The study of water isotopes in Antarctica is key to improve our understanding of the atmospheric water cycle and to reconstruct past climates from ice cores.
Climate models equipped with water isotopes are a valuable tool to help interpret the water isotope signal in firn and ice archives, but they need to be thoroughly evaluated to test their reliability. In our study, we evaluate the LMDZ6iso global atmospheric model against surface snow isotopes over the Antarctic continent, and against daily precipitation and continuous water vapour isotopes at two East Antarctic stations: Dumont d’Urville, at the coast, and Concordia, inland. These observations are used to assess simulated spatial, seasonal and diurnal isotopic variations. Then, we analyse individual process contributions to boundary layer water vapour isotopes to identify the key drivers of clear-sky isotopic daily cycles, and to understand the discrepancies between the model and the observation. Our results suggest that to further improve water isotopes in LMDZ6iso, efforts should focus on including isotopic exchanges during sublimation and condensation for low temperature.
Authors: Niels Dutrievoz, Cécile Agosta, Camille Risi, Étienne Vignon, Sébastien Nguyen, Amaëlle Landais, Elise Fourré, Christophe Leroy-Dos Santos, Mathieu Casado, Valérie Masson-Delmotte, Jean Jouzel, Thomas Dubos, Inès Ollivier, Barbara Stenni, Giuliano Dreossi, Mauro Masiol, Bénédicte Minster, Frédéric Prié.
JGR Amospheres _ Research Article: https://doi.org/10.1029/2024JD042073