Impact of BrO on dimethylsulfide in the remote marine boundary layer

摘要

We have used a global three-dimensional chemical transport model coupled to a detailed size-resolved aerosol microphysics module to study the impact of BrO on dimethylsulfide (DMS) in the remote marine boundary layer. Our model results suggest BrO contributes 16 of the global annual DMS oxidation sink. This effect is most profound over the SH oceans where low NO, concentrations and a high sea salt aerosol source, coupled with high DMS concentrations, drives a large contribution of BrO to DMS oxidation (>20). Bromine chemistry also results in an 18 reduction in the global DMS burden and lifetime. In addition, when we use an alternative DMS source parameterization resulting in a factor 2 increase in DMS flux the release of bromine from sea salt aerosol increases by 50-60 in the southern hemisphere summer because of additional aerosol acidity. This suggests a possible DMS-S0_2-sea salt-BrO marine aerosol feedback mechanism that acts to reduce the sensitivity of the DMS lifetime to increases in DMS emission.