Experimental observation of transient δ18O interaction between snow and advective airflow under various temperature gradient conditions
- 1WSL Institute for Snow and Avalanche Research SLF, 7260 Davos Dorf, Switzerland
- 2LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette CEDEX, France
- 3Center for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- 4Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari of Venice, Venice, Italy
- 5Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
Abstract. Stable water isotopes (δ18O) obtained from snow and ice samples of polar regions are used to reconstruct past climate variability, but heat and mass transport processes can affect the isotopic composition. Here we present an experimental study on the effect of airflow on the snow isotopic composition through a snow pack in controlled laboratory conditions. The influence of isothermal and controlled temperature gradient conditions on the δ18O content in the snow and interstitial water vapour is elucidated. The observed disequilibrium between snow and vapour isotopes led to the exchange of isotopes between snow and vapour under non-equilibrium processes, significantly changing the δ18O content of the snow. The type of metamorphism of the snow had a significant influence on this process. These findings are pertinent to the interpretation of the records of stable isotopes of water from ice cores. These laboratory measurements suggest that a highly resolved climate history is relevant for the interpretation of the snow isotopic composition in the field.