ANALYSIS OF LARGE-SCALE SULFATE, NITRATE, CHLORIDE AND AMMONIUM CONCENTRATIONS IN THE NETHERLANDS USING AN AEROSOL MEASURING NETWORK

SO42-, NO3-, Cl- and N4+ concentrations in aerosol together with the gaseous components SO2, NO, NO2 and O3 and meteorological parameters were measured in The Netherlands in the period 1979-1986 using a measuring network. Variations in time and space of concentrations measured were investigated. From eigenvector analysis it appeared that, contrary to their primary components SO2, NO and NH3, which are mainly determined by local conditions, concentrations of SO42-, NO3- and NH4+ of different stations are strongly correlated and thus homogeneously distributed over The Netherlands. Cl- shows a more small-scale type of behaviour. In the summer months concentrations of NO3- and NH4+ are determined by conversion processes and local emissions at ground level. The relation between interpolation error and network density is discussed. It appeared that aerosol concentrations at one typical station give a first approximation of SO42- concentrations over the whole area of The Netherlands.