sediment.in

Sediment Model Input Script - sediment.in

The sediment model input ASCII file sediment.in is organized in several sections as shown below, with links to more detailed explanation where required. The format is keyword == value(s); the order in which keywords appear in the file is not important.

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 0.06d0 0.10d0

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

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

• Particle settling velocity (mm/s).
  MUD_WSED == 0.1d0 1.0d0 2.0d0

• Surface erosion rate (kg/m2/s).
  MUD_ERATE == 5.0d-5 5.0d-5 5.0d-5

• Critical shear for erosion (N/m2).
  MUD_TAU_CE == 0.05d0 0.05d0 0.05d0

• Critical stress for deposition (N/m2), not used.
  MUD_TAU_CD == 0.01d0 0.01d0 0.01d0

• Porosity (nondimensional): Vwater/(Vwater+Vsed). Its values range between 0 and 1.
  MUD_POROS == 0.0d0 0.0d0 0.0d0

• Lateral, harmonic and biharmonic, constant, diffusion coefficient.
  MUD_TNU2 == 0.0d0 0.0d0 0.0d0  ! m2/s
  MUD_TNU4 == 0.0d0 0.0d0 0.0d0  ! m4/s

• Vertical diffusion coefficients.
  MUD_AKT_BAK == 5.0d-6 5.0d-6 5.0d-6  ! m2/s

• Nudging/relaxation time scales, inverse scales will be computed internally.
  MUD_TNUDG == 0.0d0 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 1.0d0  ! nondimensional

• 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 == 1.0d-5

• Critical shear for erosion and deposition (N/m2).
  SAND_TAU_CE == 0.07d0
  SAND_TAU_CD == 0.02d0

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

• Lateral, harmonic and biharmonic, constant, diffusion coefficient.
  SAND_TNU2 == 0.0d0  ! m2/s
  SAND_TNU4 == 0.0d0  ! m4/s

• Vertical diffusion coefficients.
  SAND_AKT_BAK == 5.0d-6  ! 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 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