A solution for constraining past marine Polar Amplification
Most climate proxies of sea surface temperatures suffer from severe limitations when applied to cold temperatures that characterize Arctic environments. These limitations prevent us from constraining uncertainties for some of the most sensitive climate tipping points that can trigger rapid and dramatic global climate change such as Arctic/Polar Amplification, the disruption of the Atlantic Meridional Overturning Circulation, sea ice loss, and permafrost melting. Here, we present an approach to reconstructing sea surface temperatures globally using paired Mg/Ca - δ<sup>18</sup>O<sub>c</sub> recorded in tests of the polar to subpolar planktonic foraminifera Neogloboquadrina pachyderma. We show that the fidelity of Mg/Ca-based paleoclimate reconstructions is compromised by variations in seawater carbonate chemistry which can be successfully quantified and isolated from paleotemperature reconstructions using a multiproxy approach. By applying the calibration to the last glacial maximum, we show that marine polar amplification has been underestimated by up to 3.0 ± 1.0 °C in model-based estimates.
Authors
- Rachel R. Cave (ORCID: https://orcid.org/0000-0003-0812-6903)
- Ulysses S. Ninnemann (ORCID: https://orcid.org/0000-0002-1410-9571)
- M. Raitzsch
- Julie Meilland (ORCID: https://orcid.org/0000-0001-8966-3115)
- Thomas B. Chalk (ORCID: https://orcid.org/0000-0002-2880-3847)
- Jelle Bijma (ORCID: https://orcid.org/0000-0003-4371-1438)
- Audrey Morley (ORCID: https://orcid.org/0000-0002-8971-0222)
- Gavin L. Foster (ORCID: https://orcid.org/0000-0003-3688-9668)
- Michal Kučera (ORCID: https://orcid.org/0000-0002-7817-9018)
- Janina Büscher (ORCID: https://orcid.org/0000-0003-2399-4020)
- E. de la Vega
Institutions
- University College Dublin (IE)
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (DE)
- University of Ulster (GB)
- University of Bremen (DE)
- Ollscoil na Gaillimhe – University of Galway (IE)
- National Oceanography Centre (GB)
- Bjerknes Centre for Climate Research (NO)
- Centre de Recherche et d’Enseignement de Géosciences de l’Environnement (FR)
- University of Southampton (GB)
- University of Bergen (NO)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-10-18
- DOI
- https://doi.org/10.1038/s41467-024-53424-w
- Citations
- 4
- Primary Topic
- Geology and Paleoclimatology Research
- Type
- article
- Field-Weighted Citation Impact
- 1.51
Funders
- Science Foundation Ireland
- Deutsche Forschungsgemeinschaft
- Agence Nationale de la Recherche
- Belgian Federal Science Policy Office
- Ministero dell’Istruzione, dell’Università e della Ricerca
- Fundação para a Ciência e a Tecnologia