| 14 | %\end{center} | %\end{center} | 
| 15 |  |  | 
| 16 | \section[Barotropic Gyre MITgcm Example]{Barotropic Ocean Gyre In Cartesian Coordinates} | \section[Barotropic Gyre MITgcm Example]{Barotropic Ocean Gyre In Cartesian Coordinates} | 
| 17 | \label{www:tutorials} | %\label{www:tutorials} | 
| 18 | \label{sect:eg-baro} | \label{sec:eg-baro} | 
| 19 | \begin{rawhtml} | \begin{rawhtml} | 
| 20 | <!-- CMIREDIR:eg-baro: --> | <!-- CMIREDIR:eg-baro: --> | 
| 21 | \end{rawhtml} | \end{rawhtml} | 
| 39 | equation | equation | 
| 40 |  |  | 
| 41 | \begin{equation} | \begin{equation} | 
| 42 | \label{EQ:eg-baro-fcori} | \label{eq:eg-baro-fcori} | 
| 43 | f(y) = f_{0}+\beta y | f(y) = f_{0}+\beta y | 
| 44 | \end{equation} | \end{equation} | 
| 45 |  |  | 
| 46 | \noindent where $y$ is the distance along the ``north-south'' axis of the | \noindent where $y$ is the distance along the ``north-south'' axis of the | 
| 47 | simulated domain. For this experiment $f_{0}$ is set to $10^{-4}s^{-1}$ in | simulated domain. For this experiment $f_{0}$ is set to $10^{-4}s^{-1}$ in | 
| 48 | (\ref{EQ:eg-baro-fcori}) and $\beta = 10^{-11}s^{-1}m^{-1}$. | (\ref{eq:eg-baro-fcori}) and $\beta = 10^{-11}s^{-1}m^{-1}$. | 
| 49 | \\ | \\ | 
| 50 | \\ | \\ | 
| 51 | The sinusoidal wind-stress variations are defined according to | The sinusoidal wind-stress variations are defined according to | 
| 52 |  |  | 
| 53 | \begin{equation} | \begin{equation} | 
| 54 | \label{EQ:eg-baro-taux} | \label{eq:eg-baro-taux} | 
| 55 | \tau_x(y) = \tau_{0}\sin(\pi \frac{y}{L_y}) | \tau_x(y) = \tau_{0}\sin(\pi \frac{y}{L_y}) | 
| 56 | \end{equation} | \end{equation} | 
| 57 |  |  | 
| 59 | $\tau_0$ is set to $0.1N m^{-2}$. | $\tau_0$ is set to $0.1N m^{-2}$. | 
| 60 | \\ | \\ | 
| 61 | \\ | \\ | 
| 62 | Figure \ref{FIG:eg-baro-simulation_config} | Figure \ref{fig:eg-baro-simulation_config} | 
| 63 | summarizes the configuration simulated. | summarizes the configuration simulated. | 
| 64 |  |  | 
| 65 | %% === eh3 === | %% === eh3 === | 
| 76 | \caption{Schematic of simulation domain and wind-stress forcing function | \caption{Schematic of simulation domain and wind-stress forcing function | 
| 77 | for barotropic gyre numerical experiment. The domain is enclosed bu solid | for barotropic gyre numerical experiment. The domain is enclosed bu solid | 
| 78 | walls at $x=$~0,1200km and at $y=$~0,1200km.} | walls at $x=$~0,1200km and at $y=$~0,1200km.} | 
| 79 | \label{FIG:eg-baro-simulation_config} | \label{fig:eg-baro-simulation_config} | 
| 80 | \end{figure} | \end{figure} | 
| 81 |  |  | 
| 82 | \subsection{Equations Solved} | \subsection{Equations Solved} | 
| 83 | \label{www:tutorials} | %\label{www:tutorials} | 
| 84 | The model is configured in hydrostatic form. The implicit free surface form of the | The model is configured in hydrostatic form. The implicit free surface form of the | 
| 85 | pressure equation described in Marshall et. al \cite{marshall:97a} is | pressure equation described in Marshall et. al \cite{marshall:97a} is | 
| 86 | employed. | employed. | 
| 88 | dissipation. The wind-stress momentum input is added to the momentum equation | dissipation. The wind-stress momentum input is added to the momentum equation | 
| 89 | for the ``zonal flow'', $u$. Other terms in the model | for the ``zonal flow'', $u$. Other terms in the model | 
| 90 | are explicitly switched off for this experiment configuration (see section | are explicitly switched off for this experiment configuration (see section | 
| 91 | \ref{SEC:code_config} ), yielding an active set of equations solved in this | \ref{sec:eg-baro-code_config} ), yielding an active set of equations solved | 
