Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales
In this study, we assess systematically the impact of different initialisation procedures on the predictability of the sea ice in the Southern Ocean. These initialisation strategies are based on three data assimilation methods:the nudging, the particle filter with sequential importance resampling an...
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ftunistlouisbrus:oai:dial.uclouvain.be:boreal:158573 2024-05-12T07:53:55+00:00 Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales Zunz, Violette Goosse, Hugues Dubinkina, Svetlana UCL - SST/ELI/ELIC - Earth & Climate 2014 http://hdl.handle.net/2078.1/158573 https://doi.org/10.1007/s00382-014-2344-9 eng eng Springer-Verlag Germany boreal:158573 http://hdl.handle.net/2078.1/158573 doi:10.1007/s00382-014-2344-9 urn:ISSN:0930-7575 urn:EISSN:1432-0894 info:eu-repo/semantics/restrictedAccess Climate Dynamics, Vol. 44, no.7-8, p. 2267-2286 (2014) CISM:CECI Predictability Initialisation Data assimilation Southern Ocean Sea ice 1443 info:eu-repo/semantics/article 2014 ftunistlouisbrus https://doi.org/10.1007/s00382-014-2344-9 2024-04-18T17:50:49Z In this study, we assess systematically the impact of different initialisation procedures on the predictability of the sea ice in the Southern Ocean. These initialisation strategies are based on three data assimilation methods:the nudging, the particle filter with sequential importance resampling and the nudging proposal particle filter. An Earth system model of intermediate complexity is used to perform hindcast simulations in a perfect model approach. The predictability of the Antarctic sea ice at interannual to multi-decadal timescales is estimated through two aspects: the spread of the hindcast ensemble, indicating the uncertainty of the ensemble, and the correlation between the ensemble mean and the pseudo-observations, used to assess the accuracy of the prediction. Our results show that at decadal timescales more sophisticated data assimilation methods as well as denser pseudo-observations used to initialise the hindcasts decrease the spread of the ensemble. However, our experiments did not clearly demonstrate that one of the initialisation methods systematically provides with a more accurate prediction of the sea ice in the Southern Ocean than the others. Overall, the predictability at interannual timescales is limited to 3 years ahead at most. At multi-decadal timescales, the trends in sea ice extent computed over the time period just after the initialisation are clearly better correlated between the hindcasts and the pseudo-observations if the initialisation takes into account the pseudo-observations. The correlation reaches values larger than 0.5 in winter. This high correlation has likely its origin in the slow evolution of the ocean ensured by its strong thermal inertia, showing the importance of the quality of the initialisation below the sea ice. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean DIAL@USL-B (Université Saint-Louis, Bruxelles) Antarctic Southern Ocean The Antarctic Climate Dynamics 44 7-8 2267 2286 |
institution |
Open Polar |
collection |
DIAL@USL-B (Université Saint-Louis, Bruxelles) |
op_collection_id |
ftunistlouisbrus |
language |
English |
topic |
CISM:CECI Predictability Initialisation Data assimilation Southern Ocean Sea ice 1443 |
spellingShingle |
CISM:CECI Predictability Initialisation Data assimilation Southern Ocean Sea ice 1443 Zunz, Violette Goosse, Hugues Dubinkina, Svetlana Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales |
topic_facet |
CISM:CECI Predictability Initialisation Data assimilation Southern Ocean Sea ice 1443 |
description |
In this study, we assess systematically the impact of different initialisation procedures on the predictability of the sea ice in the Southern Ocean. These initialisation strategies are based on three data assimilation methods:the nudging, the particle filter with sequential importance resampling and the nudging proposal particle filter. An Earth system model of intermediate complexity is used to perform hindcast simulations in a perfect model approach. The predictability of the Antarctic sea ice at interannual to multi-decadal timescales is estimated through two aspects: the spread of the hindcast ensemble, indicating the uncertainty of the ensemble, and the correlation between the ensemble mean and the pseudo-observations, used to assess the accuracy of the prediction. Our results show that at decadal timescales more sophisticated data assimilation methods as well as denser pseudo-observations used to initialise the hindcasts decrease the spread of the ensemble. However, our experiments did not clearly demonstrate that one of the initialisation methods systematically provides with a more accurate prediction of the sea ice in the Southern Ocean than the others. Overall, the predictability at interannual timescales is limited to 3 years ahead at most. At multi-decadal timescales, the trends in sea ice extent computed over the time period just after the initialisation are clearly better correlated between the hindcasts and the pseudo-observations if the initialisation takes into account the pseudo-observations. The correlation reaches values larger than 0.5 in winter. This high correlation has likely its origin in the slow evolution of the ocean ensured by its strong thermal inertia, showing the importance of the quality of the initialisation below the sea ice. |
author2 |
UCL - SST/ELI/ELIC - Earth & Climate |
format |
Article in Journal/Newspaper |
author |
Zunz, Violette Goosse, Hugues Dubinkina, Svetlana |
author_facet |
Zunz, Violette Goosse, Hugues Dubinkina, Svetlana |
author_sort |
Zunz, Violette |
title |
Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales |
title_short |
Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales |
title_full |
Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales |
title_fullStr |
Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales |
title_full_unstemmed |
Impact of the initialisation on the predictability of the Southern Ocean sea ice at interannual to multi-decadal timescales |
title_sort |
impact of the initialisation on the predictability of the southern ocean sea ice at interannual to multi-decadal timescales |
publisher |
Springer-Verlag Germany |
publishDate |
2014 |
url |
http://hdl.handle.net/2078.1/158573 https://doi.org/10.1007/s00382-014-2344-9 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_source |
Climate Dynamics, Vol. 44, no.7-8, p. 2267-2286 (2014) |
op_relation |
boreal:158573 http://hdl.handle.net/2078.1/158573 doi:10.1007/s00382-014-2344-9 urn:ISSN:0930-7575 urn:EISSN:1432-0894 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1007/s00382-014-2344-9 |
container_title |
Climate Dynamics |
container_volume |
44 |
container_issue |
7-8 |
container_start_page |
2267 |
op_container_end_page |
2286 |
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1798845520901308416 |