Downloading Input Data

Input data for GEOS-Chem is available from the following FTP servers:

Notably, you will need four types of input data to run GCHP:

Restart file (initial conditions)

These are initial conditions for the simulation. You can find some reasonable default initial conditions in the GEOSCHEM_RESTARTS/ directory. Default run directories have symlinks to these default restart files.

Meteorological data

GCHP is driven by meteorological data from GEOS-FP or MERRA2. The GEOS-FP data is in GEOS_0.5x0.625/MERRA2/ and the MERRA2 data is in GEOS_0.25x0.3125/GEOS_FP/. Default run directories have a symlink (./MetDir) to the local copy of this data.

Emissions data

Emissions data is in the HEMCO/ directory. In this directory are INVENTORY/vYYYY-MM/ subdirectories, where INVENTORY is the name of the inventory, and vYYYY-MM is the date of the inventory version. Default run directories have a symlink (./HcoDir) to the local copy of this data.

Chemistry inputs

These are miscellaneous data files for GEOS-Chem. They are in the CHEM_INPUTS/ directory. Default run directories have a symlink (./ChemDir) to the local copy of this data.

You can get a url list for the input data for a simulation by running (in your run directory)

$ ./utils/listInputDataFiles 20190101 20190108 --wget-urls > urls.txt
... <answer prompts> ...

Replace 20190101 with your desired start date and 20190108 with your desired end date. For climatological data you will be asked to select a year. If the climatology covers your simulation period, you can leave it blank (hit enter). If the climatology doesn’t cover your simulation period, pick the closest year. Note that this script does not include restart files, and it’s a “best effort” estimation of the input data for your simulation. At runtime you might encounter errors due from missing data files (download these yourself).

You can download the files in urls.txt like so (replace /ExtData with the path to your local copy of GEOS-Chem input data)

$ cp urls.txt /ExtData/urls.txt  # copy url list to local /ExtData directory
$ cd /ExtData                    # cd to root of local /ExtData directory
$ wget -i urls.txt -cxnH --cut-dirs=1   # download all the data