Install ClimaCore

ClimaCore.jl is a registered Julia package and requires Julia 1.10 or later. juliaup installs and updates Julia.

Install the registered release

In a Julia session, from the project environment you want to use:

using Pkg
Pkg.add("ClimaCore")

Install the development version

The main branch carries changes that have not been released:

using Pkg
Pkg.add(url = "https://github.com/CliMA/ClimaCore.jl", rev = "main")

Run the test suite

using Pkg
Pkg.test("ClimaCore")

The suite runs for a long time on a laptop; see test/runtests.jl for how to select a subset.

Enable GPU or MPI backends

ClimaCore reads its compute device and communication context from ClimaComms.jl, which loads CUDA.jl and MPI.jl on demand. Add the backend packages to your default environment once, then select them per run with environment variables:

CLIMACOMMS_DEVICE=CUDA julia --project script.jl
CLIMACOMMS_CONTEXT=MPI mpiexec -n 4 julia --project script.jl

Every script that should honor these variables starts with

import ClimaComms
ClimaComms.@import_required_backends

The ClimaComms how-to guides describe the environment variables and backend loading; the shared developer guide running_on_gpu.md covers first-time machine setup, including CUDA driver and runtime compatibility.