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dc.rights.licenseopenen_US
dc.contributor.authorGREEN, Ryan A.
dc.contributor.authorMENVIEL, Laurie
dc.contributor.authorMEISSNER, Katrin J.
dc.contributor.authorCROSTA, Xavier
dc.contributor.authorCHANDAN, Deepak
dc.contributor.authorLOHMANN, Gerrit
dc.contributor.authorPELTIER, W. Richard
dc.contributor.authorSHI, Xiaoxu
dc.contributor.authorZHU, Jiang
dc.date.accessioned2022-11-15T17:28:46Z
dc.date.available2022-11-15T17:28:46Z
dc.date.issued2022-04-20
dc.identifier.issn1814-9324en_US
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/170279
dc.description.abstractEnSouthern hemispheric sea-ice impacts ocean circulation and the carbon exchange between the atmosphere and the ocean. Sea-ice is therefore one of the key processes in past and future climate change and variability. As climate models are the only tool available to project future climate change, it is important to assess their performance against observations for a range of different climate states. The Last Glacial Maximum (LGM, ∼21 000 years ago) represents an interesting target as it is a relatively well-documented period with climatic conditions very different from preindustrial conditions. Here, we analyze the LGM seasonal Southern Ocean sea-ice cover as simulated in numerical simulations as part of the Paleoclimate Modelling Intercomparison Project (PMIP) phases 3 and 4. We compare the model outputs to a recently updated compilation of LGM seasonal Southern Ocean sea-ice cover and summer sea surface temperature (SST) to assess the most likely LGM Southern Ocean state. Simulations and paleo-proxy records suggest a fairly well-constrained glacial winter sea-ice edge between 50.5 and 51∘ S. However, the spread in simulated glacial summer sea-ice is wide, ranging from almost ice-free conditions to a sea-ice edge reaching 53∘ S. Combining model outputs and proxy data, we estimate a likely LGM summer sea-ice edge between 61 and 62∘ S and a mean summer sea-ice extent of 14–15×106 km2, which is ∼20 %–30 % larger than previous estimates. These estimates point to a higher seasonality of southern hemispheric sea-ice during the LGM than today. We also analyze the main processes defining the summer sea-ice edge within each of the models. We find that summer sea-ice cover is mainly defined by thermodynamic effects in some models, while the sea-ice edge is defined by the position of Southern Ocean upwelling in others. For models included in both PMIP3 and PMIP4, this thermodynamic or dynamic control on sea-ice is consistent across both experiments. Finally, we find that the impact of changes in large-scale ocean circulation on summer sea-ice within a single model is smaller than the natural range of summer sea-ice cover across the models considered here. This indicates that care must be taken when using a single model to reconstruct past climate regimes.
dc.language.isoENen_US
dc.rightsAttribution 3.0 United States*
dc.rights.urihttp://creativecommons.org/licenses/by/3.0/us/*
dc.title.enEvaluating seasonal sea-ice cover over the Southern Ocean at the Last Glacial Maximum
dc.typeArticle de revueen_US
dc.identifier.doi10.5194/cp-18-845-2022en_US
dc.subject.halSciences de l'environnementen_US
bordeaux.journalClimate of the Pasten_US
bordeaux.page845-862en_US
bordeaux.volume18en_US
bordeaux.hal.laboratoriesEPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805en_US
bordeaux.issue4en_US
bordeaux.institutionUniversité de Bordeauxen_US
bordeaux.institutionCNRSen_US
bordeaux.peerReviewedouien_US
bordeaux.inpressnonen_US
bordeaux.identifier.funderIDAustralian Research Councilen_US
hal.identifierinsu-03678656
hal.version1
hal.exportfalse
dc.rights.ccPas de Licence CCen_US
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Climate%20of%20the%20Past&rft.date=2022-04-20&rft.volume=18&rft.issue=4&rft.spage=845-862&rft.epage=845-862&rft.eissn=1814-9324&rft.issn=1814-9324&rft.au=GREEN,%20Ryan%20A.&MENVIEL,%20Laurie&MEISSNER,%20Katrin%20J.&CROSTA,%20Xavier&CHANDAN,%20Deepak&rft.genre=article


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