Application of a Lagrangian Model FRAME to Estimate Reduced Nitrogen Deposition and Ammonia Concentrations in Poland

This paper presents the preliminary results of modelling the annual average NH₃ concentrations and reduced nitrogen depositions in Poland. The Lagrangian Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME) model is applied here, working with 5×5 km grid size. The input data are briefly described, including emission inventory and meteorological information used. The results are compared with the EMEP Unified model estimates of NH₃ concentrations and NH_x dry and wet depositions and checked against the available point measurements of NH₃ air concentrations. FRAME dry and wet deposition budget for Poland is calculated, showing good agreement with the EMEP model estimates and measurement-based wet deposition budget calculated by Chief Inspectorate of Environmental Protection.

Emissions of reduced nitrogen in Poland have fallen by 41% since 1985, compared to a 72% reduction of SO₂ and 46% reduction of NO_x emissions (Olendrzyński et al. 2004, 2007). While SO₂ and, to the less extent, NO_x emissions still show a downward trend, the NH₃ emission level has stabilized at about 320 Gg since the year 2000. The substantial reduction of SO₂ and NO_x emissions is a result of successful application of abatement strategies in Poland and economic transformations in 1990s (Mill 2006). The reduction of emissions resulted not only in decreased nitrogen and acid deposition but also the relative contribution of chemical species in acid and eutrophic deposition has changed, with the NH_x deposition gaining in importance. The EMEP estimates for the year 2004 show that the nitrogen input from NH_x deposition in Poland is about 20% larger than from oxidised nitrogen.