Dansgaard-Oeschger and Heinrich event temperature anomalies in the North Atlantic set by sea ice, frontal position and thermocline structure

• Published in: Quaternary Science Reviews
• Main Authors: Pedro, J. B., Andersson, C., Vettoretti, G., Voelker, A. H. L., Waelbroeck, Claire, Dokken, T. M., Jensen, M. F., Rasmussen, S. O., Sessford, E. G., Jochum, M., Nisancioglu, K. H.
• Other Authors: Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Institute for Marine and Antarctic Studies Hobart (IMAS), University of Tasmania Hobart, Australia (UTAS), IT University of Copenhagen (ITU), Norwegian Research Center (NORCE), Instituto Português de Investigação do Mar e da Atmosfera (IPMA), Centro de Ciências do Mar Faro (CCMAR), Universidade do Algarve (UAlg), Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Earth Science Bergen (UiB), University of Bergen (UiB), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences Bergen (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Center for Earth Evolution and Dynamics, University of Oslo, University of Oslo (UiO), European Project: 610055,EC:FP7:ERC,ERC-2013-SyG,ICE2ICE(2014), European Project: 339108,EC:FP7:ERC,ERC-2013-ADG,ACCLIMATE(2014)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Dansgaard-Oeschger event; Heinrich event; abrupt climate change; marine sediment core; ice core; sea ice; [SDU]Sciences of the Universe [physics]; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Arctic; Greenland; Nordic Seas; North Atlantic; Sea ice
• Online Access: https://insu.hal.science/insu-03746437; https://insu.hal.science/insu-03746437/document; https://insu.hal.science/insu-03746437/file/1-s2.0-S027737912200230X-main.pdf; https://doi.org/10.1016/j.quascirev.2022.107599

International audience We use eighteen timescale-synchronised near-surface temperature reconstructions spanning 10-50 thousand years before present to clarify the regional expression of Dansgaard-Oeschger (D-O) and Heinrich (H) events in the North Atlantic. The North Atlantic Drift region shows D-O temperature variations of ca. 2-5° with Greenland-like structure. The Western Iberian Margin region also shows Greenland-like structure, but with more pronounced surface cooling between interstadials and Heinrich stadials (ca. 6-9 °C) than between interstadials and non-Heinrich stadials (ca. 2-3 °C). The southern Nordic Seas show smaller D-O temperature anomalies (ca. 1-2 °C) that appear out of phase with Greenland. These spatial patterns are replicated in a new global climate model simulation that features unforced (D-O-like) and freshwater forced (H-like) abrupt climate changes. The model simulations and observations suggest consistently that the spatial expression and amplitude of D-O and H event temperature anomalies are dominated by coupled changes in the Atlantic Meridional Overturning, sea ice extent, polar front position and thermocline structure.