Photolysis and chemistry configuration files¶

Note

You won’t need to edit these configuration files unless you are changing the photolysis and/or chemistry mechanisms used in your GEOS-Chem Classic simulation.

Photolysis configuration files¶

These are found in the ExtData/CHEM_INPUTS/FAST_JX/ directory structure. Please see Input files for FAST-JX v7.0 for details.

Chemical mechanism configuration files¶

GEOS-Chem Classic simulations use source code generated by The Kinetic PreProcessor. If you need to update the default chemistry mechanism, you will need to do the following steps:

Modify the relevant KPP configuration files (described below);
Run KPP to generate updated source code for GEOS-Chem Classic;
Compile GEOS-Chem Classic to create a new executable;
Start your GEOS-Chem Classic simulation.

Chemical mechanism configuration files are located in these folders:

KPP/fullchem¶

Contains configuration files for the default “full-chemistry” mechanism (NOx + Ox + aerosols + Br + Cl + I).

fullchem.kpp: Main configuration file for the fullchem mechanism.
fullchem.eqn: List of species and reactions for the fullchem mechanism.

KPP/carbon¶

Contains configuration files for the carbon gases mechanism (CH4-CO2-CO-OCS):

carbon.kpp: Main configuration file for the carbon mechanism.
carbon.eqn: List of species and reactions for the carbon mechanism.

KPP/custom¶

Contains configuration files that you can edit if you need to create a custom mechanism. We recommend that you create the custom in this folder and leave KPP/fullchem and KPP/Hg untouched.

custom.kpp: Copy of fullchem.kpp
custom.eqn: Copy of fullchem.eqn.

KPP/Hg¶

Contains configuration files for the mercury chemistry mechanism:

Hg.kpp: Main configuration file for the Hg mechanism.
Hg.eqn: List of species and reactions for the Hg mechanism.

Please see the following references for more information about KPP:

The KPP user manual (kpp.readthedocs.io)
Supplemental Guide: Update chemical mechanisms with KPP