Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20-50 ka)

Type Article
Date 2016-11
Language English
Author(s) Burckel PierreORCID1, 2, Waelbroeck Claire1, Luo Yiming3, Roche Didier M.ORCID1, 4, Pichat Sylvain5, Jaccard Samuel L.6, 7, Gherardi Jeanne1, Govin AlineORCID1, Lippold Jörg6, 7, Thil Francois1
Affiliation(s) 1 : Univ Paris Saclay, CEA CNRS UVSQ, LSCE IPSL, Lab Sci Climat & Environm, F-91191 Gif Sur Yvette, France.
2 : Univ Sorbonne Paris Cite, Inst Phys Globe Paris, F-75238 Paris, France.
3 : Dalhousie Univ, Dept Oceanog, 1355 Oxford St,POB 15000, Halifax, NS B3H 4J1, Canada.
4 : Vrije Univ Amsterdam, Fac Earth & Life Sci, Earth & Climate Cluster, Dept Earth Sci, Amsterdam, Netherlands.
5 : Ecole Normale Super Lyon, Lab Geol Lyon LGL TPE, 46 Allee Italie, F-69007 Lyon, France.
6 : Univ Bern, Inst Geol Sci, Baltzerstr 1 & 3, CH-3012 Bern, Switzerland.
7 : Univ Bern, Oeschger Ctr Climate Change Res, Baltzerstr 1 & 3, CH-3012 Bern, Switzerland.
Source Climate Of The Past (1814-9324) (Copernicus Gesellschaft Mbh), 2016-11 , Vol. 12 , N. 11 , P. 2061-2075
DOI 10.5194/cp-12-2061-2016
WOS© Times Cited 22
Abstract

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 southern-sourced deep water was likely larger than that of the modern Antarctic bottom water (AABW). Our results further show that during Heinrich stadial 2, the deep Atlantic was probably directly affected by a southern-sourced water mass below 2500 m depth, while a slow, southward-flowing water mass originating from the North Atlantic likely influenced depths between 1500 and 2500 m down to the equator.

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Publisher's official version 15 3 MB Open access
Supplement title page 17 1 MB Open access
Supplementary material 13 1 MB Open access
Table S02-MD09-3256Q-Age Model 9 KB Open access
Table S06-Opal 9 KB Open access
Table S07-MD09-3256Q-Pa Th 13 KB Open access
Table S08-SU90-03-PaTh 11 KB Open access
Table S09-MD09-3256Q-d13C 14 KB Open access
Table S10-MD09-3256Q-TiCa 14 KB Open access
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How to cite 

Burckel Pierre, Waelbroeck Claire, Luo Yiming, Roche Didier M., Pichat Sylvain, Jaccard Samuel L., Gherardi Jeanne, Govin Aline, Lippold Jörg, Thil Francois (2016). Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20-50 ka). Climate Of The Past, 12(11), 2061-2075. Publisher's official version : https://doi.org/10.5194/cp-12-2061-2016 , Open Access version : https://archimer.ifremer.fr/doc/00421/53212/