Bromine release in the high Arctic: what is the role of aerosols?
Exponential build-up of bromine in the polar troposphere is linked to severe multi-day ozone depletion events in springtime. Recent research suggests that saline snowpack and aerosols are the main sources of bromine, but the exact mechanisms of, and conditions required for these ‘bromine explosions’ are not well understood. The two main sources of aerosol in the Arctic spring are transported pollution (Arctic haze), and larger particles produced from the open ocean or potentially through the sublimation of blowing snow. Both types of particles are rich in sea salt and could contribute to bromine release. Eureka, Nunavut (80°N) is an excellent location to monitor springtime bromine explosions and aerosol concentrations. Profiles of bromine monoxide (BrO) retrieved from Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements show that there is no clear correlation between BrO concentration and haze aerosol. However, larger aerosols correlate well with observed BrO, indicating that these aerosols are likely a source of bromine. This talk investigates the potential direct and indirect links between bromine activation and aerosols in the high Arctic