Particulate and gaseous halogens in the Antarctic atmosphere

Surface level atmospheric particulate and gas samples were collected near McMurdo station (77°51′S, 166°40′E) and Amundsen-Scott station (90°S) during November and December, 1970. Particulate samples were analyzed for iodine, bromine, and chlorine and gas samples for iodine and bromine by thermal neutron activation. There was evidence of camp contamination for some of these samples at both stations. For uncontaminated samples the mean halogen concentrations were as follows: Considerations of variations in the gaseous and particulate I/Br ratios and the gaseous to particulate iodine and bromine ratios in Antarctica and Hawaii suggest that particulate bromine and gaseous bromine both have shorter residence times in the marine atmosphere than the respective iodine species and that gaseous iodine and bromine both have relatively long residence times (of the order of months) over the polar plateau.