Organic bromine compounds produced in sea ice in Antarctic winter

• Published in: Nature Communications
• Main Authors: Abrahamsson, Katarina, Granfors, Anna, Ahnoff, Martin, Cuevas, Carlos A., Saiz-Lopez, A.
• Other Authors: Swedish Research Council, Swedish Polar Research Secretariat, Consejo Superior de Investigaciones Científicas (España), National Center for Atmospheric Research (US), National Science Foundation (US), Department of Energy (US), European Research Council
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Publishing Group 2018
• Subjects: Antarctic; Southern Ocean; The Antarctic; Antarc*; Sea ice
• Online Access: http://hdl.handle.net/10261/244337; https://doi.org/10.1038/s41467-018-07062-8; https://doi.org/10.13039/501100003339; https://doi.org/10.13039/100000015; https://doi.org/10.13039/501100000781; https://doi.org/10.13039/100000001

8 pags, 8 figs, 2 tabs During polar springtime, active bromine drives ozone, a greenhouse gas, to near-zero levels. Bromine production and emission in the polar regions have so far been assumed to require sunlight. Here, we report measurements of bromocarbons in sea ice, snow, and air during the Antarctic winter that reveal an unexpected new source of organic bromine to the atmosphere during periods of no sunlight. The results show that Antarctic winter sea ice provides 10 times more bromocarbons to the atmosphere than Southern Ocean waters, and substantially more than summer sea ice. The inclusion of these measurements in a global climate model indicates that the emitted bromocarbons will disperse throughout the troposphere in the southern hemisphere and through photochemical degradation to bromine atoms, contribute ~ 10% to the tropospheric reactive bromine budget. Combined together, our results suggest that winter sea ice could potentially be an important source of atmospheric bromine with implications for atmospheric chemistry and climate at a hemispheric scale. This work was financed by the Swedish Research Council VR. The support by the Swedish Polar Secretariat is acknowledged. This work was also supported by the Consejo Superior de Investigaciones Científicas (CSIC) of Spain. The National Center for Atmospheric Research (NCAR) is funded by the National Science Foundation (NSF). Computing resources were provided by the Climate Simulation Laboratory at NCAR’s Computational, and the Information Systems Laboratory (CISL), sponsored by the NSF, provided computing resources. The CESM project (which includes CAM-Chem) is supported by the NSF and the office of Science (BER) of the US Department of Energy. This study has received funding from the European Research Council Executive Agency under the European Union´s Horizon 2020 Research and innovation programme (Project ‘ERC-2016-COG 726349 CLIMAHAL’).