ctsm5.4.049: Fix typo, 'expontential' --> 'exponential' in fates c starvation model

[r-ward]

… namelist settings

Description of changes

Fixes a typo in src/utils/clmfates_interfaceMod.F90 for the fates c starvation namelist option ("expontential" --> "exponential") that causes runs using fates_cstarvation_model=exponential (valid options =linear, exponential) to abort at init with error message "Invalid carbon starvation model".

Specific notes

Contributors other than yourself, if any:

• None

CTSM issues resolved or otherwise addressed, if any:

• None

Any user interface changes (namelist or namelist defaults changes)?
None, this makes the already valid exponential fates c starvation model functional

Testing planned or performed, if any:

• tested with single point FATES run at BCI, Panama on Derecho; fix allows running with fates_cstarvation_model=exponential on ctsm5.3.077, PR branch is on current master because change is a single character typo fix, outcome should be identical

Requirements before merge:

• I have followed the CTSM contribution guidelines.

• The code in this PR branch builds with no errors. (one-character string-literal change; identical fix built and run on Derecho; ctsm5.3.077)
• The code in this PR branch runs with no errors. Briefly describe tested configuration(s): tested on ctsm5.3.077
• This either (a) does not change answers, (b) it only changes answers at roundoff level, or (c) I have performed a scientific evaluation of the answer changes. Which?: (a) does not change answers, allows fates_cstarvation_model=exponential configuration to function

• I have reviewed relevant parts of the CLM documentation Tech Note or User's Guide to determine if anything needs to be changed or added. If it does, describe:
• This PR either (a) does not create a need to update the documentation or (b) includes required documentation updates (see guidelines for contributing documentation). Which?:(a)

[samsrabin]

Good catch! @glemieux will handle this, including adding a test.

[glemieux]

Thanks for making this @r-ward! I've made a PR to this branch to bring in the tests: r-ward#2

[glemieux]

r-ward#2 to be integrated first

[wwieder]

@slevis-lmwg can you bring this in?

[slevis-lmwg]

@slevis-lmwg note to self: After the b4b-dev merge (.048)

• run the aux_clm and
• fates test suites
• Update ChangeLog/Sum
• and merge

[ekluzek]

@slevis-lmwg this is ready to go now. I'll send fates tests for ctsm5.4.048 in a bit.

[ekluzek]

Oh, I realized that the baselines for:

fates-sci.1.92.7_api.46.0.0-ctsm5.4.047

will be sufficient, so I don't really need to do ctsm5.4.048 fates baselines.

[slevis-lmwg]

Submitted on derecho and izumi:

./run_sys_tests -s aux_clm -c ctsm5.4.048 -g ctsm5.4.049
./run_sys_tests -s fates -c fates-sci.1.92.7_api.46.0.0-ctsm5.4.047 -g fates-sci.1.92.7_api.46.0.0-ctsm5.4.049

[slevis-lmwg]

@r-ward @glemieux, I submitted testing.

This PR will also need updated ChangeLog and ChangeSum files. Do you wish to handle that? If you prefer that I do it, then Rachel will need to grant me collaborator permissions:
Click Settings near the top middle-right of this page.
Click Collaborators and teams.
Then follow github's directions.

[slevis-lmwg]

@r-ward @glemieux this new izumi test fails in the build phase:
/scratch/cluster/slevis/tests_0731-163358iz/ERP_Ld90.f45_f45_mg37.I2000Clm60FatesRs.izumi_nag.clm-FatesColdCStarvationExp.GC.0731-163358iz_nag
The error message feels unhelpful to me:

Panic: /fs/cgd/data0/slevis/git_people/rward/fix_cstarv_model_typo/src/fates/parteh/PRTAllometricCNPMod.F90: Unexpected expr node type 434
Internal Error -- please report this bug
Abort
gmake: *** [/scratch/cluster/slevis/tests_0731-163358iz/ERP_Ld90.f45_f45_mg37.I2000Clm60FatesRs.izumi_nag.clm-FatesColdCStarvationExp.GC.0731-163358iz_nag/Tools/Makefile:975: PRTAllometricCNPMod.o] Error 3

and may suggest switching the test to a different compiler. Thoughts?

[glemieux]

@slevis-lmwg this may be due to #3331. Would you try changing the test to a debug test and see if it passes? If that works, I think we should just update the test in that manner and move forward with the near-term fix.

[slevis-lmwg]

@glemieux thank you!

I submitted the debug version to confirm. Let's see how it goes:
./create_test ERP_D_Ld90.f45_f45_mg37.I2000Clm60FatesRs.izumi_nag.clm-FatesColdCStarvationExp -g /fs/cgd/csm/ccsm_baselines/fates-sci.1.92.7_api.46.0.0-ctsm5.4.049

[slevis-lmwg]

Ok, this one built and ran, though I'm resubmitting due to one of the inexplicable failures where case2run finishes but does not wrap up gracefully.

I will push my code change for your review.