Execute a dry-run simulation¶
Follow the steps below to perform a GEOS-Chem Classic dry-run simulation:
Tip
Also be sure to watch our video tutorial Using the updated dry-run capability in GEOS-Chem 13.2.1 and later versions at our GEOS-Chem Youtube Channel, which will guide you through these steps.
Complete preliminary setup¶
Make sure that you have done the following steps;
Then doublecheck these settings in the following configuration files:
-
geoschem_config.yml
¶
start_date
: Set the start date and time for your simulation.end_date
: Setthe end date and time for your simulation.met_field
: Check if the meteorology setting (GEOS-FP
,MERRA2
,GCAP2
) is correct for your simulation.root_data_dir
: Make sure that the path toExtData
is correct.
-
HISTORY.rc
¶
Set the frequency and duration for the HISTORY diagnostic collections to be consistent with the settings in
geoschem_config.yml
.
-
HEMCO_Config.rc
¶
Check the Settings section to make sure that diagnostic frequency
DiagnFreq
: is set to the interval that you wish (e.g.Monthly
,Daily
,YYYYMMDD hhmmss
, etc).Check the Extension Settings section, to make sure all of the required emissions inventories and data sets for your simulation have been switched on.
Tip
You can reduce the amount of data that needs to be downloaded for your simulation by turning off inventories that you don’t need.
Run the executable with the --dryrun
flag¶
Run the GEOS-Chem Classic executable file at the command line with the --dryrun command-line argument as shown below:
$ ./gcclassic --dryrun | tee log.dryrun
The tee command will send the output of the dryrun to the
screen as well as to a file named log.dryrun
.
The log.dryrun
file will look somewhat like a regular
GEOS-Chem log file but will also contain a list of data files and
whether each file was found on disk or not. This information will be
used by the download_data.py
script in the next step.
You may use whatever name you like for the dry-run output
log file (but we prefer log.dryrun
). You will need this file
to download data (see the next chapter).