The TA192A water stable isotope and chemical firn core records , Adélie Land, Antarctica
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| Main Authors: | , , , , , |
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| Format: | Dataset Open Access |
| Language: | en |
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PANGAEA
2018
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| _version_ | 1867171860151533568 |
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| author | Goursaud, Sentia Masson-Delmotte, Valerie Favier, Vincent Preunkert, Suzanne Legrand, Michel R Minster, Bénédicte |
| author_facet | Goursaud, Sentia Masson-Delmotte, Valerie Favier, Vincent Preunkert, Suzanne Legrand, Michel R Minster, Bénédicte |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | 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 as the collection of more isotopic measurements in Adélie Land are needed for an accurate interpretation of our signals. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_896623 |
| institution | PANGAEA |
| language | en |
| publishDate | 2018 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | The TA192A water stable isotope and chemical firn core records , Adélie Land, Antarctica Goursaud, Sentia Masson-Delmotte, Valerie Favier, Vincent Preunkert, Suzanne Legrand, Michel R Minster, Bénédicte Age; Antarctic; Core; CORE; DEPTH, ice/snow; Deuterium excess; Methanesulfonic acid; Number; Original value; Sodium; Sulfate; TA192A__Adelie_Land; δ18O 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 as the collection of more isotopic measurements in Adélie Land are needed for an accurate interpretation of our signals. |
| title | The TA192A water stable isotope and chemical firn core records , Adélie Land, Antarctica |
| topic | Age; Antarctic; Core; CORE; DEPTH, ice/snow; Deuterium excess; Methanesulfonic acid; Number; Original value; Sodium; Sulfate; TA192A__Adelie_Land; δ18O |
| url | https://doi.org/10.1594/PANGAEA.896623 |