Where can I find the values of surface roughness and thermodynamic roughness in the CLM5.0 land surface model?

[zqzq]

Dear all，
I performed a single-point simulation using clm5.0, but the results showed that the sensible heat flux near the ground was overestimated, while the temperature difference between the ground and the air was underestimated. I speculated that it was caused by inaccurate aerodynamic impedance. The reason, but I now need to know what the roughness value calculated by the model is. In which folder can you find it? I have found the file for calculating the roughness, but I don't know where the output value can be found. Hope to get your help, thank you.

 

[oleson]

There are various roughness lengths in biogeophys/FrictionVelocityMod.F90 (e.g., Z0MG, Z0MV). They are inactive by default, so you'll have to activate them using fincl1 in your user_nl_clm to get history output.

 

[zqzq]

thank you for your reply，Currently I can directly output the value of Z0MG，but when I try to output Z0MV, there is a problem， the error message is:ERROR: ERROR in histFileMod.F90 at line 699.In addition, what does the value of Z0M that the model can output represent? Is it the average value of vegetation and surface roughness?My user_nl_clm settings are as shown in the attached picture. What command do I need to add?

 

[oleson]

The error is because you have specified 'Z0mv', not 'Z0MV'.
Z0M is the same as Z0MV in this version of the model, it was removed in later versions since it is redundant.

 

[zqzq]

thank you for your reply，I modified it to Z0MV before, but still reported the same error as above, so I tried to modify it to z0mv. However, there are problems with both spellings. Do you have any suggestions?

But Z0M and Z0MG can output normally.

 

[zqzq]

The error is because you have specified 'Z0mv', not 'Z0MV'.
Z0M is the same as Z0MV in this version of the model, it was removed in later versions since it is redundant.

thank you for your reply，I modified it to Z0MV before, but still reported the same error as above, so I tried to modify it to z0mv. However, there are problems with both spellings. Do you have any suggestions?

But Z0M and Z0MG can output normally.

 

[oleson]

Apparently you are using SP mode not BGC mode. In that case you'll also have to comment out the "use_cn" if statement to get Z0MV output:

if (use_cn) then
this%z0mv_patch(begp:endp) = spval
call hist_addfld1d (fname='Z0MV', units='m', &
avgflag='A', long_name='roughness length over vegetation, momentum', &
ptr_patch=this%z0mv_patch, default='inactive')
end if

 

[zqzq]

Apparently you are using SP mode not BGC mode. In that case you'll also have to comment out the "use_cn" if statement to get Z0MV output:

if (use_cn) then
this%z0mv_patch(begp:endp) = spval
call hist_addfld1d (fname='Z0MV', units='m', &
avgflag='A', long_name='roughness length over vegetation, momentum', &
ptr_patch=this%z0mv_patch, default='inactive')
end if

Thanks for your reply，Do you mean I can just delete the if statement and get Z0MV? If I do not change the program code, can the current output value of Z0M be used as Z0MV?

 

[zqzq]

Apparently you are using SP mode not BGC mode. In that case you'll also have to comment out the "use_cn" if statement to get Z0MV output:

if (use_cn) then
this%z0mv_patch(begp:endp) = spval
call hist_addfld1d (fname='Z0MV', units='m', &
avgflag='A', long_name='roughness length over vegetation, momentum', &
ptr_patch=this%z0mv_patch, default='inactive')
end if

I removed the if statement that controls the output of ZOMV according to your suggestion, but still cannot output the value of ZOMV. Why is this?

 

[zqzq]

I removed the if statement that controls the output of ZOMV according to your suggestion, but still cannot output the value of ZOMV. Why is this?

 

[oleson]

What version of the model are your using (what is the output of git describe?)?

 

[zqzq]

What version of the model are your using (what is the output of git describe?)?

Thank you for your patience，I currently use CLM5.0，And I also want to output aerodynamical resistance（RAM1），Although its if conditional statement has been deleted, and RAM1 has been added to the user_nl_clm file, the problem encountered is the same as the output Z0MV. I look forward to your answers.

 

[oleson]

What is the output of git describe?

 

[zqzq]

What is the output of git describe?

I'm very sorry that I don't know what git describe you pointed out is. Where can I find this?

 

[oleson]

Actually, it would help if you did this:

Please include this information in all help requests:

• Document the version of the code are you using:
  • In CESM2.1.2 and later, run the script ./describe_version from the top level of your CESM clone (that is, from the directory containing cime, components, etc.). Either:
    • Copy and paste the full output into your post
    • Redirect the output to a file (./describe_version > version_info.txt) then attach the file to your post.

