Port ice_shelf_2d test cases

[cbegeman]

This is largely a direct port of the ice_shelf_2d test cases from compass. The main changes are the following:

• Port does not include thin film and tidal forcing tests. Their utility remains unclear from my wetting-and-drying work.
• [WIP I will increase time steps to their original values] Barotropic time step has been reduced from 15s to 5s for the 5km-resolution configuration. This is not necessary, but I thought that the ratio of baroclinic:barotropic time steps should be increased from 2 to 6 to be more representative of typical configurations.
• The restart test now shares the forward step (the first run) with the default test. This is motivated mostly by computational efficiency.

Checklist

• User's Guide has been updated
• Developer's Guide has been updated
• API documentation in the Developer's Guide (api.md) has any new or modified class, method and/or functions listed
• Documentation has been built locally and changes look as expected
• Testing comment in the PR documents testing used to verify the changes
• New tests have been added to a test suite

[cbegeman]

@xylar This PR includes the ssh_adjustment framework I added. Please suggest changes if something different would be more convenient for isomip_plus.

[cbegeman]

@xylar Also, when you have a chance, let me know what you think of this restart test approach. I'd like to do something similar for the baroclinic channel test.

[xylar]

@cbegeman, thanks so much for this work! I'll take a look as soon as I can.

[xylar]

@cbegeman, what excellent work, as usual! I have some fairly minor suggestions focused on ssh adjustment for now, since I am interested in that shared functionality.

[cbegeman]

@xylar I think I've made all the changes you requested to the ssh_adjustment framework. Please let me know if there's anything else that is holding up your isomip_plus work. Otherwise, I'll move on to finishing up the rest of the tests in the group and docs and docstrings.

[xylar]

@cbegeman, I haven't had a chance to look over the latest updates today but I do think I have what I need for isomip_plus and you can finalize the docs and anything else remaining for this development when you have time.

[cbegeman]

@xylar Also, when you have a chance, let me know what you think of this restart test approach. I'd like to do something similar for the baroclinic channel test.

@xylar Whenever you have time

[xylar]

Oh, thanks! I lost track of that one.

[xylar]

The restart approach you have here looks great to me!

[cbegeman]

Testing

All new single_layer and z-star tests have been run on chrys with intel, impi.

[cbegeman]

@xylar I think this is all set to review. It took changing the number of vertical levels (from 20 to 50, though I didn't test values in between) to revive z-level (otherwise ssh_adjustment hangs).

[xylar]

@cbegeman, I'm sorry for not doing a thorough enough review the last time through. I noticed another issue in the SSH-adjustment framework that will need to be addressed (and maybe one we should discuss).

I also started testing the ice_shelf_2d tasks themselves on Perlmutter but it's about to go down for maintenance.

[cbegeman]

@xylar When you have a chance, you can try the new setup_ssh_adjustment_steps approach with an ssh_forward class and an overridden compute_cell_count method.

[xylar]

@cbegeman, wow, that was fast work! I'll try this out again tomorrow.

[xylar]

I'm back to working on SSH adjustment in ISOMIP+. I ran into a few more things for us to chat about.

[cbegeman]

@xylar This is ready for your review. Thanks!

[xylar]

@cbegeman, very exciting to finally get this in!

I ran all the ice_shelf_2d test cases on Chrysalis:

/lcrc/group/e3sm/ac.xylar/polaris_0.3/chrysalis/test_20240717/ice_shelf_2d

[cbegeman]

@xylar Thanks for your review and testing!