North Atlantic Ice‐Rafting, Ocean and Atmospheric Circulation During the Holocene: Insights From Western Mediterranean Speleothems

• Published in: Geophysical Research Letters
• Main Authors: Brahim, Y. Ait, Wassenburg, J. A., Sha, L., Cruz, F. W.
• Format: Text
• Language: unknown
• Published: Digital Commons @ University of South Florida 2019
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: https://digitalcommons.usf.edu/kip_articles/7214; https://doi.org/10.1029/2019GL082405

In this study, we present a Holocene rainfall index based on three high-resolution speleothem records from the Western Mediterranean, a region under the influence of the westerly winds belt modulated by the North Atlantic Oscillation (NAO). On centennial to millennial timescales, we show that the North Atlantic ice-rafting events were likely associated with negative NAO-like conditions during the Early Holocene and the Late Holocene. However, our data reveal that this is not clearly the case for the mid-Holocene ice-rafting events, during which we also show evidence of positive NAO-like patterns from other paleo-oceanographic and paleo-atmospheric data. Hence, contradictory mechanisms involving prolonged periods of both north and south shifts of the westerly winds belt (resembling positive and negative NAO-like patterns) might at least partially trigger or amplify the ice-rafting events and the slowdown of the Atlantic Meridional Overturning Circulation.