Abstract. Emissions of most land based air pollutants in western Europe have decreased in the last decades. Over the same period emissions from shipping have also decreased, but with large differences depending on species and sea area. At sea, sulphur emissions in the SECAs (Sulphur Emission Control Areas) have decreased following the implementation of a 0.1 % limit on sulphur in marine fuels from 2015. In Europe the North Sea and the Baltic Sea are designated as SECAs by the International maritime Organisation (IMO). Model calculations assuming present (2016) and future (2030) emissions have been made with the regional scale EMEP model covering Europe and the sea areas surrounding Europe including the North Atlantic east of 30 degrees west. The main focus in this paper is on the effects of ship emissions from the Baltic Sea. To reduce the influence of meteorological variability, all model calculations are presented as averages for 3 meteorological years (2014, 2015, 2016). For the Baltic Sea, model calculations have also been made with higher sulphur emissions representative of year 2014 emissions. From Baltic Sea shipping the largest effects are calculated for NO2 in air, but effects are also seen for PM2.5 and depositions of oxidised nitrogen, mainly in coastal zones close to the main shipping lanes. As a result country averaged contributions from ships are small for large countries that extend far inland like Germany and Poland, and larger for smaller countries like Denmark and the Baltic states Estonia, Latvia and Lithuania, where ship emissions are among the largest contributors to concentrations and depositions of anthropogenic origin. Following the implementations of stricter SECA regulations, sulphur emissions from ships in the Baltic Sea shipping now have virtually no effects on PM2.5 concentrations and sulphur depositions in the Baltic Sea region. Following the expected reductions in European emissions, model calculated NO2 and PM2.5 concentrations, depositions of oxidised nitrogen, and partially also surface ozone levels, in the Baltic Sea region are expected to decrease in the next decade. Parts of these reductions are caused by reductions in the Baltic Sea ship emissions mainly as a result of the Baltic Sea being defined as a Nitrogen Emission Control Area from 2021.
Supplementary material to "Ship plumes in the Baltic Sea Sulphur Emission Control Area: Chemical characterization and contribution to coastal aerosol concentrations"
