Spatial and temporal variations of fractionation of stable isotopes in East-Antarctic snow

• Published in: Journal of Glaciology
• Main Authors: Chuanjin Li, Jiawen Ren, Guitao Shi, Hongxi Pang, Yetang Wang, Shugui Hou, Zhongqin Li, Zhiheng Du, Minghu Ding, Xiangyu Ma, Jiao Yang, Aihong Xie, Puyu Wang, Xiaoming Wang, Bo Sun, Cunde Xiao
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2021
• Subjects: East Antarctica; fractionation; MWL slopes; stable isotopes; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Antarctic; Zhongshan; Zhongshan Station; Antarc*; Antarctica; ice core; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2021.5; https://doaj.org/article/b26fd86dede247888488c3e4a5e25b39

Stable isotope ratios (δ18O and δD) in Antarctic snow and ice are basic proxy indices of climate in ice core studies. The relation between the ratios has important indicative significance for moisture sources. In general, the fractionation characteristics of the two isotopes vary with different meteorological and topographical conditions. This paper presents the spatial and temporal distribution of meteoric water line (MWL) slopes along a traverse from the Zhongshan Station (ZSS) to Dome A in East Antarctica. It is found that the slopes decrease with the increasing distance inland from the coast and the lowest slope occurred at Dome A, where the long-range transported moisture dominates and clear sky snowing have an influence. The slopes in different layers of the snowpack showed a decreasing trend with depth and this is attributed to the fractionation during the interstitial sublimation and re-condensation processes of the water vapor. Frost flower development on the interior plateau surface can greatly alter the depth evolution of the MWL slope. The coastal snow pits also go through the post-depositional smoothing effect, but their influences are not so significant as the inland regions.