Welcome to JAX-GCM’s documentation!

JAX-GCM is a differentiable atmospheric general circulation model written in JAX. Its pluggable dynamical-core interface currently ships with the Dinosaur spectral backend and couples it to modular SPEEDY, Held-Suarez, and ECHAM-style physics packages.

For the v2.0 release line, the main target configuration is ECHAM physics on the T63L47 hybrid grid with RRTMGP radiation (physics=echam-rrtmgp grid=echam_t63_l47_hybrid). The SPEEDY package remains the lightweight default for quick tests, tutorials, and optimization examples.

Note

New development targets the dev branch. Tagged release candidates and clean releases are promoted through main.

Contents

Contents:

• Getting Started
  • Installation
  • Command-line interface
  • Quick Start Examples
  • Calendar-aware durations and resampling
  • Long forcing time-series and chunked runs
  • Checkpointing for preemptible runs
  • Nudging the model toward an external state
  • Multi-Device Parallelization
  • Analyzing Output
  • Overriding physical constants
  • Next Steps
• SPEEDY Physics Package
  • Overview
  • Physics Parameterizations
  • Forcing and Boundary Conditions
  • Using Custom Parameters
  • Composable Physics API
  • Scientific References
  • Assumptions and Limitations
  • Performance Characteristics
  • Comparison with Other Physics Packages
  • Next Steps
• ECHAM Physics Package
  • Overview
  • Physics Parameterizations
  • Forcing and Boundary Conditions
  • Using Custom Parameters
  • Composable Physics API
  • Scientific References
  • Assumptions and Limitations
  • Comparison with SPEEDY Physics
  • Next Steps
• Release Notes
  • v2.0.0b1
• v1 to v2 Migration Guide
  • Install the Beta
  • Model Construction
  • Output Conversion
  • Composable Physics
  • Forcing and Calendars
  • Physical Constants
• Speedy Variable Translation
  • Condensation
  • Convection
  • Date
  • Humidity
  • Land_model
  • Longwave_rad
  • Mod_radcon
  • Shortwave_rad
  • Surface_flux
• API
  • jcm.model
  • jcm.model.Model
  • jcm.dycore
  • jcm.dycore.base.DynamicalCore
  • jcm.dycore.dinosaur.DinosaurDycore
  • jcm.physics_interface
  • jcm.physics_interface.PhysicsState
  • jcm.physics_interface.PhysicsTendency
  • jcm.physics_interface.Physics
  • jcm.checkpoint
• Architecture & Design
  • Composable physics
  • Operator-split physics
  • Writing a Physics Scheme
  • Core Architecture
  • Design Principles
  • Ease of Use
  • Code Quality
  • Physics Directory Organization
  • Future Directions
• Developer Guide
  • Contributing to JAX-GCM
  • Development Tips
  • Communication