Effects of traffic emission reduction on urban air quality episode using WRF/Chem

Abstract

Traffic emission control strategies have been tested in order to reduce the effects of traffic on pollution concentrations in Madrid (Spain) during an air quality episode with very large NOx concentrations. The meteorology-chemistry model WRF/Chem allows forecasting these effects with high spatial resolution (1 km). It was necessary to develop very detailed emission inventories with a bottom-up methodology. For traffic emissions, the traffic flow simulation model SUMO has been applied, using the real time traffic counters data, Madrid vehicle fleet distribution, and emission factors from EMEP-CORINAIR Tier 3 methodology. The base or control simulation has been compared with data from the Madrid air quality monitoring network. The control simulation reproduces satisfactorily the high NO2 concentration values. The traffic reduction strategies which were taken on 28 and 29 December 2016, did not contribute substantially to improve the air quality in Madrid.