Ground based in situ observations of organic_mass at Payerne (CH0002R) using AMS. These measurements are gathered as a part of the following projects EMEP, CAMPAIGN and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: organic_mass in pm1_non_refractory (mass_concentration_of_organic_mass_in_non_refractory_pm1_in_air)