Configuration

Two APIs

Use Case	API
Quick start	`create_simple_config()` → `run_simple_simulation()`
Full control	`default_params()` → `setup_model()` → manual stepping

Different Defaults

Flag	Simple API	Full API
`inviscid`	`true`	`false`
`no_wave_feedback`	`false`	`true`

Simple API

config = create_simple_config(
    # Domain (REQUIRED)
    Lx=500e3, Ly=500e3, Lz=4000.0,
    # Grid
    nx=64, ny=64, nz=32,
    # Time
    dt=0.001, total_time=1.0,
    # Physics
    ybj_plus=true, inviscid=true, linear=false,
    # Output
    output_interval=100
)
result = run_simple_simulation(config)

Full API

par = default_params(
    Lx=500e3, Ly=500e3, Lz=4000.0,
    nx=64, ny=64, nz=32,
    dt=0.001, nt=1000,
    f₀=1.0, N²=1.0,
    ybj_plus=true, inviscid=false
)

G, S, plans, a_ell = setup_model(par)
init_random_psi!(S, G; amplitude=0.1)
compute_q_from_psi!(S, G, plans, a_ell)

first_projection_step!(S, G, par, plans, a_ell)
for step = 2:par.nt
    leapfrog_step!(S, G, par, plans, a_ell)
end

IMEX

Use imex_cn_step!() instead of leapfrog_step!() for ~10× faster wave-dominated problems.

Parameter Reference

Domain (REQUIRED)

Parameter	Description
`Lx`, `Ly`	Horizontal domain size [m]
`Lz`	Vertical depth [m]
`nx`, `ny`, `nz`	Grid points (default: 64)

Physics

Parameter	Default	Description
`f₀`	1.0	Coriolis parameter
`N²`	1.0	Buoyancy frequency squared
`γ`	1e-3	Robert-Asselin filter

Unicode: type f\_0<tab> → f₀, \nu<tab> → ν

Model Flags

Flag	Default	Effect
`ybj_plus`	true	Use YBJ+ formulation
`inviscid`	false	Disable dissipation
`linear`	false	Disable nonlinear terms
`no_wave_feedback`	true	Disable qʷ term
`no_dispersion`	false	Disable wave dispersion
`fixed_flow`	false	Keep ψ constant

Dissipation

Two hyperdiffusion operators: ν₁(-∇²)^ilap1 + ν₂(-∇²)^ilap2

Parameter	Default	Description
`νₕ₁`, `νₕ₂`	0.01, 10.0	Hyperviscosity (flow)
`ilap1`, `ilap2`	2, 6	Laplacian power
`νₕ₁ʷ`, `νₕ₂ʷ`	0.0, 10.0	Hyperviscosity (waves)

Higher ilap = more scale-selective: 1 (∇²), 2 (∇⁴), 4 (∇⁸)

Examples

QG-Only (No Waves)

par = default_params(Lx=500e3, Ly=500e3, Lz=4000.0, no_dispersion=true)

Linear Wave Propagation

config = create_simple_config(
    Lx=500e3, Ly=500e3, Lz=4000.0,
    linear=true, inviscid=true, no_wave_feedback=true
)

Save/Load

using JLD2
@save "config.jld2" par
@load "config.jld2" par