By default turn off resolution checking in CTSM

[ekluzek]

The CTSM build-namelist by default turns on the option "-chk_res" which then checks that the input resolution is a valid one that CTSM knows about. This is set in the namelist_defaults_overall.xml file. Since, it's now more common to run at unsupported resolutions, we want to make this default off. The user could still turn it on if they want to. This also leaves in the place the supported resolution list that we find useful for running the CTSM inputfile tool chain. That toolchain already has a way to run an unsupported resolution, so the list of supported resolutions is still useful in that context. If someone provides an unsupported resolution, the namelist will still fail when it doesn't find the needed input surface dataset.

@barlage @negin513

[ekluzek]

This was something requested by the variable mesh group. It was something that I thought we should fix for sometime (and thought we had an issue for it), but I was thinking the solution was to change the valid resolution list to reading the list of grids in cime config_grids.xml. Doing that would be a bigger project. This solution is so simple that we can take advantage of it right away.

[ekluzek]

Here's the code diff to do this...

diff --git a/bld/namelist_files/namelist_defaults_overall.xml b/bld/namelist_files/namelist_defaults_overall.xml
index f7f2d041..042a973b 100644
--- a/bld/namelist_files/namelist_defaults_overall.xml
+++ b/bld/namelist_files/namelist_defaults_overall.xml
@@ -43,8 +43,7 @@ determine default values for namelists.
 <sim_year_range>constant</sim_year_range>
 
 <!-- Check resolution and land/mask before continuing -->
-<chk_res mode="clm_stndln" >1</chk_res>
-<chk_res mode="ext_cesm"   >0</chk_res>
+<chk_res >0</chk_res>
 
 <!-- Add note to namelist files documenting the options given to build-namelist -->
 <note mode="clm_stndln" >1</note>

(NOTE: the above "mode" attribute is a holdover from CLM3.5 when CLM had it's own "standalone" mode. That attribute is no longer used. Note, also that it was setup to only check
resolution when the CLM standalone mode was used, not for CESM. So it's a bug that crept in
when CESM became the standard way of running the model.)

To turn if off based on XML variables in current versions, you can add this to a given case...

./xmlchange --append CLM_BLDNML_OPTS="-no-chk_res"

[ekluzek]

There are some grids defined in the release branch, that aren't in our resolution list. So this change should go on the release branch as well.

[patcal]

Erik,
I verified that adding ./xmlchange --append CLM_BLDNML_OPTS="-no-chk_res" to the shell_commands file solves this problem for adding VRM grids.

[billsacks]

@ekluzek did this make it onto the release branch? @mvertens was wondering about it.

[ekluzek]

Yes, it's on the release branch.