Overview
A coupling describes an aspect of how two model realms interact with each other via the sharing of physical variables.
The couplings for the CMIP6 models are documented and published using spreadsheets; each model’s couplings are collected in a separate spreadsheet. Below are instructions for collecting couplings using these spreadsheets.
1. Open the spreadsheet using Microsoft Excel, LibreOffice, or another spreadsheet editor.
The spreadsheets are found in the institutional GitHub repository in the cmip6/models directory (see the layout of institutional GitHub repositories). The spreadsheet for each model is found in the sub-directory for that model.
The spreadsheet is composed of three pages. The first page contains a link to these instructions.
The second page contains some example coupling entries to demonstrate how it works.
The third page is where you can enter your own realm coupling details.
2. Create a coupling
The third, “Couplings” page contains five columns for describing each coupling:
- Variable: Name the physical variable being coupled. It is recommended to use the variable’s CF standard name or CMIP6 variable name if it exists, otherwise any other unambiguous description may be entered.
- Source Realm and Target Realm: Select the realms that the variable is being coupled from and to (left-click in the required cell to activate the pull-down menu button).
- Time Frequency: Specify the time frequency of the coupling, in seconds.
- Coupling details (optional): Provide any further information on the coupling process (e.g. coupling algorithm, interpolation details, etc.).
As many couplings as you like can be described, each one on a separate row of the spreadsheet. To provide another coupling, copy the entire row by
- right-clicking over the row number on the left hand side,
- right-clicking again in the same place and inserting one row below, and
- pasting the copied row into the newly created row below.
The new row will have the all of the functionality of the original row, including the pull-down menus in the “Source realm” and “Target realm” columns.
3. Upload the couplings to the institutional GitHub repository
Upload the coupling spreadsheet to the institutional GitHub repository.
When the model documents are created and entered into the ES-DOC archive, the requested couplings are automatically copied from the coupling spreadsheet into the published model descriptions.
Updating the coupling spreadsheet in the institutional GitHub repository will trigger an update to the published model documents, provided publication is set to “on” for that realm in the cmip6/model_publication.json file.