The TA192A water stable isotope and chemical firn core records , Adélie Land, Antarctica

• Main Authors: Goursaud, Sentia, Masson-Delmotte, Valerie, Favier, Vincent, Preunkert, Suzanne, Legrand, Michel R, Minster, Bénédicte
• Format: Dataset
• Language: English
• Published: PANGAEA 2018
• Subjects: Age; Antarctic; Core; DEPTH; ice/snow; Deuterium excess; Methane sulfonic acid; Number; Original value; Sodium; Sulfate; TA192A__Adelie_Land; δ18O; Austral; Dumont d'Urville; Dumont d'Urville Station; Dumont-d'Urville; East Antarctica; Indian; Pacific; West Antarctic Ice Sheet; Antarc*; Antarctica; Ice Sheet; Sea ice; The Cryosphere
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.896623; https://doi.org/10.1594/PANGAEA.896623

A new 21.3m firn core was drilled in 2015 at a coastal Antarctic high accumulation site in Adélie Land (66.78°S; 139.56°E, 602ma.s.l.). The core was dated by annual layers counting based on non-sea-salt sulfate and methanesulfonate summer peaks, refined by a comparison between the reconstructed surface mass balance (hereafter, SMB) and the closest available stake data. The mean reconstructed SMB of 75.2 ± 15.0cmw.e. y−1 is consistent with local stake data, and remarkably high for coastal East Antarctica. The resulting inter-annual and sub-annual variations in isotopic records (δ18O and deuterium excess, hereafter d-excess) are explored for 1998–2014 and are systematically compared with a couple of climatic time series: an updated database of Antarctic surface snow isotopic composition, SMB stake data, meteorological observations from Dumont d'Urville station, sea-ice concentration based on passive microwave satellite data, precipitation outputs of atmospheric reanalyses, climate and water stable isotope outputs from the atmospheric general circulation model ECHAM5-wiso, as well as air mass origins diagnosed using 5-days back-trajectories. The mean isotopic values (−19.3 ± 3.1‰ for δ18O and 5.4 ± 2.2‰ for d-excess) are consistent with other coastal Antarctic values. No significant isotope-temperature relationship can be evidenced at any timescale, ruling out a simple interpretation of in terms of local temperature. An observed asymmetry in the δ18O seasonal cycle may be explained by the precipitation of air masses coming from Indian and Pacific/West Antarctic Ice Sheet sectors in autumn and winter times, recorded in the d-excess signal showing outstanding values in austral spring versus autumn. Significant positive trends are observed in the annual d-excess record and local sea-ice extent (135°E–145°E) over the period 1998–2014. However, processes studies focusing on resulting isotopic compositions and particularly the d-excess-δ18O relationship, evidenced as a potential fingerprint of moisture origins, as well ...