Development of a high-resolution (1 km × 1 km, 1 h) emission model for Spain: The High-Elective Resolution Modelling Emission System (HERMES)

This work presents the results of the development and application of the High-Elective Resolution Modelling Emission System (HERMES). HERMES generates the emissions for Spain needed for the application of high-resolution chemistry transport models, taking the year 2004 as reference with a temporal resolution of 1 h and a spatial resolution of 1 km2 considering both anthropogenic (power generation, industrial activities, on-road traffic, ports, airports, solvent use, domestic and commercial fossil fuel use) and biogenic sources (vegetation), using a bottom–up approach, up-to-date information and state-of-the-art methodologies for emission estimation. HERMES is capable of calculating emissions by sector-specific sources or by individual installations and stacks. The annual addition of hourly sectorial emissions leads to an estimation of total annual emissions as follows: NOx, 795 kt; NMVOCs, 1025 kt; CO, 1236 kt; SO2, 1142 kt and TSP, 180 kt; which are distributed principally in the greater areas of the main cities, highways and large point sources. NOx, SO2 and PM2.5 highly correlate with the power generation by coal use, achieving higher emission levels during summertime due to the increase of electricity demand by cooling systems. NMVOCs show high correlation with temperature and solar radiation (mainly as a consequence of the important weight of biogenic emissions) causing the maximum emissions during the daylight hours of summer months. CO emissions are mostly influenced by the on-road traffic; consequently the higher emissions are attained in summer because of the increase of daily average traffic during holidays. The most significant total emission sources are on-road traffic (38%), combustion in power generation plants (33%), biogenic sources (12%) and combustion in manufacturing industries (9%). The inventory generated with HERMES emission model has been successfully integrated within the Spanish Ministry of the Environmentʹs air quality forecasting system (Caliope project), being the emission core for the validation and assessment of air quality simulations in Spain.