‌Located on the west coast of Ireland, the Mace Head Atmospheric Research Station in Carna, County Galway has been a site for aerosol measurements since 1958. The location is unique in Europe, offering westerly exposure to the North Atlantic ocean (clean sector, 180 degrees through west to 300 degrees) and the opportunity to study atmospheric composition under Northern Hemispheric background conditions as well as European continental emissions when the winds favour transport from that region.The mission of Mace Head Atmospheric Research Station is the monitor the long-term trends of atmospheric composition change, essential climate variables and air pollution and to facilitate key-process research into the evolution of atmospheric composition and to its impacts on climate change, concomitant with the promotion of knowledge transfer and the underpinning of policy development and education in the areas of atmospheric climate, and air pollution.