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

We have updated the BEHR product to version 3.0B (from 3.0A) on 24 July 2018. This update uses the NASA SP version 3 as the base. Compared to v3.0A, the key changes are:

• New method of calculating surface pressure (following Zhou et al. 2009)
• Tropopause height calculating using the WMO thermal tropopause definition on WRF temperature profiles
• Bug in BEHRQualityFlags fixed

This is in addition to the key changes introduced in v3.0A:

• Surface reflectance based on the MODIS MCD43D BRDF product
• New calculation of visible-only NO2 column densities
• New daily (as well as monthly) a priori profiles that include lightning NO2 and are updated to 2012 emissions
• New temperature profiles
• New gridding algorithm

Please see the Changelog.txt for the full list of changes.

The core code of the BEHR algorithm is available at https://github.com/CohenBerkeleyLab/BEHR-core. It has several additional repositories as dependencies, these can be downloaded with the setup.sh script found in root of that repository.

MATLAB utilities for working with BEHR data are available at https://github.com/CohenBerkeleyLab/BEHR-analysis-utils. These rely on code in the BEHR core utilities and general MATLAB utilities repositories.

BEHR files may be downloaded individually below or as compressed tarballs from the four UC Dash repositories (each for one of the four subproducts, see below). The latter have DOIs assigned, and so are generally the preferred method of access. If you download the products from this page, please include a link to here and reference Laughner et al. 2018 in any resulting publications. If you download from the UC Dash repositories, please reference the repository DOI and Laughner et al. 2018 in any publications.

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 2005-2014 available with daily profiles by early 2019, 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 v3.0B.

Laughner et al. 2018b carried out an uncertainty analysis on BEHR v3.0B. The seasonal, gridded uncertainties in the BEHR NO2 VCDs may be downloaded here as an HDF version 5 file. Please see the BEHR-User-Guide.pdf for details.

Tools for working with .hdf files are available at http://www.hdfgroup.org/downloads/index.html. 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.

The WRF-Chem simulations used to provide the daily a priori profiles may be accessed by contacting the BEHR maintainer listed above. Currently, simulations for 2005-2010 and 2012-2014 are available. The simulations are conducted at 12 km horizontal resolution with 29 vertical layers on the continental US domain shown here:

The chemical mechanism used is that described in Zare et al. (ACP, 2018), with methyl peroxynitrate (MPN) chemistry added. Anthropogenic emissions are scaled to the model year, and lightning NOx emissions are included. For full details, see Laughner et al. (ESSD, 2018). Model years 2006 and 2010 have a reduced set of variables stored; all other years have a full set of output variables.

We are working on a method to allow these files to be directly accessed through the website. Check back for updates!

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

Click the link below to download BEHR v3.0C products over the Hong Kong domain in Mak et al. 2018.

BEHR v3.0C specialized for Hong Kong

Click the link below to access the BEHR v3.0C products over the US domain in Zhu et al. 2019 to study the impact of lightning NOx on a priori NO2 profiles and retrieved NO2 columns.

BEHR v3.0C specialized for US

To cite Gridded pixels monthly profiles use: https://doi.org/10.6078/D16X1T

To cite Native pixels daily profiles use:https://doi.org/10.6078/D1BM2B

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 BEHR_Readme.pdf 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

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. 3.0B of BEHR. The BEHR User Guide should be dated July 23, 2018; if not, please clear your browser's cached files.

• BEHR User Guide
• Changelog

This document describes the custom DISCOVER-AQ retrievals (based on v2.1A) in more detail:

• BEHR DISCOVER-AQ Product Readme

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.