sediment.in

Sediment Model Input Script - sediment.in

The sediment.in file sets the parameters for sediment output. The name of this file is set by the SPARNAM keyword in the ocean.in file. This standard input ASCII file is organized in several sections as shown below, with links to more detailed explanation where required.

Notice: Detailed information about ROMS input script file syntax can be found here.

Notice: A default sediment.in input script is provided in the User/External subdirectory. Also there are several sediment input scripts in the ROMS/External subdirectory which are used in the distributed test cases. They are usually named sediment_app.in where app is the lowercase of the test case CPP option.

Sediment Model Control Switches

• Switch is used to control sediment model computation within nested and/or multiple connected grids, [1:Ngrids] values are expected.
  Lsediment == T

General Sediment Bed Model Controls

• Depositional bed layer thickness (m) criteria to create a new layer. If deposition exceeds this value, then a new layer is created, [1:Ngrids] values are expected.
  NEWLAYER_THICK == 0.01d0

• Bed load transport rate coefficient, [1:Ngrids] values are expected.
  BEDLOAD_COEFF == 0.05d0

Suspended Cohesive Sediment Parameters

There are NCS cohesive (mud) sediment tracers per nested grid in ROMS. Therefore, [1:NCS,1:Ngrids] values are expected for these parameters.

• Median sediment grain diameter (mm).
  MUD_SD50 == 0.01d0 0.005d0

• Sediment concentration (kg/m³).
  MUD_CSED == 0.0d0 0.0d0

• Sediment grain density (kg/m³).
  MUD_SRHO == 2650.0d0 2400.0d0

• Particle settling velocity (mm/s).
  MUD_WSED == 0.1d0 0.01d0

• Surface erosion rate (kg/m²/s).
  MUD_ERATE == 5.0d-4 5.0d-4

• Critical shear for erosion and deposition (N/m²).
  MUD_TAU_CE == 0.1d0 0.1d0
  MUD_TAU_CD == 0.1d0 0.1d0

• Porosity (nondimensional): Vwater/(Vwater+Vsed). Its values range between 0 and 1.
  MUD_POROS == 0.9d0 0.9d0

• Lateral, constant, harmonic/biharmonic horizontal diffusion of tracer for the nonlinear model and adjoint-based algorithms.
  MUD_TNU2 == 0.0d0 0.0d0  ! m²/s
  MUD_TNU4 == 0.0d0 0.0d0  ! m⁴/s
  
  ad_MUD_TNU2 == 0.0d0 0.0d0  ! m²/s
  ad_MUD_TNU4 == 0.0d0 0.0d0  ! m⁴/s

• Vertical mixing coefficients for tracers in nonlinear model and basic state scale factor in adjoint-based algorithms.
  MUD_AKT_BAK == 5.0d-6 5.0d-6  ! m²/s
  MUD_AKT_fac == 2*1.0d0  ! m²/s

• Nudging/relaxation time scales, inverse scales will be computed internally.
  MUD_TNUDG == 0.0d0 0.0d0  ! days

• Morphological time scale factor (greater than or equal to 1.0). A value of 1.0 has no scale effect.
  MUD_MORPH_FAC == 1.0d0 1.0d0  ! nondimensional

• Logical switch (TRUE/FALSE) to specify which variables to consider on tracers point Sources/Sinks (like river runoff).
  MUD_Ltracer == F F

• Logical switch (TRUE/FALSE) to activate writing of cohesive sediment into output NetCDF file(s).
  Hout(idmud) == T  ! suspended concentration
  Hout(iMfrac) == T  ! bed layer fraction
  Hout(iMmass) == T  ! bed layer mass
  Hout(iMUbld) == T  ! bed load at U-points
  Hout(iMVbld) == T  ! bed load at V-points

Non-cohesive Sediment Parameters

There are NNS non-cohesive (sand) sediment tracers per nested grid in ROMS. Therefore, [1:NNS,1:Ngrids] values are expected for these parameters.

• Median sediment grain diameter (mm).
  SAND_SD50 == 1.0d0

• Sediment concentration (kg/m³).
  SAND_CSED == 0.0d0

• Sediment grain density (kg/m³).
  SAND_SRHO == 2650.0d0

• Particle settling velocity (mm/s).
  SAND_WSED == 1.0d0

• Surface erosion rate (kg/m²/s).
  SAND_ERATE == 5.0d-4

• Critical shear for erosion and deposition (N/m²).
  SAND_TAU_CE == 0.01d0
  SAND_TAU_CD == 0.01d0

• Porosity (nondimensional): Vwater/(Vwater+Vsed). Its values range between 0 and 1.
  SAND_POROS == 0.5d0

• Lateral, constant, harmonic/biharmonic horizontal diffusion of tracer for the nonlinear model and adjoint-based algorithms.
  SAND_TNU2 == 0.0d0  ! m²/s
  SAND_TNU4 == 0.0d0  ! m⁴/s
  
  ad_SAND_TNU2 == 0.0d0  ! m²/s
  ad_SAND_TNU4 == 0.0d0  ! m⁴/s

• Vertical mixing coefficients for tracers in nonlinear model and basic state scale factor in adjoint-based algorithms.
  SAND_AKT_BAK == 5.0d-6  ! m²/s
  SAND_AKT_fac == 1.0d0  ! m²/s

• Nudging/relaxation time scales, inverse scales will be computed internally.
  SAND_TNUDG == 0.0d0  ! days

• Morphological time scale factor (greater than or equal to 1.0). A value of 1.0 has no scale effect.
  SAND_MORPH_FAC == 1.0d0  ! nondimensional

• Logical switch (TRUE/FALSE) to specify which variables to consider on tracers point Sources/Sinks (like river runoff).
  SAND_Ltracer == F

• Logical switches (TRUE/FALSE) to activate writing of non-cohesive sediment fields into output NetCDF file(s).
  Hout(isand) == T  ! suspended concentration
  Hout(iSfrac) == T  ! bed layer fraction
  Hout(iSmass) == T  ! bed layer mass
  Hout(iSUbld) == T  ! bed load at U-points
  Hout(iSVbld) == T  ! bed load at V-points

Bed Layer and Bottom Sediment Parameters

• Logical switches (TRUE/FALSE) to activate writing of bed layer and bottom sediment fields into output NetCDF file(s), [1:Ngrids] values are expected.
  Hout(ithck) == T  ! sediment layer thickness
  Hout(iaged) == T  ! sediment layer age
  Hout(iporo) == T  ! sediment layer porosity
  Hout(idiff) == F  ! biodiffusivity