The EPICA Dome C (EDC) ice core provides the longest continuous climatic record covering the last 800,000 years (800 kyrs). The high resolution (11 cm) water isotopic record (δ¹⁸O and δD) is available for the EDC ice core and accounting for water isotopic diffusion provides a unique opportunity to investigate decadal to millennial variability during past glacial and interglacial periods.

We present a continuous compilation of the EDC water isotopic record at a sample resolution of 11 cm that composed of 27,000 δ18O measurements and 7,920 δD measurements (covering respectively 94 % and 27 % of the whole EDC record), including both published and new measurements (2,900 for both δ¹⁸O and δD) over the last 800 kyrs on the EDC ice core. Here, we demonstrate that repeat water isotope measurements on the EDC ice core using different analytical methods on the same samples from different depth intervals are comparable within analytical uncertainty. From this comparison we combine EDC water isotope measurements to generate a high resolution (11 cm) data set over the past 800 kyrs (Figure 1). A frequency decomposition of the most complete δ¹⁸O record and a simple assessment of the possible influence of diffusion on the measured profile shows that the variability during glacial periods at multi-decadal to multi-centennial timescale is higher than variability of the interglacial periods. This analysis shows as well that during interglacial periods characterized by a temperature optimum at its beginning, the multi-centennial variability is the strongest over this temperature optimum.

Auteurs: Antoine Grisart, Mathieu Casado, Vasileios Gkinis, Bo Vinther, Philippe Naveau, Mathieu Vrac, Thomas Laepple, Bénédicte Minster,  Frederic Prié, Barbara Stenni, Elise Fourré, Hans-Christian Steen Larsen, Jean Jouzel, Martin Werner, Katy Pol, Valérie Masson-Delmotte, Maria Hoerhold, Trevor Popp, Amaelle Landais

Référence: Clim. Past, 18, 2289–2301, https://doi.org/10.5194/cp-18-2289-2022, 2022