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dc.contributor.authorDanabasoglu, Gokhan  Concept link
dc.contributor.authorYeager, Stephen G.  Concept link
dc.contributor.authorKwon, Young-Oh  Concept link
dc.contributor.authorTribbia, Joseph J.  Concept link
dc.contributor.authorPhillips, Adam S.  Concept link
dc.contributor.authorHurrell, James W.  Concept link
dc.date.accessioned2012-09-05T14:36:11Z
dc.date.available2014-10-22T08:57:23Z
dc.date.issued2012-08-01
dc.identifier.citationJournal of Climate 25 (2012): 5153–5172en_US
dc.identifier.urihttps://hdl.handle.net/1912/5360
dc.descriptionAuthor Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 25 (2012): 5153–5172, doi:10.1175/JCLI-D-11-00463.1.en_US
dc.description.abstractAtlantic meridional overturning circulation (AMOC) variability is documented in the Community Climate System Model, version 4 (CCSM4) preindustrial control simulation that uses nominal 1° horizontal resolution in all its components. AMOC shows a broad spectrum of low-frequency variability covering the 50–200-yr range, contrasting sharply with the multidecadal variability seen in the T85 × 1 resolution CCSM3 present-day control simulation. Furthermore, the amplitude of variability is much reduced in CCSM4 compared to that of CCSM3. Similarities as well as differences in AMOC variability mechanisms between CCSM3 and CCSM4 are discussed. As in CCSM3, the CCSM4 AMOC variability is primarily driven by the positive density anomalies at the Labrador Sea (LS) deep-water formation site, peaking 2 yr prior to an AMOC maximum. All processes, including parameterized mesoscale and submesoscale eddies, play a role in the creation of salinity anomalies that dominate these density anomalies. High Nordic Sea densities do not necessarily lead to increased overflow transports because the overflow physics is governed by source and interior region density differences. Increased overflow transports do not lead to a higher AMOC either but instead appear to be a precursor to lower AMOC transports through enhanced stratification in LS. This has important implications for decadal prediction studies. The North Atlantic Oscillation (NAO) is significantly correlated with the positive boundary layer depth and density anomalies prior to an AMOC maximum. This suggests a role for NAO through setting the surface flux anomalies in LS and affecting the subpolar gyre circulation strength.en_US
dc.description.sponsorshipThe CCSM project is supported by NSF and the Office of Science (BER) of the U.S. Department of Energy. SGY and YOK were supported by the NOAA Climate Program Office under Climate Variability and Predictability Program Grants NA09OAR4310163 and NA10OAR4310202, respectively.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Meteorological Societyen_US
dc.relation.urihttps://doi.org/10.1175/JCLI-D-11-00463.1
dc.subjectMeridional overturning circulationen_US
dc.subjectCoupled modelsen_US
dc.subjectOcean modelsen_US
dc.subjectOceanic variabilityen_US
dc.titleVariability of the Atlantic meridional overturning circulation in CCSM4en_US
dc.typeArticleen_US
dc.description.embargo2013-02-01en_US
dc.identifier.doi10.1175/JCLI-D-11-00463.1


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