Modelling the episodic pollutants deposition over the EMEP 17,6 cell

摘要

EMEP 17,6 cell is a 150x150 km~2 area located at the Northwest of Spain, that includes several complex features in air pollution dispersion and chemical transformation, such as different and complex pollutants sources, and a coastal and complex terrain environment, with changeable weather. Considering these features, in order to estimate the pollutants' deposition at this location and the relative contribution of the main sources, episodic simulations of the pollutants' transport was done using the Sulphur Transport Eulerian Model 2 (STEM-II), for dry and wet deposition conditions. Emissions were obtained from CORINE AIR and stack measurements (when available). BVOC emissions were considered too. As the main result, the S and N depositions are increased by the action of the oxidants (such as H_2O_2, due to the VOCs photochemical mechanisms) in the coastal plumes, over the SO_2 (and NO_x) from power plants plumes. The increment of S deposition (as sulphate) is around 4 times (respect to the S deposition as SO_2, without the VOCs-NO_x emissions influence); in the case of N deposition, an additional influence over the coastline was observed, so the maximum deposition is located over the Northeastern coast. Therefore, for the management of the S and N deposition in this area, not only SO_2 and NO_x sources, but also VOCs sources should be considered.