Fast and slow components of interstadial warming in the North Atlantic during the last glacial

• Published in: Communications Earth & Environment
• Main Authors: Margari, Vasiliki, Skinner, Luke C., Menviel, Laurie, Capron, Emilie, Rhodes, Rachael H., Mleneck-Vautravers, Maryline J., Ezat, Mohamed M., Martrat, Belen, Grimalt, Joan O., Hodell, David A., Tzedakis, Polychronis C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: MILLENNIAL-SCALE VARIABILITY; ABRUPT CLIMATE-CHANGE; OCEAN; CIRCULATION; SYSTEM; OSCILLATIONS; SEDIMENTS; PATTERNS; RAINFALL; MONSOON; Greenland; Greenland ice core; Greenland ice cores; ice core; North Atlantic; Sea ice
• Online Access: https://curis.ku.dk/portal/da/publications/fast-and-slow-components-of-interstadial-warming-in-the-north-atlantic-during-the-last-glacial(b2f4faaf-089e-422e-8bcb-f034278a3195).html; https://doi.org/10.1038/s43247-020-0006-x; https://curis.ku.dk/ws/files/270164827/s43247_020_0006_x.pdf

The abrupt nature of warming events recorded in Greenland ice-cores during the last glacial has generated much debate over their underlying mechanisms. Here, we present joint marine and terrestrial analyses from the Portuguese Margin, showing a succession of cold stadials and warm interstadials over the interval 35-57 ka. Heinrich stadials 4 and 5 contain considerable structure, with a short transitional phase leading to an interval of maximum cooling and aridity, followed by slowly increasing sea-surface temperatures and moisture availability. A climate model experiment reproduces the changes in western Iberia during the final part of Heinrich stadial 4 as a result of the gradual recovery of the Atlantic meridional overturning circulation. What emerges is that Greenland ice-core records do not provide a unique template for warming events, which involved the operation of both fast and slow components of the coupled atmosphere-ocean-sea-ice system, producing adjustments over a range of timescales. Interstadial North Atlantic warming during the last glacial period involved the operation of both fast and slow components of the coupled atmosphere-ocean-sea-ice system, according to analyses from the Portuguese Margin and climate model simulations.