The challenge of improving urban air quality: effects of hybrid cars, introduction in Barcelona and Madrid (Spain)

WRF-ARW/HERMES/CMAQ modelling system is applied with high resolution (1 km2, 1 h) to assess changes in Madrid and Barcelona (Spain) air quality due to hybrid cars introduction. The substitution of the oldest cars by hybrids is effective to reduce NO2 and PM2.5 levels in the conurbations (up to 35%/12% in Madrid downtown, when 30% of cars are changed). In VOC-limited areas, as Barcelona, the NOx emissions abatement locally increases tropospheric ozone concentration. Downwind, however, the precursors’ emissions reduction leads to lower O3 levels. Air quality models, applied with high resolution, prove to be useful tools to manage urban air quality.Peer ReviewedPostprint (published version