Change default for SNOW_ALBEDO_INFO (GEOS_SurfaceGridComp.rc)

[gmao-rreichle]

@biljanaorescanin, @sdrabenh, @mathomp4,

I'm wondering how we can go about changing the default for the SNOW_ALBEDO_INFO resource parameter. The newest "v12" bcs are meant to be used with SNOW_ALBEDO_INFO=1, both in the new (post-Krok) AGCM (w/ increased vertical resolution etc) and in the new SMAP L4_SM Version 8 system. Going forward, we don't want users to run the model with the old SNOW_ALBEDO_INFO=0 by default. We can't keep instructing users to make this change manually just to keep current with the latest development, and we need to find a way to change the default for both the AGCM and GEOSldas.

Changing the default in the GEOS_SurfaceGridComp.rc (as in 1c12f21) should work for GEOSldas, owing to the preprocessing of GEOS_SurfaceGridComp.rc during ldas_setup. But this will upset the GEOSldas (nightly) regression tests (which also still use NLv3 bcs). To fix this, we could either change the tests to use v12 bcs (plus the new SNOW_ALBEDO_INFO default) and re-baseline, or we could add an explicit specification of SNOW_ALBEDO_INFO=0 in the GEOSldas test config (and keep using the old NLv3 bcs).

For the AGCM, the edit that engages the new default should be 2c236b0. (I think gcm_setup mostly ignores GEOS_SurfaceGridComp.rc.) But this will likewise upset the AGCM regression tests. Same choice here -- switch to new bcs and re-baseline, or augment with explicit SNOW_ALBEDO_INFO=0 config.

Please advise, thanks!

PS: I'm not sure if this change should be labeled 0-diff or non-0-diff, so I added both labels.

PPS: The above assumes that the default bcs version is also updated to v12. (SNOW_ALBEDO_INFO=1 will fail with NL3 bcs.)

[mathomp4]

@gmao-rreichle Well, gcm_setup does have a bit of "fiddle with Surface rc":

# Update LAND_PARAMS Choices
# ------------------------------------------------------------------
/bin/mv $EXPDIR/RC/GEOS_SurfaceGridComp.rc $EXPDIR/RC/GEOS_SurfaceGridComp.tmp
cat $EXPDIR/RC/GEOS_SurfaceGridComp.tmp | sed -e 's?# GEOSagcm=>?            ?g' > $EXPDIR/RC/GEOS_SurfaceGridComp.rc


if( $LSM_CHOICE == 2 ) then
    /bin/mv $EXPDIR/RC/GEOS_SurfaceGridComp.rc $EXPDIR/RC/GEOS_SurfaceGridComp.tmp
    cat $EXPDIR/RC/GEOS_SurfaceGridComp.tmp | sed -e '/^ *LAND_PARAMS:/ s/NRv7.2/CN_CLM40/' > $EXPDIR/RC/GEOS_SurfaceGridComp.rc
endif


if( $LSM_BCS == "ICA" ) then
    /bin/mv $EXPDIR/RC/GEOS_SurfaceGridComp.rc $EXPDIR/RC/GEOS_SurfaceGridComp.tmp
    cat $EXPDIR/RC/GEOS_SurfaceGridComp.tmp | \
    awk '{ if ($1~"LAND_PARAMS:") { sub(/NRv7.2/,"Icarus") }; print }' > $EXPDIR/RC/GEOS_SurfaceGridComp.rc


    /bin/mv $EXPDIR/RC/GEOS_SurfaceGridComp.rc $EXPDIR/RC/GEOS_SurfaceGridComp.tmp
    cat $EXPDIR/RC/GEOS_SurfaceGridComp.tmp | \
    awk '{ if ($1~"Z0_FORMULATION:") { sub(/4/,"2") }; print }' > $EXPDIR/RC/GEOS_SurfaceGridComp.rc
endif

We could do something similar if the land choice is v12. (Or, I suppose change the default to 1 and then if not v12, set to 0?)

[gmao-rreichle]

Thanks, @mathomp4. I'm not sure we want to add more fiddle to gcm_setup, but it should work to add something along the lines of (pseudo-code):

if ( $LSM_BCS == "ICA" .or. $LSM_BCS == "NL3" .or. [any other bcs versions that do not allow using SNOW_ALBEDO_INFO=1])
  [insert SNOW_ALBEDO_INFO: 0 into rc file]
end

Adding this should let us continue with the tests as they are. Ultimately, we'll want to update the tests to reflect more recent config choices, so eventually we'll want to update the tests. It's more of a question of when, not if. If we want to postpone updating the tests, @biljanaorescanin can implement the above code snippet.