Modelling ozone fluxes over Hungary

This paper presents and utilises a coupled Eulerian photochemical reaction–transport model and a detailed ozone dry-deposition model for the investigation of ozone fluxes over Hungary. The reaction–diffusion–advection equations relating to ozone formation, transport and deposition are solved on an unstructured triangular grid using the SPRINT2D code. The model domain covers Central Europe including Hungary, which is located at the centre of the domain and is covered by a high-resolution nested grid. The sophisticated dry-deposition model estimates the dry-deposition velocity of ozone by calculating the aerodynamic, the quasi-laminar boundary layer and the canopy resistance. The meteorological data utilised in the model were generated by the ALADIN meso-scale limited area numerical weather prediction model used by the Hungarian Meteorological Service. The ozone fluxes were simulated for three soil wetness states, corresponding to wet, moderate and dry conditions. The work demonstrates that the spatial distribution of ozone concentration is a less accurate measure of effective ozone load, than the spatial distribution of ozone fluxes. The fluxes obtained show characteristic spatial patterns, which depend on the soil wetness, the meteorological conditions, the ozone concentration and the underlying land use.