Implementation of resuspension from paved roads for the improvement of CALIOPE air quality system in Spain

Emissions of resuspensed particles from paved roads (RPR) have received an increasing attention in air quality modeling, since chemistry transport models are generally unable to reproduce particulate levels near road traffic. However, among the models operated in the forecasting mode in Europe, there is a lack of systems including the contribution of RPR on an hourly basis. Therefore, this contribution describes the inclusion of the resuspension of particulate matter within HERMES emission model (operationally implemented in the CALIOPE forecasting system) and the improvements obtained in the simulations of the PM10 mass over a domain covering Spain for a whole year of simulation (2004). The results indicate a remarkable improvement of the PM10 predictions, reducing the biases and errors around 15–18% and 2.6 μg m−3 for the average bias in all Spain. The RPR emission have strong local effects on the modeled particle concentration in or near the largest urban zones (up to 7 μg m−3 as the annual average), albeit those positive effects are more limited in background areas, since the deposition mechanism was found to be a significant sink for RPR in the chemistry transport model. This approach is accurate and effective in order to improve the prediction of the PM10 mass and becomes essential to achieve the standards set in the regulations for modeling applications.