Atmos. Chem. Phys., 19, 14211–14232, 2019 https://doi.org/10.5194/acp-19-14211-2019 © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License. Analysis of summer O3 in the Madrid air basin with the LOTOS-EUROS chemical transport model Miguel Escudero1,2, Arjo Segers2, Richard Kranenburg2, Xavier Querol3, Andrés Alastuey3, Rafael Borge4, David de la Paz4, Gotzon Gangoiti5, and Martijn Schaap2 1Centro Universitario de la Defensa (CUD) de Zaragoza, Academia General Militar, Ctra. de Huesca s/n, 50090 Zaragoza, Spain 2TNO, P.O. Box 80015, 3584 TA, Utrecht, the Netherlands 3Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain 4Department of Chemical and Environmental Engineering, Technical University of Madrid (UPM), c/José Gutiérrez Abascal 2, 28006 Madrid, Spain 5Escuela Técnica Superior de Ingeniería de Bilbao, Departamento de Ingeniería Química y del Medio Ambiente, Universidad del País Vasco (UPV/EHU), Urkixo Zumarkalea, s/n, 48013 Bilbao, Spain Correspondence: Miguel Escudero (
[email protected]) Received: 6 April 2019 – Discussion started: 30 April 2019 Revised: 1 October 2019 – Accepted: 5 October 2019 – Published: 26 November 2019 Abstract. Tropospheric O3 remains a major air-quality issue duce the highest O3 due to the reduced ventilation associated in the Mediterranean region. The combination of large an- with low wind speeds and the contribution of reservoir layers thropogenic emissions of precursors, transboundary contri- formed by vertical transport of O3 formed near the surface in butions, a warm and dry aestival climate, and topographical the previous days of the event. NAD events, usually asso- features results in severe cases of photochemical pollution.