A multi-scale chemistry-transport model
for atmospheric composition
analysis and forecast

Current version: CHIMERE v2020r3

    What's new?
  • [2023/06]: CHIMERE Workshop in Paris on June 22 and 23, 2023
  • [2022/11]: Release of emiSURF_v2020r4
  • [2022/09]: Wikipedia CHIMERE web pages [FR], [ENG], [FA]
  • [2022/09]: Documentation "How is the code distributed?" [FR] [ENG]
  • [2021/11]: Release of the v2020r3 version
  • [2021/07]: Release of the v2020r2 version
  • [2020/11]: Release of the v2020r1 version

    New functionalities in v2020 version    

  1. WRF-CHIMERE online coupled model: The model can be used offline (with interfaces for ECMWF, WRF) or online coupled with WRF, for direct and indirect aerosol effects. Please read the WRF public notice
  2. Natural emissions: with the addition of dimethyl sulfide, new schemes for sea-salt, improvements for mineral dust and biomass burning and addition of NOx from lightning.
  3. Aerosols chemistry: with the addition of the SOAP thermodynamical model, as well as Volatility Basis Set scheme and the new H2O aerosol scheme for organic aerosols
  4. Subgrid scale variability: for cells with anthropogenic emissions with several activity sectors, it is possible to have pollutant concentrations for each.
  5. Vertical transport: Updated strategy for vertical advection of pollutants and implementation of the Despres and Lagoutiere (1999) antidiffusive advection scheme

    Recent results    

  • Mailler S., R.Pennel, L.Menut, and A.Cholakian, An improved version of the Piecewise Parabolic Method advection scheme: description and performance assessment in a bidimensional testcase with stiff chemistry in toyCTM v1.0., Geosci. Model Dev. Discuss. [preprint], , accepted, 2023.

  • Menut, L., Cholakian, A., Siour, G., Lapere, R., Pennel, R., Mailler, S., and Bessagnet, B.: Impact of Landes forest fires on air quality in France during the summer 2022, Atmos. Chem. Phys., 23, 7281-7296, 2023, .

  • Cholakian, A.; Bessagnet, B.; Menut, L.; Pennel, R.; Mailler, S. Anthropogenic Emission Scenarios over Europe with the WRF-CHIMERE-v2020 Models: Impact of Duration and Intensity of Reductions on Surface Concentrations during the Winter of 2015. Atmosphere 2023, 14, 224. https://doi.org/10.3390/atmos14020224,

    Model description

    General presentation    

  • CHIMERE is an open source multi-scale chemistry-transport model designed to produce (i) accurate analysis of pollution episodes, (ii) daily forecasts of ozone, aerosols and other pollutants, (iii) long-term simulations (entire seasons or years) for emission control scenarios.
  • CHIMERE runs over a range of spatial scale, from the hemispheric to the urban scale with resolutions from 1km to several degrees.
  • CHIMERE has many different options for simulations which make it also a powerful research tool for testing parameterizations. CHIMERE is a parallel model that has been tested on machines ranging from desktop PCs running the GNU/Linux operating system, to massively parallel supercomputers (HPCD at ECMWF).
  • On this server, documentation and source codes are free to access. The model is proposed with a complete environment: global model climatologies for boundary conditions, programs for emissions (anthropogenic with emisurf, biomass burning).
  • To learn how to use and modify the model, training sessions are organized once a year (see pictures from previous training sessions)

    Reference papers    

  • Online coupling
    • Tuccella P., et al., Implementation of aerosol-cloud interaction within WRF-CHIMERE online coupled model: evaluation and investigation of the indirect radiative effect from anthropogenic emission reduction on the Benelux, Atmosphere 2019, 10, 20; doi:10.3390/atmos10010020,
    • Briant, R. et al., Aerosol-radiation interaction modelling using online coupling between the WRF 3.7.1 meteorological model and the CHIMERE 2016 chemistry-transport model, through the OASIS3-MCT coupler, Geosci. Model Dev., 10, 927-944, doi:10.5194/gmd-10-927-2017, 2017,
  • Model overviews
    • Menut L., B. Bessagnet, R.Briant, A.Cholakian, F.Couvidat, S.Mailler, R.Pennel, G.Siour, P.Tuccella, S.Turquety, and M.Valari, The CHIMERE v2020r1 online chemistry-transport model, Geoscientific Model Development, 14, 6781-6811, 2021, .
    • Mailler S. et al., CHIMERE-2017: from urban to hemispheric chemistry-transport modeling , Geosci. Model Dev., 10, 2397-2423, https://doi.org/10.5194/gmd-10-2397-2017, , 2017

    Download the model

    Documentation, scripts, publications...

    Download the source codes and databases, register on the users mailing list
  1. New user?
    To obtain the login/password for download, please first register here. You will also be registered on the users mailing list.
  2. Already registered user?
    Please click here to access the download database
Other open-source and free access programs:

  • Fires: Biomass burning emissions (APIFLAME and Copernicus CAMS)
  • Explume: a model for personal exposure to ambient O3 and PM2.5

    Where is the model used?

The model is used in research institutes and in operational centers for forecast:


In order to know about or contact the developers.

    About this web site
This server is designed to provide source codes of the model, data from long-term simulations, and experimental forecasts made at IPSL. All data provided on this server should be used in a professional context. The CHIMERE model is provided under the GNU General Public License (since 2000). This server is located at the Ecole Polytechnique and maintened by Laurent MENUT. Copyright (C) Institut Pierre-Simon Laplace, Ecole Polytechnique, CNRS.