The spatial distribution and particle size of some inorganic nitrogen, sulphur and chlorine species over the North Sea

• Published in: Atmospheric environment 1992, Vol.26 (9), p.1689-1699
• Main Authors: Ottley, C.J., Harrison, Roy M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheric pollution; chlorine; Dry deposition; Exact sciences and technology; Marine; marine atmosphere; nitrogen compounds; North Sea; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; sulphur
• ISSN: 0960-1686; 0004-6981
• DOI: 10.1016/0960-1686(92)90067-U

The use of filter packs and a cascade impactor during a series of research cruises in the southern area of the North Sea has yielded detailed spatial distribution patterns of aerosol concentrations, Cl −, NO 3 −, SO 4 2−1 and NH 4 + and gaseous concentrations, HCl, HNO 3 and NH 3. The overall distribution of the atmospheric concentrations closely parallels published modelled results for metallic species. The chemical transformations of these aerosols and gases are investigated together with their interactions with the seasalt aerosol. Aerosol chloride loss is greatest in the more polluted areas, whilst concentrations products of NH 3 with HNO 3 and HCl appear insufficient to sustain the existence of NH 4NO 3 and NH 4Cl. Nitrate is associated predominantly with larger particles and appears to be present substantially as a surface coating on marine aerosol. The total dry deposition input for nitrogen species is calculated for the southern sector with extrapolation to the whole of the North Sea, using particle size weighted deposition velocities of 0.63 and 0.21 cm s −1 for NO 3 −1 and NH 4 +, respectively, and literature-derived values for the gaseous constituents. Finally the use of air-mass back trajectories illustrates the role of source regions in influencing the chemical composition of the North Sea atmosphere.