WRF-Chem is the Weather Research and Forecasting (WRF) model coupled with Chemistry. The model simulates the emission, transport, mixing, and chemical transformation of trace gases and aerosols simultaneously with the meteorology. The model is used for investigation of regional-scale air quality, field program analysis, and cloud-scale interactions between clouds and chemistry.

The development of WRF-Chem is a collaborative effort among the community. NOAA/ESRL scientists are the leaders and caretakers of the code. The Official WRF-Chem web page is located at the NOAA web site. Our model development is closely linked with both NOAA/ESRL and DOE/PNNL efforts. Description of PNNL WRF-Chem model development is located at the PNNL web site as well as the PNNL Aerosol Modeling Testbed.

Tools for the Community

NCAR/ACOM Chemistry Options

     MOZART trace gas chemistry with GOCART aerosol scheme: Users Guide
     MOZART trace gas chemistry with MOSAIC aerosol scheme: Users Guide

With WRF-Chem V3.9 a new TUV photolysis option has been included (phot_opt=4). This option requires an additional data file. Please refer to the Instructions on how to run WRF-Chem with the new TUV photolysis option.

Please see the Best Practices 2015 Tutorial Presentation that includes example namelists for running with MOZCART and MOZART-MOSAIC.


NCAR/ACOM preprocessors include tools for using global model output for initial and boundary conditions, creating MEGAN biogenic, FINN fire, and global anthropogenic emissions. Go to the TOOLS page to learn more.

Submit questions regarding the tools and developments from our group to the WRF-Chem Discussion Forum.
For all other requests we refer to the WRF-Chem Helpdesk

Please see the Frequently Asked Questions Page for updates on our Tools.


WRF-Chem/DART is being used for: (i) development of efficient satellite retrieval data assimilation methods (compact phase space retrievals); (ii) independent and joint assimilation of atmospheric composition and meteorological observations, and (iii) estimating/constraining emission with the state augmentation methods. WRF-Chem/DART is being applied to two field campaigns, FRAPPE and KORUS-AQ, for atmospheric composition forecasting and data assimilation research. WRF-Chem/DART is also being applied to the MarcoPolo - Panda project for regional air quality forecasting in China.


  • Analysis
    • Formation of organic aerosols, learn more
    • Aqueous-phase formation of secondary organic aerosols
    • Air quality in China, learn more
    • Wet scavenging of trace gases and aerosols in deep convection, learn more
    • Formation of ozone in upper tropospheric convective outflow
    • Production of nitrogen oxides from lightning
  • Chemistry-Climate Studies
  • Model Intercomparisons, AQMEII
  • Field Project Forecasting
    • Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ), forecasts in the field catalog
    • Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS)
    • Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks (NOMADSS)
    • Deep Convective Clouds and Chemistry (DC3), forecasts in the field catalog
    • Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen (BEACHON)




ACOM | Atmospheric Chemistry Observations & Modeling