Documentation need for generic single point with nuopc

[wwieder]

Here are the steps needed to create and run a single point case with nupoc.
Users will have to crease a surface dataset first and then make a few manual changes (mainly to shell_commands).

NOTE the mods to user_nl_mosart seem like an (unnecessary?) gotcha

Erik's example case is here:

/glade/work/erik/ctsm_worktrees/branch1/cime/scripts/cases/RandomBoreal_0

With create_newcase command:

./create_newcase --case cases/RandomBoreal_0 --compset I2000Clm51Bgc --res CLM_USRDAT --driver nuopc --user-mods-dirs newton_krylov_spinup --mpilib mpi-serial --run-unsupported
(note I used the mpi-serial library for MPI because it's just a single point case)

I did these xml commands (added them to shell_commands)

./xmlchange CLM_USRDAT_NAME="BOREAL1"
./xmlchange PTS_LON=55.
./xmlchange PTS_LAT=57.958115183246
./xmlchange CASESTR="Random Boreal"

NOTE: CASESTR is not required, but makes sure a few things are set with something besides UNSET

Added this to user_nl_clm

fsurdat = '/glade/scratch/wwieder/single_point/surfdata_hist_16pfts_Irrig_CMIP6_simyr2000_RandomBoreal_c210823.nc'

and this to user_nl_mosart

frivinp_rtm = '/dev/null'

(This is something that is required with latest updates in externals, when MOSART_MODE=null (i.e. when compset has MOSART rather than SROF). This is a little glitch that we should fix in CTSM so you don't have to do this (There's a MOSART issue about this)

Originally posted by @ekluzek in #1457 (comment)

Definition of Done:

• We've created a discussion of how this is done (How do I create a single-point run with the NUOPC (default) coupler? #1833)
• [ ] Add documentation on this to the users-guide

[adrifoster]

Thanks @wwieder! I am working on adding the relevant commands/file updates for using subset climate data with NUOPC.

@ekluzek the user_nl_datm_streams files gives good notes for how to update things like files, etc. But it also mentions the meshfile. If I remember correctly we do not need mesh files for single-point runs? Is this correct for the datm data as well? If so, should we update this meshfile value to be blank?

[ekluzek]

OK, I wasn't sure about this myself. But, I looked into how it's done for the NEON data and we should be able to copy how it does it.

The header for the NEON data looks likes this...

  <stream_info name="NEON.NIWO">
   <taxmode>cycle</taxmode>
   <tintalgo>linear</tintalgo>
   <readmode>single</readmode>
   <mapalgo>none</mapalgo>
   <dtlimit>1.5</dtlimit>
   <year_first>2018</year_first>
   <year_last>2018</year_last>
   <year_align>2018</year_align>
   <vectors>null</vectors>
   <meshfile>none</meshfile>
   <lev_dimname>null</lev_dimname>

So mapalgo is none, meshfile is none, and there's only one point of data. If all of those are true we shouldn't need a meshfile for the datm part of this. For regional cases with more than one datapoint for datm we would need to provide a meshfile.

[ekluzek]

So @adrifoster yes you should set meshfile to something besides blank, you should set it to "none" and also set mapalgo to "none".

[wwieder]

for what it's worth, setting up this single point run was super simple after creating the surface dataset, but it's just using the global datm data

/glade/work/wwieder/ctsm/ctsm5.1_N-K_test/cime/scripts/RandomBoreal_0c

[adrifoster]

Great, thanks! @ekluzek

Definitely, @wwieder I think it will be easy going once we get the user_nl_datm_streams files set up for the datm data too.

[adrifoster]

@ekluzek I tried setting mapalgo=none in the user_nl_datm_streams file but I got this error:

Create namelist for component datm
   Calling /project/tss/afoster/ctsm_fates/components/cdeps/datm/cime_config/buildnml
ERROR: mapalgo can only have values of ['bilinear', 'nn', 'redist', 'mapconsd', 'mapconf'] for stream CLMGSWP3v1.Solar in file /project/tss/afoster/FATES_cases/BONA_080_719baba6_38495279/user_nl_datm_streams

[ekluzek]

@adrifoster OK thanks for pointing that out. This sounds like a problem in CDEPS. Let me look into this a bit, I can probably give you a workaround for it. But, we'll likely need to get a change in CDEPS to fix this. Since it allows none for NEON it obviously can work this way.