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| Lippold, Jorg; Gherardi, Jeanne Marie; Luo, Yiming. |
| Variations of the Atlantic Meridional Overturning Circulation (AMOC) are believed to have crucially influenced Earth's climate due to its key role in the inter-hemispheric redistribution of heat and carbon. To assess its past strength, the sedimentary Pa-231/Th-230 proxy has been developed and improved but also contested due to its sensitivity to other factors beyond ocean circulation. In order to provide a better basis for the understanding of the Atlantic Pa-231/Th-230 system, and therefore to shed light on the controversy, we compare new measurements of Holocene sediments from the north Brazilian margin to water column data and the output of a two-dimensional scavenging-circulation model, based on modern circulation patterns and reversible scavenging... |
| Tipo: Text |
Palavras-chave: 231Pa/230Th; Atlantic Meridional Overturning Circulation; Holocene; Deep sea sediments. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00215/32576/31045.pdf |
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| Burckel, Pierre; Waelbroeck, Claire; Luo, Yiming; Roche, Didier M.; Pichat, Sylvain; Jaccard, Samuel L.; Gherardi, Jeanne; Govin, Aline; Lippold, Jörg; Thil, Francois. |
| We reconstruct the geometry and strength of the Atlantic meridional overturning circulation during the Heinrich stadial 2 and three Greenland interstadials of the 2050 ka period based on the comparison of new and published sedimentary Pa-231/Th-230 data with simulated sedimentary Pa-231/Th-230. We show that the deep Atlantic circulation during these interstadials was very different from that of the Holocene. Northern-sourced waters likely circulated above 2500 m depth, with a flow rate lower than that of the present-day North Atlantic deep water (NADW). Southern-sourced deep waters most probably flowed northwards below 4000 m depth into the North Atlantic basin and then southwards as a return flow between 2500 and 4000 m depth. The flow rate of this... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53212/54867.pdf |
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