Potential Impact of a Low Emission Zone on Street-Level Air Quality in Barcelona City Using CALIOPE-Urban Model

Abstract

Barcelona city (Spain) has a very high vehicle density (approx. 5500 vehicles km−2) being the majority diesel (64%). Barcelona traffic stations report chronic exceedances of nitrogen dioxide (NO2) European annual regulatory limits since the year 2000. In December 2017, a Low Emission Zone (LEZ) has been implemented in Barcelona to restrict access to the ring-road area to gasoline-powered passenger cars before 2000, diesel passenger cars before 2006 and vans before Euro 1 (registered before 1994) during air pollution episodes. This policy is planned to become permanent on December 2020. This work is an initial step towards evaluating the impact of Barcelona LEZ on air quality using CALIOPE-Urban. CALIOPE-Urban is a street-scale modelling system that couples CALIOPE air quality mesoscale modelling system, which provides air quality forecasts at 1 km horizontal resolution over Barcelona city, with R-LINE. Here we evaluate CALIOPE-Urban and assess its sensitivity to structural reductions of NOx emissions. We evaluate the coupled modeling system using observations from an experimental campaign in April to May 2013 in Barcelona city.