CLM6 vs. CLM5 surface dataset

[michelle_dvorak]

Hello, I am currently using mksurfdata_esmf to create a paleoclimate land surface dataset that works with CLM6. I already have a surface dataset file compatible with CLM5, although identical file inputs (fgacier, fsoiltex, etc.) don't seem to work perfectly with the mksurfdata utility. I am wondering if I can get away with using the CLM5 dataset with a few modifications. The only obvious difference I see is the inclusion of a SLOPE variable in CLM6.

Are there any other differences that are critical for running CLM6? If not, how might the use of a preindustrial control SLOPE field affect CLM at run-time?

Thanks for your help.

Michelle

 

[oleson]

I thought SLOPE was already in CLM5. See this post:

O

Post in thread 'low soil temperature when running a single point clm5.0'

Mar 3, 2021

Well, I learn something new about the model every day....
There is a "SLOPE" variable on the surface dataset. However, that appears to be used only for hydrology, in particular for surface water:

Redirecting...

and for lateral drainage, e.g.,

Redirecting...

This doesn't affect radiation...

• oleson

• 

I don't know of a comprehensive list of incompatibilites in surface datasets between CLM5 and CLM6, but I think there are some error conditions that will be triggered, for example,

' ERROR: PCT_OCEAN NOT on surfdata file but required when running ctsm5.2 or newer; ' // &
' you are advised to generate a new surfdata file using the mksurfdata_esmf tool ' // errMsg(sourcefile, __LINE__))

 

[michelle_dvorak]

I thought SLOPE was already in CLM5. See this post:

O

Post in thread 'low soil temperature when running a single point clm5.0'

Mar 3, 2021

Well, I learn something new about the model every day....
There is a "SLOPE" variable on the surface dataset. However, that appears to be used only for hydrology, in particular for surface water:

Redirecting...

and for lateral drainage, e.g.,

Redirecting...

This doesn't affect radiation...

• oleson

• 

I don't know of a comprehensive list of incompatibilites in surface datasets between CLM5 and CLM6, but I think there are some error conditions that will be triggered, for example,

' ERROR: PCT_OCEAN NOT on surfdata file but required when running ctsm5.2 or newer; ' // &
' you are advised to generate a new surfdata file using the mksurfdata_esmf tool ' // errMsg(sourcefile, __LINE__))

Oh I see. Thank you for that information! I'll try to get a new dataset up using that tool...more questions to follow I'm sure...