Model setup

This section describes all the options and features that can be used to set up a model. For more detailed information consult the API documentation.

Each structure covered in this section can be constructed and passed to the models' constructors. For examples of model construction, see the examples. The validation experiments provide more advanced examples.

For reference, here are all the option or keyword arguments that can be passed to the currently implemented models. See the different sections on the sidebar for more details and examples for each keyword argument.

NonhydrostaticModel

Oceananigans.Models.NonhydrostaticModels.NonhydrostaticModelType
NonhydrostaticModel(;           grid,
                                clock = Clock{eltype(grid)}(time = 0),
                            advection = Centered(),
                             buoyancy = nothing,
                             coriolis = nothing,
                         stokes_drift = nothing,
                  forcing::NamedTuple = NamedTuple(),
                              closure = nothing,
      boundary_conditions::NamedTuple = NamedTuple(),
                              tracers = (),
                          timestepper = :RungeKutta3,
        background_fields::NamedTuple = NamedTuple(),
        particles::ParticlesOrNothing = nothing,
biogeochemistry::AbstractBGCOrNothing = nothing,
                           velocities = nothing,
              nonhydrostatic_pressure = CenterField(grid),
         hydrostatic_pressure_anomaly = DefaultHydrostaticPressureAnomaly(),
                   diffusivity_fields = nothing,
                      pressure_solver = nothing,
                     auxiliary_fields = NamedTuple())

Construct a model for a non-hydrostatic, incompressible fluid on grid, using the Boussinesq approximation when buoyancy != nothing. By default, all Bounded directions are rigid and impenetrable.

Keyword arguments

  • grid: (required) The resolution and discrete geometry on which the model is solved. The architecture (CPU/GPU) that the model is solved on is inferred from the architecture of the grid. Note that the grid needs to be regularly spaced in the horizontal dimensions, $x$ and $y$.
  • advection: The scheme that advects velocities and tracers. See Oceananigans.Advection.
  • buoyancy: The buoyancy model. See Oceananigans.BuoyancyModels.
  • coriolis: Parameters for the background rotation rate of the model.
  • stokes_drift: Parameters for Stokes drift fields associated with surface waves. Default: nothing.
  • forcing: NamedTuple of user-defined forcing functions that contribute to solution tendencies.
  • closure: The turbulence closure for model. See Oceananigans.TurbulenceClosures.
  • boundary_conditions: NamedTuple containing field boundary conditions.
  • tracers: A tuple of symbols defining the names of the modeled tracers, or a NamedTuple of preallocated CenterFields.
  • timestepper: A symbol that specifies the time-stepping method. Either :QuasiAdamsBashforth2 or :RungeKutta3 (default).
  • background_fields: NamedTuple with background fields (e.g., background flow). Default: nothing.
  • particles: Lagrangian particles to be advected with the flow. Default: nothing.
  • biogeochemistry: Biogeochemical model for tracers.
  • velocities: The model velocities. Default: nothing.
  • nonhydrostatic_pressure: The nonhydrostatic pressure field. Default: CenterField(grid).
  • hydrostatic_pressure_anomaly: An optional field that stores the part of the nonhydrostatic pressure in hydrostatic balance with the buoyancy field. If CenterField(grid) (default), the anomaly is precomputed by vertically integrating the buoyancy field. In this case, the nonhydrostatic_pressure represents only the part of pressure that deviates from the hydrostatic anomaly. If nothing, the anomaly is not computed.
  • diffusivity_fields: Diffusivity fields. Default: nothing.
  • pressure_solver: Pressure solver to be used in the model. If nothing (default), the model constructor chooses the default based on the grid provide.
  • auxiliary_fields: NamedTuple of auxiliary fields. Default: nothing
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HydrostaticFreeSurfaceModel

Oceananigans.Models.HydrostaticFreeSurfaceModels.HydrostaticFreeSurfaceModelType
HydrostaticFreeSurfaceModel(; grid,
                            clock = Clock{eltype(grid)}(time = 0),
                            momentum_advection = VectorInvariant(),
                            tracer_advection = Centered(),
                            buoyancy = SeawaterBuoyancy(eltype(grid)),
                            coriolis = nothing,
                            free_surface = default_free_surface(grid, gravitational_acceleration=g_Earth),
                            forcing::NamedTuple = NamedTuple(),
                            closure = nothing,
                            boundary_conditions::NamedTuple = NamedTuple(),
                            tracers = (:T, :S),
                            particles::ParticlesOrNothing = nothing,
                            biogeochemistry::AbstractBGCOrNothing = nothing,
                            velocities = nothing,
                            pressure = nothing,
                            diffusivity_fields = nothing,
                            auxiliary_fields = NamedTuple())

Construct a hydrostatic model with a free surface on grid.

