Modelling the contribution of sea salt and dimethyl sulfide derived aerosol to marine CCN Y. J. Yoon1,2 and P. Brimblecombe1 1School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK 2Now at: Department of Experimental Physics, National University of Ireland Galway, Galway, Ireland
Abstract. The concentration of cloud condensation nuclei (CCN) in the marine
boundary layer (MBL) was estimated from dimethyl sulfide (DMS) flux, sea
emission, and aerosols entrained from the free troposphere (FT). Only under clean air
conditions, did the nucleation of DMS derived sulfur (DMS CCN) contribute significantly to the MBL CCN. The accommodation coefficient for sulfuric acid mass
transfer was found to be a very important parameter in the modeling the contribution
of DMS to MBL CCN. The relationship between seawater DMS and MBL CCN was found to be non-linear mainly due to the transfer processes of sulfuric acid onto
aerosols. In addition, sea salt derived CCN (SS CCN) and entrained aerosol from the FT
(FT CCN) affected the MBL CCN directly, by supplying CCN, and indirectly, by
behaving as an efficient sink for sulfuric acid. The SS CCN explained more than
50% of the total predicted MBL CCN when wind speeds were moderate and high.
and FT aerosol may often be more efficient sources of MBL CCN than DMS.
Citation: Yoon, Y. J. and Brimblecombe, P.: Modelling the contribution of sea salt and dimethyl sulfide derived aerosol to marine CCN, Atmos. Chem. Phys., 2, 17-30, doi:10.5194/acp-2-17-2002, 2002.