In collaboration with other European experts, VITO has developed a technical support document on the use of modelling for various fields of application within the framework of the Ambient Air Quality Directive, entitled ”Air quality modelling for air quality policy”. The project highlights the recognition and reputation of VITO's ATMOSYS air quality team in terms of policy support and modelling expertise.
The importance of models
“Over the past decades, scientific understanding of the driving principles of atmospheric pollution has improved significantly. This increased insight in combination with unprecedented computer power and novel computational and statistical techniques have resulted in air quality modelling systems capable of capturing the fundamental processes of air pollution. Air quality modelling systems represent and comprise our current understanding of atmospheric pollution processes”, explains Stijn Janssen, Air Quality Program Manager at VITO . As a result, they are a mature and essential part of the toolbox to support air quality assessment and management practices from the global to the local scale.
In the revised European Ambient Air Quality Directive (Directive (EU) 2024/2881), modelling is given a more prominent role as Europe recognises that the development of an effective air quality policy should also be supported by solid modelling results. This has long been regarded as best practice in Flanders where VITO’s ATMOSYS air quality modelling system has supported the policy making process at various governance levels.
Guidance document
Hence, in 2020 the European Commission – DG Environment commissioned a study to strengthen air quality monitoring, modelling and plans under the Ambient Air Quality Directives. One of the key outcomes was the recommendation to prepare several technical guidance documents to fill gaps in technical knowledge and understanding regarding implementation of the provisions on monitoring, modelling and air quality plans.
Preparation of the subsequent technical support documents on the use of modelling and monitoring under the Ambient Air Quality Directive were awarded to a consortium comprising of Ricardo, NILU and VITO.
Under the expert lead of Stijn Janssen, VITO was responsible for writing the technical support document on the use of modelling for various application domains under the Ambient Air Quality Directive, together with a group of 5 air quality modelling experts from across the EU.
Expert guidance for efficient use of air quality models
Guidance on the use of modelling systems is provided for each of the following application domains:
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Assessment of the spatial representativeness of sampling points and overall design of a monitoring network, including the relocation of sampling points.
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Assessment of air pollutant concentration levels, including the estimation of exceedance situations, the contribution of natural sources, and the contribution from the resuspension of particulates following winter-sanding or winter-salting.
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Estimation of source apportionment to assess the contribution of the relevant sources of air pollution and quantify the potential impacts of their reduction as a starting point for the planning process.
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Contribution to the design and selection of a set of measures and the overall quantification of the impact and effectiveness of an air quality plan to mitigate an exceedance situation in the shortest possible timeframe.
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Short-term air quality forecasts to warn the public about potential episodes and exceedances of the information and alert thresholds.
The document was extensively reviewed by FAIRMODE (the Forum for Air Quality Modelling), AQUILA, (the European Network of National Air Quality Reference Laboratories communities), and the Air Quality Expert Group.
The final version of the guidance document can be found on the official European Union website: https://data.europa.eu/doi/10.2779/3343596