Keyword arguments

  • grid: (required) The resolution and discrete geometry on which model is solved. The architecture (CPU/GPU) that the model is solved is inferred from the architecture of the grid.
  • momentum_advection: The scheme that advects velocities. See Oceananigans.Advection.
  • tracer_advection: The scheme that advects tracers. See Oceananigans.Advection.
  • buoyancy: The buoyancy model. See Oceananigans.BuoyancyModels.
  • coriolis: Parameters for the background rotation rate of the model.
  • free_surface: The free surface model. The default free-surface solver depends on the geometry of the grid. If the grid is a RectilinearGrid that is regularly spaced in the horizontal the default is an ImplicitFreeSurface solver with solver_method = :FFTBasedPoissonSolver. In all other cases, the default is a SplitExplicitFreeSurface.
  • tracers: A tuple of symbols defining the names of the modeled tracers, or a NamedTuple of preallocated CenterFields.
  • forcing: NamedTuple of user-defined forcing functions that contribute to solution tendencies.
  • closure: The turbulence closure for model. See Oceananigans.TurbulenceClosures.
  • boundary_conditions: NamedTuple containing field boundary conditions.
  • particles: Lagrangian particles to be advected with the flow. Default: nothing.
  • biogeochemistry: Biogeochemical model for tracers.
  • velocities: The model velocities. Default: nothing.
  • pressure: Hydrostatic pressure field. Default: nothing.
  • diffusivity_fields: Diffusivity fields. Default: nothing.
  • auxiliary_fields: NamedTuple of auxiliary fields. Default: nothing.
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ShallowWaterModel

Oceananigans.Models.ShallowWaterModels.ShallowWaterModelType
ShallowWaterModel(; grid,
                    gravitational_acceleration,
                          clock = Clock{eltype(grid)}(time = 0),
             momentum_advection = UpwindBiased(order=5),
               tracer_advection = WENO(),
                 mass_advection = WENO(),
                       coriolis = nothing,
            forcing::NamedTuple = NamedTuple(),
                        closure = nothing,
                     bathymetry = nothing,
                        tracers = (),
             diffusivity_fields = nothing,
boundary_conditions::NamedTuple = NamedTuple(),
            timestepper::Symbol = :RungeKutta3,
                    formulation = ConservativeFormulation())

Construct a shallow water model on grid with gravitational_acceleration constant.

Keyword arguments

  • grid: (required) The resolution and discrete geometry on which model is solved. The architecture (CPU/GPU) that the model is solve is inferred from the architecture of the grid.
  • gravitational_acceleration: (required) The gravitational acceleration constant.
  • clock: The clock for the model.
  • momentum_advection: The scheme that advects velocities. See Oceananigans.Advection. Default: UpwindBiased(order=5).
  • tracer_advection: The scheme that advects tracers. See Oceananigans.Advection. Default: WENO().
  • mass_advection: The scheme that advects the mass equation. See Oceananigans.Advection. Default: WENO().
  • coriolis: Parameters for the background rotation rate of the model.
  • forcing: NamedTuple of user-defined forcing functions that contribute to solution tendencies.
  • closure: The turbulence closure for model. See Oceananigans.TurbulenceClosures.
  • bathymetry: The bottom bathymetry.
  • tracers: A tuple of symbols defining the names of the modeled tracers, or a NamedTuple of preallocated CenterFields.
  • diffusivity_fields: Stores diffusivity fields when the closures require a diffusivity to be calculated at each timestep.
  • boundary_conditions: NamedTuple containing field boundary conditions.
  • timestepper: A symbol that specifies the time-stepping method. Either :QuasiAdamsBashforth2 or :RungeKutta3 (default).
  • formulation: Whether the dynamics are expressed in conservative form (ConservativeFormulation(); default) or in non-conservative form with a vector-invariant formulation for the non-linear terms (VectorInvariantFormulation()).
Formulation-grid compatibility requirements

The ConservativeFormulation() requires RectilinearGrid. Use VectorInvariantFormulation() with LatitudeLongitudeGrid.

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