Snapshots of mean ocean temperature over the last 700 000 years using noble gases in the EPICA Dome C ice core ...

• Main Authors: Haeberli, Marcel, Baggenstos, Daniel, Schmitt, Jochen, Grimmer, Markus, Michel, Adrien, Kellerhals, Thomas, Fischer, Hubertus
• Format: Text
• Language: unknown
• Published: Copernicus Publications 2021
• Subjects: 530 Physics; Antarc*; Antarctic; EPICA; ice core
• Online Access: https://dx.doi.org/10.48350/155896; https://boris.unibe.ch/155896/

Together with the latent heat stored in glacial ice sheets, the ocean heat uptake carries the lion’s share of glacial–interglacial changes in the planetary heat content, but little direct information on the global mean ocean temperature (MOT) is available to constrain the ocean temperature response to glacial–interglacial climate perturbations. Using ratios of noble gases and molecular nitrogen trapped in the Antarctic EPICA Dome C ice core, we are able to reconstruct MOT for peak glacial and interglacial conditions during the last 700 000 years and explore the differences between these extrema. To this end, we have to correct the noble gas ratios for gas transport effects in the firn column and gas loss fractionation processes of the samples after ice core retrieval using the full elemental matrix of N2, Ar, Kr, and Xe in the ice and their individual isotopic ratios. The reconstructed MOT in peak glacials is consistently about 3.3+-0.4°C cooler compared to the Holocene. Lukewarm interglacials before the ...