DISCOVER-AQ data archive containing Data from Baltimore MD, San Juaquin Valley CA, Houston TX, and Denver CO studies. Data may be from NASA Aircraft and both EPA and non EPA ground based measurements. Portions of this dataset are inaccessible because: The data set for this manuscript contains both EPA owned and non-EPA generated data for which EPA does not have permission to house on ScienceHub. As such it is most feasable to house the data in one location and provide the link in ScienceHub where users can access and download data if desired. They can be accessed through the following means: Final datasets are located at the following public data archive: https://www-air.larc.nasa.gov/missions/discover-aq/discover-aq.html. Users can access and download the data at this site. Format: Files follow metadata and data requirements for NASA ICARTT file format (https://earthdata.nasa.gov/esdis/eso/standards-and-references/icartt-file-format) and have been run through the ICARTT file checker prior to posting on the publicly available DISCOVER-AQ data archive. This dataset is associated with the following publication: Long, R., and J. Szykman. Comprehensive evaluations of diurnal NO2 measurements during DISCOVER-AQ 2011: effects of resolution-dependent representation of NOx emissions. Atmospheric Chemistry and Physics. Copernicus Publications, Katlenburg-Lindau, GERMANY, 21(14): 11133-11160, (2021).