Update the icepack submodule to v1.5.0

[eclare108213]

DRAFT PR to enable early review while I complete testing.

Replaces the Icepack submodule in E3SM with Icepack version 1.5.0 and updates MPAS-seaice to accommodate the new code.

This PR is not BFB due to changes in the Icepack column physics modules to fix a bug in a flux-limiting term, to fix a bug in the lateral melting code, to fix conservation issues associated with the floe size distribution, and to support testing the 5-band SNICAR radiation data.

[not BFB]

[github-actions]

PR Preview Action v1.4.8
🚀 Deployed preview to https://E3SM-Project.github.io/E3SM/pr-preview/pr-6767/
on branch gh-pages at 2024-11-22 21:15 UTC

[eclare108213]

There are some necessary changes in MPAS-seaice to enable Icepack v1.5.0 to run. Icepack now takes the (category, cell) array for the fraction of lateral ice melting instead of just (cell). This array has been added to Registry without removing the old one, which is still used by the the old column physics code (and will be deprecated in a future PR).

USE_SNICAR is no longer used in Icepack. This is the default behavior and so the cpp has simply been removed.

Two Icepack subroutine names changed to better describe what the subroutines do:

use icepack_therm_shared , only: icepack_init_thermo => icepack_init_salinity
use icepack_therm_shared , only: icepack_init_trcr => icepack_init_enthalpy

The code changes are more fully described in https://acme-climate.atlassian.net/wiki/spaces/ICE/pages/4765843553/Overview+of+Icepack+synchronization+version+1.5.0

[njeffery]

@eclare108213 : The build failed when I just checked out your branch. I suspect I'm pointing to the wrong Icepack? Could you send me the icepack commit or checkout command? Thanks

[eclare108213]

The build failed when I just checked out your branch. I suspect I'm pointing to the wrong Icepack? Could you send me the icepack commit or checkout command? Thanks

Hmmm, not sure why it wouldn't work straight from this branch. The icepack submodule should be pointing to this hash:
22b8769 (HEAD -> main, origin/main, origin/HEAD) Merge pull request # 35 from CICE-Consortium/main

If it isn't, then in the E3SM directory try

git submodule sync
git submodule update --init

(which might point it back to E3SM's current icepack submodule, I'm not sure). If that doesn't work, then just do it manually,

cd components/mpas-seaice/src
mv icepack icepack.orig
git clone [email protected]:E3SM-Project/Icepack icepack

[njeffery]

git submodule sync
git submodule update --init

@eclare108213 : That worked! pointing to the right hash now. I'll try again. How should I set the alternative congelation flag?

[eclare108213]

How should I set the alternative congelation flag?

@njeffery Yay! See description in
https://acme-climate.atlassian.net/wiki/spaces/ICE/pages/4795236381/Alternative+congelation+freezing+method

[njeffery]

Trying config_congelation_freezing_method = 'one-step' but keeping the congelation porosity the same.

[njeffery]

@eclare108213 : I've finished the 15-year fully coupled bgc runs and compared with a baseline Mat ran. Figures are here: https://acme-climate.atlassian.net/wiki/spaces/HESF/pages/4806148098/20241124.v3.LR.icepack1.5.0.CBGC

The run is too short to see much of a difference in the physics or sea ice bgc, but certainly no concerns. However there is a difference in the sea ice carbon conservation for the Arctic. The new frazil/congelation partition appears to noticeably reduce the carbon error. Yay!

[eclare108213]

@njeffery That's awesome! Thank you. The new congelation option is turned off in this PR but I do recommend that E3SM start using it. We can discuss how to go about that offline.

I have a 100-year B case running now, started from the v3.0.0 historical simulation.

[njeffery]

Does your 100-yr run change the congelation porosity too or just tests the one-step?

[eclare108213]

I'm testing the code as it is currently PR'd, so only one-step. The run is only 9 years in so far, and I could easily stop and restart but I think that test should be in a separate PR.

[njeffery]

I agree.