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

• Published in: The Cryosphere
• Main Authors: STENNI, Barbara, DREOSSI, GIULIANO, Scarchilli, Claudio, Masson Delmotte, Valerie, Schlosser, Elisabeth, Ciardini, Virginia, Grigioni, Paolo, Bonazza, Mattia, Cagnati, Anselmo, Karlicek, Daniele, Risi, Camille, Udisti, Roberto, Valt, Mauro
• Other Authors: Stenni, Barbara, Dreossi, Giuliano
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: Water Science and Technology; Earth-Surface Processes; Settore GEO/08 - Geochimica e Vulcanologia; Antarctic; East Antarctica; Concordia Station; Dome F; Antarc*; Antarctica; EPICA
• Online Access: http://hdl.handle.net/10278/3684307; https://doi.org/10.5194/tc-10-2415-2016; http://www.the-cryosphere.net/volumes_and_issues.html

Past temperature reconstructions from Antarctic ice cores require a good quantification and understanding of the relationship between snow isotopic composition and 2m 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 degrees C with respect to 2m 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 degrees 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 2m air temperature than to inversion temperature at all timescales (e.g. R-2 = 03 and 0.44, respectively for daily values). The slope of the temporal relationship between daily delta O-18 and 2m air temperature is approximately 2 times smaller (0.49 parts per thousand degrees C-1) than the average Antarctic spatial (0.8 parts per thousand degrees 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 anticorrelated with delta O-18 at daily and monthly scales, reaching maximum values in winter. Hoar frost precipitation samples have a specific fingerprint with more depleted delta O-18 (about 5% below average) and higher deuterium excess (about 8% above average) values than other ...