4 Sides Boundary makes ROMs running errors

[remit]

Dear Community,

I have a problem with the ROMS running related to gridding. Ffor your information, I use local bathymetry with a size of 3000 * 3000. After extracting it produces landmasses on the 4 sides of the boundary (red line).



I tried to remove the 4 walls, but when running it produces the following error:

Code: Select all

223 2022-09-10 13:51:30.00  1.815116E-02  1.168819E+04  1.168821E+04  2.025419E+14
                     (056,001,19)  3.369694E-03  4.471618E-03  1.550959E+00  8.154932E+00
       224 2022-09-10 13:52:00.00  1.896066E-02  1.168820E+04  1.168822E+04  2.025419E+14
                     (056,001,17)  6.909299E-03  2.697324E-03  2.002230E+00  8.537422E+00
       225 2022-09-10 13:52:30.00  1.981141E-02  1.168822E+04  1.168824E+04  2.025419E+14
                     (056,001,19)  1.273624E-02  1.900309E-04  2.419246E+00  9.029784E+00
       226 2022-09-10 13:53:00.00  2.044380E-02  1.168826E+04  1.168828E+04  2.025419E+14
                     (056,001,20)  1.542050E-02  2.901312E-03  2.806010E+00  1.019415E+01
 Found Error: 01   Line: 321      Source: ROMS/Nonlinear/main3d.F
 Found Error: 01   Line: 298      Source: ROMS/Drivers/nl_roms.h, ROMS_run

 Blowing-up: Saving latest model state into  RESTART file
     REASON: MaxDensity =  4.3E+02

  WRT_RST_NF90     - wrote re-start    fields (Index=1,1) in record = 3

Elapsed wall CPU time for each process (seconds):

 Thread #    0 CPU:     239.876
 Total:                 239.876

 Nonlinear model elapsed CPU time profile, Grid: 01

This my settings:
! Time-Stepping parameters.

NTIMES == 240
DT == 30.0d0
NDTFAST == 25

LBC(isFsur) == Per Clo Per Clo ! free-surface
LBC(isUbar) == Per Clo Per Clo ! 2D U-momentum
LBC(isVbar) == Per Clo Per Clo ! 2D V-momentum
LBC(isUvel) == Per Clo Per Clo ! 3D U-momentum
LBC(isVvel) == Per Clo Per Clo ! 3D V-momentum
LBC(isMtke) == Per Clo Per Clo ! mixing TKE

LBC(isTvar) == Per Clo Per Clo \ ! temperature
Per Clo Per Clo ! salinity

but when it is not removed running ROMs run completely with well.. can anyone solve this problem?

[arango]

This application does not make sense to me. You specified a land mask around all four edges of the grid. However, you are setting East-West periodic with the LBC parameter in roms.in . You will get an unphysical solution closing all four boundaries. It would help if you had a strategy for open boundary conditions that are not periodic.

[wilkin]

You definitely want to remove the perimeter wall.

Then you need some sensible open boundary conditions. Presently you have east-east periodic, which would only be admissible in this situation if you contrived to match the land/sea mask at the left and right boundaries, or ensured both were entirely open water. But for this very local grid covering Java I doubt you want that.

Start with simple radiation boundary conditions that don't need any external domain information, e.g.

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   LBC(isFsur) ==   Cha    Cha    Cha    Cha         ! free-surface
   LBC(isUbar) ==   Fla    Fla   Fla  Fla         ! 2D U-momentum
   LBC(isVbar) ==   Fla    Fla   Fla  Fla          ! 2D V-momentum
   LBC(isUvel) ==   Rad   Rad   Rad   Rad        ! 3D U-momentum
   LBC(isVvel) ==   Rad   Rad   Rad   Rad          ! 3D V-momentum
   LBC(isMtke) ==   Gra   Gra  Gra   Gra         ! mixing TKE

   LBC(isTvar) ==   Rad   Rad   Rad   Rad    \    ! temperature
                    Rad   Rad   Rad   Rad         ! salinity

But eventually you will need some information on the surrounding ocean, such as from a global model, and introduce that with combined radiaton and nudging "RadNud" for tracers, and by adding sea level and ubar/bar information.