Abstract
This Editorial offers an overview of the results presented in the series of coordinated articles included in the Atmosphere special issue on Atmospheric Processes over Complex Terrain. In particular, the variety of approaches and methods, as well as the main outcomes of recent progress in the field, are outlined, along with open questions and challenges for future developments. The possible outreach of future research in the field is also pointed out, especially in connection with the ongoing international cooperation initiative Multi-scale transport and exchange processes in the atmosphere over mountains programme and experiment (TEAMx).