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

• Published in: Communications Earth & Environment
• Main Authors: Margari, V, Skinner, LC, Menviel, L, Capron, E, Rhodes, RH, Mleneck-Vautravers, MJ, Ezat, MM, Martrat, B, Grimalt, JO, Hodell, DA, Tzedakis, PC
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer Nature 2020
• Subjects: 13 Climate Action; Greenland; Greenland ice core; Greenland ice cores; ice core; North Atlantic; Sea ice
• Online Access: http://hdl.handle.net/1959.4/unsworks_79025; https://doi.org/10.1038/s43247-020-0006-x

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.