Also, are you running SP or BGC?
Thanks.

 

[zqzq]

Thank you for your kind reply，I don’t seem to understand what you mean. I only generated an empty file after running the code (script ./describe_version) in a folder containing cime and other files.I apologize again, I am a newbie using CLM5.0, for the time being I am not sure whether I am using SP or BGC

 

[zqzq]

Actually, it would help if you did this:

Please include this information in all help requests:

• Document the version of the code are you using:
  • In CESM2.1.2 and later, run the script ./describe_version from the top level of your CESM clone (that is, from the directory containing cime, components, etc.). Either:
    • Copy and paste the full output into your post
    • Redirect the output to a file (./describe_version > version_info.txt) then attach the file to your post.

Also, are you running SP or BGC?
Thanks.

Thank you for your kind reply，I don’t seem to understand what you mean. I only generated an empty file after running the code (script ./describe_version) in a folder containing cime and other files.I apologize again, I am a newbie using CLM5.0, for the time being I am not sure whether I am using SP or BGC

 

[oleson]

Just run "./describe_version", not "script ./describe_version".

What compset did you select for your case? That will tell you whether your are running SP or BGC. Can you attach your README.case from your case directory please?

I've tried outputting Z0M, Z0MG, and Z0MV using release-cesm2.2.0 and it works fine here.
I wonder if your compiler is not picking up your changes to the code (I'm still assuming your are running SP mode).
You could try cleaning and rebuilding the case:

./case.build --clean-all
./case.build

Can you also attach your lnd.log file from your failed run?

 

[zqzq]

1.When I enter the code (./describe_version), it shows that the command does not exist, as shown in Figure 1.
2../create_newcase --case case5 --compset I1PtClm50SpRsGs --res CLM_USRDAT --mach bscca5
3.README.case :
2021-10-08 16:24:35: ./create_newcase --case wyy --compset I1PtClm50SpRsGs --res CLM_USRDAT --mach jn
---------------------------------------------------
2021-10-08 16:24:35: Compset longname is 2000_DATM%1PT_CLM50%SP_SICE_SOCN_SROF_SGLC_SWAV_SIAC_SESP
---------------------------------------------------
2021-10-08 16:24:35: Compset specification file is /es01/paratera/sce0489/cesm2.2/my_cesm_sandbox/components/clm//cime_config/config_compsets.xml
---------------------------------------------------
2021-10-08 16:24:35: Pes specification file is /es01/paratera/sce0489/cesm2.2/my_cesm_sandbox/components/clm//cime_config/config_pes.xml
---------------------------------------------------
2021-10-08 16:24:35: Forcing is 1972-2004
---------------------------------------------------
2021-10-08 16:24:35: Using None coupler instances
---------------------------------------------------
2021-10-08 16:24:35: Component ATM is Data driven ATM single point tower site data set
---------------------------------------------------
2021-10-08 16:24:35: ATM_GRID is CLM_USRDAT
---------------------------------------------------
2021-10-08 16:24:35: Component LND is clm5.0:Satellite phenology:
---------------------------------------------------
2021-10-08 16:24:35: LND_GRID is CLM_USRDAT
---------------------------------------------------
2021-10-08 16:24:35: Component ICE is Stub ice component
---------------------------------------------------
2021-10-08 16:24:35: ICE_GRID is null
---------------------------------------------------
2021-10-08 16:24:35: Component OCN is Stub ocn component
---------------------------------------------------
2021-10-08 16:24:35: OCN_GRID is null
---------------------------------------------------
2021-10-08 16:24:35: Component ROF is Stub river component
---------------------------------------------------
2021-10-08 16:24:35: ROF_GRID is null
---------------------------------------------------
2021-10-08 16:24:35: Component GLC is Stub glacier (land ice) component
---------------------------------------------------
2021-10-08 16:24:35: GLC_GRID is null
---------------------------------------------------
2021-10-08 16:24:35: Component WAV is Stub wave component
---------------------------------------------------
2021-10-08 16:24:35: WAV_GRID is null
---------------------------------------------------
2021-10-08 16:24:35: Component IAC is Stub iac component
---------------------------------------------------
2021-10-08 16:24:35: IAC_GRID is null
---------------------------------------------------
2021-10-08 16:24:35: Component ESP is Stub external system processing (ESP) component
---------------------------------------------------
2021-10-08 16:24:35: ESP_GRID is None
---------------------------------------------------