Lateral Boundary Conditions
The lateral boundary conditions are specified by logical switches to facilitate applications with nested grids. It also allows to set different boundary conditions between the nonlinear model and the adjoint/tangent models. In addition, we can have different boundary conditions between active and passive tracers. The LBC structure is allocated as:
where 1:4 are the numbered boundary edges, nLBCvar is the number of LBC state variables, and Ngrids is the number of nested grids. The boundary order is: 1=west, 2=south, 3=east, and 4=north. That is, anticlockwise starting at the western boundary.
For example, the free-surface gradient boundary conditions are specified as:
The structure is declared in mod_param.F as:
integer ::
nLBCvar TYPE T_LBC
logical :: acquire ! process lateral boundary data
logical :: Chapman
logical :: clamped
logical :: closed
logical :: Flather
logical :: gradient
logical :: nested
logical :: nudging
logical :: periodic
logical :: radiation
logical :: reduced
END TYPE T_LBC
TYPE (T_LBC), allocatable ::
LBC(:,:,:)
TYPE (T_LBC), allocatable ::
ad_LBC(:,:,:)
TYPE (T_LBC), allocatable ::
tl_LBC(:,:,:)
Conversion Tables
Starting with ROMS version 3.6, the CPP options for lateral boundary conditions (user defined and internal) are deprecated and replaced with logical switches that are specified in the standard input files. The following tables show the conversion from CPP options to logical switches for each state variable using the LBC structure:
| Free-surface
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WEST_FSCHAPMAN
|
LBC(iwest, isFsur, ng) % Chapman
|
| EAST_FSCHAPMAN
|
LBC(ieast, isFsur, ng) % Chapman
|
| SOUTH_FSCHAPMAN
|
LBC(isouth, isFsur, ng) % Chapman
|
| NORTH_FSCHAPMAN
|
LBC(inorth, isFsur, ng) % Chapman
|
| WEST_FSCLAMPED
|
LBC(iwest, isFsur, ng) % clamped
|
| EAST_FSCLAMPED
|
LBC(ieast, isFsur, ng) % clamped
|
| SOUTH_FSCLAMPED
|
LBC(isouth, isFsur, ng) % clamped
|
| NORTH_FSCLAMPED
|
LBC(inorth, isFsur, ng) % clamped
|
| WESTERN_WALL
|
LBC(iwest, isFsur, ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isFsur, ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isFsur, ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isFsur, ng) % closed
|
| WEST_FSGRADIENT
|
LBC(iwest, isFsur, ng) % gradient
|
| EAST_FSGRADIENT
|
LBC(ieast, isFsur, ng) % gradient
|
| SOUTH_FSGRADIENT
|
LBC(isouth, isFsur, ng) % gradient
|
| NORTH_FSGRADIENT
|
LBC(inorth, isFsur, ng) % gradient
|
| WEST_FSNUDGING
|
LBC(iwest, isFsur, ng) % nudging
|
| EAST_FSNUDGING
|
LBC(ieast, isFsur, ng) % nudging
|
| SOUTH_FSNUDGING
|
LBC(isouth, isFsur, ng) % nudging
|
| NORTH_FSNUDGING
|
LBC(inorth, isFsur, ng) % nudging
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isFsur, ng) % periodic
LBC(ieast, isFsur, ng) % periodic
|
| NS_PERIODIC
|
NSperiodic(ng)
LBC(isouth, isFsur, ng) % periodic
