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dc.contributor.authorGebbie, Geoffrey A.  Concept link
dc.date.accessioned2012-12-06T19:00:32Z
dc.date.available2014-10-22T08:57:23Z
dc.date.issued2012-09-06
dc.identifier.citationPaleoceanography 27 (2012): PA3225en_US
dc.identifier.urihttps://hdl.handle.net/1912/5597
dc.descriptionAuthor Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 27 (2012): PA3225, doi:10.1029/2011PA002273.en_US
dc.description.abstractThe midpoint of the Last Termination occurred 4,000 years earlier in the deep Atlantic than the deep Pacific according to a pair of benthic foraminiferal δ18O records, seemingly implying an internal circulation shift because the lag is much longer than the deep radiocarbon age. Here a scenario where the lag is instead caused by regional surface boundary condition changes, delays due to oceanic transit timescales, and the interplay between temperature and seawater δ18O (δ18Ow) is quantified with a tracer transport model of the modern-day ocean circulation. Using an inverse method with individual Green functions for 2,806 surface sources, a time history of surface temperature and δ18Ow is reconstructed for the last 30,000 years that is consistent with the foraminiferal oxygen-isotope data, Mg/Ca-derived deep temperature, and glacial pore water records. Thus, in the case that the ocean circulation was relatively unchanged between glacial and modern times, the interbasin lag could be explained by the relatively late local glacial maximum around Antarctica where surface δ18Ow continues to rise even after the North Atlantic δ18Ow falls. The arrival of the signal of the Termination is delayed at the Pacific core site due to the destructive interference of the still-rising Antarctic signal and the falling North Atlantic signal. This scenario is only possible because the ocean is not a single conveyor belt where all waters at the Pacific core site previously passed the Atlantic core site, but instead the Pacific core site is bathed more prominently by waters with a direct Antarctic source.en_US
dc.description.sponsorshipG.G. is supported by NSF grant OIA-1124880 and the WHOI Arctic Research Initiative.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2011PA002273
dc.subjectDeglaciationen_US
dc.subjectForaminiferal dataen_US
dc.subjectInverse methodsen_US
dc.subjectNumerical modelingen_US
dc.subjectOxygen-18en_US
dc.subjectTracersen_US
dc.titleTracer transport timescales and the observed Atlantic-Pacific lag in the timing of the Last Terminationen_US
dc.typeArticleen_US
dc.description.embargo2013-03-06en_US
dc.identifier.doi10.1029/2011PA002273


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