Glossary
Short definitions of the symbols and terms that recur across the ClimaAtmos source code and documentation. Each entry links to the page that covers it in depth.
State and cache
ClimaAtmos integrates a prognostic state vector forward in time. A handful of single-letter names appear throughout the code:
| Symbol | Meaning |
|---|---|
Y | The prognostic state vector — the quantities integrated in time. Y.c holds cell-center variables (e.g. density ρ, total energy ρe_tot, horizontal velocity uₕ); Y.f holds face variables (e.g. vertical velocity u₃). |
Yₜ | The tendency vector, i.e. the time derivative ∂Y/∂t. Yₜ.sfc holds surface tendencies. |
p | The cache: parameters, precomputed fields (radiation fluxes, surface conditions, precipitation fluxes), model configuration, and slab/surface model properties. |
t | The current simulation time, in seconds from start_date. |
These are accessed through the integrator after a run, e.g. Y = simulation.integrator.u (see Your First Simulation).
Common terms
- Setup — the initial conditions, boundary conditions, and optional forcing that define a simulation case (BOMEX, DYCOMS, RICO, Held–Suarez, …). See Setups.
- Preset — a one-line shortcut (
CA.Presets) that bundles a grid, setup, and model choices for a common configuration. - Driver —
.buildkite/ci_driver.jl, the standard entry point that builds and runs a simulation from a configuration. - Integrator — the time-stepping object that advances
Y; its.ufield is the current state vector. - IMEX time stepping — the implicit–explicit scheme used by default; the implicit part is handled by the Implicit Solver.
- ITime — the integer time type used for reproducible, exactly representable simulation times. See ITime.
- EDMF — the Eddy-Diffusivity Mass-Flux turbulence/convection scheme, in prognostic and diagnostic forms.
- Diagnostics — derived output variables, as opposed to the prognostic state
Y. See Computing and saving diagnostics and the catalog of available diagnostic variables.