K. Toyota

Mercury Physicochemical and Biogeochemical Transformation in the Atmosphere and at Atmospheric Interfaces: A Review and Future Directions

Atmosphere and at Atmospheric Interfaces: A Review and Future Directions Parisa A. Ariya,*,†,‡ Marc Amyot, Ashu Dastoor, Daniel Deeds,‡ Aryeh Feinberg,† Gregor Kos,‡ Alexandre Poulain, Andrei Ryjkov, Kirill Semeniuk, M. Subir, and Kenjiro Toyota †Department of Chemistry and ‡Department of Atmospheric and Oceanic Sciences, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada, H3A 2K6 Department of Biological Sciences, Universite ́ de Montreál, 90 avenue Vincent-d’Indy, Montreal, Quebec, Canada, H3C 3J7 Air Quality Research Division, Environment Canada, 2121 TransCanada Highway, Dorval, Quebec, Canada, H9P 1J3 Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada, K1N 6N5 Department of Chemistry, Ball State University, 2000 West University Avenue, Muncie, Indiana 47306, United States Air Quality Research Division, Environment Canada, 4905 Dufferin Street, Toronto, Ontario, Canada, M3H 5T4

Modeling multi-phase halogen chemistry in the marine boundary layer with size-segregated aerosol module: Implications for quasi-size-dependent approach

A photochemical box model with size-segregated aerosol module, which explicitly accounts for size-dependent chemical properties of sea-salt particles, has been developed to simulate multi-phase chemistry of chlorine and bromine in the marine boundary layer (MBL). Simulated results are compared with those obtained by a model that only implicitly accounts for particle size dependence by applying the quasi-size-dependent approach (bulk model). It is found that the bulk model fails to capture the decreased volatilization rates of bromine from the small-sized sea-salt particles caused by rapid depletion of bromide. This leads to substantial overestimation of gas phase bromine mixing ratios by the bulk model, affecting the behavior of other species such as ozone and NO, that are sensitive to bromine chemistry. The findings warrant the use of size-segregated model in simulating MBL halogen chemistry.