Novel tool for urban air quality monitoring – AIRQ

The AIRQ project addresses the question of air pollution monitoring in the context of the European administrative litigation. In that context, local decision makers need prospective studies in order to evaluate the potential consequences of their policies. Therefore, modelling tools are requested to complete the information provided by the routine measurements and to test different scenario of urban planning. Nevertheless, dispersion models are complex tools which require to be fed with traffic emission or meteorological data... Such model should also be well suited to the particular configuration of the city so as to represent the main phenomena involved in atmospheric dispersion over the studied area.

The air quality models currently used for regulatory purposes can represent two type of terrain explicitly: open terrain where pollutant dispersion is facilitated by atmospheric turbulence and street canyon. These latter are typical in big city centres where pollution sources are essentially related to traffic emissions. Nevertheless, the situation in several Eastern EU member states is different and industrial activities still running very close to middle-size city centres. The industrial sources are thus located in densely populated area where the street network can not be necessarily described with street-canyon. Moreover, the vehicle fleet is likely to be poorly documented so that only few data are available to describe traffic emissions.

Therefore, the aim of this project is:
• To parameterise some particular mechanisms of turbulent mass and momentum transfer that are likely to happen in specific urban forms named hereafter street-half-canyon. Those mechanisms are not addressed by the current models. They will be studied thanks to wind tunnel investigations.
• To introduce that parameterisation in an existing air quality model used for regulatory purpose in France, SIRANE, so as to make this code able to address the question of industrial emissions in densely populated located directly around city centres.
• To provide the necessary entry data to feed the model (meteorological data, emission cadastre)
• To investigate the responses given by the model with emissions cadastre of different resolutions. That point is of particular interest to evaluate the quality of the simulations when traffic data remain poorly documented (current situation for several European Union members)
• To validate the new version of SIRANE with real life data provided by measurements taken in an urban environment submitted to industrial emissions.
• To install SIRANE in the city of Timisoara for air quality monitoring

As it is a joint research undertaking, the tasks will be divided between the French and the Romanian partners. The main goal of the research team in France will be to investigate the turbulent mechanisms responsible for dispersion over street-half-canyon, to develop the new module for the dispersion model, to provide an adapted methodology so as to obtain a relevant emission cadastre, to configure the dispersion model for operational simulations over the site of Timisoara, and to provide the results for the specific case of the city of Timisoara. The Romanian team will provide the data required for running the software. It will also perform measurements for validation of the model simulations. Expected results include an environmental cadastre of emissions, accounting for both anthropogenic and natural pollution sources. Three dimensional maps of pollutant species concentrations would be also simulated thanks to a new version of SIRANE. This specific model will be developed during the project. It would allow decision makers to identify the most likely reasons for exceeding the regulatory concentration thresholds. Also, based on the results provided by this new tool, a better urban planning would be possible, so that a higher air quality can be ensured.