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Gong L, Holbourn A, Kuhnt W, Opdyke B, Zhang Y, Ravelo AC, Zhang P, Xu J, Matsuzaki K, Aiello I, Beil S, Andersen N. Middle Pleistocene re-organization of Australian Monsoon. Nat Commun 2023; 14:2002. [PMID: 37037802 PMCID: PMC10086051 DOI: 10.1038/s41467-023-37639-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 03/24/2023] [Indexed: 04/12/2023] Open
Abstract
The sensitivity of the Australian Monsoon to changing climate boundary conditions remains controversial due to limited understanding of forcing processes and past variability. Here, we reconstruct austral summer monsoonal discharge and wind-driven winter productivity across the Middle Pleistocene Transition (MPT) in a sediment sequence drilled off NW Australia. We show that monsoonal precipitation and runoff primarily responded to precessional insolation forcing until ~0.95 Ma, but exhibited heightened sensitivity to ice volume and pCO2 related feedbacks following intensification of glacial-interglacial cycles. Our records further suggest that summer monsoon variability at the precessional band was closely tied to the thermal evolution of the Indo-Pacific Warm Pool and strength of the Walker circulation over the past ~1.6 Myr. By contrast, productivity proxy records consistently tracked glacial-interglacial variability, reflecting changing rhythms in polar ice fluctuations and Hadley circulation strength. We conclude that the Australian Monsoon underwent a major re-organization across the MPT and that extratropical feedbacks were instrumental in driving short- and long-term variability.
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Affiliation(s)
- Li Gong
- Institute of Geosciences, Christian-Albrechts-University, D-24118, Kiel, Germany
| | - Ann Holbourn
- Institute of Geosciences, Christian-Albrechts-University, D-24118, Kiel, Germany.
| | - Wolfgang Kuhnt
- Institute of Geosciences, Christian-Albrechts-University, D-24118, Kiel, Germany
| | - Bradley Opdyke
- Research School of Earth Sciences, Australian National University, Mills Road, Acton, ACT, 2601, Australia
| | - Yan Zhang
- Ocean Sciences Department, University of California, 1156 High Street, Santa Cruz, CA, 95064, USA
| | - Ana Christina Ravelo
- Ocean Sciences Department, University of California, 1156 High Street, Santa Cruz, CA, 95064, USA
| | - Peng Zhang
- Institute of Cenozoic Geology and Environment, State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, 710069, Xi'an, China
| | - Jian Xu
- Institute of Cenozoic Geology and Environment, State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, 710069, Xi'an, China
| | - Kenji Matsuzaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Ivano Aiello
- Department of Geological Oceanography, Moss Landing Marine Laboratories, San Jose State University, Moss Landing, CA, 95039, USA
| | - Sebastian Beil
- Institute of Geosciences, Christian-Albrechts-University, D-24118, Kiel, Germany
| | - Nils Andersen
- Leibniz Laboratory for Radiometric Dating and Stable Isotope Research, Christian-Albrechts-University Kiel, D-24118, Kiel, Germany
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