Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG42] Biogeochemical linkages between the surface ocean and atmosphere

Wed. May 29, 2019 10:45 AM - 12:15 PM 102 (1F)

convener:Yuzo Miyazaki(Institute of Low Temperature Science, Hokkaido University), Jun Nishioka(Hokkaido University, Institute of low temperature sciences), Koji Suzuki(Hokkaido University), Yoko Iwamoto(Graduate School of Biosphere Science, Hiroshima University), Chairperson:Yuzo Miyazaki(Institute of low temperature science, Hokkaido University), Jun Nishioka(Institute of low temperature science, Hokkaido University)

10:45 AM - 11:00 AM

[ACG42-01] Production of bromoform in sea ice and emission to the atmosphere

*Daiki Nomura1, Atsushi Ooki1, Ellen Damm2, Gerhard Dieckmann2, Bruno Delille3, Markus Frey4, Mats Granskog5, Klaus Meiners6,7, Anna Silyakova8, Takeshi Tamura9, Jean-Louis Tison10, Youhei Yamashita11 (1.Faculty of Fisheries Sciences, Hokkaido University, 2.Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, 3.Université de Liège, Liège, Belgium., 4.British Antarctic Survey, Cambridge, United Kingdom., 5.Norwegian Polar Institute, Tromsø, Norway., 6.Antarctic Climate andEcosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia., 7.Australian Antarctic Division, Kingston, Australia., 8.Centre for Arctic Gas Hydrate, Environment and Climate, Tromsø, Norway., 9.National Institute of Polar Research, Tokyo, Japan., 10.Université Libre de Bruxelles, Bruxelles, Belgium., 11.Graduate School of Environmental Sceince, Hokkaido University, Sapporo, Japan.)

Keywords:sea ice, bromoform, polar ocean

Bromoform (CHBr3) is one of the important bromine containing volatile halocarbons that are involved in ozone depletion in the atmosphere. Although the possible source of reactive bromine species from snow and sea ice has been discussed, mechanisms that control CHBr3 production within sea ice and emission to the atmosphere remain unclear. Here, we show evidence of massive CHBr3 production at sea ice surface-snow interfaces and its strong emission to the atmosphere from five field-campaigns to the Arctic Ocean, the Southern Ocean, and the Sea of Okhotsk in the winter and spring, in addition to supporting laboratory experiments. We found that the ice-related strong CHBr3 emission was linked to the production of the CHBr3 at the snow-sea ice interface through the haloform reaction. Our results suggest that sea ice acts as a strong CHBr3 source for the atmosphere, indicating a significant contribution to the atmospheric bromine cycle.