Abstract

The depletion of the stratospheric ozone due to reactive halogen species (RHS) is well known. Most of the RHS in the stratosphere come from the long-lived halocarbons (e.g. CFCs etc.). Very short-lived substances (VSLS), uch as CHBr3, etc., mainly from tropical oceans, could reach stratosphere through vertical transport. However, the inorganic products from the degradation of the VSLS could also make contribution to the stratospheric RHS . In the tropical marine boundary layer, several pptv of BrO were observed near Cape Verde, but not in Borneo. The possible reason for this discrepancy and implication for the sea salt bromine source will be discussed. In the polar boundary layer, significant ozone depletion events (ODEs) during spring have been observed in both Antarctic and Arctic, which is thought attributed to catalytic destruction by bromine radicals (Br and BrO), especially during bromine explosion events (BEs). However, neither the exact source of the bromine nor the formation of ODEs is completely understood. Here in this presentation, I will introduce a novel bromine source from sea salt produced over sea ice, and show a detailed comparison between model and observation. The bromine effect on polar surface HOx and global mercury oxidation will also be presented in the talk.