For questions or problems, contact jlaughner-AT-berkeley-DOT-edu

Update to v3.0A

We have updated the BEHR product to version 3.0A (from 2.1C) on 30 October 2017. This update uses the NASA SP version 3 as the base and includes a number of additional refinements, including:
  • Surface reflectance based on the MODIS MCD43D BRDF product
  • New calculation of visible-only NO2 column densities
  • New a priori profiles that include lightning NO2 and are updated to 2012 emissions
  • New temperature profiles
  • New gridding algorithm

Please see the changelog for the full list of changes.

NOTE: Currently, this version should be considered in BETA while full validation is ongoing. Known bugs that will be resolved in v3.0B:

  • The summary bits of the BEHRQualityFlags field are incorrect. For now, users should reject pixels for which VcdQualityFlags is not an even integer, XTrackQualityFlags is not 0, and BEHRAMFTrop or BEHRAMFTropVisOnly <= 1e-6, in addition to filtering for clouds (typically, reject pixels with CloudFraction > 0.2).

Code availability

The core code of the BEHR algorithm is available at It has several additional repositories as dependencies, these can be downloaded with the script found in root of that repository.

MATLAB utilities for working with BEHR data are available at These rely on code in the BEHR core utilities and general MATLAB utilities repositories.

Download New Behr Data

Generation of the BEHR product has been successfully automated.  The limiting factor is the availability of the MODIS MCD43D dataset. This imposes about a one month lag in production. 

Starting with v3.0A, BEHR is split into two subproducts. The first continues to use monthly NO2 profiles, the second uses daily NO2 profiles as recommended in Laughner et al. 2016. Because of the computational expense involved in generating these profiles, the daily subproduct will not be available for all years.  We plan to have 2005, 2007-2009, and 2012-2014 available with daily profiles by the end of 2018, and will extend that forward and backwards as time allows. (NOTE: 2005 and 2006 profiles must be simulated with boundary conditions from a different global CTM than 2007 on. Users are advised to be cautious calculating trends with 2005 and 2006 daily profile data.)

The tools available to help download BEHR data will be posted here as soon as they are updated for v3.0A.

Download files individually...

If you use our data, please cite Russell et al. 2011 and provide a link to this page.

Continental United States
Monthly NO2 Profiles
Native OMI Pixel Product
Gridded (0.05o) Product
Daily NO2 Profiles
Native OMI Pixel Product
Gridded (0.05o) Product

Version 2.1C data will remain available here until we finish validation of v3.0A.

Tools for working with .hdf files are available at Some people have had difficulty opening the BEHR .hdf files, especially when using older software; the files can be opened in MATLAB (versions 2012a-2014b tested), and we have also included some Python code which can be used to open the files (please click here).  Note that the BEHR .hdf files use Version 5 of the HDF format, and that some programs have different tools for opening Version 4 and Version 5 .hdf files.


Click the link below to access the prototype products used in Laughner et al. 2016 to study the effect of temporal resolution of the a priori NO2 profiles.

Prototype retrievals


Specialized BEHR products are now available for the four DISCOVER-AQ campaigns, specifically for days that the P3 flew. These files are based on v. 2.1A (a.k.a. v. 2.1Arev0) of BEHR (see this changelog for the differences).  These files also include AMFs derived from the P3B spiral profiles and NO2 tropospheric column densities calculated using those AMFs. (See this readme for details.)

If you are looking for BEHR data during DISCOVER campaigns on days when the P3 did not fly, these are available as part of the full record above.

NOTICE: There was a bug in the version of the InSitu files uploaded before 18 Sept 2015 (at 1615 PDT) that affected the BEHRColumnAmountNO2Trop and BEHRAMFTrop fields.  (See here for an explanation of the bug.) If you downloaded any InSitu files prior to 18 Sept 2015, please redownload the updated version. Note that this only affected the InSitu files, not the standard OMI_BEHR files.

Download zipped P3 flight day files by campaign

  HDF Files -
     Native OMI Pixel     
HDF Files -
Text Files -
     Native OMI Pixel      
D-AQ Maryland Download  Download Download
D-AQ California  Download Download Download
D-AQ Texas  Download Download Download
D-AQ Colorado  Download Download Download

Download Files Individually

.hdf at native OMI pixel resolution

.txt at native OMI pixel resolution

.hdf at regridded (0.05º × 0.05º) resolution


The following documentation covers features available in v. 2.1C of BEHR. The BEHR User Guide should be dated February 5, 2018; if not, please clear your browser's cached files.


To the extent possible under law, The Cohen Research Lab has waived all copyright and related or neighboring rights to Berkeley High-Resolution NO2 Retrieval. This work is published from: United States.