The image, created in the framework of the ESA TEMIS project, shows the annual mean tropospheric nitrogen dioxide column for the year of 2003 derived from SCIAMACHY measurements. Over 2003, a total of about 30 million measurements are available.
The emissions of oxides of nitrogen (NO and NO2) and sulphur (SO2) lead to acid rain and result in photochemical smog and ozone formation. Large-scale fossil fuel combustion and fossil fuel related activities, but also biomass burning events are important nitrogen emission sources and are encountered as high column densities in the image.