Modelling the impact of sea-salt particles on the exceedances of daily PM10 air quality standards in the Netherlands

Particles generated at the sea surface contribute to PM10 levels in coastal areas. Current estimates suggest annual average contributions of up to 10 mu g/m(3) along the North Sea coast in the Netherlands. In this paper the generation of size-segregated sea salt particles is described as a function of meteorological parameters. These particles are fed into a model where transport and deposition processes are taken into account as a function of particle size and relative humidity. Modelled values are compared with daily measurements of Cl- concentrations in air (particles < 3.5 mu m, 7 locations) and monthly averages of wet Na+ deposition (particles < 100 mu m, 14 locations). Results indicate a much lower impact on exceedances of the daily limit value than on annual average PM10 values.