200-years ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results

• Main Authors: Burgay, François, Fernández, Rafael Pedro, Segato, Delia, Turetta, Clara, Blaszczak-Boxe, Christopher S., Rhodes, Rachael H., Scarchilli, Claudio, Ciardini, Virginia, Barbante, Carlo, Saiz-Lopez, Alfonso, Spolaor, Andrea
• Format: Text
• Language: English
• Published: 2022
• Subjects: Antarctic; East Antarctica; The Antarctic; Antarc*; Antarctica; ice core; Sea ice
• Online Access: https://doi.org/10.5194/tc-2022-139; https://tc.copernicus.org/preprints/tc-2022-139/

Bromine enrichment (Brenr) has been proposed as an ice core proxy for past sea-ice reconstruction. Understanding the processes that influence bromine preservation in the ice is crucial to achieve a reliable interpretation of ice core signals and to potentially relate them to past sea-ice variability. Here, we present a 210-years bromine record that sheds light on the main processes controlling bromine preservation in the snow and ice at Dome C, East Antarctic plateau. Using observations alongside a modelling approach, we demonstrate that the bromine signal is preserved at Dome C, and it is not affected by the strong variations in ultraviolet radiation reaching the Antarctic plateau due to the stratospheric ozone hole. Based on this, we investigate whether the Dome C Brenr record can be used as an effective tracer of past Antarctic sea-ice. Due to the limited time window covered by satellite measurements and the low sea-ice variability observed during the last 30 years in East Antarctica, at this stage we cannot fully validate Brenr as an effective proxy for past sea-ice reconstructions at Dome C.