Confusing "Segment data are not on the supergrid" error message when OBC files have the incorrect name.

[uwagura]

This is more of a MOM6 issue, but I am documentating here for our group's reference. If you start are run with OBC files whose name does not match the name set by OBC_SEGMENT_00X_DATA = in MOM_input, you'll get the following error message:

WARNING from PE     7: Brushcutter mode sizes    160     0                                                                                                                                                                                                                              INPUT/obcs.nc u_segment_003


FATAL from PE     7: segment data are not on the supergrid

This message is a bit confusing, and the solution is to just update your MOM_input file to match the names of your OBC files.

[theresa-cordero]

I agree this is a confusing message for the real error. I think I have also had this error when my OBC file was missing.
We could change the MOM6 error message to have more information, something like:

segment data are not on the supergrid. Your OBC file name may not match the name in MOM_input or be missing. 

[yichengt900]

@uwagura and @theresa-cordero, thanks for opening this issue and providing a possible solution. @theresa-cordero, I like your idea. Eventually, we will probably need to review the OBC code and do a major refactor. But for now, I think a more informative error message should be sufficient

[yichengt900]

This issue has been resolved through MOM6 PR #851. Closing now.