Modelling multi-phase halogen chemistry in the remote marine boundary layer: investigation of the influence of aerosol size resolution on predicted gas- and condensed-phase chemistry D. Lowe, D. Topping, and G. McFiggans School of Earth, Atmospheric and Environmental Science, University of Manchester, Manchester, UK
Abstract. A coupled box model of photochemistry and aerosol microphysics which explicitly
accounts for size-dependent chemical properties of the condensed-phase has been
developed to simulate the multi-phase chemistry of chlorine, bromine and iodine in
the marine boundary layer (MBL). The model contains separate seasalt and
non-seasalt modes, each of which may be composed of 1–16 size-bins. By
comparison of gaseous and aerosol compositions predicted using different
size-resolutions with both fixed and size-dependent aerosol turnover rates, it
was found that, for halogen-activation processes, the physical property
initialisation of the aerosol-mode has a significant influence on gas-phase
chemistry. Failure to adequately represent the appropriate physical properties
can lead to substantial errors in gas-phase chemistry. The size-resolution of
condensed-phase composition has a less significant influence on gas-phase chemistry.
Citation: Lowe, D., Topping, D., and McFiggans, G.: Modelling multi-phase halogen chemistry in the remote marine boundary layer: investigation of the influence of aerosol size resolution on predicted gas- and condensed-phase chemistry, Atmos. Chem. Phys., 9, 4559-4573, doi:10.5194/acp-9-4559-2009, 2009.