Boundary condition problems

[zhangtianhao]

Hi forum,

I met some problems when dealing with boundary conditions:

Code: Select all

   LBC(isFsur) ==   Clo     Che     Clo     Che        ! free-surface
   LBC(isUbar) ==   Clo     Shc     Clo     Shc        ! 2D U-momentum
   LBC(isVbar) ==   Clo     Shc     Clo     Shc        ! 2D V-momentum
   LBC(isUvel) ==   Clo     RadNud     Clo     RadNud        ! 3D U-momentum
   LBC(isVvel) ==   Clo     RadNud     Clo     RadNud        ! 3D V-momentum
   LBC(isMtke) ==   Clo     Gra     Clo     Gra        ! mixing TKE
  
   LBC(isTvar) ==   Clo     RadNud     Clo     RadNud\      ! temperature
                    Clo     RadNud     Clo     RadNud       ! salinity

Shc in 2d momentum requirs for external zeta and uvbar values;

RadNud in 3d momentum requirs for externtal zeta, uv and TS values;

I doubt that if I can only offer zeta, uv and TS values in boundary netcdf file and ROMS can calculate uvbar by uv? Or I have to calculate uvbar by myself and input them in nc file？

And the same question in init netcdf file, can I only input uv but not uvbar?

In fact, I do see some guys input uvbar in init and boundary files. however, I tried to calcute case without uvbar in both boundary netcdf file and init netcdf file, it seems fine but I don't find the code in .F file about the calculation process. I want to have a look at it.

Thanks

[kate]

I'm not sure about the boundary conditions, but for the initial conditions, the ubar/vbar fields are set in ini_fields.F.

[wilkin]

The Shchepetkin boundary conditions needs ubar and vbar so you have to provide them in the boundary conditions file. If you have u,v and are using the myroms Matlab tools then the function uv_barotropic.m will do the calculation. It can work on both boundary and initial conditions files.

[zhangtianhao]

Thanks, Kate and Wilkin,

To sum up for other users,

ROMS can calculate uvbar by uv values in ini_fields.F (if not define PERFACT_START). So it is not necessary to input uvbar in init file.

However, Fla, Shc, (and Red?) boundary condition requir for uvbar, so we have to calculate uvbar by uv_barotropic.m file or by other tools ( In fact, uv_barotropic need Hz values... ) and then input them in boundary file.

Cheers,

Hoty

[zzyfathead]

Hz could be calculated by modifying set_depth.m:
for k=1:N(ng)
Hz(i,j,k)=z_w(i,j,k)-z_w(i,j,k-1)

zzy