Long-Term Record (1981—2005) of Ammonia and Ammonium Concentrations at K-Puszta Hungary and the Effect of Sulphur Dioxide Emission Change on Measured and Modelled Concentrations

In the 3 years of political and economical changes in Hungary (1989—1991) the number of animals and the use of fertilizers highly decreased with parallel decrease of calculated ammonia emission (Fig. 12.1). In an earlier study (Horvath and Sutton 1998) long-term trend of background ammonia/ammonium concentrations were analysed between 1981 and 1995 at Hungarian K-puszta station (longitude 19′33″, latitude 46′58″, h=125 m a.s.l.). Despite the reduction in NH₃ emission, the concentration of ammonia remained at the same level. Only small reductions were observed both for particle ammonium concentration and wet ammonium deposition. It was suggested that the reasons for the discrepancy included changing SO₂ emissions as well as buffering of the atmospheric NH₃ concentration by vegetation compensation points.