Three-year monitoring of stable isotopes of precipitation at Concordia Station, East Antarctica
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,...
Published in: | The Cryosphere |
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Main Authors: | , , , , , , , , , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2016
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Subjects: | |
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 |
Summary: | 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 ... |
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