Atmospheric sulfur and nitrogen budgets for southeast Europe

This paper presents atmospheric sulfur and nitrogen budgets for the region of southeast Europe, including Albania, Bulgaria, Greece, Italy, Romania, the western part of th Anthropogenic and natural emission fluxes are estimated from information in the literature; wet and dry deposition fluxes are determined from both EMEP measurements and modelling results and the input and output terms are based on EMEP modelling results. For sulfur, the total inputs and outputs for the region range from 3.8 to 4.4 and 4.0 to 7.2 Tg Sy⁻¹, respectively; for nitrogen, the inputs and outputs are 2.1 to 3.8 and 2.0 to 6.6 TgNy⁻¹, respectively. On average, the nitrogen fluxes consist of approximately equal parts of oxidized and reduced forms. Despite the presence of strong upwind sources, anthropogenic emission within the region dominate the inputs, accounting for approximately 70% of the total inputs for both S and N. The three output terms, outflow, wet and dry de'position, are of similar magnitude for both species, but all have considerable uncertainties (ca 50%). The cycling of S and N in the atmosphere of southeast Europe has common features with that in eastern North America and west-central Europe, in that anthropogenic S and N dominate the natural cycles of these substances, anthropogenic emissions within the region significantly exceed inflows to the region, and the region is a net exporter of S and N species.