Stalagmite-inferred European westerly drift in the early Weichselian with centennial-scale variability in marine isotope stage 5a

• Main Authors: Chung Yun-Chuan, Menviel Laurie, Marchionne Arianna, Mii Horng-Sheng, Michel Véronique, Valensi Patricia, Jiang Xiuyang, Simon Patrick, Rossoni-Notter Elena, Moussous Abdelkader, Seppä Heikki, Chien Yu-Tang, Wu Chung-Che, Hu Hsun-Ming, Shen Chuan-Chou
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: https://zenodo.org/record/7386291; https://doi.org/10.5281/zenodo.7386291

The Weichselian glaciation is characterized by significant ocean circulation variations starting from ∼115 thousand years ago (ka) and terminating at ∼11.5 ka. The early Weichselian (115–74 ka), especially marine isotope stage (MIS) 5a at 85–74 ka, provides a window for understanding the linkage between the European westerlies and Mediterranean climate. However, lack of highly-resolved paleoclimate records with absolute chronologies hampers our knowledge of decadal-to-centennial-scale climate changes and forcings in the circum-Mediterranean realm. Here, we present 230Th-dated stalagmite-inferred hydroclimate records from Observatoire cave (43°44′ N, 7°25′ E), Monaco, for the period between 88.7 ± 0.4 and 80.3 ± 0.1 ka, covering portions of MIS 5b and 5a. Agreement between Observatoire and circum-Mediterranean stalagmite records confirm large-scale warming over the Atlantic-Europe territory during the transition from MIS 5b to 5a. Subdecadally-resolved Observatoire δ18O and δ13C records express four multi-centennial arid intervals in southern Europe at 84–80 ka in the first-half of MIS 5a, suggesting centennial westerly drifts, a finding supported by a model simulation. Westerly changes and associated arid events can be attributed to slowdowns of the Atlantic meridional overturning circulation, North Atlantic Oscillation states, and solar activity.