An improved system for modelling Spanish emissions: HERMESv2.0

Emission models play a key role in the development of high-resolution air quality modelling systems (AQMS). To minimise the uncertainty presented by these models, it is essential to match the high-resolution requirements of chemical transport models (CTMs) and to use up-to-date information and emission methodologies. During 2005 and 2006, the Barcelona Supercomputing Center – Centro Nacional de Supercomputación (BSC-CNS) developed the High-Elective Resolution Modelling Emissions System (HERMES04), which is a model that estimates anthropogenic and biogenic emissions for Spain with a temporal and spatial resolution of 1 h and 1 km2, taking 2004 as the reference period. Due to both the changes in Spanish emissions patterns and the age of the activity data and methodologies used, it has become necessary to update and improve the whole system. Hence, a new high-resolution emission model for Spain (HERMESv2.0) has been developed. This work introduces the improved emission estimation methodologies and data on which the model is based, as well as an analysis of the results obtained. The annual emissions estimated by HERMESv2.0 for Spain in 2009 are: NOx, 924 kt; NMVOCs, 2331 kt; SO2, 278 kt; CO, 2178 kt; NH3, 339 kt; PM10, 139 kt; and PM2.5, 105 kt. Compared with HERMES04, major differences are found in NMVOCs (+1172 kt) and SO2 (−870 kt). Important changes in emission patterns are also observed in terms of spatial and temporal distributions. A numerical comparison of both models with the Spanish National Emission Inventory indicates that previous underestimations have been heavily reduced in HERMESv2.0, especially for NOx (from −669 kt·year−1 to −176 kt·year−1), CO (from −761 kt·year−1 to 271 kt·year−1) and NMVOCs (from −1217 kt·year−1 to 135 kt·year−1). The new model substitutes HERMES04 as the emission core of the operational air quality forecasting system for Spain CALIOPE.