Millennial-scale atmospheric CO2 variations during the Marine Isotope Stage 6 period (190–135 ka) ...

• Main Authors: Shin, Jinhwa, Nehrbass-Ahles, Christoph, Grilli, Roberto, Chowdhry Beeman, Jai, Parrenin, Frédéric, Teste, Grégory, Landais, Amaelle, Schmidely, Loïc, Silva, Lucas, Schmitt, Jochen, Bereiter, Bernhard, Stocker, Thomas F., Fischer, Hubertus, Chappellaz, Jérôme
• Format: Text
• Language: English
• Published: Copernicus Publications 2020
• Subjects: 530 Physics; Antarctic; The Antarctic; Antarc*; EPICA; ice core; North Atlantic
• Online Access: https://dx.doi.org/10.7892/boris.148172; https://boris.unibe.ch/148172/

Using new and previously published CO2 data from the EPICA Dome C ice core (EDC), we reconstruct a new high-resolution record of atmospheric CO2 during Marine Isotope Stage (MIS) 6 (190 to 135 ka) the penultimate glacial period. Similar to the last glacial cycle, where highresolution data already exists, our record shows that during longer North Atlantic (NA) stadials, millennial CO2 variations during MIS 6 are clearly coincident with the bipolar seesaw signal in the Antarctic temperature record. However, during one short stadial in the NA, atmospheric CO2 variation is small (ca. 5 ppm) and the relationship between temperature variations in EDC and atmospheric CO2 is unclear. The magnitude of CO2 increase during Carbon Dioxide Maxima (CDM) is closely related to the NA stadial duration in both MIS 6 and MIS 3 (60–27 ka). This observation implies that during the last two glacials the overall bipolar seesaw coupling of climate and atmospheric CO2 operated similarly. In addition, similar to the last glacial ...