Title Snow-sourced bromine and its implications for polar tropospheric ozone
Author Yang, X.; Pyle, J.A.; Cox, R.A.; Theys, N.; van Roozendael, M.
Author Affil Yang, X., National Centre for Atmospheric Science, Cambridge, United Kingdom. Other: University of Cambridge, United Kingdom; Belgisch Instituut voor Ruimte-AŽronomie, Belgium
Source Atmospheric Chemistry and Physics, 10(16), p.7763-7773. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2010
Notes In English. Published in Atmospheric Chemistry and Physics Discussions: 29 March 2010, http://www.atmos-chem-phys- discuss.net/10/8135/2010/acpd-10-8135- 2010.html ; accessed in June, 2011. 50 refs. GeoRef Acc. No: 310023. CRREL Acc. No: 65006829
Index Terms aerosols; boundary layer; ice; ozone; polar regions; salinity; simulation; snow; stratosphere; sublimation; Antarctica; Arctic region; polar regions; atmospheric transport; bromine; chemical explosions; depletion; explosions; gaseous phase; Global Ozone Monitoring Experiment; halogens; inorganic materials; sea ice; suspension; transport; troposphere; winds
Abstract In the last two decades, significant depletion of boundary layer ozone (ozone depletion events, ODEs) has been observed in both Arctic and Antarctic spring. ODEs are attributed to catalytic destruction by bromine radicals (Br plus BrO), especially during bromine explosion events (BEs), when high concentrations of BrO periodically occur. However, neither the exact source of bromine nor the mechanism for sustaining the observed high BrO concentrations is completely understood. Here, by considering the production of sea salt aerosol from snow lying on sea ice during blowing snow events and the subsequent release of bromine, we successfully simulate the BEs using a global chemistry transport model. We find that heterogeneous reactions play an important role in sustaining a high fraction of the total inorganic bromine as BrO. We also find that emissions of bromine associated with blowing snow contribute significantly to BrO at mid-latitudes. Modeled tropospheric BrO columns generally compare well with the tropospheric BrO columns retrieved from the GOME satellite instrument (Global Ozone Monitoring Experiment). The additional blowing snow bromine source, identified here, reduces modeled high latitude lower tropospheric ozone amounts by up to an average 8% in polar spring.
URL http://www.atmos-chem-phys.net/10/7763/2010/acp-10-7763-2010.pdf
Publication Type journal article
Record ID 91474