Changing Q10 in user_nl_clm

[V.Dutch.33]

Hi,

I'm running PTCLM with the 2000_DATM%1PT_CLM50%BGC_SICE_SOCN_MOSART_SGLC_SWAV compset, and I want to change the Q10 value for frozen and unfrozen soils. I can change the q10 for frozen soil by adding froz_q10=newvalue to the end of my user_nl_clm file, but when I add Q10=newvalue (to change the q10 of unfrozen soil) I get the following error when I build the case:

Error: in _validate_pair (package Build::NamelistDefinition): Variable name q10 not found in the .../clm/bld/namelist_files/namelist_definition_drv.xml, ..../namelist_definition_drv_flds.xml, .../namelist_definition_clm4_5.xml

And true enough, it's not in any of those 3 files. Can I just add it to the /namelist_definition_clm4_5.xml file where froz_q10 is mentioned?

I've checked the CNSharedParamsMod.F90 file, and the syntax for froz_q10 and Q10 is again the same. I've also checked the SoilBiogeochemDecompCascadeBGCMod.F90 file, which I think is the first time my new Q10 should be used, and my syntax matches the source code variable.

I then looked at the online list of namelist options, and Q10 is not there (just froz_q10). Why? Where do I need to change the source code to add a new value for Q10 to the namelist?

Please advise.

Thanks!

 

[oleson]

Q10 is on the parameter file. It has the name q10_mr. See biogeochem/CNSharedParamsMod.F90

tString='q10_mr'
call ncd_io(varname=trim(tString),data=tempr, flag='read', ncid=ncid, readvar=readv)
if ( .not. readv ) call endrun(msg=trim(errCode)//trim(tString)//errMsg(sourcefile, __LINE__))
CNParamsShareInst%Q10=tempr

I see that froz_q10 is also on the parameter file, as well as being defined in namelist_definition_clm4_5.xml, but I don't see any evidence of the namelist version being used. So I would expect that setting a different value for froz_q10 in user_nl_clm wouldn't have any effect on the simulation. Does it change answers for your simulation? If not, I'll file an issue to have it removed from the namelist.

 

[V.Dutch.33]

Sorted, thanks!