Influence of Summer Sublimation on δD, δ 18 O, and δ 17 O in Precipitation, East Antarctica, and Implications for Climate Reconstruction From Ice Cores

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Pang, Hongxi, Shugui, Hou, LANDAIS, AMAELLE, Masson‐Delmotte, Valérie, Jouzel, Jean, Steen-Larsen, Hans Christian, Risi, Camille, Zhang, Wangbin, Wu, Shuangye, Li, Yuansheng, An, Chunlei, Wang, Yetang, Prie, Frederic, Minster, Bénédicte, Falourd, Sonia, Stenni, Barbara, Scarchilli, Claudio, Fujita, Koji, Grigioni, Paolo
• Other Authors: School of Geography and Ocean Science, Nanjing University (NJU), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Environmental Sciences, Informatics and Statistics Venezia, University of Ca’ Foscari Venice, Italy, Graduate School of Environmental Studies Nagoya, Nagoya University
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; East Antarctica; Antarc*; Antarctica
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-02347124; https://doi.org/10.1029/2018JD030218

International audience In central Antarctica, where accumulation rates are very low, summer sublimation of surface snow is a key element of the surface mass balance, but its fingerprint in isotopic composition of water (δD, δ 18 O, and δ 17 O) remains unclear. In this study, we examined the influence of summer sublimation on δD, δ 18 O, and δ 17 O in precipitation using data sets of isotopic composition of precipitation at various sites on the inland East Antarctica. We found unexpectedly low δ 18 O values in the summer precipitation, decoupled from surface air temperatures. This feature can be explained by the combined effects of weak or nonexistent temperature inversion and moisture recycling associated with sublimation-condensation processes in summer. Isotopic fractionation during the moisture-recycling process also explains the observed high values of d-excess and 17 O-excess in summer precipitation. Our results suggest that the local cycle of sublimation-condensation in summer is an important process for the isotopic composition of surface snow, water vapor, and consequently precipitation on inland East Antarctica.