Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine ...

• Main Authors: Maselli, OJ, Chellman, NJ, Grieman, M, Layman, L, McConnell, Pasteris, D, Rhodes, RH, Saltzman, E, Sigl, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2017
• Subjects: 37 Earth Sciences; 3709 Physical Geography and Environmental Geoscience; 3705 Geology; Arctic; Greenland; Greenland ice core; ice core; Sea ice
• Online Access: https://dx.doi.org/10.17863/cam.8949; https://www.repository.cam.ac.uk/handle/1810/263597

Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH$_3$SO$_3$H) and bromine, covering the time period 1750–2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA ...