Ground based in situ observations of high_performance_liq at Waldhof (DE0002R). 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: ethanal in air (mass_concentration_of_ethanal_in_air), methanal in air (mass_concentration_of_methanal_in_air)