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Abstract: Ozone concentrations ([O3]) and meteorological parameters were measured with a mobile monitoring station at two coastal and five inland sites in southwest Sweden. Three of the five inland sites were located topographically low and two high compared to the surrounding landscape. In addition, [O3] data from six permanent monitoring stations in southern Sweden were analysed in relation to the positions of the measurement sites in the landscape. [O3] was also measured with passive diffusion samplers at two other sites. Both the diurnal temperature range (DTR) and the diurnal [O3] range (DOR) were to a large extent explained by the strength of the nocturnal temperature inversions at the sites. To investigate the influence of topography, the relative altitude of the sites was defined as the average altitude within a 3 km radius subtracted from the altitude of the site. Statistically significant relationships were obtained for average [O3] as well as DOR with relative altitude. Inland low sites experienced stronger nocturnal temperature inversions, lower average [O3] and larger DOR compared to inland high and coastal sites. Relative altitude was found to be superior to site altitude in explaining the variation of average [O3] and DOR in the landscape. This study underlines the importance of including local topography, as well as vicinity to the coast, in modelling [O3] and in O3 environmental risk assessments. [Copyright &y& Elsevier]

The dry and wet deposition of nitrate, NO 3 −, and ammonium, NH 4 +, were estimated for Norway spruce forests at ten monitoring sites across Sweden for the years 2014–2017. The particulate dry deposition was estimated based on measurements using Teflon string samplers as surrogate surfaces, in combination with the net throughfall deposition for sodium (throughfall subtracted with wet deposition). The wet deposition was estimated from bulk deposition measurements, corrected for dry deposition to the collectors. There was a strong gradient for total inorganic nitrogen (N) deposition across Sweden from north to southwest, ranging from 2 to 20 kg N ha−1 yr−1. The values for N deposition derived from measurements were for most sites exceeding the corresponding values derived from modelling with the MATCH and EMEP models, in southern Sweden by up to 4–6 kg N ha−1 y−1. Based on comparisons between total and throughfall deposition, the canopy uptake of atmospheric N deposition to Norway spruce forests in Sweden was estimated to be in the range of 0–7 kg N ha−1 yr−1. Image 1 • Dry deposition of particulate N to forests was estimated with surrogate surfaces. • The total deposition of N was higher compared with model predictions. • The canopy uptake of N to spruce in Sweden was on the order of 0–7 kg N ha−1 yr−1. • The critical load for N deposition to spruce forests was exceeded at most sites. [ABSTRACT FROM AUTHOR]