science 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
air-sea fluxes ensemble generation stochastic physics bulk formulas ocean simulations Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
air-sea fluxes ensemble generation stochastic physics bulk formulas ocean simulations Science Q General. Including nature conservation geographical distribution QH1-199.5 Andrea Storto Chunxue Yang Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
topic_facet |
air-sea fluxes ensemble generation stochastic physics bulk formulas ocean simulations Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
Advancing the representation of uncertainties in ocean general circulation numerical models is required for several applications, ranging from data assimilation to climate monitoring and extended-range prediction systems. The atmospheric forcing represents one of the main uncertainty sources in numerical ocean models. Here, we formulate and revise different approaches to perturb the air-sea fluxes used within the atmospheric boundary conditions. In particular, perturbation of the fluxes is performed either through i) stochastic modulation of the air-sea transfer coefficients; ii) stochastic modulation of the air-sea flux tendencies; iii) coarse-graining of stochastic sub-grid computation of the fluxes; or iv) multiple bulk formulas. The schemes are implemented and tested in the NEMO4 ocean model, implemented at an eddy-permitting resolution on a domain covering the North Atlantic and Arctic oceans and the Mediterranean Sea. A series of 22-year 4-member ensemble experiments with different stochastic schemes are performed and analyzed for the period 2000-2021, and results are compared in terms of the ensemble mean and, when applicable, ensemble spread of the principal oceanic diagnostics. Results indicate that the schemes, in general, can significantly improve some verification skill scores (e.g. against drifter current speed, SST analyses, and hydrographic profiles) and, in some cases, enhance the mesoscale activity and weaken the large-scale circulation. The response, however, is different depending on the specific scheme, whose choice thus depends on the target application, as detailed in the paper. These findings foster the adoption of these schemes in both extended-range operational ocean forecasts and coupled long-range climate prediction systems, where the boundary conditions perturbations may contribute to performance increases. |
format |
Article in Journal/Newspaper |
author |
Andrea Storto Chunxue Yang |
author_facet |
Andrea Storto Chunxue Yang |
author_sort |
Andrea Storto |
title |
Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
title_short |
Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
title_full |
Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
title_fullStr |
Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
title_full_unstemmed |
Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
title_sort |
stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models |
publisher |
Frontiers Media S.A. |
publishDate |
2023 |
url |
https://doi.org/10.3389/fmars.2023.1155803 https://doaj.org/article/1193439d710a44a9a9e3bd1ed7335231 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic North Atlantic |
genre_facet |
Arctic North Atlantic |
op_source |
Frontiers in Marine Science, Vol 10 (2023) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2023.1155803/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2023.1155803 https://doaj.org/article/1193439d710a44a9a9e3bd1ed7335231 |
op_doi |
https://doi.org/10.3389/fmars.2023.1155803 |
container_title |
Frontiers in Marine Science |
container_volume |
10 |
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1766344024094932992 |