CloudMicrophysics.jl

CloudMicrophysics.jl provides a library of cloud microphysics and aerosol parameterizations for the CliMA Earth System Model. It implements bulk microphysics schemes for cloud formation, precipitation, and aerosol processes, designed for high-performance climate simulations.

Features

Bulk Microphysics Schemes

• 0-moment scheme: Simple precipitation removal
• 1-moment scheme: Marshall-Palmer distributions for rain and snow
• 2-moment scheme: Seifert & Beheng (2006) with mass and number concentration
• P3 scheme: Morrison & Milbrandt (2015) predicted particle properties for ice

Ice Nucleation

• Heterogeneous nucleation: Deposition, immersion freezing (ABIFM)
• Homogeneous nucleation: Koop et al. (2000) parameterization
• INP distributions: Frostenberg et al. (2023)

Aerosol Processes

• Aerosol activation: Abdul-Razzak & Ghan (2000) parameterization
• Aerosol nucleation: H₂SO₄ and organic nucleation pathways
• Aerosol model: Modal distributions with κ-Köhler theory

High Performance

• Type-stable and GPU-compatible (CUDA.jl, AMDGPU.jl)
• AD-compatible (ForwardDiff.jl) for differentiable physics
• Optimized for minimal allocations

Installation

using Pkg
Pkg.add("CloudMicrophysics")
Pkg.add("ClimaParams")

Quick Example

import CloudMicrophysics.Microphysics1M as CM1
import CloudMicrophysics.Parameters as CMP

# Create microphysics parameters
rain = CMP.Rain(Float64)
vel = CMP.Blk1MVelType(Float64).rain

# Compute rain terminal velocity
ρ = 1.2      # air density [kg/m³]
q_rai = 1e-3 # rain specific content [kg/kg]
v_term = CM1.terminal_velocity(rain, vel, ρ, q_rai)

Documentation

• Getting Started - Installation and first steps
• API Reference - Detailed function documentation
• Microphysics Schemes - Scheme descriptions

Integration with Climate Models

CloudMicrophysics.jl is used throughout the CliMA ecosystem:

• ClimaAtmos - Atmospheric model
• KinematicDriver - 1D/2D kinematic framework
• Thermodynamics - Moist thermodynamics

Contributing

Contributions are welcome. See the Developer's Guide and AGENTS.md, which points to the shared CliMA developer guides in docs/dev-guides/.

To run the test suite locally:

julia --project=test
julia>]
pkg> dev .
pkg> instantiate
julia> include("test/runtests.jl")

For questions, check the documentation or open an issue on GitHub.