Concentration and isotopic composition of bromine and chlorine in Antarctic sea ice

• Published in: Geochimica et Cosmochimica Acta
• Main Authors: Vallelonga, P, de Gois, JS, Borges, DLG, Costas-Rodriguez, M, Gkinis, V, Lannuzel, D, Spolaor, A, Vanhaecke, F
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Pergamon-Elsevier Science Ltd 2021
• Subjects: Antarctic; sea ice; halogens; isotopes; trace elements; SIPEX-2; chlorophyll-a; brine; multi-collector ICP-MS; Southern Ocean; Austral; Antarc*; Sea ice
• Online Access: https://eprints.utas.edu.au/35376/

This work presents the first investigation of Br and Cl isotopic partitioning in Southern Ocean sea ice. The sea ice samples characterized were collected during the Australian-led Sea Ice Physics and Ecosystem eXperiment-2 (SIPEX-2) marine voyage in austral spring of 2012 (26 Sept – 10 Nov), within the area bounded by 115–125°E and 62–66oS off the East Antarctic coast. Bromine concentrations ranged from 710 ± 20 μg L-1 to 31440 ± 570 μg L-1 and chlorine concentrations ranged from 218 ± 12 mg L-1 to 7945 ± 351 mg L-1. Bromine and chlorine concentrations were positively correlated with a slope of 0.0038 (r=0.996, p81Br with respect to SMOB isotopic reference) varied from -0.64 to 0.10‰ with a mean of -0.16‰ and standard deviation of 0.04‰. Chlorine isotopic compositions (denoted δ37Cl with respect to SMOC isotopic reference) varied from -1.10‰ to 0.43‰ with a mean of -0.26‰ and standard deviation of 0.10‰. Despite their strong concentration correlation, there was a much less consistent relation between Br and Cl isotopic compositions (r=0.74, p