SeawaterBuoyancy_LinearEquationOfState

[phyo-wai-thaw]

Hi all,

I'm looking for a simple way to verify that the thermal expansion (α) and haline contraction (β) coefficients in the SeawaterBuoyancy model (linear equation of state) are working correctly. Specifically, I want to compare it with the simple calculation of buoyancy frequency (N²).

I would appreciate any suggestions or advice.

Thanks in advance!

[glwagner]

If you'd like to run a simulation and verify that the physics are correct, you could start by adapting the internal wave example:

https://github.com/CliMA/Oceananigans.jl/blob/main/examples/internal_wave.jl

[phyo-wai-thaw]

Thank @glwagner for your suggestion.
I am also wondering about the unit of the thermal expansion (α) coefficient which has shown as per Kelvin in Oceananigans.
I am using temperature in Celsius and α in per Celsius. Do I need the unit conversion for α in SeawaterBuoyancy?
Thanks again!

[glwagner]

Don't worry about that --- in this context, Celsius and Kelvin are identical (they represent the same scale and only differ in offset).

Another idea is to construct a simulation with a mode-1 wave. For what you're trying to do, you don't need the packet that is used in the internal wave example. To initialize a mode-1 wave, you need to change the initial conditions here:

Oceananigans.jl/examples/internal_wave.jl

Lines 105 to 109 in 3c9afd4

	u₀(x, z) = a(x, z) * k * ω / (ω^2 - f^2) * cos(k * x + m * z)
	v₀(x, z) = a(x, z) * k * f / (ω^2 - f^2) * sin(k * x + m * z)
	w₀(x, z) = a(x, z) * m * ω / (ω^2 - N^2) * cos(k * x + m * z)
	b₀(x, z) = a(x, z) * m * N^2 / (ω^2 - N^2) * sin(k * x + m * z)