z0mr parameters are all the same in the default parameter file, inconsistant with CLM definitions.

[rosiealice]

The default parameters for fates_turb_z0mr (the "Ratio of momentum roughness length to canopy top height") are all 0.055. These are the same as the NLT values in CLM5 (table 2.5.1) but are likely wrongly defined for the other PFTs where the values are 0.075 for broadleaf evergreen trees and 0.12 for shrubs and grasses.

https://escomp.github.io/ctsm-docs/versions/release-clm5.0/html/tech_note/Fluxes/CLM50_Tech_Note_Fluxes.html

As far as i can tell, the required change to the parameter file is:

• fates_turb_z0mr = 0.055, 0.055, 0.055, 0.055, 0.055, 0.055, 0.055, 0.055,
• 0.055, 0.055, 0.055, 0.055, 0.055, 0.055 ;

• fates_turb_z0mr = 0.075, 0.055, 0.055, 0.075, 0.055, 0.055, 0.12, 0.12,
• 0.12, 0.12, 0.12, 0.12, 0.12, 0.12

This has non-trivial impacts on fluxes esp in semi arid regions.
https://ns9560k.web.sigma2.no/datalake/diagnostics/noresm/rosief/FATES-SP_rebaseddrydep.zengwang.twostream/compare/FATES-SP_rebaseddrydep.zengwang.twostream.z0mr/ANN/

Boundary layer conductance

Sensible Heat

Latent Heat

[glemieux]

Note to self: add this to the Monday software meeting agenda