| 92 | configuration as follows | in this configuration as follows | 
| 93 |  |  | 
| 94 | \begin{eqnarray} | \begin{eqnarray} | 
| 95 | \label{EQ:eg-baro-model_equations} | \label{eq:eg-baro-model_equations} | 
| 96 | \frac{Du}{Dt} - fv + | \frac{Du}{Dt} - fv + | 
| 97 | g\frac{\partial \eta}{\partial x} - | g\frac{\partial \eta}{\partial x} - | 
| 98 | A_{h}\nabla_{h}^2u | A_{h}\nabla_{h}^2u | 
| 115 |  |  | 
| 116 |  |  | 
| 117 | \subsection{Discrete Numerical Configuration} | \subsection{Discrete Numerical Configuration} | 
| 118 | \label{www:tutorials} | %\label{www:tutorials} | 
| 119 |  |  | 
| 120 | The domain is discretised with | The domain is discretised with | 
| 121 | a uniform grid spacing in the horizontal set to | a uniform grid spacing in the horizontal set to | 
| 124 | model is configured with a single layer with depth, $\Delta z$, of $5000$~m. | model is configured with a single layer with depth, $\Delta z$, of $5000$~m. | 
| 125 |  |  | 
| 126 | \subsubsection{Numerical Stability Criteria} | \subsubsection{Numerical Stability Criteria} | 
| 127 | \label{www:tutorials} | %\label{www:tutorials} | 
| 128 |  |  | 
| 129 | The Laplacian dissipation coefficient, $A_{h}$, is set to $400 m s^{-1}$. | The Laplacian dissipation coefficient, $A_{h}$, is set to $400 m s^{-1}$. | 
| 130 | This value is chosen to yield a Munk layer width \cite{adcroft:95}, | This value is chosen to yield a Munk layer width \cite{adcroft:95}, | 
| 131 |  |  | 
| 132 | \begin{eqnarray} | \begin{eqnarray} | 
| 133 | \label{EQ:eg-baro-munk_layer} | \label{eq:eg-baro-munk_layer} | 
| 134 | M_{w} = \pi ( \frac { A_{h} }{ \beta } )^{\frac{1}{3}} | M_{w} = \pi ( \frac { A_{h} }{ \beta } )^{\frac{1}{3}} | 
| 135 | \end{eqnarray} | \end{eqnarray} | 
| 136 |  |  | 
| 146 |  |  | 
| 147 |  |  | 
| 148 | \begin{eqnarray} | \begin{eqnarray} | 
| 149 | \label{EQ:eg-baro-laplacian_stability} | \label{eq:eg-baro-laplacian_stability} | 
| 150 | S_{l} = 4 \frac{A_{h} \delta t}{{\Delta x}^2} | S_{l} = 4 \frac{A_{h} \delta t}{{\Delta x}^2} | 
| 151 | \end{eqnarray} | \end{eqnarray} | 
| 152 |  |  | 
| 158 | \cite{adcroft:95} | \cite{adcroft:95} | 
| 159 |  |  | 
| 160 | \begin{eqnarray} | \begin{eqnarray} | 
| 161 | \label{EQ:eg-baro-inertial_stability} | \label{eq:eg-baro-inertial_stability} | 
| 162 | S_{i} = f^{2} {\delta t}^2 | S_{i} = f^{2} {\delta t}^2 | 
| 163 | \end{eqnarray} | \end{eqnarray} | 
| 164 |  |  | 
| 170 | horizontal flow speed of $ | \vec{u} | = 2 ms^{-1}$ | horizontal flow speed of $ | \vec{u} | = 2 ms^{-1}$ | 
| 171 |  |  | 
| 172 | \begin{eqnarray} | \begin{eqnarray} | 
| 173 | \label{EQ:eg-baro-cfl_stability} | \label{eq:eg-baro-cfl_stability} | 
| 174 | S_{a} = \frac{| \vec{u} | \delta t}{ \Delta x} | S_{a} = \frac{| \vec{u} | \delta t}{ \Delta x} | 
| 175 | \end{eqnarray} | \end{eqnarray} | 
| 176 |  |  | 
| 178 | of 0.5 and limits $\delta t$ to $1200s$. | of 0.5 and limits $\delta t$ to $1200s$. | 
| 179 |  |  | 
| 180 | \subsection{Code Configuration} | \subsection{Code Configuration} | 
| 181 | \label{www:tutorials} | %\label{www:tutorials} | 
| 182 | \label{SEC:eg-baro-code_config} | \label{sec:eg-baro-code_config} | 
| 183 |  |  | 
| 184 | The model configuration for this experiment resides under the | The model configuration for this experiment resides under the | 
| 185 | directory {\it verification/tutorial\_barotropic\_gyre/}. | directory {\it verification/tutorial\_barotropic\_gyre/}. | 
| 199 | to these files associated with this experiment. | to these files associated with this experiment. | 
