ShallowWaters.jl - A type-flexible 16-bit shallow water model

A shallow water model with a focus on type-flexibility and 16-bit number formats. ShallowWaters allows for Float64/32/16, Posit32/16/8, BFloat16, LogFixPoint16, Sonum16, Float32/16 & BFloat16 with stochastic rounding and in general every number format with arithmetics and conversions implemented. ShallowWaters also allows for mixed-precision and reduced precision communication.

ShallowWaters uses an energy and enstrophy conserving advection scheme and a Smagorinsky-like biharmonic diffusion operator. Tracer advection is implemented with a semi-Lagrangian advection scheme. Strong stability-preserving Runge-Kutta schemes of various orders and stages are used with a semi-implicit treatment of the continuity equation. Boundary conditions are either periodic (only in x direction) or non-periodic super-slip, free-slip, partial-slip, or no-slip. Output via NetCDF.

Please feel free to raise an issue if you discover bugs or have an idea how to improve ShallowWaters.

Requires: Julia 1.2 or higher

How to use

julia> using ShallowWaters
julia> run_model()
Starting ShallowWaters on Thu, 20 Jan 2022 15:44:30 without output.
100% Integration done in 0.61s.

You just successfully ran ShallowWaters.jl! For more examples and arguments to pass on to run_model see the documentation.

Installation

ShallowWaters.jl is a registered package, so simply do

julia> ] add ShallowWaters

References

ShallowWaters.jl was used and is described in more detail in

[1] Klöwer M, PD Düben, and TN Palmer, 2020. Number formats, error mitigation and scope for 16-bit arithmetics in weather and climate modelling analysed with a shallow water model. Journal of Advances in Modeling Earth Systems, 10.1029/2020MS002246

[2] Klöwer M, PD Düben, and TN Palmer, 2019. Posits as an alternative to floats for weather and climate models. In: Proceedings of the Conference for Next Generation Arithmetic 2019, Singapore, ACM, 10.1145/3316279.3316281

If you use this package please cite us.