NO₂ concentrations were measured at 11 LWF plots (1999/2000) with passive samplers (Palmes-type diffusion tubes) during one year. Three samplers per site and period (usually 14 days) were installed in the open area of the LWF plots and, at Beatenberg, Novaggio and Vordemwald, under the forest as well (weather station). In 2014, NO2 concentrations were measured again at 14 plots, using two samplers per site and period (usually 28 days). At Lausanne and Vordemwald, concentrations were also measured below the canopy. ### Purpose: ### To assess air concentrations of nitrogen dioxide (NO2) and, using deposition velocities available from the literature, to quantify the dry deposition of NO2 (alternative method to the throughfall method).