Impact of reactive bromine chemistry in the troposphere

R. von Glasow, R. von Kuhlmann, M. G. Lawrence, U. Platt, P. J. Crutzen

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177 Citations (Scopus)

Abstract

Recently several field campaigns and satellite observations have found strong indications for the presence of bromine oxide (BrO) in the free troposphere. Using a global atmospheric chemistry transport model we show that BrO mixing ratios of a few tenths to 2 pmol mol-1 lead to a reduction in the zonal mean O3 mixing ratio of up to 18% in widespread areas and regionally up to 40% compared to a model run without bromine chemistry. A lower limit approach for the marine boundary layer, that does not explicitly include the release of halogens from sea salt aerosol, shows that for dimethyl sulfide (DMS) the effect is even larger, with up to 60% reduction of its tropospheric column. This is accompanied by dramatic changes in DMS oxidation pathways, reducing its cooling effect on climate. In addition there are changes in the HO2:OH ratio that also affect NOx and PAN. These results imply that potentially significant strong sinks for O3 and DMS have so far been ignored in many studies of the chemistry of the troposphere.
Original languageEnglish
Pages (from-to)2481-2497
Number of pages17
JournalAtmospheric Chemistry and Physics
Volume4
Issue number11/12
DOIs
Publication statusPublished - 8 Dec 2004

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