Bipolar control on millennial atmospheric CO2 changes over the past glacial cycle
- 1Laoshan Laboratory, China (jiminyuanu@gmail.com)
- 2Research School of Earth Sciences, Australian National University
- 3Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W/PO Box 1000, Palisades, NY, 10964-8000, USA
- 4SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
- 5Dept. of Geography, University College London, London, UK
- 6CEREGE, Aix-Marseille Univ, CNRS, IRD, INRA, Coll de Fr, Aix en Provence, France
- 7Institute of Global Environmental Change, Xi’an Jiaotong University, 710054 Xi’an, China
- 8Climate Change Research Centre, Earth and Sustainability Science Research Centre, University of New South Wales, Sydney, Australia
- 9State Key Laboratory of Marine Geology, Tongji University, Shanghai, 200092, China
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. In this study, I will show a high-resolution deep-water acidity record from the Iberian Margin in the North Atlantic, a unique setting that allows us to construct a robust chronology for confident comparisons between marine and ice-core records. The new data combined with ice-core CO2 records reveal multiple ocean ventilation modes involving an interplay of the two polar regions, rather than by the Southern Ocean alone. These modes governed past deep-sea carbon storage and thereby atmospheric CO2 variations on millennial timescales. Overall, our record suggests a bipolar control on millennial atmospheric CO2 changes during the past glacial cycle.
How to cite: Yu, J., Anderson, R., Jin, Z., Ji, X., Thornalley, D., Wu, L., Thouveny, N., Cai, Y., Tan, L., Zhang, F., Menviel, L., Tian, J., Xie, X., Rohling, E., and McManus, J.: Bipolar control on millennial atmospheric CO2 changes over the past glacial cycle, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9143, https://doi.org/10.5194/egusphere-egu24-9143, 2024.
