Downloading data from WashU

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Compute Canada directory structure

If you are downloading the GEOS-FP or MERRA-2 met data, then please note that you must download the "CN" (constant) data files for each horizontal grid that you are using.

For GEOS-FP these are timestamped for 2011/01/01 and are found in these data directories:

  • ExtData/GEOS_0.25x0.3125/GEOS_FP/2011/01/GEOSFP.20110101.CN.025x03125.nc
  • ExtData/GEOS_0.25x0.3125_AS/GEOS_FP/2011/01/GEOSFP.20110101.CN.025x03125.AS.nc
  • ExtData/GEOS_0.25x0.3125_CH/GEOS_FP/2011/01/GEOSFP.20110101.CN.025x03125.CH.nc
  • ExtData/GEOS_0.25x0.3125_EU/GEOS_FP/2011/01/GEOSFP.20110101.CN.025x03125.EU.nc
  • ExtData/GEOS_0.25x0.3125_NA/GEOS_FP/2011/01/GEOSFP.20110101.CN.025x03125.NA.nc
  • ExtData/GEOS_2x2.5/GEOS_FP/2011/01/GEOSFP.20110101.CN.2x25.nc
  • ExtData/GEOS_4x5/GEOS_FP/2011/01/GEOSFP.20110101.CN.4x5.nc

For MERRA-2 these are timestamped for 2015/01/01 and are found in these data directories :

  • ExtData/GEOS_0.5x0.625/MERRA2/2015/01/MERRA2.20150101.CN.05x0625.nc4
  • ExtData/GEOS_0.5x0.625_AS/MERRA2/2015/01/MERRA2.20150101.CN.05x0625.AS.nc4
  • ExtData/GEOS_0.5x0.625_CH/MERRA2/2015/01/MERRA2.20150101.CN.05x0625.CH.nc4
  • ExtData/GEOS_0.5x0.625_EU/MERRA2/2015/01/MERRA2.20150101.CN.05x0625.EU.nc4
  • ExtData/GEOS_0.5x0.625_NA/MERRA2/2015/01/MERRA2.20150101.CN.05x0625.NA.nc4
  • ExtData/GEOS_2x2.5/MERRA2/2015/01/MERRA2.20150101.CN.2x25.nc4
  • ExtData/GEOS_4x5/MERRA2/2015/01/MERRA2.20150101.CN.4x5.nc4

Additional notes:

  • Prior to downloading GEOS-FP data, please be aware of caveats regarding use of GEOS-FP. See the GEOS-FP wiki page for more information.


Directory Description
ExtData/ Root data directory containing all meteorlogy fields, emissions data, and chemistry input data.
ExtData/CHEM_INPUTS/ Contains non-emissions data for GEOS-Chem chemistry modules
ExtData/HEMCO/ Contains emissions data for the HEMCO emissions component
ExtData/GEOSCHEM_RESTARTS/ Contains sample restart files uses to initialize GEOS-Chem simulations.
0.25° x 0.3125° Data Directories Description
ExtData/GEOS_0.25x0.3125/GEOS_FP/YYYY/MM/ 0.25° x 0.3125° GEOS-FP global met fields
ExtData/GEOS_0.25x0.3125_AS/GEOS_FP/YYYY/MM/ 0.25° x 0.3125° GEOS-FP met fields cropped to the Asia domain
ExtData/GEOS_0.25x0.3125_CH/GEOS_FP/YYYY/MM/ 0.25° x 0.3125° GEOS-FP met fields cropped to the China domain
ExtData/GEOS_0.25x0.3125_EU/GEOS_FP/YYYY/MM/ 0.25° x 0.3125° GEOS-FP met fields cropped to the Europe domain
ExtData/GEOS_0.25x0.3125_NA/GEOS_FP/YYYY/MM/ 0.25° x 0.3125° GEOS-FP met fields cropped to the North America domain
0.5° x 0.625° Data Directories Description
ExtData/GEOS_0.5x0.625/MERRA2/YYYY/MM/ 0.5° x 0.625° MERRA-2 global met fields
ExtData/GEOS_0.5x0.625_AS/MERRA2/YYYY/MM/ 0.5° x 0.625° MERRA-2 met fields cropped to the Asia domain
ExtData/GEOS_0.5x0.625_CH/MERRA2/YYYY/MM/ 0.5° x 0.625° MERRA-2 met fields cropped to the China domain
ExtData/GEOS_0.5x0.625_EY/MERRA2/YYYY/MM/ 0.5° x 0.625° MERRA-2 met fields cropped to the Europe domain
ExtData/GEOS_0.5x0.625_NA/MERRA2/YYYY/MM/ 0.5° x 0.625° MERRA-2 met fields cropped to the North America domain
2° x 2.5° Data Directories Description
ExtData/GEOS_2x2.5/GEOS_FP/YYYY/MM 2° x 2.5° GEOS-FP global met fields
ExtData/GEOS_2x2.5/MERRA2/YYYY/MM 2° x 2.5° MERRA-2 global met fields
4° x 5° Data Directories Description
ExtData/GEOS_4x5/GEOS_FP/YYYY/MM/ 4° x 5° GEOS-FP global met fields
gcgrid/data/ExtData/GEOS_4x5/MERRA2/YYYY/MM/ 4° x 5° MERRA-2 global met fields


See the table below for the DIRECTORY_NAME options. The -R "*.html" option will reject HTML files.

Data download commands

We recommend that you use the wget utility to download data from Compute Canada.

For example, this command will download an entire directory (and its subdirectories) from Compute Canada to your current folder:

wget -r -np -nH -R "*.html" "http://geoschemdata.computecanada.ca/ExtData/DIRECTORY_NAME"

Or if you wish to download the folder to a different directory:

wget -r -np -nH -R "*.html" -P /your/data/root "http://geoschemdata.computecanada.ca/ExtData/DIRECTORY_NAME"

The options to wget are as follows:

-r   Specifies recursive directory transfer (i.e. will download all subdirectories)
-np Will not allow ascent to the parent directory 
-nH  Will store all directories and subdirectories in DIRECTORY_NAME, not geoschemdata.computecanada.ca/DIRECTORY_NAME
-R "*.html" Will reject any file ending in .html

If you wish to trim the name of the downloaded directory (i.e., so it downloads as DIRECTORY_NAME, not pub/geos-chem/data/DIRECTORY_NAME), then use the --cut-dirs option:

wget -r -np -nH -R "*.html" --cut-dirs=X "http://geoschemdata.computecanada.ca/DIRECTORY_NAME/"

where X is the number of directories to trim.

NOTE: The URL must be enclosed in quotes for file transfer to occur. If you omit the quotes then wget will just return a directory listing in a file named index.html without any files being downloaded.

--Bob Yantosca (talk) 19:15, 11 December 2019 (UTC)