SSP cases get rcp45 anomalies

[samsrabin]

(This was originally filed as ESCOMP/CTSM#2301, but during the SE meeting yesterday it was suggested this might be a CDEPS issue.)

Brief summary of bug

When setting up an SSP case with anomaly forcings requested, by default it gets rcp45 anomalies, regardless of SSP requested.

General bug information

CTSM version you are using: ctsm5.1.dev159
CDEPS version you are using: cdeps1.0.24
See also Externals.cfg.

Does this bug cause significantly incorrect results in the model's science? Yes, if not manually corrected.

Configurations affected: Probably any SSP compset where anomaly forcings are created. Tested with ssp245, ssp370, and ssp585.

Important details of your setup / configuration so we can reproduce the bug

Tested on Derecho with the bash script /glade/u/home/samrabin/ctsm_cdeps_ssp-temperature/setup_case.sh, which

1. takes one argument, of ssp number (e.g., 245);
2. sets up a test case with compset using that SSP;
3. specifies anomaly_forcing = 'Anomaly.Forcing.Temperature' in user_nl_datm;
4. prints the compset of that case; and
5. prints the datafile associated with Anomaly.Forcing.Temperature in CaseDocs/datm.streams.xml.

Important output or errors that show the problem

No matter what SSP is specified, datm.streams.xml has this:

  <stream_info name="Anomaly.Forcing.Temperature">
   <taxmode>cycle</taxmode>
   <tintalgo>nearest</tintalgo>
   <readmode>single</readmode>
   <mapalgo>bilinear</mapalgo>
   <dtlimit>1.5</dtlimit>
   <year_first>2006</year_first>
   <year_last>2300</year_last>
   <year_align>2006</year_align>
   <vectors>null</vectors>
   <meshfile>/glade/campaign/cesm/cesmdata/inputdata/atm/datm7/anomaly_forcing/domain.permafrostRCN_P2.c2013.nc</meshfile>
   <lev_dimname>null</lev_dimname>
   <datafiles>
      <file>/glade/campaign/cesm/cesmdata/inputdata/atm/datm7/anomaly_forcing/af.tas.ccsm4.rcp45.2006-2300.nc</file>
   </datafiles>
   <datavars>
      <var>tas   Sa_tbot_af</var>
   </datavars>
   <offset>0</offset>
  </stream_info>

[wwieder]

@ekluzek noted that CTSM SEs will do this.
@samsrabin noted this seems like an easy fix, but a bad bug. Can we do sooner, rather than later?