Variation in ozone exposure in the landscape of southern Sweden with consideration of topography and coastal climate

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 lands cape. [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 land-scape.

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.