What is a restart file?
Restart files contain species concentrations, as well as other quantities that are needed to initialize GEOS-Chem simulations. GEOS-Chem simulations use two separate restart files.
- GEOSChem.Restart.YYYYMMDD_hhmmz.nc4
Format: netCDF
Description: The GEOS-Chem Classic restart file. Contains species concentrations that are read at simulation startup.
GEOS-Chem writes a restart file at the end of each simulation. This allows a long simulation to be split into several individal run stages. For example, the restart file that was created at 00:00 UTC on August 1, 2019 is named:
GEOSChem.Restart.20190801_0000z.nc4. Thezcharacter indicates “Zulu” time (aka UTC).GEOS-Chem restart files are created in the
Restarts/folder of your GEOS-Chem run directory directory.
- HEMCO_restart.YYYYMMDDhhmm.nc
Format: netCDF
Description: The HEMCO restart file. HEMCO archives certain quantities (mostly pertaining to soil NOx and biogenic emissions in order to facilitate long GEOS-Chem simulations with several run stages.
HEMCO restart files are created in the
Restarts/folder of your GEOS-Chem run directory directory.
When you run a GEOS-Chem simulation, it will write new GEOS-Chem restart files at the intervals you specify in HISTORY.rc. New HEMCO restart files are written with frequency configured in HEMCO_Config.rc.
Viewing and manipulating restart files
Please see the following sections of our Supplemental Guide: Work with netCDF files for more information on how you can view and manipulate data in restart files: