Script vs Config Interface

ClimaAtmos provides two ways to set up and run simulations. Both produce an AtmosSimulation that is run with solve_atmos!.

Script API

Build a simulation directly from Julia keyword arguments:

import ClimaAtmos as CA

simulation = CA.AtmosSimulation{Float64}(;
    model = CA.AtmosModel(),
    grid = CA.SphereGrid(Float64; z_elem = 45, h_elem = 6),
    initial_condition = CA.Setups.DecayingProfile(; perturb = true),
    dt = 600,
    t_end = 86400 * 10,
    job_id = "my_run",
)
CA.solve_atmos!(simulation)

Best for: interactive exploration, notebooks, custom scripts, programmatic parameter sweeps.

See AtmosSimulation for more information on how to customize your simulation.

Config API

Define the simulation in a YAML file, then load it:

# config.yml
initial_condition: "DecayingProfile"
perturb_initstate: true
config: "sphere"
z_elem: 45
h_elem: 6
dt: "600secs"
t_end: "10days"
job_id: "my_run"

import ClimaAtmos as CA

config = CA.AtmosConfig("config.yml")
simulation = CA.AtmosSimulation(config)
CA.solve_atmos!(simulation)

Best for: reproducible runs, CI pipelines, and sharing configurations.

See the Creating custom configurations reference for the complete list of YAML options.

Comparison

	Script API	Config API
Entry point	`AtmosSimulation{FT}(; kwargs...)`	`AtmosConfig("file.yml")`
Model	Pass `AtmosModel()` directly	Built from YAML keys
Grid	Pass grid object	`config` key + grid parameters
Setup	Pass setup instance	`initial_condition` string
Timestep	`dt = 600` (number)	`dt: "600secs"` (string)
Duration	`t_end = 864000` (number)	`t_end: "10days"` (string)

Common mappings

Script kwarg	YAML key
`grid = ColumnGrid(...)`	`config: "column"` + `z_max`, `z_elem`
`grid = SphereGrid(...)`	`config: "sphere"` + `h_elem`, `z_elem`
`grid = BoxGrid(...)`	`config: "box"` + `x_max`, `y_max`, etc.
`initial_condition = Setups.Bomex()`	`initial_condition: "Bomex"`
`dt = 5`	`dt: "5secs"`
`t_end = 21600`	`t_end: "6hours"`
`default_diagnostics = true`	`output_default_diagnostics: true`
`job_id = "my_run"`	`job_id: "my_run"`
`checkpoint_frequency = 3600`	`dt_save_state_to_disk: "1hours"`