Ground based in situ observations of filter_2pack at Jungfraujoch (CH0001G). These measurements are gathered as a part of the following projects ACTRIS, EMEP and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: ammonium in pm1 (mass_concentration_of_ammonium_in_pm1_in_air), ammonium_nitrate in pm1 (mass_concentration_of_ammonium_nitrate_in_pm1_in_air), calcium in pm1 (mass_concentration_of_calcium_in_pm1_in_air), chloride in pm1 (mass_concentration_of_chloride_in_pm1_in_air), magnesium in pm1 (mass_concentration_of_magnesium_in_pm1_in_air), nitrate in pm1 (mass_concentration_of_nitrate_in_pm1_in_air), oxalate in pm1 (mass_concentration_of_oxalate_in_pm1_in_air), potassium in pm1 (mass_concentration_of_potassium_in_pm1_in_air), sodium in pm1 (mass_concentration_of_sodium_in_pm1_in_air), sulphate_total in pm1