Download data with a dry-run simulation

Tip

If you are located at an institution with many other GEOS-Chem users, then the necessary input data might have already been downloaded and stored in a commmon directory on your system. Ask your sysadmin or IT support staff.

Please see our Download input data chapter for other ways in which you can download the necessary input data for GEOS-Chem.

A dry-run is a is a GEOS-Chem Classic simulation that steps through time, but does not perform computations or read data files from disk. Instead, a dry-run simulation prints a list of all data files that a regular GEOS-Chem simulation would have read. The dry-run output also denotes whether each data file was found on disk, or if it is missing. This output can be fed to a script which will download the missing data files to your computer system.

You may generate dry-run output for any of the GEOS-Chem Classic simulation types (fullchem, carbon, TransportTracers, etc.)

In the following chapters, you will learn how to you can download data using the output from a dry-run simulation:

• Execute a dry-run simulation
  • Complete preliminary setup
  • Run the executable with the --dryrun flag
• Download data from dry-run output
  • Choose a data portal
  • Run the download_data.py script on the dryrun log file
  • Skip download, but create log of unique files