EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Water Isotopic Signature of Surface Snow Metamorphism in Antarctica

Mathieu Casado1,2,3, Alexandra Zuhr1,2,4, Amaëlle Landais1, Ghislain Picard5, Laurent Arnaud5, Giuliano Dreossi6, Barbara Stenni7, and Frederic Prié1
Mathieu Casado et al.
  • 1Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif sur Yvette, France
  • 2Alfred Wegener Institut Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
  • 3Geo- und Umweltforschungszentrum, Universität Tübingen, Tübingen, Germany
  • 4Institute for Geoscience, University of Potsdam, Potsdam, Germany
  • 5Institut des Geosciences de l'Environnement (IGE), Université Grenoble Alpes / CNRS, UMR 5001, Grenoble, France
  • 6Institute of Polar Sciences, Consiglio Nazionale delle Ricerche, Mestre-Venezia, Italy
  • 7Dipartimento di Scienze Ambientali, Informatica e Statistica, DAIS, Ca'Foscari University of Venice, Mestre-Venezia, Italy

Water isotope ratios of ice cores are a key source of information on past temperatures. Through fractionation within the hydrological cycle, temperature is imprinted in the water isotopic composition of snowfalls. However, this signal of climatic interest is modified after deposition when snow remains at the surface exposed to the atmosphere. Comparing time series of surface snow isotopic composition at Dome C with satellite observations of surface snow metamorphism, we found that long summer periods without precipitation favor surface snow metamorphism altering the surface snow isotopic  composition. Using excess parameters (combining dD, d17O, and d18O fractions) allow the identification of this alteration caused by sublimation and condensation of surface hoar. The combined measurement of all three isotopic compositions could help identifying ice core sections influenced by snow metamorphism in sites with very low snow accumulation.

How to cite: Casado, M., Zuhr, A., Landais, A., Picard, G., Arnaud, L., Dreossi, G., Stenni, B., and Prié, F.: Water Isotopic Signature of Surface Snow Metamorphism in Antarctica, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13161,, 2022.