The North Atlantic Marine Boundary Layer EXperiment (NAMBLEX) campaign was an atmospheric composition campaign conducted at Mace Head in Ireland from 24 July 2002 to 3 September 2002. The data consist of chemical and meteorological atmospheric measurements, model data and trajectories from a number of instruments, including several from the Universities Facility for Atmospheric Measurements (UFAM). The chemical species measured includes: O3, CO, H2, DMS, CH4, NMHC, NOx, NOy, PAN, VOCs, HCHO, peroxides, organo-halogenated species, a range of shorter lived halogen species (I2, OIO, IO, BrO), NO3 radicals, photolysis frequencies, and the free radicals OH, HO2 and (HO2 + Σ RO2). The BADC is the primary archiving and distribution data centre for NAMBLEX.