LBC(inorth, isFsur, ng) % periodic
|
| WEST_FSRADIATION
|
LBC(iwest, isFsur, ng) % radiation
|
| EAST_FSRADIATION
|
LBC(ieast, isFsur, ng) % radiation
|
| SOUTH_FSRADIATION
|
LBC(isouth, isFsur, ng) % radiation
|
| NORTH_FSRADIATION
|
LBC(inorth, isFsur, ng) % radiation
|
| WEST_FSOBC
|
LBC(iwest, isFsur, ng) % acquire
|
| EAST_FSOBC
|
LBC(ieast, isFsur, ng) % acquire
|
| SOUTH_FSOBC
|
LBC(isouth, isFsur, ng) % acquire
|
| NORTH_FSOBC
|
LBC(inorth, isFsur, ng) % acquire
|
| 2D U-momentum
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WEST_M2CLAMPED
|
LBC(iwest, isUbar, ng) % clamped
|
| EAST_M2CLAMPED
|
LBC(ieast, isUbar, ng) % clamped
|
| SOUTH_M2CLAMPED
|
LBC(isouth, isUbar, ng) % clamped
|
| NORTH_M2CLAMPED
|
LBC(inorth, isUbar, ng) % clamped
|
| WESTERN_WALL
|
LBC(iwest, isUbar, ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isUbar, ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isUbar, ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isUbar, ng) % closed
|
| WEST_M2FLATHER
|
LBC(iwest, isUbar, ng) % Flather
|
| EAST_M2FLATHER
|
LBC(ieast, isUbar, ng) % Flather
|
| SOUTH_M2FLATHER
|
LBC(isouth, isUbar, ng) % Flather
|
| NORTH_M2FLATHER
|
LBC(inorth, isUbar, ng) % Flather
|
| WEST_M2GRADIENT
|
LBC(iwest, isUbar, ng) % gradient
|
| EAST_M2GRADIENT
|
LBC(ieast, isUbar, ng) % gradient
|
| SOUTH_M2GRADIENT
|
LBC(isouth, isUbar, ng) % gradient
|
| NORTH_M2GRADIENT
|
LBC(inorth, isUbar, ng) % gradient
|
| WEST_M2NUDGING
|
LBC(iwest, isUbar, ng) % nudging
|
| EAST_M2NUDGING
|
LBC(ieast, isUbar, ng) % nudging
|
| SOUTH_M2NUDGING
|
LBC(isouth, isUbar, ng) % nudging
|
| NORTH_M2NUDGING
|
LBC(inorth, isUbar, ng) % nudging
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isUbar, ng) % periodic
LBC(ieast, isUbar, ng) % periodic
|
| NS_PERIODIC
|
NSperiodic(ng)
LBC(isouth, isUbar, ng) % periodic
LBC(inorth, isUbar, ng) % periodic
|
| WEST_M2RADIATION
|
LBC(iwest, isUbar, ng) % radiation
|
| EAST_M2RADIATION
|
LBC(ieast, isUbar, ng) % radiation
|
| SOUTH_M2RADIATION
|
LBC(isouth, isUbar, ng) % radiation
|
| NORTH_M2RADIATION
|
LBC(inorth, isUbar, ng) % radiation
|
| WEST_M2REDUCED
|
LBC(iwest, isUbar, ng) % reduced
|
| EAST_M2REDUCED
|
LBC(ieast, isUbar, ng) % reduced
|
| SOUTH_M2REDUCED
|
LBC(isouth, isUbar, ng) % reduced
|
| NORTH_M2REDUCED
|
LBC(inorth, isUbar, ng) % reduced
|
| WEST_M2OBC
|
LBC(iwest, isUbar, ng) % acquire
|
| EAST_M2OBC
|
LBC(ieast, isUbar, ng) % acquire
|
| SOUTH_M2OBC
|
LBC(isouth, isUbar, ng) % acquire
|
| NORTH_M2OBC
|
LBC(inorth, isUbar, ng) % acquire
|
| 2D V-momentum
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WEST_M2CLAMPED
|
LBC(iwest, isVbar, ng) % clamped
|
| EAST_M2CLAMPED
|
LBC(ieast, isVbar, ng) % clamped
|
| SOUTH_M2CLAMPED
|
LBC(isouth, isVbar, ng) % clamped
|
| NORTH_M2CLAMPED
|
LBC(inorth, isVbar, ng) % clamped
|
| WESTERN_WALL
|
