Add sw_redist option to CICE

[dabail10]

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please refer to: https://github.com/CICE-Consortium/About-Us/wiki/Resource-Index#information-for-developers

PR checklist

• Short (1 sentence) summary of your PR:
  This integrates the sw_redist changes from Icepack into CICE.
• Developer(s):
  dabail10 (D. Bailey)
• Suggest PR reviewers from list in the column to the right.
• Please copy the PR test results link or provide a summary of testing completed below.
  https://github.com/CICE-Consortium/Test-Results/wiki/cice_by_mach_forks#cheyenne
• How much do the PR code changes differ from the unmodified code?
  • bit for bit
  • different at roundoff level
  • more substantial
• Does this PR create or have dependencies on Icepack or any other models?
  • Yes
  • No
• Does this PR add any new test cases?
  • Yes
  • No
• Is the documentation being updated? ("Documentation" includes information on the wiki or in the .rst files from doc/source/, which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/. A test build of the technical docs will be performed as part of the PR testing.)
  • Yes
  • No, does the documentation need to be updated at a later time?
    • Yes
    • No
• Please provide any additional information or relevant details below:
  The alt03 and alt04 test cases have been updated so that ktherm=1 is bfb. The default settings are such that ktherm=2 is bfb. This is the other piece to addressing issue shortwave redistribution #485 and shortwave modification for mushy thermo layers melting completely Icepack#280.

[eclare108213]

It looks like Icepack will be updated with this PR. Is that intentional?

[dabail10]

Yes! This change was already merged in Icepack.

[eclare108213]

Looks good. This CICE PR also updates other changes to Icepack in addition to sw redistribution.

[apcraig]

The changes in CICE here are related to turning on the new options in Icepack. There are 3 new namelist for CICE and these are basically passed to Icepack. The changes in the alt options preserve the current CICE testing where ktherm=1 sets sw_redist=.true.. That is consistent with the bl99 having this feature hardwired before and mushy not. As we move forward, we probably want to add a test where mushy turns on the sw_redist feature and bl99 does not to be more complete.

[apcraig]

I am testing this now on gordon just to make sure it's all bit-for-bit (as we expect). I will merge once that test is complete.

[proteanplanet]

Approved!

[apcraig]

90% of the tests are completed on gordon and everything that has run has passed, https://github.com/CICE-Consortium/Test-Results/wiki/cice_by_hash_forks#91acad70660303035754f32c36eca863f00b29d1. A few are sitting in the queue, but I'm fairly confident it's all fine. I will merge this now and then update the test results when they have completed.

[phil-blain]

For easier future lookups (it took me a while), here is the corresponding Icepack PR: CICE-Consortium/Icepack#326