OceanTurb.jl

How inappropriate to call this planet Earth when it is quite clearly Ocean.
Arthur C. Clark

OceanTurb.jl implements one-dimensional partial differential equations that model turbulent convection and diffusion in the ocean surface boundary layer. It's purpose is the exploration, development, and practical usage of ocean turbulence models.

In the scheme of things

Just beneath the surface of the ocean, atmospheric fluxes of energy, heat fresh water, salinity, and momentum due to wind, waves, precipitation, evaporation, heating, cooling, and radiation drive turbulence and mediate the exchange of quantities like heat, momentum, and carbon between the atmosphere and ocean interior. Models that approximate the effects of atmospheric forcing on turbulence and turbulent mixing in the upper ocean are critical components in ocean circulation models and coupled climate models.

Installation

Open julia, press ] at the Julian prompt to enter package manager mode, and type

pkg> add OceanTurb

Use help mode by typing ? to find information about key functions:

help?> iterate!

which should give the information

OceanTurb.iterate! — Function.

iterate!(model; Δt, Nt)

Step model forward in time for Nt steps with step size Δt.

source

Step forward m by Δt with the backward Euler method.

source

Modules and models

Solvers for various turbulence models are implemented in submodules of OceanTurb.jl. For example, our simplest module solves the 1D diffusion equation. A diffusion Model is instantiated by writing

using OceanTurb

# 100-grid point model with height 1.0 and diffusivity 0.01.
model = Diffusion.Model(grid = UniformGrid(N=100, L=1.0), parameters = Parameters(K=0.01))

Setting an initial condition is done by writing

c₀(z) = exp(-(z + 0.5)^2 / 0.005)
model.solution.c = c₀

Time stepping a model forward looks like

iterate!(model, Δt=0.01, Nt=100)

This example, and more, can be found in the /examples directory.

In addition to simple diffusion we have models for

The K-Profile-Parameterization proposed by Large et al (1994)
A 'modular', and therefore generic, $K$-profile parameterization that has multiple models for diffusivity, diffusivity shapes and profiles, nonlocal fluxes including a diagnostic plume model, and mixing depth.
The Pacanowski-Philander parameterization

Authors

The author of this software is Gregory L. Wagner.