Scientists at IQFR and the University of Gothenburg show in Nature Communications that Antarctic winter sea ice produces organic bromine compounds in the absence of sunlight.

Natural emissions of bromocarbons contribute to ozone loss in the troposphere and stratosphere. These species are emitted from the oceans and polar regions. Bromine production and emission in the polar regions have so far been assumed to require sunlight. In this work, new measurements of bromocarbons in sea ice, snow, and air during the Antarctic winter reveal an unexpected new source of bromine to the atmosphere during periods of no sunlight. The inclusion of these measurements in a global climate model indicates that the emitted bromocarbons will disperse throughout the troposphere in the sourthern hemisphere, even reach the stratosphere and contribute to ozone loss in the lower atmosphere.

Katarina Abrahamsson, Anna Granfors, Martin Ahnoff, Carlos A. Cuevas & Alfonso Saiz-Lopez. Organic bromine compounds produced in sea ice in Antarctic winter. Nature Communications. DOI: 10.1038/s41467-018-07062-8, 2018.