LBC(iwest, isVbar, ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isVbar, ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isVbar, ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isVbar, ng) % closed
|
| WEST_M2FLATHER
|
LBC(iwest, isVbar, ng) % Flather
|
| EAST_M2FLATHER
|
LBC(ieast, isVbar, ng) % Flather
|
| SOUTH_M2FLATHER
|
LBC(isouth, isVbar, ng) % Flather
|
| NORTH_M2FLATHER
|
LBC(inorth, isVbar, ng) % Flather
|
| WEST_M2GRADIENT
|
LBC(iwest, isVbar, ng) % gradient
|
| EAST_M2GRADIENT
|
LBC(ieast, isVbar, ng) % gradient
|
| SOUTH_M2GRADIENT
|
LBC(isouth, isVbar, ng) % gradient
|
| NORTH_M2GRADIENT
|
LBC(inorth, isVbar, ng) % gradient
|
| WEST_M2NUDGING
|
LBC(iwest, isVbar, ng) % nudging
|
| EAST_M2NUDGING
|
LBC(ieast, isVbar, ng) % nudging
|
| SOUTH_M2NUDGING
|
LBC(isouth, isVbar, ng) % nudging
|
| NORTH_M2NUDGING
|
LBC(inorth, isVbar, ng) % nudging
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isVbar, ng) % periodic
LBC(ieast, isVbar, ng) % periodic
|
| NS_PERIODIC
|
NSperiodic(ng)
LBC(isouth, isVbar, ng) % periodic
LBC(inorth, isVbar, ng) % periodic
|
| WEST_M2RADIATION
|
LBC(iwest, isVbar, ng) % radiation
|
| EAST_M2RADIATION
|
LBC(ieast, isVbar, ng) % radiation
|
| SOUTH_M2RADIATION
|
LBC(isouth, isVbar, ng) % radiation
|
| NORTH_M2RADIATION
|
LBC(inorth, isVbar, ng) % radiation
|
| WEST_M2REDUCED
|
LBC(iwest, isVbar, ng) % reduced
|
| EAST_M2REDUCED
|
LBC(ieast, isVbar, ng) % reduced
|
| SOUTH_M2REDUCED
|
LBC(isouth, isVbar, ng) % reduced
|
| NORTH_M2REDUCED
|
LBC(inorth, isVbar, ng) % reduced
|
| WEST_M2OBC
|
LBC(iwest, isVbar, ng) % acquire
|
| EAST_M2OBC
|
LBC(ieast, isVbar, ng) % acquire
|
| SOUTH_M2OBC
|
LBC(isouth, isVbar, ng) % acquire
|
| NORTH_M2OBC
|
LBC(inorth, isVbar, ng) % acquire
|
| 3D U-momentum
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WEST_M3CLAMPED
|
LBC(iwest, isUvel, ng) % clamped
|
| EAST_M3CLAMPED
|
LBC(ieast, isUvel, ng) % clamped
|
| SOUTH_M3CLAMPED
|
LBC(isouth, isUvel, ng) % clamped
|
| NORTH_M3CLAMPED
|
LBC(inorth, isUvel, ng) % clamped
|
| WESTERN_WALL
|
LBC(iwest, isUvel, ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isUvel, ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isUvel, ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isUvel, ng) % closed
|
| WEST_M3GRADIENT
|
LBC(iwest, isUvel, ng) % gradient
|
| EAST_M3GRADIENT
|
LBC(ieast, isUvel, ng) % gradient
|
| SOUTH_M3GRADIENT
|
LBC(isouth, isUvel, ng) % gradient
|
| NORTH_M3GRADIENT
|
LBC(inorth, isUvel, ng) % gradient
|
| WEST_M3NUDGING
|
LBC(iwest, isUvel, ng) % nudging
|
| EAST_M3NUDGING
|
LBC(ieast, isUvel, ng) % nudging
|
| SOUTH_M3NUDGING
|
LBC(isouth, isUvel, ng) % nudging
|
| NORTH_M3NUDGING
|
LBC(inorth, isUvel, ng) % nudging
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isUvel, ng) % periodic
LBC(ieast, isUvel, ng) % periodic
|
| NS_PERIODIC
|
NSperiodic(ng)
LBC(isouth, isUvel, ng) % periodic
LBC(inorth, isUvel, ng) % periodic
|
