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

• Verfasst von: Burckel, Pierre [VerfasserIn]
• Verfasst von: Waelbroeck, Claire [VerfasserIn]
• Verfasst von: Luo, Yiming [VerfasserIn]
• Verfasst von: Roche, Didier M. [VerfasserIn]
• Verfasst von: Pichat, Sylvain [VerfasserIn]
• Verfasst von: Jaccard, Samuel L. [VerfasserIn]
• Verfasst von: Gherardi, Jeanne [VerfasserIn]
• Verfasst von: Govin, Aline [VerfasserIn]
• Verfasst von: Lippold, Jörg [VerfasserIn]
• Verfasst von: Thil, François [VerfasserIn]
• Titel: Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20-50 ka)
• Verf.angabe: Pierre Burckel, Claire Waelbroeck, Yiming Luo, Didier M. Roche, Sylvain Pichat, Samuel L. Jaccard, Jeanne Gherardi, Aline Govin, Jörg Lippold, and François Thil
• E-Jahr: 2016
• Jahr: 08 November 2016
• Umfang: 15 S.
• Illustrationen: Diagramme
• Teil: volume:12
• Teil: year:2016
• Teil: number:11
• Teil: pages:2061-2075
• Teil: extent:15
• Fussnoten: Gesehen am 21.07.2021
• Titel Quelle: Enthalten in: Climate of the past
• Ort Quelle: Katlenburg-Lindau : Copernicus Ges., 2005
• Jahr Quelle: 2016
• Band/Heft Quelle: 12(2016), 11, Seite 2061-2075
• ISSN Quelle: 1814-9332
• DOI: doi:10.5194/cp-12-2061-2016
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1764092007

Abstract

We reconstruct the geometry and strength of the Atlantic meridional overturning circulation during the Heinrich stadial 2 and three Greenland interstadials of the 20-50 ka period based on the comparison of new and published sedimentary ²³¹Pa / ²³⁰Th data with simulated sedimentary ²³¹Pa / ²³⁰Th. 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.</p>