A decade (2008–2017) of water stable isotope composition of precipitation at Concordia Station, East Antarctica
Résumé
A 10-year record of oxygen and hydrogen isotopic composition of precipitation is presented here: from 2008 to 2017, 1483 daily precipitation samples were collected yearround on a raised platform at Concordia Station, East Antarctica. Weather data were retrieved from the Italian Antarctic Meteo-Climatological Observatory automatic weather station (AWS), while ERA5 was used to estimate total precipitation. The δ-temperature relationships were moderately high for daily data (r 2 = 0.63 and 0.64 for δ 18 O and δ 2 H, respectively) and stronger using monthly data (r 2 = 0.82 for both δ 18 O and δ 2 H), with a slope of about 0.5 ‰ °C-1 for δ 18 O/T AWS (3.5 ‰ °C-1 for δ 2 H/T AWS ), which remains consistent also using annual averages. The isotopic composition of precipitation is the input signal of the snow-ice system, and this dataset will be useful to improve the interpretation of paleoclimate records and promote a better understanding of the post-depositional processes affecting the isotopic signal in ice cores. This dataset represents a benchmark for the evaluation of isotope-enabled general circulation models. Here, the ECHAM6-wiso output was compared to experimental data, showing moderately good relationships for δ 18 O and δ 2 H but not for d-excess, nonetheless marking a substantial improvement from the previous release of the model.
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