Ground based in situ observations of low_vol_sampler at Pic du Midi (FR0019R). These measurements are gathered as a part of the following projects EMEP and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: acetate in aerosol (mass_concentration_of_acetate_in_dry_aerosol_particles_in _air), ammonium in aerosol (mass_concentration_of_ammonium_expressed_as_nitrogen_in_dry_aerosol_particles_in _air), ammonium in aerosol (mass_concentration_of_ammonium_in_dry_aerosol_particles_in _air), calcium in aerosol (mass_concentration_of_calcium_in_dry_aerosol_particles_in _air), carbonate in aerosol (mass_concentration_of_carbonate_in_dry_aerosol_particles_in _air), chloride in aerosol (mass_concentration_of_chloride_in_dry_aerosol_particles_in _air), flow_rate in aerosol, formate in aerosol (mass_concentration_of_formate_in_dry_aerosol_particles_in _air), magnesium in aerosol (mass_concentration_of_magnesium_in_dry_aerosol_particles_in _air), nitrate in aerosol (mass_concentration_of_nitrate_expressed_as_nitrogen_in_dry_aerosol_particles_in _air), nitrate in aerosol (mass_concentration_of_nitrate_in_dry_aerosol_particles_in _air), nitrite in aerosol (mass_concentration_of_nitrite_in_dry_aerosol_particles_in _air), nitrite in aerosol (mass_concentration_of_nitrite_in_dry_aerosol_particles_in _air), oxalate in aerosol (mass_concentration_of_oxalate_in_dry_aerosol_particles_in _air), potassium in aerosol (mass_concentration_of_potassium_in_dry_aerosol_particles_in _air), sodium in aerosol (mass_concentration_of_sodium_in_dry_aerosol_particles_in _air), sulphate_total in aerosol (mass_concentration_of_total_sulphateexpressed_as_sulphur_in_dry_aerosol_particles_in_air), sulphate_total in aerosol (mass_concentration_of_total_sulphateexpressed_as_sulphur_in_dry_aerosol_particles_in_air)