| 200 |  |  | 
| 201 | \subsubsection{File {\it input/data}} | \subsubsection{File {\it input/data}} | 
| 202 | \label{www:tutorials} | %\label{www:tutorials} | 
| 203 |  |  | 
| 204 | This file, reproduced completely below, specifies the main parameters | This file, reproduced completely below, specifies the main parameters | 
| 205 | for the experiment. The parameters that are significant for this configuration | for the experiment. The parameters that are significant for this configuration | 
| 311 | \end{small} | \end{small} | 
| 312 |  |  | 
| 313 | \subsubsection{File {\it input/data.pkg}} | \subsubsection{File {\it input/data.pkg}} | 
| 314 | \label{www:tutorials} | %\label{www:tutorials} | 
| 315 |  |  | 
| 316 | This file uses standard default values and does not contain | This file uses standard default values and does not contain | 
| 317 | customizations for this experiment. | customizations for this experiment. | 
| 318 |  |  | 
| 319 | \subsubsection{File {\it input/eedata}} | \subsubsection{File {\it input/eedata}} | 
| 320 | \label{www:tutorials} | %\label{www:tutorials} | 
| 321 |  |  | 
| 322 | This file uses standard default values and does not contain | This file uses standard default values and does not contain | 
| 323 | customizations for this experiment. | customizations for this experiment. | 
| 324 |  |  | 
| 325 | \subsubsection{File {\it input/windx.sin\_y}} | \subsubsection{File {\it input/windx.sin\_y}} | 
| 326 | \label{www:tutorials} | %\label{www:tutorials} | 
| 327 |  |  | 
| 328 | The {\it input/windx.sin\_y} file specifies a two-dimensional ($x,y$) | The {\it input/windx.sin\_y} file specifies a two-dimensional ($x,y$) | 
| 329 | map of wind stress ,$\tau_{x}$, values. The units used are $Nm^{-2}$. | map of wind stress ,$\tau_{x}$, values. The units used are $Nm^{-2}$. | 
| 334 | code for creating the {\it input/windx.sin\_y} file. | code for creating the {\it input/windx.sin\_y} file. | 
| 335 |  |  | 
| 336 | \subsubsection{File {\it input/topog.box}} | \subsubsection{File {\it input/topog.box}} | 
| 337 | \label{www:tutorials} | %\label{www:tutorials} | 
| 338 |  |  | 
| 339 |  |  | 
| 340 | The {\it input/topog.box} file specifies a two-dimensional ($x,y$) | The {\it input/topog.box} file specifies a two-dimensional ($x,y$) | 
| 346 | code for creating the {\it input/topog.box} file. | code for creating the {\it input/topog.box} file. | 
| 347 |  |  | 
| 348 | \subsubsection{File {\it code/SIZE.h}} | \subsubsection{File {\it code/SIZE.h}} | 
| 349 | \label{www:tutorials} | %\label{www:tutorials} | 
| 350 |  |  | 
| 351 | Two lines are customized in this file for the current experiment | Two lines are customized in this file for the current experiment | 
| 352 |  |  | 
| 369 | \end{small} | \end{small} | 
| 370 |  |  | 
| 371 | \subsubsection{File {\it code/CPP\_OPTIONS.h}} | \subsubsection{File {\it code/CPP\_OPTIONS.h}} | 
| 372 | \label{www:tutorials} | %\label{www:tutorials} | 
| 373 |  |  | 
| 374 | This file uses standard default values and does not contain | This file uses standard default values and does not contain | 
| 375 | customizations for this experiment. | customizations for this experiment. | 
| 376 |  |  | 
| 377 |  |  | 
| 378 | \subsubsection{File {\it code/CPP\_EEOPTIONS.h}} | \subsubsection{File {\it code/CPP\_EEOPTIONS.h}} | 
| 379 | \label{www:tutorials} | %\label{www:tutorials} | 
| 380 |  |  | 
| 381 | This file uses standard default values and does not contain | This file uses standard default values and does not contain | 
| 382 | customizations for this experiment. | customizations for this experiment. |