A model-based analysis of SO2 and NO2 dynamics from coal-fired power plants under representative synoptic circulation types over the Iberian Peninsula

Emissions of SO2 and NO2 from coal-fired power plants are a significant source of air pollution. In order to typify the power plants' plumes dynamics and quantify their contribution to air quality, a comprehensive characterisation of seven coal-fired power plant plumes has been performed under six representative circulation types (CTs) identified by means of a synoptic classification over the Iberian Peninsula. The emission and the transport of SO2 and NO2 have been simulated with the CALIOPE air quality forecasting system that couples the HERMES emission model for Spain and WRF and CMAQ models. For the facilities located in continental and Atlantic areas (As Pontes, Aboño, and Compostilla) the synoptic advection controls pollutant transport, however for power plants located along the Mediterranean or over complex-terrains (Guardo, Andorra, Carboneras, and Los Barrios), plume dynamics are driven by a combination of synoptic and mesoscale mountain–valley and sea–land breezes. The contribution of power plants to surface concentration occurs mainly close to the source (< 20 km) related to a fumigation process when the emission injection takes place within the planetary boundary layer reaching up to 55 µg SO2 m- 3 and 32 µg NO2 m- 3. However, the SO2 and NO2 plumes can reach long distances (> 250 km from the sources) especially for CTs characterised by Atlantic advection.