The OMI Nitrogen Dioxide (NO2) tropospheric parameter displays the tropospheric component of the total NO2 column measured in molecules/cm². Nitrogen dioxide is an important chemical species in both, the stratosphere where it plays a key role in ozone chemistry, and in the troposphere where it is a precursor to ozone production. In the troposphere, it is produced in various combustion processes and in lightning and is an indicator of poor air quality and urban smog.

The Ozone Monitoring Instrument (OMI) Level-3 NO2 (OMNO2d) product provides daily gridded global coverage with a temporal resolution of 1 day, imagery resolution of 2 km and sensor/algorithm resolution where pixel level data of good quality are binned and "averaged" into 0.25 x 0.25 degree global grids.

References: OMNO2d README; DOI: 10.5067/Aura/OMI/DATA3007