One of the first images from @CopernicusEU #Sentinel-5P shows how ozone is distributed around the world. While ozone in the stratosphere is a good thing, lower down in the atmosphere it is a harmful pollutant #Tropomihttps://t.co/OdgIyNUDDq pic.twitter.com/Ge1yj6xGIL

— ESA (@esa) December 2, 2017