| WEST_M3RADIATION
|
LBC(iwest, isUvel, ng) % radiation
|
| EAST_M3RADIATION
|
LBC(ieast, isUvel, ng) % radiation
|
| SOUTH_M3RADIATION
|
LBC(isouth, isUvel, ng) % radiation
|
| NORTH_M3RADIATION
|
LBC(inorth, isUvel, ng) % radiation
|
| WEST_M3OBC
|
LBC(iwest, isUvel, ng) % acquire
|
| EAST_M3OBC
|
LBC(ieast, isUvel, ng) % acquire
|
| SOUTH_M3OBC
|
LBC(isouth, isUvel, ng) % acquire
|
| NORTH_M3OBC
|
LBC(inorth, isUvel, ng) % acquire
|
| 3D V-momentum
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WEST_M3CLAMPED
|
LBC(iwest, isVvel, ng) % clamped
|
| EAST_M3CLAMPED
|
LBC(ieast, isVvel, ng) % clamped
|
| SOUTH_M3CLAMPED
|
LBC(isouth, isVvel, ng) % clamped
|
| NORTH_M3CLAMPED
|
LBC(inorth, isVvel, ng) % clamped
|
| WESTERN_WALL
|
LBC(iwest, isVvel, ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isVvel, ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isVvel, ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isVvel, ng) % closed
|
| WEST_M3GRADIENT
|
LBC(iwest, isVvel, ng) % gradient
|
| EAST_M3GRADIENT
|
LBC(ieast, isVvel, ng) % gradient
|
| SOUTH_M3GRADIENT
|
LBC(isouth, isVvel, ng) % gradient
|
| NORTH_M3GRADIENT
|
LBC(inorth, isVvel, ng) % gradient
|
| WEST_M3NUDGING
|
LBC(iwest, isVvel, ng) % nudging
|
| EAST_M3NUDGING
|
LBC(ieast, isVvel, ng) % nudging
|
| SOUTH_M3NUDGING
|
LBC(isouth, isVvel, ng) % nudging
|
| NORTH_M3NUDGING
|
LBC(inorth, isVvel, ng) % nudging
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isVvel, ng) % periodic
LBC(ieast, isVvel, ng) % periodic
|
| NS_PERIODIC
|
NSeriodic(ng)
LBC(isouth, isVvel, ng) % periodic
LBC(inorth, isVvel, ng) % periodic
|
| WEST_M3RADIATION
|
LBC(iwest, isVvel, ng) % radiation
|
| EAST_M3RADIATION
|
LBC(ieast, isVvel, ng) % radiation
|
| SOUTH_M3RADIATION
|
LBC(isouth, isVvel, ng) % radiation
|
| NORTH_M3RADIATION
|
LBC(inorth, isVvel, ng) % radiation
|
| WEST_M3OBC
|
LBC(iwest, isVvel, ng) % acquire
|
| EAST_M3OBC
|
LBC(ieast, isVvel, ng) % acquire
|
| SOUTH_M3OBC
|
LBC(isouth, isVvel, ng) % acquire
|
| NORTH_M3OBC
|
LBC(inorth, isVvel, ng) % acquire
|
| TKE mixing
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WESTERN_WALL
|
LBC(iwest, isMtke, ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isMtke, ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isMtke, ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isMtke, ng) % closed
|
| WEST_KGRADIENT
|
LBC(iwest, isMtke, ng) % gradient
|
| EAST_KGRADIENT
|
LBC(ieast, isMtke, ng) % gradient
|
| SOUTH_KGRADIENT
|
LBC(isouth, isMtke, ng) % gradient
|
| NORTH_KGRADIENT
|
LBC(inorth, isMtke, ng) % gradient
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isMtke, ng) % periodic
LBC(ieast, isMtke, ng) % periodic
|
| NS_PERIODIC
|
NSperiodic(ng)
LBC(isouth, isMtke, ng) % periodic
LBC(inorth, isMtke, ng) % periodic
|
| WEST_KRADIATION
|
LBC(iwest, isMtke, ng) % radiation
|
| EAST_KRADIATION
|
