Ground based in situ observations of sulphate_total at Alert (CA0420G) using high_vol_sampler. These measurements are gathered as a part of the following projects AMAP_public, AMAP 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)