Three-year monitoring of stable isotopes of precipitation at ConcordiaStation, East Antarctica

• Published in: The Cryosphere
• Main Authors: Stenni, Barbara, Scarchilli, Claudio, Masson-Delmotte, Valerie, Schlosser, Elisabeth, Ciardini, Virginia, Dreossi, Giuliano, Grigioni, Paolo, Bonazza, Mattia, Cagnati, Anselmo, Karlicek, Daniele, Risi, Camille, Udisti, Roberto, Valt, Mauro
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: stable isotopes; Concordia Station; Antarctica; Antarctic; East Antarctica; Dome F; Antarc*; EPICA
• Online Access: http://resolver.sub.uni-goettingen.de/purl?gs-1/13974; https://doi.org/10.5194/tc-10-2415-2016

Past temperature reconstructions from Antarctic ice cores require a good quantification and understanding of the relationship between snow isotopic composition and 2 m air or inversion (condensation) temperature. Here, we focus on the French–Italian Concordia Station, central East Antarctic plateau, where the European Project for Ice Coring in Antarctica (EPICA) Dome C ice cores were drilled. We provide a multi-year record of daily precipitation types identified from crystal morphologies, daily precipitation amounts and isotopic composition. Our sampling period (2008–2010) encompasses a warmer year (2009, +1.2 °C with respect to 2 m air temperature long-term average 1996–2010), with larger total precipitation and snowfall amounts (14 and 76 % above sampling period average, respectively), and a colder and drier year (2010, −1.8 °C, 4 % below long-term and sampling period averages, respectively) with larger diamond dust amounts (49 % above sampling period average). Relationships between local meteorological data and precipitation isotopic composition are investigated at daily, monthly and inter-annual scale, and for the different types of precipitation. Water stable isotopes are more closely related to 2 m air temperature than to inversion temperature at all timescales (e.g. R2 = 0.63 and 0.44, respectively for daily values). The slope of the temporal relationship between daily δ18O and 2 m air temperature is approximately 2 times smaller (0.49 ‰ °C−1) than the average Antarctic spatial (0.8 ‰ °C−1) relationship initially used for the interpretation of EPICA Dome C records. In accordance with results from precipitation monitoring at Vostok and Dome F, deuterium excess is anti-correlated with δ18O at daily and monthly scales, reaching maximum values in winter. Hoar frost precipitation samples have a specific fingerprint with more depleted δ18O (about 5 ‰ below average) and higher deuterium excess (about 8 ‰ above average) values than other precipitation types. These datasets provide a basis for comparison with ...