DO-like events of the penultimate climate cycle: the loess point of view

• Main Authors: Rousseau, Denis-Didier, Antoine, Pierre, Boers, Niklas, Lagroix, France, Ghil, Michael, Lomax, Johanna, Fuchs, Markus, Debret, Maxime, Hatté, Christine, Moine, Olivier, Gauthier, Caroline, Jordanova, Diana, Jordanova, Neli
• Format: Text
• Language: English
• Published: 2019
• Subjects: Greenland; Greenland ice core; ice core
• Online Access: https://doi.org/10.5194/cp-2019-122; https://www.clim-past-discuss.net/cp-2019-122/

The global character of the millennial-scale climate variability associated with the Dansgaard-Oeschger (DO) events in Greenland has been well-established for the last glacial cycle. Mainly due to the sparsity of reliable data, however, the spatial coherence of corresponding variability during the penultimate cycle is less clear. New investigations of European loess records from MIS 6 reveal the occurrence of alternating loess intervals and paleosols (incipient soil horizons), similar to those from the last climatic cycle. These paleosols are correlated based on their stratigraphical position and numbers, and available optically stimulated luminescence (OSL) dates with interstadials described in various Northern Hemisphere records as well as in GLt_syn, the synthetic 800-kyr record of Greenland ice core δ 18 O. Therefore, referring to the interstadials described in the record of the last climate cycle in European loess sequences, the MIS 6 interstadials can confidently be interpreted as DO-like events of the penultimate climate cycle. The statistical similarity between the millennial-scale loess-paleosol oscillations during the last and penultimate climate cycle provides direct empirical evidence that the cycles of the penultimate cycle are indeed of the same nature as the DO cycles originally discovered for the last glacial cycle. Our results thus imply that their underlying cause and global imprint was characteristic of at least the last two climate cycles.