The role of sea-salt emissions and heterogeneous chemistry in the air quality of polluted coastal areas

E. Athanasopoulou (1) , M. Tombrou (1) , S. N. Pandis (2) , A. G. Russell (3)

1 Department of Environmental Physics and Meteorology [Zografou campus]
2 Department of Chemical Engineering
3 School of Civil and Environmental Engineering [Atlanta]

Open-ocean and surf-zone sea-salt aerosol (SSA) emissions algorithms are incorporated in the CAMx aerosol model and applied over an area with an extended Archipelago (Greece), with a fine grid nested over the highly populated Attica peninsula. The maximum indirect impact of SSA on PM₁₀ mass (35%) is located over a marine area with moderate SSA production and elevated shipping emissions (central Aegean Sea) where SSA interacts with anthropogenic nitric acid forming sodium nitrate. SSA increases PM₁₀ levels in the Athens city center up to 27% during stable onshore winds. Under such conditions both open-ocean and surf-zone mechanisms contribute to aerosol production over Attica. A hybrid scheme for gas-to-particle mass transfer is necessary for accurately simulating semi-volatile aerosol components when coarse SSA is included. Dynamically simulating mass transfer to the coarse particles leads to a quadrupling of predicted PM₁₀ nitrate in the Athens city center and up to two orders of magnitude in its coarse mass in comparison to using a bulk equilibrium approach.

Domaines: Océan, Atmosphère

E. Athanasopoulou, M. Tombrou, S. N. Pandis, A. G. Russell. The role of sea-salt emissions and heterogeneous chemistry in the air quality of polluted coastal areas. Atmospheric Chemistry and Physics Discussions, 2008, 8 (1), pp.3807-3841. ⟨hal-00303365⟩