As I understand this -- it will ensure anomaly_forcing is forced to be on for SSP compsets. But, I don't think that's what we want. I think that the default certainly should be for it to be on, but the user should be able to turn it off if they want. The AF forcing is also specific to the DATM_MODE so it should only do this depending on both the compset and DATM_MODE. And since the DATM_MODE the AF forcing matches will be changing, it would be better for this to be in the XML data rather than in the python code. Better to be data driven when possible.

As such I'm thinking this part should be reverted.

See below for what I suggest to add to the namelist_definition file. We will also need to make sure compset is a valid field in the namelist defintion file.

The anomaly_forcing option none is designed to handle situations where the user wants to turn off anomaly forcing for an SSP compset. See diff below:

anomaly_forcing = nmlgen.get_value("anomaly_forcing")
-    if anomaly_forcing[0] is not None:
+    if anomaly_forcing[0] is not None and anomaly_forcing[0] != "none":
        streamlist += anomaly_forcing

This is confirmed by comparing the namelists from the CTSM branch's tests without and with the new clm-noAnomalyForcing testdef:

suitedir="/glade/derecho/scratch/samrabin/tests_0219-152958de"
cd "${suitedir}"
testdir_anom_on="SMS_D_Ld5.f10_f10_mg37.ISSP245Clm50BgcCrop.derecho_intel.clm-default.0219-152958de_int"
testdir_anom_off="${testdir_anom_on/clm-default/clm-default--clm-noAnomalyForcing}"
cd "${testdir_anom_on}/CaseDocs"
for f in *; do
   echo $f
   diff $f ../../${testdir_anom_off}/CaseDocs/$f
   echo " "; echo " "
done

Relevant outputs:

datm_in
12c12
<   anomaly_forcing = "Anomaly.Forcing.cmip6.ssp245"
---
>   anomaly_forcing = 'none'


datm.streams.xml
698,726d697
<
<   <stream_info name="Anomaly.Forcing.cmip6.ssp245">
<    <taxmode>cycle</taxmode>
<    <tintalgo>nearest</tintalgo>
<    <readmode>single</readmode>
<    <mapalgo>bilinear</mapalgo>
<    <dtlimit>1.5</dtlimit>
<    <year_first>2015</year_first>
<    <year_last>2100</year_last>
<    <year_align>2015</year_align>
<    <vectors>null</vectors>
<    <meshfile>/glade/campaign/cesm/cesmdata/inputdata/share/meshes/fv0.9x1.25_141008_polemod_ESMFmesh.nc</meshfile>
<    <lev_dimname>null</lev_dimname>
<    <datafiles>
<       <file>/glade/campaign/cesm/cesmdata/inputdata/atm/datm7/anomaly_forcing/CMIP6-SSP2-4.5/af.allvars.CESM.SSP2-4.5.2015-2100_c20220628.nc</file>
<    </datafiles>
<    <datavars>
<       <var>huss  Sa_shum_af</var>
<       <var>pr    Faxa_prec_af</var>
<       <var>ps    Sa_pbot_af</var>
<       <var>rlds  Faxa_lwdn_af</var>
<       <var>rsds  Faxa_swdn_af</var>
<       <var>tas   Sa_tbot_af</var>
<       <var>uas   Sa_u_af</var>
<       <var>vas   Sa_v_af</var>
<    </datavars>
<    <offset>0</offset>
<   </stream_info>
<

@ekluzek Pinging, as discussed.

Near the top of the file streamslist is being set with a setting for GSWP3 like this:

      <value datm_mode="CLMGSWP3v1">
        CLMGSWP3v1.Solar,CLMGSWP3v1.Precip,CLMGSWP3v1.TPQW
      </value>

This should be expanded to have an option for GSWP3 forcing and SSP compsets. So something like:

      <value datm_mode="CLMGSWP3v1" compset_period="SSP585">
        CLMGSWP3v1.Solar,CLMGSWP3v1.Precip,CLMGSWP3v1.TPQW,Anomaly.Forcing.cmip6.ssp585
      </value>

There might be a way to append just the AF file to the end, which would be preferred. But, we'd need to figure that out. The matching needs to be figured out to make sure it works right. And of course all the SSP options need to be added.

Note that compset_period needs to be added to the buildnml file which I'll sketch out below.

Changes to buildnml:

buildnml needs to:

• Get the compset from the case
• Extract out the period part of the compset
• Send compset_period to the config object

So something like...

    caseroot = case.get_value("CASEROOT")
    datm_mode = case.get_value("DATM_MODE")
    datm_topo = case.get_value("DATM_TOPO")
    compset = case.get_value("COMPSET")
.
.
.
    # Do some reg-ex or other magic to get the compset_period from it
    compset_period = something(compset)

    config['datm_mode'] = datm_mode
    config['datm_co2_tseries'] = datm_co2_tseries
    config['compset_period'] compset_period
.
.
.