First image of nitrogen dioxide from Copernicus Sentinel-4
The new Copernicus Sentinel-4 mission has delivered its first images, highlighting concentrations of atmospheric nitrogen dioxide, sulphur dioxide and ozone.
This image, based on the Sentinel-4 very first measurements acquired on 8 October 2025, depicts tropospheric nitrogen dioxide with clear pollution hotspots visible along the Mediterranean coast and over Italy’s Po Valley.
As a major air pollutant released during the combustion of fossil fuels, such as in vehicle engines, power plants and heating systems, concentrations of nitrogen dioxide can change rapidly. It is toxic on its own and also contributes to the formation of secondary pollutants like ozone and particulate matter both of which have serious impacts on human health and the environment.
Despite being preliminary, these images mark a major milestone in Europe’s ability to monitor air quality all the way from geostationary orbit, 36,000 kilometres above Earth.
More about Copernicus Sentinel-4 here.
