The Climate Modeling Alliance

Software Design Issue 📜

Implement SingleColumnModel interfaces required for ClimaEarth prototype (1 dt), use BOMEX and ClimaOcean SCM as examples. Goal: completes sim.

Purpose

We need to demonstrate the simplest case for coupling the Clima component models, namely ClimaAtmos and ClimaOcean. This issue focuses on interfaces only (few timesteps using the Single column models suffices).

More details to follow.

Cost/Benefits/Risks

People and Personnel

• Lead: @glwagner
• Collaborators: @LenkaNovak @juliasloan25

Components

1. Illustrate how to set up the atmos and ocean columns (height, number of grid points, variable grid spacing).
2. Illustrate how to change shared parameters via ClimaParams.
3. Illustrate how to configure the physics of the single column models (configure turbulence parameterizations, Coriolis forces, etc).
4. Take a few time steps, showing that fluxes are computed and exchanged correctly, and illustrating how to inspect the solution (probably using callbacks).

Inputs

Results and Deliverables

• Documentation detailing functions and showing how to run simulation
• Driver that runs coupled atmos/ocean simulation and produces animation

Task Breakdown And Schedule

• Merge CliMA/ClimaAtmos.jl#2855
• Add SingleColumnAtmosOceanModel example #5

SDI Revision Log

CC

@tapios @simonbyrne @cmbengue

(WIP)

The Climate Modeling Alliance

Software Design Issue 📜

Purpose

Showcase a new design for coupling ClimaOcean and ClimaCore-based models. The current ClimaCoupler assumes ClimaCore-based underlying objects, whereas ClimaOcean assumes Oceananigans-based objects, making the two difficult to communicate with each other. With this effort we aim to

• unify the interfaces required to couple a component model to ClimaEarth, where the simulation will be setup
• present a prototype as the basis for CMIP (on which we can iterate based on feedback)

Cost/Benefits/Risks

• b: implements minimal features for ocean/atmosphere coupling
• r: reasonable time investment

People and Personnel

• Lead: @glwagner
• Collaborators: @juliasloan25 @LenkaNovak
• Reviewers:

Components

• ClimaEarth.jl
  • Abstract Simulations from Oceananigans and generalize for use by other models
  • Coupler functionality (for prototyping, keep here, and later will likely be moved to out)
    • regridding
      • stagerring (use Oceananigans)
      • FV-FE (Cartesian available in ClimaCore)
    • masking and area fractions (perhaps not needed here?)
    • prescribed data readers (perhaps not needed here?)
    • flux calculation (NB: flux calculation outside of Atmos only really makes sense for one-timestep coupling)
    • flux accumulation
    • global checks
      • conservation checks: energy, water, mass, momentum
    • performance metrics
    • I/O readers/writers (checkpoints, restarts, diagnostics)
• Atmosphere: a simple dry HeldSuarez that mimics the role of ClimaAmtos
• Ocean: ClimaOcean model setup using ClimaEarth Simulations

Inputs

• ClimaCore HeldSuarez example
• Oceananigans exmaple
• ClimaCoupler functionality in src
• generalised interface for flux exchange (using ideas from
  CliMA/ClimaCoupler.jl#211 and DoubleTrouble.jl)

Results and Deliverables

• Simulations in ClimaEarth.jl (QA: oceananigans runs as before)
• ClimaHeldSuarez with tracers and Simulations interface (QA: same output as the example in ClimaCore)
• Coupling prototype of the in a rectangular domain (QA: conservation and visual checks match)
• Detailed CMIP Roadmap (QA: approved by higher management)

Task Breakdown And Schedule

• ClimaHeldSuarez.jl

  • migrate ClimaCore example to ClimaHeldSuarez.jl and ensure it runs
  • implement ClimaHeldSuarezModel compatible with Simulations
  • write a CoupedModelComponent method dispatched AtmosModel

• Oceananigans.jl / ClimaOcean.jl

  • Simulation refactor (move implementation to front of Oceananigans)
  • Modify Simulation creation process to use ClimaEarth
  • Develop ocean setup ready for coupling in ClimaOcean
  • write a CoupedModelComponent method dispatched on OceanModel

• ClimaEarth.jl

  • Setup CoupedModel, CoupedModelComponent, ... interface
  • Setup regridding (staggering in Oceananigans, FV-SE in ClimaCore)
  • Develop EarthSystemModel coupling ClimaOcean.jl and ClimaHeldSuarez.jl
  • conservation checks
  • Migrate Simulations from Oceananigans
  • I/O + simple diagnostics

SDI Revision Log

CC

@tapios @simonbyrne @cmbengue