Reactive bromine chemistry in Mount Etna's volcanic plume: the influence of total Br, high-temperature processing, aerosol loading and plume-air mixing

摘要

Volcanic emissions present a source of reactive halogens to the troposphere, through rapid plume chemistry that converts the emitted HBr to more reactive forms such as BrO. The nature of this process is poorly quantified, yet is of interest in order to understand volcanic impacts on the troposphere, and infer volcanic activity from volcanic gas measurements (i.e. BrO / SO2 ratios). Recent observations from Etna report an initial increase and subsequent plateau or decline in BrO / SO2 ratios with distance downwind.