dEdd aerosol fixes

[apcraig]

PR checklist

• [X] Short (1 sentence) summary of your PR: dEdd aerosol fixes

• [X] Developer(s): apcraig, eclare108213

• [X] Suggest PR reviewers from list in the column to the right.

• [X] Please copy the PR test results link or provide a summary of testing completed below. bit-for-bit against current Icepack trunk, https://github.com/CICE-Consortium/Test-Results/wiki/icepack_by_hash_forks#0717620693e6545c0c693cb17987a5e412162b79. Also testing CICE suite on cheyenne.

• How much do the PR code changes differ from the unmodified code?

  • [X] bit for bit except when tr_aero is on (added to test suite)
  • [ ] different at roundoff level
  • [ ] more substantial

• Does this PR create or have dependencies on CICE or any other models?

  • [ ] Yes
  • [X] No

• Does this PR add any new test cases?

  • [X] Yes, modal
  • [ ] 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/.)

  • [ ] Yes
  • [X] No, does the documentation need to be updated at a later time?
    • [ ] Yes
    • [X] No

• [X] Please provide any additional information or relevant details below:

• update g/w0/tau calculation, get rid of use of puny

• add missing g/w0/tau calculation after "aerosol in snow" calculation

• fix bug in computation of modal_aero taer/waer/gaer, changed divide to multiple of rnilyr/rnslyr

• refactor divides of rnilyr/rnslyr to multiplies of real(nilyr/nslyr)

• add modal option, update test suite

[apcraig]

This is a draft because we should discuss whether these changes are correct and whether this is what we want to do. Otherwise, I think these changes are working.

[dabail10]

I have to test this out in CESM.

Dave

[dabail10]

After four years, the answers are definitely different. I want to run it longer to see if it is "climate" changing.

[eclare108213]

I wouldn't be surprised if these mods are "climate changing" when tr_aero=T and modal_aero=F, when comparing CICE6 before/after this PR. Is that what you're testing @dabail10?

These are bugs in CICE6 that were not present in CICE5, and should be fixed regardless of whether they are deemed to be climate changing, right away. If this modified code produces reasonable-looking answers, then I think we should merge it and keep moving forward. More careful comparisons with CICE5 might be needed to understand differences between the code versions, but let's at least get the obvious bugs fixed ASAP. We may need to make further modifications later, as we continue the BGC merge. Is this plan okay with those of you reading this thread?

[apcraig]

@eclare108213, I agree that these things need to be fixed. We should try to understand the impact of the bug and document that, but that could be done over days/weeks as needed.

[eclare108213]

@dabail10 How are your runs going? I'd like to merge this one.

[dabail10]

I have 20 years of both. Here are some diagnostics:

https://webext.cgd.ucar.edu/B1850/b.cesm3_cam058_mom_e.B1850WscMOM.ne30_L58_t061.camdev_cice6.026b2/ice/b.cesm3_cam058_mom_e.B1850WscMOM.ne30_L58_t061.camdev_cice6bugfix.026b-b.cesm3_cam058_mom_e.B1850WscMOM.ne30_L58_t061.camdev_cice6.026b/yrs1-21/

Basically I can't really tell as it is only 20 years, but it does not appear to be climate changing. I will run these out for 100 years.

Dave

[apcraig]

Can we merge while we continue to assess?

[dabail10]

I would say go ahead.