Hi Liejun,
Yes, there are several ways to add bottom stress in ROMS:
Code:
1) Linear RDRG > 0, RDRG2 = 0, Zob = 0
2) quadratic RDRG = 0, RDRG2 > 0, Zob = 0
3) law of wall RDRG = 0, RDRG2 = 0, Zob > 0
4) bottom boundary layer model
Notice that in schemes 1 to 3, only one value is greater than zero. This is a must in order to have the appropriate code executed.
The logarithmic law of the wall is only apply to 3D configurations. It does not make sense, I think, to apply this to shallow-water applications neither to barotropic components "ubar" and "vbar". It is only applied to bottom baroclinic velocities!!! In 3D applications, the logarithmic bottom stress or other BBL formulations enter in the 2D equations (step2d) in the vertically integrated residual terms "rufrc" and "rvfrc".
Do this makes sense?
Good luck,
Hernan G. Arango
arango@imcs.rutgers.edu