The interaction between sea-salt aerosol and marine gaseous chemistry

In smog-chamber experiments the activation of Br- and Cl- to atomic Br and Cl in sea-spray aerosol was investigated. No activation was observed in the presence of O3, hydrocarbons and NaCl aerosol alone. By adding Br- to the aerosol, the chain reaction: Br + O3=>BrO, BrO+HO2=>HOVr, HOBr=>HOBr(aq), HOBr(aq) + H+ + Br- => Br2(6), HOBr(aq)+H+ + Cl- 0> BRCl(7) was verified. The step from reaction (6) to (7) is accompanied by a decrease of the Br-/Cl- ratio from 1/600 to less than 1/2000. In the absence of sulphate, the chain is initiated by the reaction of OH(aq) with Br-.