The role of snow in controlling halogen chemistry and boundary layer oxidation during Arctic spring: A 1D modeling case study

However, halogen production mechanisms from snow remain highly uncertain, making it difficult for most models to include descriptions of halogen snow emissions and to understand the impact on atmospheric chemistry. We investigate the influence of Arctic halogen emissions from snow on boundary layer oxidation processes using a one-dimensional atmospheric chemistry and transport model (PACT-1D).

To understand the combined impact of snow emissions and boundary layer dynamics on atmospheric chemistry, we model Cl-2 and Br-2 primary emissions from snow and include heterogeneous recycling of halogens on both snow and aerosols. We focus on a 2-day case study from the 2009 Ocean-Atmosphere-Sea Ice-Snowpack campaign at Utqia x121;vik, Alaska. The model reproduces both the diurnal cycle and high quantity of Cl-2 observed, along with the measured concentrations of Br-2, BrO, and HOBr.