| 133 | 
 \begin{eqnarray} | 
 \begin{eqnarray} | 
| 134 | 
 \label{EQ:model_equations} | 
 \label{EQ:model_equations} | 
| 135 | 
 \frac{Du}{Dt} - fv +  | 
 \frac{Du}{Dt} - fv +  | 
| 136 | 
   \frac{1}{\rho}\frac{\partial p^{'}}{\partial \lambda} -  | 
   \frac{1}{\rho}\frac{\partial p^{\prime}}{\partial \lambda} -  | 
| 137 | 
   A_{h}\nabla_{h}^2u - A_{z}\frac{\partial^{2}u}{\partial z^{2}}  | 
   A_{h}\nabla_{h}^2u - A_{z}\frac{\partial^{2}u}{\partial z^{2}}  | 
| 138 | 
 & = & | 
 & = & | 
| 139 | 
 \cal{F} | 
 \cal{F} | 
| 140 | 
 \\ | 
 \\ | 
| 141 | 
 \frac{Dv}{Dt} + fu +  | 
 \frac{Dv}{Dt} + fu +  | 
| 142 | 
   \frac{1}{\rho}\frac{\partial p^{'}}{\partial \varphi} -  | 
   \frac{1}{\rho}\frac{\partial p^{\prime}}{\partial \varphi} -  | 
| 143 | 
   A_{h}\nabla_{h}^2v - A_{z}\frac{\partial^{2}v}{\partial z^{2}}  | 
   A_{h}\nabla_{h}^2v - A_{z}\frac{\partial^{2}v}{\partial z^{2}}  | 
| 144 | 
 & = & | 
 & = & | 
| 145 | 
 0 | 
 0 | 
| 154 | 
 & = & | 
 & = & | 
| 155 | 
 0 | 
 0 | 
| 156 | 
 \\ | 
 \\ | 
| 157 | 
 p^{'} & = & | 
 p^{\prime} & = & | 
| 158 | 
 g\rho_{0} \eta + \int^{0}_{-z}\rho^{'} dz | 
 g\rho_{0} \eta + \int^{0}_{-z}\rho^{\prime} dz | 
| 159 | 
 \\ | 
 \\ | 
| 160 | 
 \rho^{'} & = &- \alpha_{\theta}\rho_{0}\theta^{'} | 
 \rho^{\prime} & = &- \alpha_{\theta}\rho_{0}\theta^{\prime} | 
| 161 | 
 \\ | 
 \\ | 
| 162 | 
 {\cal F} |_{s} & = & \frac{\tau_{x}}{\rho_{0}\Delta z_{s}} | 
 {\cal F} |_{s} & = & \frac{\tau_{x}}{\rho_{0}\Delta z_{s}} | 
| 163 | 
 \\ | 
 \\ | 
| 166 | 
  | 
  | 
| 167 | 
 \noindent where $u$ and $v$ are the components of the horizontal | 
 \noindent where $u$ and $v$ are the components of the horizontal | 
| 168 | 
 flow vector $\vec{u}$ on the sphere ($u=\dot{\lambda},v=\dot{\varphi}$). | 
 flow vector $\vec{u}$ on the sphere ($u=\dot{\lambda},v=\dot{\varphi}$). | 
| 169 | 
  | 
 The terms $H\hat{u}$ and $H\hat{v}$ are the components of the term | 
| 170 | 
  | 
 integrated in eqaution \ref{eq:free-surface}, as descirbed in section | 
| 171 | 
  | 
  | 
| 172 | 
 The suffices ${s},{i}$ indicate surface and interior of the domain. | 
 The suffices ${s},{i}$ indicate surface and interior of the domain. | 
| 173 | 
 The forcing $\cal F$ is only applied at the surface. | 
 The forcing $\cal F$ is only applied at the surface. | 
| 174 | 
 The pressure field $p^{'}$ is separated into a barotropic part | 
 The pressure field, $p^{\prime}$, is separated into a barotropic part | 
| 175 | 
 due to variations in sea-surface height, $\eta$, and a hydrostatic | 
 due to variations in sea-surface height, $\eta$, and a hydrostatic | 
| 176 | 
 part due to variations in density, $\rho^{'}$, over the water column. | 
 part due to variations in density, $\rho^{\prime}$, over the water column. | 
| 177 | 
  | 
  | 
| 178 | 
 \subsection{Discrete Numerical Configuration} | 
 \subsection{Discrete Numerical Configuration} | 
| 179 | 
  | 
  | 
| 182 | 
  $\Delta \lambda=\Delta \varphi=1^{\circ}$, so  | 
  $\Delta \lambda=\Delta \varphi=1^{\circ}$, so  | 
| 183 | 
 that there are sixty grid cells in the zonal and meridional directions.  | 
 that there are sixty grid cells in the zonal and meridional directions.  | 
| 184 | 
 Vertically the  | 
 Vertically the  | 
| 185 | 
 model is configured with a four layers with constant depth,  | 
 model is configured with four layers with constant depth,  | 
| 186 | 
 $\Delta z$, of $500$~m. The internal, locally orthogonal, model coordinate  | 
 $\Delta z$, of $500$~m. The internal, locally orthogonal, model coordinate  | 
| 187 | 
 variables $x$ and $y$ are initialised from the values of | 
 variables $x$ and $y$ are initialised from the values of | 
| 188 | 
 $\lambda$, $\varphi$, $\Delta \lambda$ and $\Delta \varphi$ in | 
 $\lambda$, $\varphi$, $\Delta \lambda$ and $\Delta \varphi$ in |