Multiple carbon cycle mechanisms associated with the glaciation of Marine Isotope Stage 4 Journal Article uri icon



  • AbstractHere we use high-precision carbon isotope data (δ13C-CO2) to show atmospheric CO2 during Marine Isotope Stage 4 (MIS 4, ~70.5-59 ka) was controlled by a succession of millennial-scale processes. Enriched δ13C-CO2 during peak glaciation suggests increased ocean carbon storage. Variations in δ13C-CO2 in early MIS 4 suggest multiple processes were active during CO2 drawdown, potentially including decreased land carbon and decreased Southern Ocean air-sea gas exchange superposed on increased ocean carbon storage. CO2 remained low during MIS 4 while δ13C-CO2 fluctuations suggest changes in Southern Ocean and North Atlantic air-sea gas exchange. A 7 ppm increase in CO2 at the onset of Dansgaard-Oeschger event 19 (72.1 ka) and 27 ppm increase in CO2 during late MIS 4 (Heinrich Stadial 6, ~63.5-60 ka) involved additions of isotopically light carbon to the atmosphere. The terrestrial biosphere and Southern Ocean air-sea gas exchange are possible sources, with the latter event also involving decreased ocean carbon storage.

publication date

  • September 16, 2022

has restriction

  • gold

Date in CU Experts

  • February 12, 2024 2:32 AM

Full Author List

  • Menking JA; Shackleton SA; Bauska TK; Buffen AM; Brook EJ; Barker S; Severinghaus JP; Dyonisius MN; Petrenko VV

author count

  • 9

Other Profiles

Electronic International Standard Serial Number (EISSN)

  • 2041-1723

Additional Document Info


  • 13


  • 1


  • 5443