GEOS-Chem configuration files
- Minimum system requirements
- Downloading source code
- Downloading data directories
- Creating run directories
- Configuring runs
- Output files
- Visualizing and processing output
- Coding and debugging
- Further reading
This page describes the configuration files that are read by GEOS-Chem. Configuration files are automaticaly added to a GEOS-Chem run directory when it is created. The configuration files contain "out-of-the-box" default settings for each type of GEOS-Chem simulation. But you can edit these files to customize your GEOS-Chem simulation with different options.
List of GEOS-Chem configuration files
Below is a table listing GEOS-Chem input files that reside in the run directory.
|GEOS-Chem user input files|
|input.geos||File containing all GEOS-Chem user options. In this file, you may specify the following options:
|HEMCO_Config.rc||Specifies emission inventories that you want to include in GEOS-Chem via the HEMCO emissions component.|
|HEMCO_Diagn.rc||Specifies diagnostic archival options for emissions and related quantities computed by HEMCO emissions component.
|HISTORY.rc||Specifies which GEOS-Chem diagnostics will be archived to netCDF output (for both GEOS-Chem "Classic" and GCHP modes)
|Planeflight.dat||Specifies flight tracks for which you want to save out specific tracers, chemical species, or met field quantities.|
|GEOS-Chem photolysis mechanism files|
These are only found in the run directories for the various full-chemistry and aerosol-only simulations.
|FJX_spec.dat||Contains cross-section and quantum yields for FAST-JX photolysis species.|
|FJX_j2j.dat||Links "GEOS-Chem species" to "FAST-JX" species. FAST-JX photolysis species are defined in the data file FJX_spec.dat, GEOS-Chem species in globchem.spc. See this post for more information.|
|jv_spec_mie.dat||Contains aerosol optical properties at 5 wavelengths.|
|dust.dat||Contains aerosol optical properties for dust at multiple wavelengths for use in Fast-JX and the RRTMG radiatiaive transfer model (if enabled).|
|org.dat||Contains aerosol optical properties for organic carbon at multiple wavelengths for use in Fast-JX and the RRTMG radiatiaive transfer model (if enabled).|
|so4.dat||Contains aerosol optical properties for sulfate at multiple wavelengths for use in Fast-JX and the RRTMG radiatiaive transfer model (if enabled).|
|soot.dat||Contains aerosol optical properties for black carbon at multiple wavelengths for use in Fast-JX and the RRTMG radiatiaive transfer model (if enabled).|
|ssa.dat||Contains aerosol optical properties for accumulation mode sea salt aerosol at multiple wavelengths for use in Fast-JX and the RRTMG radiatiaive transfer model (if enabled).|
|ssc.dat||Contains aerosol optical properties for coarse mode sea salt aerosol at multiple wavelengths for use in Fast-JX and the RRTMG radiatiaive transfer model (if enabled).|
Chemical mechanism files ship with the GEOS-Chem source code
For your reference, we store the master KPP equation files for GEOS-Chem v11-02 (globchem.def, globchem.eqn, and globchem.spc) in the various subfolders of the GEOS-Chem source code directory, i.e.
If you need to add new species or reactions, you can modify these globchem.* files and then rebuild the KPP code. It is recommended that you place any custom modifications to the GEOS-Chem chemistry mechanisms into this folder:
You can ask the GEOS-Chem Support Team for assistance with this.
The HISTORY.rc file
The HISTORY.rc file allows you to specify which diagnostic quantities will be archived to netCDF diagnostics in both GEOS-Chem "Classic" and GEOS-Chem with the High-Performance Option (aka GCHP).
For a detailed description of this file, please see the Sample HISTORY.rc diagnostic input file wiki chapter.
The Planeflight.dat file
The Planeflight.dat.YYYYMMDD files allow you to specify the diagnostic quantities (species, reaction rates, met fields) that you want to print out for a specific longitude, latitude, altitude, and time. See our Planeflight diagnostic wiki page for more information.
The ObsPack input file
Please see our our ObsPack diagnostic wiki page for more information about the format of ObsPack diagnostic input files.
Input files for the photolysis mechanism
GEOS-Chem v10-01 and later versions use the FAST-JX v7.0 photolysis mechanism. Several input files for the FAST-JX photolysis mechanism ship with the GEOS-Chem run directories. You should only have to modify these files if you wish to change the chemical mechanism or photolysis mechanism.
For more information, please see our Input files for FAST-JX v7.0 wiki post.
Additional input files for GCHP
If you are using GEOS-Chem with the high-performance computing option (aka GCHP), you will require a few additional input files beyond those described above. Please see our GCHP Run Configuration Files wiki page for more information.