TY - JOUR

T1 - Dansgaard-Oeschger and Heinrich event temperature anomalies in the North Atlantic set by sea ice, frontal position and thermocline structure

AU - Pedro, J. B.

AU - Andersson, C.

AU - Vettoretti, G.

AU - Voelker, A. H.L.

AU - Waelbroeck, Claire

AU - Dokken, T. M.

AU - Jensen, M. F.

AU - Rasmussen, S. O.

AU - Sessford, E. G.

AU - Jochum, M.

AU - Nisancioglu, K. H.

N1 - Publisher Copyright: © 2022 The Authors

PY - 2022/8/1

Y1 - 2022/8/1

N2 - 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.

AB - 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.

KW - abrupt climate change

KW - Dansgaard-Oeschger event

KW - Heinrich event

KW - ice core

KW - marine sediment core

KW - sea ice

U2 - 10.1016/j.quascirev.2022.107599

DO - 10.1016/j.quascirev.2022.107599

M3 - Journal article

AN - SCOPUS:85132821879

VL - 289

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

SN - 0277-3791

M1 - 107599

ER -