The Impact of CO2 and Climate State on Whether Dansgaard–Oeschger Type Oscillations Occur in Climate Models

Malmierca-Vallet, Irene ORCID: https://orcid.org/0000-0002-2871-9741; Sime, Louise C. ORCID: https://orcid.org/0000-0002-9093-7926; Valdes, Paul J.; Klockmann, Marlene; Vettoretti, Guido; Slattery, John ORCID: https://orcid.org/0009-0004-5233-7657. 2024 The Impact of CO2 and Climate State on Whether Dansgaard–Oeschger Type Oscillations Occur in Climate Models. Geophysical Research Letters, 51 (13). 11, pp. 10.1029/2024GL110068

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Official URL: https://agupubs.onlinelibrary.wiley.com/doi/10.102...

Abstract/Summary

Greenland ice core records feature Dansgaard–Oeschger (D-O) events, which are abrupt warming episodes followed by gradual cooling during ice age climate. The three climate models used in this study (CCSM4, MPI-ESM, and HadCM3) show spontaneous self-sustained D-O-like oscillations (albeit with differences in amplitude, duration, and shape) in a remarkably similar, narrow window of carbon dioxide (CO2) concentration, roughly 185–230 ppm. This range matches atmospheric CO2 during Marine Isotopic Stage 3 (MIS 3: between 27.8 and 59.4 thousand of years BP, hereafter ka), a period when D-O events were most frequent. Insights from the three climate models point to North Atlantic (NA) sea-ice coverage as a key ingredient behind D-O type oscillations, which acts as a “tipping element.” Other climate state properties such as Mean Atlantic Meridional Overturning Circulation strength, global mean temperature and salinity gradient in the Atlantic Ocean do not determine whether D-O type behavior can occur in all three models.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1029/2024GL110068
ISSN:	0094-8276
Additional Keywords:	marine isotopic stage 3, Dansgaard-Oeschger events, millennial-scale climate oscillations
Date made live:	01 Jul 2024 08:52 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/537654

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1029/2024GL110068

ISSN:

0094-8276

Additional Keywords:

marine isotopic stage 3, Dansgaard-Oeschger events, millennial-scale climate oscillations

Date made live:

01 Jul 2024 08:52 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/537654