Uptake of HOBr from model calculation and smog chamber experiments

Recent laboratory studies, model calculations and field experiments show that chloride is activated to atomic Cl under special environmental conditions. It is established, that in the presence of sea-spray aerosol at low levelled NOx-concentration a chain reaction can be initiated (by H2SO5 or OH oxidising Br-) leading to Br2 in the gas-phase. There, HOBr is formed in the presence of ozone and hydrocarbons and, after its uptake by sea-spray aerosol, Br2 or BrCl released again. The uptake rate of HOBr is one of the key reactions in the reaction scheme. This was investigated in smog-chamber experiments and by model calculations.