North Atlantic ice‐rafting, ocean and atmospheric circulation during the Holocene: insights from Western Mediterranean speleothems

• Published in: Geophysical Research Letters
• Main Authors: Brahim, Yassine Ait, Wassenburg, J., Sha, L., Cruz, F., Deininger, M., Sifeddine, Abdelfettah, Bouchaou, Lhoussaine, Spötl, Christoph, Edwards, R., Cheng, H.
• Other Authors: Institute of Global Environmental Change China (IGEC), Xi'an Jiaotong University (Xjtu), Climate Geochemistry Department Mainz, Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Instituto de Geociências, Universidade de São Paulo, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Ibn Zohr Agadir, Department of Geology and Palaeontology, Leopold Franzens Universität Innsbruck - University of Innsbruck, University of Minnesota Twin Cities (UMN), University of Minnesota System
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; [SDU]Sciences of the Universe [physics]; North Atlantic; North Atlantic oscillation
• Online Access: https://hal.science/hal-02416060; https://hal.science/hal-02416060/document; https://hal.science/hal-02416060/file/2019GL082405.pdf; https://doi.org/10.1029/2019GL082405

International audience In this study, we present a Holocene rainfall index based on three high‐resolution speleothemrecords from the Western Mediterranean, a region under the influence of the westerly winds belt modulatedby the North Atlantic Oscillation (NAO). On centennial to millennial timescales, we show that the NorthAtlantic ice‐rafting events were likely associated with negative NAO‐like conditions during the EarlyHolocene and the Late Holocene. However, our data reveal that this is not clearly the case for themid‐Holocene ice‐rafting events, during which we also show evidence of positive NAO‐like patterns fromother paleo‐oceanographic and paleo‐atmospheric data. Hence, contradictory mechanisms involvingprolonged periods of both north and south shifts of the westerly winds belt (resembling positive and negativeNAO‐like patterns) might at least partially trigger or amplify the ice‐rafting events and the slowdownof the Atlantic Meridional Overturning Circulation