Coastal water vapor isotopic composition driven by katabatic wind variability in summer at Dumont d'Urville, coastal East Antarctica
Bréant, C.; Dos Santos, C.L.; Agosta, C.; Casado, M.; Fourré, E.; Goursaud, S.; Masson-Delmotte, V.; Favier, V.; Cattani, O.; Prié, F.; Golly, B.; Orsi, A.; Martinerie, P.; Landais, A. (2019). Coastal water vapor isotopic composition driven by katabatic wind variability in summer at Dumont d'Urville, coastal East Antarctica. Earth Planet. Sci. Lett. 514: 37-47. https://dx.doi.org/10.1016/j.epsl.2019.03.004 In: Earth and Planetary Science Letters. Elsevier: Amsterdam. ISSN 0012-821X; e-ISSN 1385-013X, more |  |
| Keyword | | | Author keywords | Antarctica; water isotopes; katabatic wind |
| Authors | | Top | - Bréant, C.
- Dos Santos, C.L.
- Agosta, C., more
- Casado, M.
- Fourré, E.
| - Goursaud, S.
- Masson-Delmotte, V.
- Favier, V.
- Cattani, O.
- Prié, F.
| - Golly, B.
- Orsi, A.
- Martinerie, P.
- Landais, A.
|
| Abstract | Dumont d'Urville station, located on the East coast of Antarctica in Adelie Land, is in one of the windiest coastal region on Earth, due to katabatic winds downslope from the East Antarctic ice sheet. In summer, the season of interest in this study, coastal weather is characterized by well-marked diel cycles in temperature and wind patterns. Our study aims at exploring the added value of water vapor stable isotopes in coastal Adelie Land to provide new information on the local atmospheric water cycle and climate. An important application is the interpretation of water isotopic profiles in snow and ice cores recently drilled in Adelie Land. We present the first continuous measurements of delta O-18 and d-excess in water vapor over Adelie Land. During our measurements period (26/12/2016 to 03/02/2017), we observed clear diel cycles in terms of temperature, humidity and isotopic composition. The cycles in isotopic composition are particularly large given the muted variations in temperature when compared to other Antarctic sites where similar monitoring have been performed. Based on data analyses and simulations obtained with the regional MAR model on the coastal Adelie Land, we suggest that the driver for delta O-18 and d-excess diel variability in summer at Dumont d'Urville is the variation of the strength of the wind coming from the continent: the periods with strong wind are associated with the arrival of relatively dry air with water vapor associated with low delta O-18 and high d-excess from the Antarctic plateau. Finally, in addition to the interpretation of snow and ice core isotopic profiles in the coastal regions, our study has implications for the evaluation of atmospheric models equipped with water isotopes. |
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