text: The different reactivity of halogens as compared to OH and ozone has broad impacts on atmospheric chemistry. These include near complete removal and deposition of mercury, alteration of oxidation fates for organic gases, and export of bromine into the free troposphere.  The deposition of reactive gaseous mercury (RGM) in snow from oxidation by enhanced halogens increases the bioavailability of mercury. Recent changes in the climate of the Arctic and state of the Arctic sea ice cover are likely to have strong effects on halogen activation and ozone depletion events. Human-induced climate change affects the quantity of snow and ice cover in the Arctic, altering the intensity of nitrogen oxide emissions. Increment in background levels of nitrogen oxide apparently strengthens the consumption of ozone and the enhancement of halogens.