Stage 2/3: Grid
The second major step in configuring your CESM case is choosing a resolution, which is a specific set of grids for each active and data model in the compset. You may select either a standard, out-of-the-box resolution or create a custom one by combining existing model grids. In Custom mode, you can also generate custom model grids for CLM and/or MOM6 using auxiliary tools included in visualCaseGen. Begin by selecting between Standard and Custom grid modes.
Note
In CESM terminology, resolution and grid are often used interchangeably, both referring to the combination of model grids used in a CESM simulation. Unless specifically noted as a model grid (i.e., a grid unique to a particular component, such as the ocean grid), the term grid in this context should be understood as resolution, meaning the full collection of model grids used in a particular CESM case.
Standard Grids
Select from the available list of resolutions (combinations of model grids) below. Resolutions known to be incompatible with your chosen compset have been omitted from this list. Use the search box to refine the list further. For exact matches, use double quotes; otherwise, the search will display all grids containing one or more of the search terms.
After selecting a grid, visualCaseGen will advance to the Launch stage, where you can create your CESM case using the chosen compset and grid configuration.
Custom Grids
In Custom Grid mode, you can build a custom grid by mixing and matching standard model grids or generating new MOM6 and/or CLM grids with specialized tools that come with visualCaseGen. Start by specifying a path to save the new grid files and a name to refer to this new grid in the configuration process and beyond.
After clicking Select, a file browser will open to help you locate your preferred directory for saving the new grid files. Once the directory is selected, enter the new grid name in the text box at the top right and click Select to proceed.
Atmosphere Grid
Next, choose an atmosphere grid from the list of compatible options based on the compset you selected in the Compset stage. Use the search box to filter options if needed. This chosen atmosphere grid will be integrated with other model grids to form your custom CESM grid (resolution).
Ocean Grid
For the ocean grid, if MOM6 is selected as the ocean model, you can either select a standard ocean grid or create a new MOM6 grid. When creating a new MOM6 grid, you’ll specify parameters such as grid extent and resolution, after which you’ll be directed to a separate notebook that uses the mom6_bathy tool to generate the new grid and bathymetry.
If using a standard ocean grid, select one from the list compatible with your chosen compset and atmosphere grid. If creating a new MOM6 grid, complete the required parameters, then proceed to launch the mom6_bathy tool for final customization.
After specifying all ocean grid parameters, click Launch mom6_bathy. This will open an auto-generated Jupyter notebook where you can fine-tune the ocean grid bathymetry and generate all necessary input files. For more details on mom6_bathy, refer to its documentation: https://ncar.github.io/mom6_bathy/
Note
If the mom6_bathy notebook doesn’t open automatically, make sure that your browser allows pop-ups from visualCaseGen. If the notebook still doesn’t open, you can manually launch it by navigating to the mom6_bathy_notebooks/ directory in your visualCaseGen installation and opening the notebook corresponding to your custom grid.
Land Grid
Following ocean grid selection or creation, you’ll move to land grid selection. If CLM is chosen as the land model, you can also modify an existing CLM grid. If so, select a base land grid for customization.
Note
Detailed instructions on customizing an existing CLM grid will be added here shortly.
Once atmosphere, ocean, and land grids have been chosen or created, custom grid setup is complete. visualCaseGen will guide you to the final stage, Launch, where you can create a CESM case based on the specified compset and grid.