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| Titel |
Ranges of moisture-source temperature estimated from Antarctic ice cores stable isotope records over glacial–interglacial cycles |
| VerfasserIn |
R. Uemura, V. Masson-Delmotte, J. Jouzel, A. Landais, H. Motoyama, B. Stenni |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 8, no. 3 ; Nr. 8, no. 3 (2012-06-29), S.1109-1125 |
| Datensatznummer |
250005600
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| Publikation (Nr.) |
 copernicus.org/cp-8-1109-2012.pdf |
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| Zusammenfassung |
| A single isotope ratio (δD or δ18O) of water is widely
used as an air-temperature proxy in Antarctic ice core records. These
isotope ratios, however, do not solely depend on air-temperature but also on
the extent of distillation of heavy isotopes out of atmospheric water vapor
from an oceanic moisture source to a precipitation site. The temperature
changes at the oceanic moisture source (Δ Tsource) and at the
precipitation site (Δ Tsite) can be retrieved by using
deuterium-excess (d) data. A new d record from Dome Fuji, Antarctica spanning
the past 360 000 yr is presented and compared with records from Vostok
and EPICA Dome C ice cores. In previous studies, to retrieve Δ Tsource and Δ Tsite information, different linear
regression equations were proposed using theoretical isotope distillation
models. A major source of uncertainty lies in the coefficient of regression,
βsite which is related to the sensitivity of d to Δ Tsite. We show that different ranges of temperature and selections of
isotopic model outputs may increase the value of βsite by more
than a factor of two. To explore the impacts of this coefficient on
reconstructed temperatures, we apply for the first time the exact same
methodology to the isotope records from the three Antarctica ice cores. We
show that uncertainties in the βsite coefficient strongly affect
(i) the glacial–interglacial magnitude of Δ Tsource; (ii) the
imprint of obliquity in Δ Tsource and in the site-source
temperature gradient. By contrast, we highlight the robustness of Δ Tsite reconstruction using water
isotopes records. |
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