We are pleased to announce the distribution of the new 2023 version of the CHIMERE model. It is is an open source multi-scale chemistry-transport model co-developed by LMD and LISA. It is designed to produce i) accurate analysis of pollution episodes, ii) daily forecasts of ozone, aerosols and other pollutants, iii) long-term simulations (seasons or whole years) for emission control scenarios. It operates at different spatial scales, from hemispheric to urban, with resolutions ranging from several degrees to 1 km.

The CHIMERE model is under continuous development, and a new version of the code is made available to users on a regular basis. In this new version (v2023r1), several numerical developments have been added, i) Online coupling with WRF 4.3, ii) new format and database for anthropogenic and fire emissions, iii) addition of XIOS libraries, modularization of routines, iv) possibility of calculating AOD by aerosols, v) new version of isorropia in Fortran 90. Processes have been updated or added, i) new formulation for turbulence and dry deposition, ii) new transport schemes, iii) pollen emissions taken into account, iii) parameterization of the impact of fires on soils and surfaces for dusts emissions, LAI, biogenic emissions and dry deposition. This new version is faster and the correlations calculated from observations over a one-year period on a European domain are significantly better. For further information: