Spatial representativeness of air quality monitoring sites : outcomes of the FAIRMODE/AQUILA intercomparison exercise

We are presenting an evaluation of the outcomes of the FAIRMODE & AQUILA intercomparison exercise (IE) on spatial representativeness (SR). To the best of our knowledge, this study is the first attempt to investigate systematically the differences in SR estimates that are achieved by applying a large set of SR approaches to the same common dataset. The assessment of the spatial representativeness (SR) of air quality monitoring stations is an important subject that is linked to several highly topical areas, including risk assessment and population exposure, the design of monitoring networks, model development, model evaluation and data assimilation. Nevertheless, European regulations lack a clear definition and provisions to determine the SR of the stations. Also in the scientific literature, there is no unified agreement to address this complex problem. In order to further explore this topic and to make progress in the harmonisation of the related assessment procedures, the FAIRMODE (Forum for Air Quality Modelling in Europe) Cross-Cutting Activity group on SR organised a comprehensive intercomparison exercise (IE). The main objective of this IE was to evaluate the possible variability of spatial representativeness results obtained by applying the range of different contemporary approaches to a jointly used example case study. In order to ensure a broad participation in this exercise, a collaborative effort has been established between FAIRMODE and AQUILA (the European Network of Air Quality Reference Laboratories). As a working basis, a shared dataset has been collected among a set of monitoring, emission and modelling data from the city of Antwerp.