Tracers

The tracers to be advected around can be specified via a list of symbols. By default the model doesn't evolve any tracers.

julia> grid = RectilinearGrid(size=(16, 16, 16), extent=(1, 1, 1));

julia> model = NonhydrostaticModel(; grid)
NonhydrostaticModel{CPU, RectilinearGrid}(time = 0 seconds, iteration = 0)
├── grid: 16×16×16 RectilinearGrid{Float64, Periodic, Periodic, Bounded} on CPU with 3×3×3 halo
├── timestepper: RungeKutta3TimeStepper
├── advection scheme: Centered(order=2)
├── tracers: ()
├── closure: Nothing
├── buoyancy: Nothing
└── coriolis: Nothing

But tracers can be added with the tracers keyword. For example, to add conservative temperature T and absolute salinity S:

julia> model = NonhydrostaticModel(; grid, tracers=(:T, :S))
NonhydrostaticModel{CPU, RectilinearGrid}(time = 0 seconds, iteration = 0)
├── grid: 16×16×16 RectilinearGrid{Float64, Periodic, Periodic, Bounded} on CPU with 3×3×3 halo
├── timestepper: RungeKutta3TimeStepper
├── advection scheme: Centered(order=2)
├── tracers: (T, S)
├── closure: Nothing
├── buoyancy: Nothing
└── coriolis: Nothing

whose fields can be accessed via model.tracers.T and model.tracers.S.

julia> model.tracers.T
16×16×16 Field{Center, Center, Center} on RectilinearGrid on CPU
├── grid: 16×16×16 RectilinearGrid{Float64, Periodic, Periodic, Bounded} on CPU with 3×3×3 halo
├── boundary conditions: FieldBoundaryConditions
│   └── west: Periodic, east: Periodic, south: Periodic, north: Periodic, bottom: ZeroFlux, top: ZeroFlux, immersed: ZeroFlux
└── data: 22×22×22 OffsetArray(::Array{Float64, 3}, -2:19, -2:19, -2:19) with eltype Float64 with indices -2:19×-2:19×-2:19
    └── max=0.0, min=0.0, mean=0.0

julia> model.tracers.S
16×16×16 Field{Center, Center, Center} on RectilinearGrid on CPU
├── grid: 16×16×16 RectilinearGrid{Float64, Periodic, Periodic, Bounded} on CPU with 3×3×3 halo
├── boundary conditions: FieldBoundaryConditions
│   └── west: Periodic, east: Periodic, south: Periodic, north: Periodic, bottom: ZeroFlux, top: ZeroFlux, immersed: ZeroFlux
└── data: 22×22×22 OffsetArray(::Array{Float64, 3}, -2:19, -2:19, -2:19) with eltype Float64 with indices -2:19×-2:19×-2:19
    └── max=0.0, min=0.0, mean=0.0

An arbitrary number of tracers may be simulated. For example, to simulate $C_1$, $CO₂$, and nitrogen as additional passive tracers,

julia> model = NonhydrostaticModel(; grid, tracers=(:T, :S, :C₁, :CO₂, :nitrogen))
NonhydrostaticModel{CPU, RectilinearGrid}(time = 0 seconds, iteration = 0)
├── grid: 16×16×16 RectilinearGrid{Float64, Periodic, Periodic, Bounded} on CPU with 3×3×3 halo
├── timestepper: RungeKutta3TimeStepper
├── advection scheme: Centered(order=2)
├── tracers: (T, S, C₁, CO₂, nitrogen)
├── closure: Nothing
├── buoyancy: Nothing
└── coriolis: Nothing