Coupler interface planning (WIP)

[juliasloan25]

Brainstorming/ideas to work towards a clean coupling interface

Changes to make

• Add examples/ folder with stable, clean simulation setups
• Config file should be optional
  • Maintain support for it, but also add examples without it
  • Config can override default values - support init either way
• Specify space in ClimaCoupler drivers
  • boundary space or full space?
• Separate AMIP, slabplanet drivers
  • this will eliminate the need to store the mode type in the CoupledSimulation; it only informs the model initialization, then we should be able to step each model with the same interface after initialization
  • alternatively, dispatch off of config_ID flag type to control differences for slabplanet, AMIP, etc (e.g. have init_x, call_callbacks, etc function that works differently for each cases)
• Move prescribed data (CO2, SST, SIC) into relevant component models (atmos, ocean, sea ice) rather than having them as independent entities in CoupledSimulation.mode
  • only needs to be updated for AMIP (not slabplanet), so might be hard before driver split

Concrete To Dos

• Allow < 4 component models
• Go through existing component model adapter files
  • Can we use component model repo directly instead? E.g. remove ClimaAtmosSimulation type in coupler
  • Can we minimize code in these files?
• Clean up/segment run_amip.jl driver as planned
• Replace modename with config_ID

Questions

• Should coupler specify just the boundary (surface) space, or all spaces (above surface, surface, subsurface)? Either way, need consistency with topography
• Do we want to continue requiring 4 component models (atmos, ocean, land, ice), or allow 1 atmos + 1-3 surface models?
  • I think it's better to allow nothing for a surface model, rather than requiring it's defined and zeroing out the contributions/area fraction

Potential CoupledSimulation contents

CoupledSimulation
- models (atmos, ocean, land, seaice)
- clock (tspan, dt_cpl, time/iteration)
- space (exchange space)
- land/sea mask (think about resolution/space)
- callback
- diagnostics/output writers
- turbulent flux partition
- coupler exchange fields
- logging
- config ID
- job ID
- initialized/running flags
- preprocessing

With similar component Simulation objects