Oceanic stochastic parametrizations in a seasonal forecast system
Stochastic parametrization provides a methodology for representing model uncertainty in ensemble forecasts. Here we study the impact of three existing stochastic parametrizations in the ocean component of a coupled model, on forecast reliability over seasonal timescales. The relative impacts of thes...
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American Meteorological Society
2016
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Online Access: | https://doi.org/10.1175/MWR-D-15-0245.1 https://ora.ox.ac.uk/objects/uuid:6d159eef-a26a-47c3-95c6-bd4c2c5c954a |
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ftuloxford:oai:ora.ox.ac.uk:uuid:6d159eef-a26a-47c3-95c6-bd4c2c5c954a 2024-10-06T13:52:58+00:00 Oceanic stochastic parametrizations in a seasonal forecast system Andrejczuk, M Cooper, F Juricke, S Palmer, T Weisheimer, A Zanna, L 2016-07-28 https://doi.org/10.1175/MWR-D-15-0245.1 https://ora.ox.ac.uk/objects/uuid:6d159eef-a26a-47c3-95c6-bd4c2c5c954a unknown American Meteorological Society doi:10.1175/MWR-D-15-0245.1 https://ora.ox.ac.uk/objects/uuid:6d159eef-a26a-47c3-95c6-bd4c2c5c954a https://doi.org/10.1175/MWR-D-15-0245.1 info:eu-repo/semantics/openAccess CC Attribution (CC BY) Journal article 2016 ftuloxford https://doi.org/10.1175/MWR-D-15-0245.1 2024-09-06T07:47:35Z Stochastic parametrization provides a methodology for representing model uncertainty in ensemble forecasts. Here we study the impact of three existing stochastic parametrizations in the ocean component of a coupled model, on forecast reliability over seasonal timescales. The relative impacts of these schemes upon the ocean mean state and ensemble spread are analyzed. The oceanic variability induced by the atmospheric forcing of the coupled system is, in most regions, the major source of ensemble spread. The largest impact on spread and bias came from the Stochastically Perturbed Parametrization Tendency (SPPT) scheme - which has proven particularly effective in the atmosphere. The key regions affected are eddy-active regions, namely the western boundary currents and the Southern Ocean where ensemble spread is increased. However, unlike its impact in the atmosphere, SPPT in the ocean did not result in a significant decrease in forecast error. Whilst there are good grounds for implementing stochastic schemes in ocean models, our results suggest that they will have to be more sophisticated. Some suggestions for next-generation stochastic schemes are made. Article in Journal/Newspaper Southern Ocean ORA - Oxford University Research Archive Southern Ocean Monthly Weather Review 144 5 1867 1875 |
institution |
Open Polar |
collection |
ORA - Oxford University Research Archive |
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ftuloxford |
language |
unknown |
description |
Stochastic parametrization provides a methodology for representing model uncertainty in ensemble forecasts. Here we study the impact of three existing stochastic parametrizations in the ocean component of a coupled model, on forecast reliability over seasonal timescales. The relative impacts of these schemes upon the ocean mean state and ensemble spread are analyzed. The oceanic variability induced by the atmospheric forcing of the coupled system is, in most regions, the major source of ensemble spread. The largest impact on spread and bias came from the Stochastically Perturbed Parametrization Tendency (SPPT) scheme - which has proven particularly effective in the atmosphere. The key regions affected are eddy-active regions, namely the western boundary currents and the Southern Ocean where ensemble spread is increased. However, unlike its impact in the atmosphere, SPPT in the ocean did not result in a significant decrease in forecast error. Whilst there are good grounds for implementing stochastic schemes in ocean models, our results suggest that they will have to be more sophisticated. Some suggestions for next-generation stochastic schemes are made. |
format |
Article in Journal/Newspaper |
author |
Andrejczuk, M Cooper, F Juricke, S Palmer, T Weisheimer, A Zanna, L |
spellingShingle |
Andrejczuk, M Cooper, F Juricke, S Palmer, T Weisheimer, A Zanna, L Oceanic stochastic parametrizations in a seasonal forecast system |
author_facet |
Andrejczuk, M Cooper, F Juricke, S Palmer, T Weisheimer, A Zanna, L |
author_sort |
Andrejczuk, M |
title |
Oceanic stochastic parametrizations in a seasonal forecast system |
title_short |
Oceanic stochastic parametrizations in a seasonal forecast system |
title_full |
Oceanic stochastic parametrizations in a seasonal forecast system |
title_fullStr |
Oceanic stochastic parametrizations in a seasonal forecast system |
title_full_unstemmed |
Oceanic stochastic parametrizations in a seasonal forecast system |
title_sort |
oceanic stochastic parametrizations in a seasonal forecast system |
publisher |
American Meteorological Society |
publishDate |
2016 |
url |
https://doi.org/10.1175/MWR-D-15-0245.1 https://ora.ox.ac.uk/objects/uuid:6d159eef-a26a-47c3-95c6-bd4c2c5c954a |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
doi:10.1175/MWR-D-15-0245.1 https://ora.ox.ac.uk/objects/uuid:6d159eef-a26a-47c3-95c6-bd4c2c5c954a https://doi.org/10.1175/MWR-D-15-0245.1 |
op_rights |
info:eu-repo/semantics/openAccess CC Attribution (CC BY) |
op_doi |
https://doi.org/10.1175/MWR-D-15-0245.1 |
container_title |
Monthly Weather Review |
container_volume |
144 |
container_issue |
5 |
container_start_page |
1867 |
op_container_end_page |
1875 |
_version_ |
1812181575714996224 |