Millennial atmospheric CO2 changes linked to ocean ventilation modes over past 150,000 years
Type | Article |
---|---|
Date | 2023-12 |
Language | English |
Author(s) | Yu J.1, 2, 3, Anderson R. F.4, Jin Z. D.3, 5, 6, Ji X., Thornalley D. J. R.7, Wu L.1, 8, Thouveny N.9, Cai Y.6, Tan L.3, 6, Zhang F., Menviel L.10, Tian J.11, Xie X.11, Rohling E. J.2, 12, McManus J. F.4 |
Affiliation(s) | 1 : Laoshan Laboratory, Qingdao, China 2 : Research School of Earth Sciences, The Australian National University, Canberra, Australia 3 : SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, China 4 : Lamont–Doherty Earth Observatory, Columbia University, Palisades, NY, USA 5 : Open Studio for Oceanic–Continental Climate and Environment Changes, Laoshan Laboratory, Qingdao, China 6 : Institute of Global Environmental Change, Xi’an Jiaotong University, Xi’an, China 7 : Department of Geography, University College London, London, UK 8 : Physical Oceanography Laboratory, Ocean University of China, Qingdao, China 9 : CEREGE, Aix-Marseille Univ, CNRS, IRD, INRA, Coll de Fr, Aix en Provence, France 10 : Climate Change Research Centre, Earth and Sustainability Science Research Centre, University of New South Wales, Sydney, New South Wales, Australia 11 : State Key Laboratory of Marine Geology, Tongji University, Shanghai, China 12 : Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK |
Source | Nature Geoscience (1752-0894) (Springer Science and Business Media LLC), 2023-12 , Vol. 16 , N. 12 , P. 1166-1173 |
DOI | 10.1038/s41561-023-01297-x |
Abstract | Ice core measurements show diverse atmospheric CO2 variations—increasing, decreasing or remaining stable—during millennial-scale North Atlantic cold periods called stadials. The reasons for these contrasting trends remain elusive. Ventilation of carbon-rich deep oceans can profoundly affect atmospheric CO2, but its millennial-scale history is poorly constrained. Here we present a well-dated high-resolution deep Atlantic acidity record over the past 150,000 years, which reveals five hitherto undetected modes of stadial ocean ventilation with different consequences for deep-sea carbon storage and associated atmospheric CO2 changes. Our data provide observational evidence to show that strong and often volumetrically extensive Southern Ocean ventilation released substantial amounts of deep-sea carbon during stadials when atmospheric CO2 rose prominently. By contrast, other stadials were characterized by weak ventilation via both Southern Ocean and North Atlantic, which promoted respired carbon accumulation and thus curtailed or reversed deep-sea carbon losses, resulting in diminished rises or even declines in atmospheric CO2. Our findings demonstrate that millennial-scale changes in deep-sea carbon storage and atmospheric CO2 are modulated by multiple ocean ventilation modes through the interplay of the two polar regions, rather than by the Southern Ocean alone, which is critical for comprehensive understanding of past and future carbon cycle adjustments to climate change. |
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