RapidAir has been deployed internationally to model air quality and to evaluate the potential impact of mitigation measures in many cities including mega cities in the Middle East and China. On behalf of the UK Foreign and Commonwealth Office, Ricardo developed a detailed model of Jinan, the capital city of china’s Shandong province, with RapidAir coupled with a regional model that incorporated sources up to several thousand kilometres from the city and local sources in the city itself. RapidAir’s capacity to consume extensive datasets, consider massive modelling domains, produce high resolution outputs and support rapid scenario testing provided unrivalled capability and flexibility to users of the model.