What is a restart file?¶
Restart files contain the initial conditions (cf. Initial conditions input data) for a GEOS-Chem simulation. GEOS-Chem simulations need two 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, 2016 is named:
GEOSChem.Restart.20160801_0000z.nc4
. Thez
indicates “Zulu” time, which is another name for UTC.GEOS-Chem restart files are created in the top-level of your GEOS-Chem run directory directory (and NOT in the
OutputDir/
folder, which is where History diagnostic files are created.
-
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 top-level of your GEOS-Chem run directory directory (and NOT in the
OutputDir/
folder, which is where History diagnostic files are created. HEMCO restart files are created in the top-level of your GEOS-Chem run
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: