Coupled idealized modelling toolkit

!!!  Note, these idealized modelling tools are still under development.  We're still working through use cases to smooth out issues and are still upgrading these tools, but they can currently be used and if you try something and it doesn't work, please post your issue to the CESM forum under "Simpler Models" !!!

Note: These tools work with CESM tag CESM2_3_beta16 or later

In order to make your own idealized configurations of CESM with user-defined ocean bathymmetry, continental geometry or land surface properties, there are three primary inputs to the model that need to be modified:

  • Ocean supergrid, bathymmetry, SCRIP files (for coupled cases only)
  • Mesh files which contain information that describes the model grid, such as the land mask.
  • The "fsurdat" file which controls the land surface properties and their time evolution.

You can find more information on mesh files and fsurdat files here.  To configure your own coupled idealized configuration, you have two options: (1) You can use VisualCaseGen for interactive configuration of your case through a GUI interface or (2) you can use tools from the command line to generate the necessary input files for each component. 

VisualCaseGen: a GUI for interactive configuration of coupled idealized modelling setups

VisualCaseGen is a GUI that runs on JupyterLab and guides users through the process of creating CESM cases.  It can be used to generate standard CESM cases, but it can also be used to generate idealized set-ups with user-defined bathymmetry, land surface properties, and continental geometries.  To download VisualCaseGen and get started please see the VisualCaseGen Quickstart guide.  

Command line options

If you would rather generate the necessary inputs for each component separately using the command line tools that exist, you will need to use the following:

  • For coupled cases, the mom6_bathy python tool can be used for the generation of: (a) the MOM6 supergrid file, (b) the topography (bathymetry) file, (c) the SCRIP file and ESMF MESH file.  The SCRIP file is used to remap between between the different components and the MESH file describes the model grid ad the mask for each cell as well as the connectivity of the cells.  You can read more about mesh files here.  Note that in coupled configurations it is the ocean MESH file that sets the landmask and mom6_bathy will generate this.     
  • For uncoupled cases, the mesh mask modifier tool can instead be used to generate the MESH file and, thereby, specify the landmask.
  • For both coupled and uncoupled cases the fsurdat modifier tool can be used to set up the land surface properties.


Step-by-step guidance for how to use these tools is provided below for specific examples.  

  • A standard CESM case !! coming soon !!
  • An uncoupled case with real world continental geometry but modified land surface properties !! coming soon !!
  • An uncoupled case with altered continental geometry.  Filling in the indian ocean with land.  visualCaseGen or command line
  • A coupled case with an idealized continents - ridge world.  visualCaseGen