Ocean-Atmos Sequential Coupling (preliminary plan)

[LenkaNovak]

End goal

• minimal coupling at ~1 deg resolution on meshes which have collocated nodes, done by June 2023

Streams

1. Two conformal cubed spheres (same mesh resolution) = minimal coupling as a proof of concept

Steps

• Atmos: rerun SWE, H-S and AMIP test cases
• Coupler:
  • parallel online remap O5.2.1 (coupler) Distributed unstructured sparse CPU & GPU matrix-vector multiply, supporting mixed precision #188
  • use TR to remap: RLL (oceananigans, TR) - equidistant CS
    • can be validated against xESMF (FV-FV) , see Explore xESMF #217 for more details.
  • Stagerring adapter: follow/use the xESMF example
  • extend TR for handling conformal cubed spheres (including super-halo exchange)
• Ocean: conformal cubed sphere implementation: Add ConformalCubedSphere grid via MultiRegion module Oceananigans.jl#2867

2. Two equiangular cubed spheres (ClimaCore + Oceananigans)

Steps

• Atmos: done (current implementation)
• Coupler: if staggered then need to extend TempestRemap-based regridding
• Ocean: implement equiangular cubed sphere in Oceananigans

3. Two equiangular cubed spheres (ClimaCore architecture also for ocean)

Steps

• Atmos: done (current implementation), but better if GPU capability is available
• Coupler: if staggered then need to extend the current TempestRemap-based regridding
• Ocean: implement equiangular cubed sphere

[LenkaNovak]

out of date. Now a milestone (https://github.com/CliMA/ClimaCoupler.jl/milestone/2)