hi,

I found that the defaut set of iocnrough is 1 in RegCM v4.3. Actually this formula is not used in RegCM v3.

Instead the formula in RegCM3 is, the roughness length of momentum: zo= (0.013*ustar*ustar)/egrav+0.11*visa/ustar , following Smith(1988).

! iocnrough: Zeng Ocean Model Roughness model

! = 1 ; (0.0065*ustar*ustar)/egrav (the RegCM V3 one)

! = 2 ; (0.013*ustar*ustar)/egrav+0.11*visa/ustar (the Zeng one)

I wonder why this default set is changed to "(0.0065*ustar*ustar)/egrav". Is there a reference for this specific equation?

Thank you very much!

Zhenyu HAN