Equations of motions

Continuous form

Boussinesq, adiabatic, hydrostatic and nonlinear shallow water equations for conservation of momentum:

\[\partial_t \mathbf{u}_n(x,y) + (\zeta_n + f) \mathbf{k}\times\mathbf{u}_n = -\nabla \Big \{ M_n + \frac{1}{2} |\mathbf{u}_n|^2 + g \Pi \Big \} + \mathbf{H}_n + \mathbf{V}_n\]

for \(n=0,\cdots N-1\) and where \(f\) is the Coriolis frequency and \(\zeta_n = \mathbf{k}\cdot (\nabla \times \mathbf{u}_n )\) is the relative vorticity, \(M_n\) is the perturbation Montgomery potential. The latter is given by:

\[ \begin{align}\begin{aligned}z_0 &= \eta\\z_n &= z_{n-1} - h_n, n > 0\end{aligned}\end{align} \]
\[ \begin{align}\begin{aligned}M_0 &= g \eta\\M_n &= M_{n-1} + g (\rho_{n}-\rho_{n-1})/\rho_n \times z_{n-1}, n>0\end{aligned}\end{align} \]
\[p_n(x,y,z) = \rho_n M_n(x,y) - g \rho_n z\]

Thickness tendency equations:

\[\partial_t h_n(x,y) + \nabla \cdot (\mathbf{u}_n h_n ) = 0.\]
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References: …

Spectral discretization

Temporal discretization

AB or RK for now, time splitting latter

Hallberg09, Vitousek14

QG formulation