Abstract
As cities are growing, the estimation of human exposure to air pollution requires detailed spatial representation, rather than homogenous fields, provided by global- or regional-scale numerical models. A critical input for urban-scale atmospheric modeling are timely and spatially resolved emission inventories. Therefore, we developed the UrbEm approach to downscale gridded emission inventories, applying open access proxy and emission data sources. As a proof-of-concept, regional anthropogenic emissions by Copernicus Atmospheric Monitoring Service (CAMS) are handled with the UrbEm approach, creating emission inventories for any city of Europe, at the desired spatial resolution down to 1 km with detailed mapping of industrial (point), (road-) transport (line), and residential / agricultural / other (area) emission sources. Line sources are of particular value for urban-scale air quality studies, as they enable their explicit treatment by state-of-the-art city-scale chemistry transport models. The UrbEm approach constitutes a fully credible option in case high-resolution emission inventories for the city/domain of interest do not exist. The evaluation of air pollution predictions over Athens and Hamburg against in situ measurements shows a better spatial representation of emission sources as well as improved air quality modeling results when using UrbEm emission outputs instead of the original CAMS emission fields.
