georefid:2012-069080SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2012-0690802012-01-01publicationgeorefid:2012-069080Govin, AlineInstitute Pierre Simon Laplace, Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvette, FranceauthorBraconnot, PascaleUniversity of Bergen, NorwayauthorCapron, EmilieauthorCortijo, ElsaauthorDuplessy, Jean-ClaudeauthorJansen, EysteinauthorLabeyrie, LaurentauthorLandais, AmaelleauthorMarti, OlivierauthorMichel, ElisabethauthorMosquet, EloiauthorRisebrobakken, BjorgauthorSwingedouw, DidierauthorWaelbroeck, ClaireauthorCopernicus, Katlenburg-Lindau, InternationalpublisherdocumentDigitalClimate of the Past8 (2)483-507Although the Last Interglacial (LIG) is often considered as a possible analogue for future climate in high latitudes, its precise climate evolution and associated causes remain uncertain. Here we compile high-resolution marine sediment records from the North Atlantic, Labrador Sea, Norwegian Sea and the Southern Ocean. We document a delay in the establishment of peak interglacial conditions in the North Atlantic, Labrador and Norwegian Seas as compared to the Southern Ocean. In particular, we observe a persistent iceberg melting at high northern latitudes at the beginning of the LIG. It is associated with (1) colder and fresher surface-water conditions in the North Atlantic, Labrador and Norwegian Seas, and (2) a weaker ventilation of North Atlantic deep waters during the early LIG (129-125 ka) compared to the late LIG. Results from an ocean-atmosphere coupled model with insolation as a sole forcing for three key periods of the LIG show warmer North Atlantic surface waters and stronger Atlantic overturning during the early LIG (126 ka) than the late LIG (122 ka). Hence, insolation variations alone do not explain the delay in peak interglacial conditions observed at high northern latitudes. Additionally, we consider an idealized meltwater scenario at 126 ka where the freshwater input is interactively computed in response to the high boreal summer insolation. The model simulates colder, fresher North Atlantic surface waters and weaker Atlantic overturning during the early LIG (126 ka) compared to the late LIG (122 ka). This result suggests that both insolation and ice sheet melting have to be considered to reproduce the climatic pattern that we identify during the early LIG. Our model-data comparison also reveals a number of limitations and reinforces the need for further detailed investigations using coupled climate-ice sheet models and transient simulations.completedQuaternary geologyaliphatic hydrocarbonsalkanesArctic OceanArctic regionAtlantic Oceanboreal environmentC-13C-13/C-12carboncarbon dioxideCenozoicclimate forcingdetritusForaminiferaglacial geologyGreenlandGreenland ice sheethydrocarbonsice raftingice sheetsicebergsinsolationinterglacial environmentInvertebrataIPSL-CM4isotope ratiosisotopesLabrador SeaLeg 162meltingmeltwatermethanemicrofossilsMIS 5nitrous oxideNorth AtlanticNorwegian SeaO-18/O-16Ocean Drilling ProgramODP Site 980organic compoundsoxygenpaleoclimatologyPleistoceneProtistaQuaternaryRockall Bankstable isotopesterrestrial environmenturn:org.iodp:exp:162urnlargerWorkCitationcampaignurn:org.iodp:exp:162:site:980urnlargerWorkCitationstudyurn:org.iodp:exp:162urnlargerWorkCitationcampaignEnglishgeoscientificInformation-14.4208-14.420855.290655.2906Published in Climate of the Past Discussion: 11 October 2011, http://www.clim-past-discuss.net/7/3239/2011/cpd-7-3239-2011.html; accessed in June, 2012application/pdfunknownSEDIS Publication Catalogue

ana.macario@awi.de

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