Water Isotopic Signature of Surface Snow Metamorphism in Antarctica

• Published in: Geophysical Research Letters
• Main Authors: Casado, Mathieu, Landais, Amaelle, Picard, Ghislain, Arnaud, Laurent, Dreossi, Giuliano, Stenni, Barbara, Prié, Frederic
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Institute of Environmental Physics Heidelberg (IUP), Universität Heidelberg Heidelberg, Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institute of Polar Sciences Venezia-Mestre (CNR-ISP), Consiglio Nazionale delle Ricerche Roma (CNR), Dipartimento di Scienze Ambientali, Informatica e Statistica Venezia (DAIS), University of Ca’ Foscari Venice, Italy
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarc*; Antarctica; EPICA
• Online Access: https://hal.science/hal-03348483; https://hal.science/hal-03348483/document; https://hal.science/hal-03348483/file/2021GL093382.pdf; https://doi.org/10.1029/2021gl093382

International audience In low accumulation regions of Antarctica, precipitation is so sparse that the processes occurring after snowfall (post-deposition), such as surface metamorphism (Picard et al., 2012), sublimation and solid condensation (Genthon et al., 2017), as well as the redistribution of snow by wind (Groot Zwaaftink et al., 2013; Picard et al., 2019), play a prominent role in how snow accumulates to build the snowpack. These processes strongly affect the physical properties (albedo, density, and grain size) and geochemical composition of snow. For instance, snow grain size, which controls the albedo (Grenfell et al., 1994; Wiscombe & Warren, 1980), is the result of the competition between precipitation which brings small size grains on the surface and metamorphism which coarsens existing grains (Picard et al., 2012). These post-deposition processes influence the snow isotopic composition (δ 18 O or δD for the first order) that are traditionally interpreted as proxies of past temperatures in ice cores. Before deposition, the link between temperature and δ 18 O is due to the Rayleigh distillation of moist air from evaporation sites at low latitudes to the high-latitude precipitation sites (Dansgaard, 1964): When temperature decreases and precipitation occurs, the condensed phase becomes enriched and the remaining moisture depleted of heavy isotopes. In Antarctica, ice cores covering several glacial-interglacial transitions have been retrieved from sites that combine two assets: large ice thickness and low accumulation (EPICA, 2004; Kawamura et al., 2017; Petit et al., 1999). However, the low accumulation lead to the contributions from poorly