How to branch-off FESOM from old spinup restart files

When you branch-off from very old FESOM ocean restart files, you may encounter the following runtime error:

read ocean restart file
NetCDF: Invalid dimension ID or name

This is because the naming of the NetCDF time dimension variable in the restart file has changed from T to time during the development of FESOM and the different FESOM versions. Therefore, recent versions of FESOM expect the name of the time dimension to be time.

In order to branch-off experiments from spinup restart files that use the old name for the time dimension, you need to rename this dimension before starting the branch-off experiment.


The following work around will change the restart file permanently. Make sure you do not apply this to the original file.

To rename a dimension variable of a NetCDF file, you can use ncrename:

ncrename -d T,time <copy_of_restart_spinup_file>.nc

where T is the old dimension and time is the new dimension.

See also

  • cookbook:How to run a branch-off experiment