The aging process of naturally emitted aerosol (sea-salt and mineral aerosol) during long range transport

The aging processes of two representative natural aerosol, sea-salt and mineral aerosol, are investigated by using a box model equipped with a thermodynamic module (SCAPE). The model is shown to successfully describe the aging processes between the gas-phase anthropogenic pollutants (SO2, NOx, and NH3) and primary aerosol particles, including self-neutralization process/chlorine depletion in the sea-salt aerosol; formation/dissipation of carbonate and bicarbonate ions in the mineral aerosol; irreversible dynamic deposition of SO2 and H2SO4; and reversible thermodynamic distribution of inorganic volatile species. It is found that SO2 and H2SO4 tend to deposit onto the mode with the largest surface area, and that ammonia deposition is controlled by preceding SO2/H2SO4 deposition. During the SO2/H2SO4 deposition, chloride and carbonate are continuously released from the sea-salt and mineral dust particles, respectively. The findings by the model predictions are consistent with field and observational studies.