OH radical reaction in sea water

Consequences of OH Radical Reaction in Sea Water Framation and Decay of Br2 Ion Radical... 

In the atmosphere DMS is oxidised mainly in the gas phase. Oxidation in cloud-water droplets is insignificant as the low solubility of DMS mitigates the effects of its rapid aqueous oxidation by ozone ( , McElroy, W.J., Central Electricity Research Laboratories, personal communication). Gas-phase oxidation is initiated principally by reaction with OH radicals ( ) and methanesulphonic acid (MSA) is one of the products (2). MSA has a very low vapour pressure and will be rapidly scavenged by aqueous aerosols and cloud droplets wherein further oxidation to sulphate by OH may occur. Although the kinetics and mechanism of this process have yet to be unambiguously determined, it is possible that emissions of DMS could be both a significant source of "background" sulphur and, upon oxidation, of non sea-salt sulphate. 

Although the uptake coefficient of the OH radical on sea salt has not been measured directly, it has been reported that active chlorine species are formed by the irradiation of O3 under the coexistence of sea salt particles in a chamber (Behnke et al. 1995). Oum et al. (1998a) confirmed that CI2 is released to the gas phase by the irradiation of UV at 254 nm to the deliquescent sea salt in the coexistence of O3, and proposed the formation of CI2 by the surface reaction of sea salt and OH produced by the photolysis of O3 in the presence of water vapor (reaction 4.3). 

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