Professor Clemens Mensink is head of the environmental modelling unit at VITO in Belgium. The unit employs over 100 researchers, ICT professionals and technicians. It develops, improves and implements methodologies and computer models to estimate the impact of human activities on air, climate, water and soil quality in a spatial context. Clemens received his PhD (1992) and a post graduate degree (1988) in fluid dynamics from the Von Karman Institute in Belgium. He studied chemical engineering, fluid mechanics and numerical mathematics, and received his MSc (1987) in mechanical engineering from University of Twente in the Netherlands. In 1998 he received the ENERO prize. Clemens is currently president of the International Technical Meeting on Air Pollution Modelling and its Applications. He is an expert in air pollution modelling and author of more than 80 peer-reviewed publications in international journals. He is professor atmospheric modelling at Ghent University in Belgium.Dr. Oriol Jorba is Co-Group leader of the Atmospheric Composition group at the Barcelona Supercomputing Center in Spain. Oriol holds a PhD degree in Environmental Engineering (2005) from the Universitat Politècnica de Catalunya in Spain. His research expertise includes high resolution air pollution modeling, development of online meteorology-chemistry models, atmospheric chemistry studies and environmental impact assessment. He has lead the research project on the development of the multiscale chemical weather forecasting system MONARCH at BSC which provides operational forecasts for the Barcelona Dust Regional Center of the World Meteorological Organization and the Copernicus Atmosphere Monitoring Service. He is part of the International Technical Meeting on Air Pollution Modelling and its Application (ITM) scientific committee since 2012 and the steering committee of the international project Monitoring, Analysis and Prediction of Air Quality (MAP-AQ)sponsored by WMO and IGAC since 2020. He has contributed to multiple European and national research projects and is author of more than 80 peer-reviewed publications in international scientific journals.