Ground based in situ observations of filter_2pack at Kosetice (NOAK) (CZ0003R). 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: nitric_acid in air (mass_concentration_of_nitric_acid_expressed_as_nitrogen_in_air), nitrogen_dioxide in air (mass_concentration_of_nitrogen_dioxide_expressed_as_nitrogen_in_air)