Fix and improve anomaly forcings for ISSP cases

[samsrabin]

Description of changes

Fixes a bug, and also makes it much simpler to run land-only SSP cases.

Specific notes

Contributors other than yourself, if any: @ekluzek

CDEPS Issues Fixed (include github issue #):

• Resolves Remove specific variable names for anomaly forcing and use a generic name #186
• Fixes SSP cases get rcp45 anomalies #258
• Resolves Add aux_cdeps tests for SSPs other than 585 #310

Are there dependencies on other component PRs (if so list): This doesn't depend on other components. However, I will soon submit a PR to CTSM that depends on this branch. (See issue ESCOMP/CTSM#2301.)

Are changes expected to change answers (bfb, different to roundoff, more substantial): Substantial, but only if people were being bitten by #258 before.

Any User Interface Changes (namelist or namelist defaults changes): Yes.

Adds anomaly_forcing options:

• Anomaly.Forcing.cmip5.rcp45
• Anomaly.Forcing.cmip6.ssp126
• Anomaly.Forcing.cmip6.ssp245
• Anomaly.Forcing.cmip6.ssp370
• Anomaly.Forcing.cmip6.ssp585

Removes all variable-specific anomaly_forcing options.

Testing performed (e.g. aux_cdeps, CESM prealpha, etc):

• New CTSM testmods using these work correctly. Existing testmod, datm_ssp126_anom_forc, is bit-for-bit identical to previous version (ctsm5.2.015).
• On top of existing aux_cdeps test of SSP585 compset, added the 3 other SSP compsets. All aux_cdeps SSP tests show diffs as expected from cdeps1.0.34.

Hashes used for testing:

• Various throughout process.

Remaining work

• Make it so that anomaly_forcing is automatically set for each ISSP compset
• If we care that it's not putting anomaly_forcing in the generated datm_in: Fix that. (Note that the anomaly forcing file IS correctly being put in datm.streams.xml.)

[samsrabin]

@ekluzek, a few questions:

• What sort of changes/additions would you like me to make to aux_cdeps?
• Does it make sense to keep the Anomaly.Forcing.Precip, Anomaly.Forcing.Temperature, etc. entries in stream_definition_datm.xml? If so, I'll need to rename them so they're specific to rcp45, then add equivalent ones for each SSP. Seems messy!
• To make the ISSP compsets automatically use the right anomaly_forcing, would I do something like this in namelist_definition_datm.xml under <entry id="anomaly_forcing">?

<default_value>''</default_value>
<value compset="^SSP126_">Anomaly.Forcing.cmip6.ssp126</value>

[jedwards4b]

@samsrabin is this ready- if not can you make it a draft please.

[jedwards4b]

It's not clear to me that anomaly_forcing will always be defined and be an array.

[samsrabin]

Force-pushed to remove premature merge of main into this branch, which was interfering with my testing.

[samsrabin]

@ekluzek This is ready, if you'd like to review!

[samsrabin]

Note that this is up-to-date with cdeps1.0.34. If you'd like me to merge in the latest tag, let me know and I'll redo the testing.

[samsrabin]

@jedwards4b This is ready to review, and @ekluzek will also make some time to look at it in the next few days. It would be nice if we can get it in soon.

[ekluzek]

Really glad you took this on. This is so great to have coming in. I'm suggesting some changes.

I think it would be better to be data driven rather than code driven. And I layout a mostly fleshed out plan on how to do that. You'll need to make sure that all works, but I think it will and it's an improvement over some of the limitations of a part of what's in here.

We should get together to go over all of this. I also have some questions about one set of changes that would be good for you to explain.

[samsrabin]

Re-requesting review from @ekluzek, because it seems like I've already addressed his concern. If approved, I'll continue by merging in the latest CTSM tag into ESCOMP/CTSM#2686 and the corresponding CDEPS tag here.

[samsrabin]

Re-pinging @ekluzek for review, since @jedwards4b seems to think things are fine as is.

[ekluzek]

Thanks for your work here @samsrabin. I really like the simplification you figured out for this. And I like that AF forcing streams have the SSP name in them. And I like that you added the "none" option.

There are two things that I think deserve a discussion, so I'll make them into issues, and if we think they are important could come in a future PR.

The only suggestion I have at this point is to add a comment about the new tests added. But, still marking this as approve so you don't have to wait on me.

[ekluzek]

This is a nice addition of good error checking for Anomaly Forcing (AF), which I think is really important to have in place. So thanks for doing this! The code is clean and clear, so good work.

I put two questions in. Longer term I'd like to have the type of forcing for AF to be in the XML data in some form, so it isn't hardcoded in the python. But, as there's only one option now, it doesn't need to start that way.

The other question is the importance of the new namelist variable option. If this is really going to be rarely used it might be good to NOT have it in the XML. But, have clear instructions on how to do. This makes the model easier to use for people by leaving off the most complex options if we think they won't be used often. But, that's up to you.

So thanks for your work here. This is great to see coming in.

[samsrabin]

@jedwards4b I think this is ready!

[jedwards4b]

@samsrabin can you merge main into your branch or give me permission to push to your fork?

[samsrabin]

@jedwards4b Done!