Oceananigans.jl

Main features:

• Multiple turbulence closures per tracer (#517)
• Anisotropic biharmonic diffusivity closure (#518)
• Craik-Leibovich terms and surface waves effects (#519)
• BoundaryFunction wrapper for simple boundary condition functions (#513)
• Start splitting code into submodules (#512)

What's new

• Velocity field is now divergence-free to machine precision during time stepping. #161 #228 #229
• Fixed bug in how the Coriolis term was calculated. #215 @jm-c
• Internal wave test and example. #229 @glwagner
• Incompressibility test #226
• Analytic solution reconstruction test for Poisson solver. #227
• Adapted BoundaryConditions with AbstractArray to play nice with CUDA.
• Coriolis parameter can be set via latitude.
• Planetary constants for Europa and Enceladus.

What's new

• Updated versions of CUDA dependencies.
• Free convection, wind stress, and mixed layer seasonal cycle examples.
• Added actual CPU and GPU examples to README and documentation.
• Updated 3D contourf plotting script to also plot vertical profile diagnostics.
• New wind stress and free convection with wind stress movies.
• Added performance benchmark plots in README.
• Added development team section to README.

What's new

• Model is ~5x faster! Buoyancy update kernel was taking quadratic time when it should have been linear. #169 #172
• NaN checker diagnostic. #38 #170
• Oceananigans.jl is a real package now! #142

Updating packages for CI and updating package version/UUID for attobot.

Tons of improvements! We need more frequent releases.

What's new

• Parameterized abstractions that work on CPU and GPU architectures.
• Flashy boundary conditions API. @glwagner
• Fourth-order tracer advection scheme. @mukund-gupta
• Much faster GPU compile times thanks to fixes in CUDAnative.jl and GPUifyLoops.jl
• Arbitrary forcing functions.
• Diagnostics framework.
• Output writer framework: checkpointer, binary output, and NetCDF output.
• Model checkpointing with JLD.
• Asynchronous NetCDF output.
• Many new tests including new unit tests, new integration tests, and two golden master tests.
• Many tests now run on the CPU and GPU.
• Performance benchmarking with CPU/GPU and Float32/64 comparisons.
• Renamed "spectral solver" to "Poisson solver".
• Revised and updated examples.
• LOTS of cleanup and refactoring to make things look neater.
• Documentation that is automatically built and deployed!

Features

• Operators were rewritten to act on individual volume elements (i.e. element-wise) which allowed the time stepping loop to be rewritten to loop over all volume elements and generically run on CPU and GPU architectures using GPUifyLoops.jl.

Sad "features"

• Lots of other things happened as well but we need to write a lot more tests (especially for the GPU), update the documentation, clean up the code, nuke crusty old code, etc. but that's for v0.5!

Features

• Main struct is now the Model instead of the Problem. It should be neater too.
• Support for no-slip boundary conditions at the top and bottom.
• Boundary condition information stored in a BoundaryConditions struct.
• Abstract output writer (checkpoints and writing fields to disk) and diagnostics framework.
• ModelMetadata struct to store architecture (e.g. :cpu or :gpu) and floating point number precision.
• ModelConfiguration struct to store physical parameters such as viscosity and diffusivity.
• Clock struct keeps track of time, time step number, and Δt.
• Refactored δ! and avg! operators to use @views @. so they work on CPUs and GPUs.
• GPU-compatible DFT! and IDFT! operators based on FFT! and IFFT! operations.
• Super hacky and very slow GPU support (but it works out of the box!). This will be overhauled ASAP.
• Support for 1D vertical models.
• More examples: stratified deep convection, Rayleigh–Bénard convection, 1D vertical.

Main bug fixes

• Added in Coriolis term for u and v-momentum equations (important for 3D simulations). https://github.com/ali-ramadhan/Oceananigans.jl/commit/1b07df1964a53661298ad721aef3896d60a0277d
• Fixed typo in u∇w! operator causing blowup in some 2D simulations (Ay and Az were mixed up). https://github.com/ali-ramadhan/Oceananigans.jl/commit/d7326c8cc75e058d5e3fbc672c0b303d0cd0ee35

• High-level abstractions for the grid, fields, field sets, constant collections, equation of state, and spectral solver parameters.
• Model code has been refactored so that all operators now modify the fields in place and no memory allocation occurs during time stepping.
• FFTs and DCTs are planned at the start so the quasi-spectral solver can do its work faster.
• Code works in 2D (vertical slices with Nx=1 or Ny=1, and horizontal slices with Nz=1).
• Many more unit tests.
• Examples: isotropic diffusion, horizontal advection, deep convection and Rayleigh-Taylor instability.

• Ocean model works!
• Nonhydrostatic algorithm including quasi-spectral solver work and do not blow the model up!
• Numerous examples run as expected in 2D and 3D.
• More tests need to be run, and the code needs to be cleaned up.