LBC(ieast, isMtke, ng) % radiation
|
| SOUTH_KRADIATION
|
LBC(isouth, isMtke, ng) % radiation
|
| NORTH_KRADIATION
|
LBC(inorth, isMtke, ng) % radiation
|
| Tracers
|
| CPP
|
Logical Switch, IF (...) THEN
|
| WEST_TCLAMPED
|
LBC(iwest, isTvar(:), ng) % clamped
|
| EAST_TCLAMPED
|
LBC(ieast, isTvar(:), ng) % clamped
|
| SOUTH_TCLAMPED
|
LBC(isouth, isTvar(:), ng) % clamped
|
| NORTH_TCLAMPED
|
LBC(inorth, isTvar(:), ng) % clamped
|
| WESTERN_WALL
|
LBC(iwest, isTvar(:), ng) % closed
|
| EASTERN_WALL
|
LBC(ieast, isTvar(:), ng) % closed
|
| SOUTHERN_WALL
|
LBC(isouth, isTvar(:), ng) % closed
|
| NORTHERN_WALL
|
LBC(inorth, isTvar(:), ng) % closed
|
| WEST_TGRADIENT
|
LBC(iwest, isTvar(:), ng) % gradient
|
| EAST_TGRADIENT
|
LBC(ieast, isTvar(:), ng) % gradient
|
| SOUTH_TGRADIENT
|
LBC(isouth, isTvar(:), ng) % gradient
|
| NORTH_TGRADIENT
|
LBC(inorth, isTvar(:), ng) % gradient
|
| WEST_TNUDGING
|
LBC(iwest, isTvar(:), ng) % nudging
|
| EAST_TNUDGING
|
LBC(ieast, isTvar(:), ng) % nudging
|
| SOUTH_TNUDGING
|
LBC(isouth, isTvar(:), ng) % nudging
|
| NORTH_TNUDGING
|
LBC(inorth, isTvar(:), ng) % nudging
|
| EW_PERIODIC
|
EWperiodic(ng)
LBC(iwest, isTvar(:), ng) % periodic
LBC(ieast, isTvar(:), ng) % periodic
|
| NS_PERIODIC
|
NSperiodic(ng)
LBC(isouth, isTvar(:), ng) % periodic
LBC(inorth, isTvar(:), ng) % periodic
|
| WEST_TRADIATION
|
LBC(iwest, isTvar(:), ng) % radiation
|
| EAST_TRADIATION
|
LBC(ieast, isTvar(:), ng) % radiation
|
| SOUTH_TRADIATION
|
LBC(isouth, isTvar(:), ng) % radiation
|
| NORTH_TRADIATION
|
LBC(inorth, isTvar(:), ng) % radiation
|
| WEST_TOBC
|
LBC(iwest, isTvar(:), ng) % acquire
|
| EAST_TOBC
|
LBC(ieast, isTvar(:), ng) % acquire
|
| SOUTH_TOBC
|
LBC(isouth, isTvar(:), ng) % acquire
|
| NORTH_TOBC
|
LBC(inorth, isTvar(:), ng) % acquire
|
Starting with ROMS version 3.6, the CPP options for volume conservation are deprecated and replaced with logical switches that are specified in the roms.in file. The following tables show the conversion from CPP options to logical switches:
NOTE: The internal C-preprocessing option NUDGING_COEF, defined previously in globaldefs.h, is eliminated and replaced with logical switch NudgingCoeff(ng). This switch is used in ana_nudgcoef.h. We recommend that you start with new version of ana_nudgecoef.h and add the code needed for your application.
NOTE: Also, the internal C-preprocessing option OBC_DATA, defined previously in globaldefs.h, is eliminated and replaced with logical switch ObcData(ng). This switch is activated internally in read_phypar.F to process lateral boundary conditions NetCDF file.
NOTE: The internal C-preprocessing option NUDGING_COEF, defined previously in globaldefs.h, is eliminated and replaced with logical switch NudgingCoeff(ng). This switch is used in ana_nudgcoef.h. We recommend that you start with new version of ana_nudgecoef.h and add the code needed for your application.
