The BEHR OMI NO₂ product reprocesses tropospheric NO₂ columns from the Ozone Monitoring Instrument (OMI) satellite using high resolution a priori NO₂ profiles, surface reflectivity, and surface elevation data. This product uses NO₂ profiles for the day retrieved, simulated by the WRF-Chem model at 12 km spatial resolution. The use of high spatial resolution NO₂ profiles has been shown to better resolve urban/rural differences in NO₂ column densities, and the use of day-to-day (rather than monthly average) profiles is especially important in applications that preferentially select observations upwind or downwind of a NO_x source.

The methods for the BEHR product are described in detail in Laughner et al. (in prep). 

Each month of BEHR data is stored as a .tar.gz file (i.e. a tar archive compressed with gzip). These can be decompressed using 7zip or (on Mac/Linux) the command "tar -xzvf <filename>", e.g. "tar -xzvf OMI_BEHR-DAILY_US_v3-0A_200501.tar.gz" will expand OMI_BEHR-DAILY_US_v3-0A_200501.tar.gz 

In addition to downloading the full dataset or manually downloading individual files, a Python program is available at https://github.com/CohenBerkeleyLab/BEHRDownloader that can perform bulk downloads of a subset of the files, as well as automatically uncompress the tar files. See the Readme in that repo for further usage information.

For details on best practices for using the BEHR data, see the user guide PDF included in this repository.