Late-glacial elevated dust deposition linked to westerly wind shifts in southern South America

• Published in: Scientific Reports
• Main Authors: Vanneste, Heleen, De Vleeschouwer, François, Martínez-Cortizas, Antonio, von Scheffer, Clemens, Piotrowska, Natalia, Coronato, Andrea, Le Roux, Gaël
• Other Authors: Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Universidade de Santiago de Compostela Spain (USC ), Silesian University of Technology, Centro Austral de Investigaciones Científicas Ushuaia (CADIC), Consejo Nacional de Investigaciones Científicas y Técnicas Buenos Aires (CONICET)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: Tierra del Fuego; Dust; Winds; Westerlies; Mineral dust; Peatlands; Holocene; Glaciers; envir; geo; Antarctic; Patagonia; The Antarctic; Antarc*
• Online Access: https://doi.org/10.1038/srep11670; https://hal.archives-ouvertes.fr/hal-01517029/file/vanneste_17701.pdf; https://hal.archives-ouvertes.fr/hal-01517029

International audience Atmospheric dust loadings play a crucial role in the global climate system. Southern South America is a key dust source, however, dust deposition rates remain poorly quantified since the last glacial termination (~17 kyr ago), an important timeframe to anticipate future climate changes. Here we use isotope and element geochemistry in a peat archive from Tierra del Fuego, to reconstruct atmospheric dust fluxes and associated environmental and westerly wind changes for the past 16.2 kyr. Dust depositions were elevated during the Antarctic Cold Reversal (ACR) and second half of the Younger Dryas (YD) stadial, originating from the glacial Beagle Channel valley. This increase was most probably associated with a strengthening of the westerlies during both periods as dust source areas were already available before the onset of the dust peaks and remained present throughout. Congruent with glacier advances across Patagonia, this dust record indicates an overall strengthening of the wind belt during the ACR. On the other hand, we argue that the YD dust peak is linked to strong and poleward shifted westerlies. The close interplay between dust fluxes and climatic changes demonstrates that atmospheric circulation was essential in generating and sustaining present-day interglacial conditions.