Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20–50 ka) - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Climate of the Past Année : 2016

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

Résumé

We reconstruct the geometry and strength of the Atlantic meridional overturning circulation during the Hein-rich stadial 2 and three Greenland interstadials of the 20– 50 ka period based on the comparison of new and published sedimentary 231 Pa / 230 Th data with simulated sedimentary 231 Pa / 230 Th. 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.
Fichier principal
Vignette du fichier
cp-12-2061-2016.pdf (3.94 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01587574 , version 1 (03-11-2017)

Identifiants

Citer

Pierre Burckel, Claire Waelbroeck, Yiming Luo, Didier M. Roche, Sylvain Pichat, et al.. Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20–50 ka). Climate of the Past, 2016, 12 (11), pp.2061-2075. ⟨10.5194/cp-12-2061-2016⟩. ⟨hal-01587574⟩
301 Consultations
114 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More