Nitrogen dioxide can impact the respiratory system, and it also contributes to the formation of other trace gases including ground-level ozone and particulates. The gas is produced primarily during the combustion of gasoline in vehicle engines and coal in power plants. Trace gases have decreased even though population and the number of cars on the roads have increased. The shift is the result of regulations, technology improvements and economic changes, scientists say.

This visualization shows tropospheric column concentrations of nitrogen dioxide as detected by the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite, averaged yearly from 2005-2022.

This video provides an overview of the study findings.  For more information, read the full story on nasa.gov.  To download a copy, please visit the release on the NASA GSFC Scientific and Visualization Studio website.  Click here to read a transcript of the video.

In February 2015, Bryan Duncan (NASA scientist) gave a Ted-style talk on air quality as seen from space.  You can also view the video on the main NASA website.