[Wrf-users] quesion about roughness length in Noah LSM in WRF3.1.1

[Liu, Peng]

Dear WRF users and developers,
  I am using Noah LSM of WRF3.1.1 and I have a specific question about the roughness length in Noah LSM.
  I read the code of module_sf_noahlsm.F and found out that for the roughness length, it is always equal to the background
roughness length even when snow exists ( in function SNOWZ0); while for albedo and emissivity, they are modified based on background values when snow exists (in function ALCALC). So I wonder why roughness length is not modified when snow exists?
  I am looking forward to your responses.

Thanks in advance.


Best,

Peng Liu