Extensive wet episodes in Late Glacial Australia resulting from high-latitude forcings

• Published in: Scientific Reports
• Main Authors: Bayon, Germain, de Deckker, Patrick, Magee, John, Germain, Yoan, Bermell, Sylvain, Tachikawa, K., Norman, Marc
• Other Authors: Research School of Earth Sciences ANU, Canberra (RSES), ANU College of Science Canberra, Australian National University (ANU)-Australian National University (ANU), Unité Géosciences Marines (GM), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarctic; Pacific; Southern Ocean; Antarc*
• Online Access: https://hal.science/hal-01691132; https://hal.science/hal-01691132/document; https://hal.science/hal-01691132/file/srep44054.pdf; https://doi.org/10.1038/srep44054

International audience Millennial-scale cooling events termed Heinrich Stadials punctuated Northern Hemisphere climate during the last glacial period. Latitudinal shifts of the intertropical convergence zone (ITCZ) are thought to have rapidly propagated these abrupt climatic signals southward, influencing the evolution of Southern Hemisphere climates and contributing to major reorganisation of the global ocean-atmosphere system. Here, we use neodymium isotopes from a marine sediment core to reconstruct the hydroclimatic evolution of subtropical Australia between 90 to 20 thousand years ago. We find a strong correlation between our sediment provenance proxy data and records for western Pacific tropical precipitations and Australian palaeolakes, which indicates that Northern Hemisphere cooling phases were accompanied by pronounced excursions of the ITCZ and associated rainfall as far south as about 32°S. Comparatively, however, each of these humid periods lasted substantially longer than the mean duration of Heinrich Stadials, overlapping with subsequent warming phases of the southern high-latitudes recorded in Antarctic ice cores. In addition to ITCZ-driven hydroclimate forcing, we infer that changes in Southern Ocean climate also played an important role in regulating late glacial atmospheric patterns of the Southern Hemisphere subtropical regions.