Ground based in situ observations of filter_2pack at Gulsvik (NO0752R). These measurements are gathered as a part of the following projects NILU and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: sulphate_total in aerosol (mass_concentration_of_total_sulphateexpressed_as_sulphur_in_dry_aerosol_particles_in_air), sulphur_dioxide in air (mass_concentration_of_sulphur_dioxide_expressed_as_sulphur_in_air)