Particulate matter pollution at regional scale in Eastern France: influence of weather types and circulation regimes and sources strength during COVID-19 Lockdowns
Résumé
This study focuses on the characterization and understanding of the particulate matter pollution in two medium-sized cities located in eastern France with contrasting air quality, Dijon and Montbéliard. Measurements of PM10 (diameter <10 μm) and PM2.5 (diameter <2.5 μm) concentrations are analyzed at two fixed measurement stations over the 2015–2022 period. If EU thresholds are being respected for PM10, this is more difficult for PM2.5, especially at the daily time step, and during the “particulate season” from October to April.
We then used the 8-km SAFRAN reanalyzed database and the 10-m Digital Terrain Model to analyze the climate and topography effects on air quality in the two cities. We completed this with the study of the influence of the atmospheric circulation regimes on daily PM levels variability, based on the qualitative “Groβwetterlagen”.
Our study shows that the weather types may help explaining the PM levels in a city, combined with the climate-topographic effects at the urban scale. Our study also highlights, through the COVID-19 case study, the complexity of the PM pollution with respect to other pollutants like NOx (more directly related to traffic). Finally, our study puts in stress that even in favorable air quality urban conditions, the daily PM2.5 concentration levels exceed the recommended threshold for human health by around 8%.
Domaines
MétéorologieOrigine | Fichiers éditeurs autorisés sur une archive ouverte |
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