This project funded by the National Centre for Atmospheric Science focuses on the importance of mid-latitude cyclones for the long range transport of atmospheric pollutants. Pollutants released in the atmospheric boundary layer can be rapidly lifted into the free troposphere by the "conveyor-belt" airflows along the surface of frontal systems. This project uses a regional-scale numerical model of the atmosphere to explore how effective this transport is for chemically-active pollutants that may also be scavenged by the associated clouds and rainfall.