Download data from dry-run output

Once you have successfully executed a GEOS-Chem dry-run, you can use the output from the dry-run (contained in the log.dryrun file) to download the data files that GEOS-Chem will need to perform the corresponding “production” simulation. You may download from one of several locations, which are described in the following sections.

Important

Before you use the download_data.py script, make sure to initialize a Mamba or Conda environment with the relevant command shown below:

$ mamba activate ENV-NAME   # If using Mamba

$ conda activate ENV-NAME   # If using Conda

Here ENV-NAME is the name of your environment.

Also make sure that you have installed the PyYAML module to your conda environment. PyYAML will allow the download_data.py script to read certain configurable settings from a YAML file in your run directory.

The Python environment for GCPy has all of the proper packages that you need to download data from a dry-run simulation. For more information, please see gcpy.readthedocs.io.

Choose a data portal

You can download input data data from one of the following locations:

The geoschemdata.wustl.edu site (aka WashU)

If you are using GEOS-Chem on your institutional computer cluster, we recommend that you download data from the WashU (Washington University in St. Louis) site (http://geoschemdata.wustl.edu). This site, which is maintained by Randall Martin’s group at WashU, is the main data site for GEOS-Chem.

Tip

We have also set up a Globus endpoint named GEOS-Chem data (WashU) on the WashU site. If you need to download many years of data, it may be faster to use Globus (particularly if your home institution supports it).

The s3://gcgrid bucket (aka Amazon)

If you are running GEOS-Chem Classic on the Amazon Web Services cloud, you can quickly download the necessary data for your GEOS-Chem simulation from the :file:`s3://gcgrid` bucket to the Elastic Block Storage (EBS) volume attached to your cloud instance.

Navigate to your GEOS-Chem Classic run directory and type:

$ ./download data.py log.dryrun amazon

This will start the data download process using the aws s3 cp commands, which should execute much more quickly than if you were to download the data from another location. It will also produce a log of unique data files.

Important

Copying data from s3://gcgrid to the EBS volume of an Amazon EC2 cloud instance is always free. But if you download data from s3://gcgrid to your own computer system, you will incur an egress fee. PROCEED WITH CAUTION!

The atmos.earth.rochester.edu site (aka Rochester)

The U. Rochester site (which is maintained by Lee Murray’s research there) contains the GCAP 2.0 met field data. This met field data is useful if you wish to perform simulations stretching back into the preindustrial period, or running into the future.

To download data from the Rochester site, type:

$ ./download data.py log.dryrun rochester

Run the download_data.py script on the dryrun log file

Navigate to your GEOS-Chem run directory where you executed the dry-run and type:

$ ./download_data.py log.dryrun washu

The download_data.py Python program is included in the GEOS-Chem run directory that you created. This Python program creates and executes a temporary bash script containing the appropriate wget commands to download the data files. (We have found that this is the fastest method.)

The download_data.py program will also generate a log of unique data files (i.e. with all duplicate listings removed), which looks similar to this:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! LIST OF (UNIQUE) FILES REQUIRED FOR THE SIMULATION
!!! Start Date       : 20160701 000000
!!! End Date         : 20160701 010000
!!! Simulation       : standard
!!! Meteorology      : GEOSFP
!!! Grid Resolution  : 4.0x5.0
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
./GEOSChem.Restart.20160701_0000z.nc4 --> /n/holylfs/EXTERNAL_REPOS/GEOS-CHEM/gcgrid/data/ExtData/GEOSCHEM_RESTARTS/v2018-11/initial_GEOSChem_rst.4x5_standard.nc
./HEMCO_Config.rc
./HEMCO_Diagn.rc
./HEMCO_restart.201607010000.nc
./HISTORY.rc
./input.geos
/n/holylfs/EXTERNAL_REPOS/GEOS-CHEM/gcgrid/data/ExtData/CHEM_INPUTS/FAST_JX/v2019-10/FJX_j2j.dat
/n/holylfs/EXTERNAL_REPOS/GEOS-CHEM/gcgrid/data/ExtData/CHEM_INPUTS/FAST_JX/v2019-10/FJX_spec.dat
/n/holylfs/EXTERNAL_REPOS/GEOS-CHEM/gcgrid/data/ExtData/CHEM_INPUTS/FAST_JX/v2019-10/dust.dat
/n/holylfs/EXTERNAL_REPOS/GEOS-CHEM/gcgrid/data/ExtData/CHEM_INPUTS/FAST_JX/v2019-10/h2so4.dat
/n/holylfs/EXTERNAL_REPOS/GEOS-CHEM/gcgrid/data/ExtData/CHEM_INPUTS/FAST_JX/v2019-10/jv_spec_mie.dat
... etc ...

This name of this “unique” log file will be the same as the log file with dryrun ouptut, with .unique appended. In our above example, we passed log.dryrun to download_data.py, so the “unique” log file will be named log.dryrun.unique. This “unique” log file can be very useful for documentation purposes.

Skip download, but create log of unique files

If you wish to only produce the *log of unique data files without downloading any data, then type the following command from within your GEOS-Chem run directory:

$ ./download_data.py log.dryrun --skip-download

or for short:

$ ./download_data.py log.dryrun --skip

This can be useful if you already have the necessary data downloaded to your system but wish to create the log of unique files for documentation purposes (such as for benchmark simulations, etc.)