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\section{Surface Driven Convection} |
\section{Surface Driven Convection} |
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\label{www:tutorials} |
%\label{www:tutorials} |
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\label{sect:eg-bconv} |
\label{sec:eg-bconv} |
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\begin{rawhtml} |
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<!-- CMIREDIR:eg-bconv: --> |
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\end{rawhtml} |
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\begin{center} |
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(in directory: {\it verification/tutorial\_deep\_convection/}) |
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\end{center} |
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\bodytext{bgcolor="#FFFFFFFF"} |
\bodytext{bgcolor="#FFFFFFFF"} |
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\begin{center} |
\begin{center} |
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\resizebox{7.5cm}{5.5cm}{ |
\resizebox{7.5cm}{5.5cm}{ |
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\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
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{part3/case_studies/doubly_periodic_convection/simulation_config.eps} } |
{s_examples/deep_convection/simulation_config.eps} } |
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\end{center} |
\end{center} |
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\caption{Schematic of simulation domain |
\caption{Schematic of simulation domain |
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for the surface driven convection experiment. The domain is doubly periodic |
for the surface driven convection experiment. The domain is doubly periodic |
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with an initially uniform temperature of 20 $^oC$. |
with an initially uniform temperature of 20 $^oC$. |
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} |
} |
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\label{FIG:eg-bconv-simulation_config} |
\label{fig:eg-bconv-simulation_config} |
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\end{figure} |
\end{figure} |
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This experiment, figure \ref{FIG:eg-bconv-simulation_config}, showcasing MITgcm's non-hydrostatic capability, was designed to explore |
This experiment, figure \ref{fig:eg-bconv-simulation_config}, showcasing MITgcm's non-hydrostatic |
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capability, was designed to explore |
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the temporal and spatial characteristics of convection plumes as they might exist during a |
the temporal and spatial characteristics of convection plumes as they might exist during a |
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period of oceanic deep convection. It is |
period of oceanic deep convection. The files for this experiment can be found in the verification |
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directory under tutorial\_deep\_convection. It is |
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|
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\begin{itemize} |
\begin{itemize} |
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\item non-hydrostatic |
\item non-hydrostatic |
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\end{itemize} |
\end{itemize} |
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|
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\subsection{Overview} |
\subsection{Overview} |
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\label{www:tutorials} |
%\label{www:tutorials} |
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|
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The model domain consists of an approximately 3 |
The model domain consists of an approximately 3 |
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km square by 1 km deep box of initially |
km square by 1 km deep box of initially |
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used in this experiment is linear |
used in this experiment is linear |
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|
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\begin{equation} |
\begin{equation} |
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\label{EQ:eg-bconv-linear1_eos} |
\label{eq:eg-bconv-linear1_eos} |
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\rho = \rho_{0} ( 1 - \alpha_{\theta}\theta^{'} ) |
\rho = \rho_{0} ( 1 - \alpha_{\theta}\theta^{'} ) |
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\end{equation} |
\end{equation} |
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|
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\noindent which is implemented in the model as a density anomaly equation |
\noindent which is implemented in the model as a density anomaly equation |
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|
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\begin{equation} |
\begin{equation} |
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\label{EQ:eg-bconv-linear1_eos_pert} |
\label{eq:eg-bconv-linear1_eos_pert} |
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\rho^{'} = -\rho_{0}\alpha_{\theta}\theta^{'} |
\rho^{'} = -\rho_{0}\alpha_{\theta}\theta^{'} |
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\end{equation} |
\end{equation} |
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|
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As the fluid in the surface layer is cooled (at a mean rate of 800 Wm$^2$), it becomes |
As the fluid in the surface layer is cooled (at a mean rate of 800 Wm$^2$), it becomes |
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convectively unstable and |
convectively unstable and |
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overturns, at first close to the grid-scale, but, as the flow matures, on larger scales |
overturns, at first close to the grid-scale, but, as the flow matures, on larger scales |
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(figures \ref{FIG:eg-bconv-vertsection} and \ref{FIG:eg-bconv-horizsection}), under the influence of |
(figures \ref{fig:eg-bconv-vertsection} and \ref{fig:eg-bconv-horizsection}), under the influence of |
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rotation ($f_o = 10^{-4}$ s$^{-1}$) . |
rotation ($f_o = 10^{-4}$ s$^{-1}$) . |
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|
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\begin{rawhtml}MITGCM_INSERT_FIGURE_BEGIN surf-convection-vertsection\end{rawhtml} |
\begin{rawhtml}MITGCM_INSERT_FIGURE_BEGIN surf-convection-vertsection\end{rawhtml} |
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\begin{center} |
\begin{center} |
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\resizebox{15cm}{10cm}{ |
\resizebox{15cm}{10cm}{ |
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\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
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{part3/case_studies/doubly_periodic_convection/verticalsection.ps} } |
{s_examples/deep_convection/verticalsection.ps} } |
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\end{center} |
\end{center} |
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\caption{ |
\caption{ |
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} |
} |
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\label{FIG:eg-bconv-vertsection} |
\label{fig:eg-bconv-vertsection} |
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\label{fig:surf-convection-vertsection} |
\label{fig:surf-convection-vertsection} |
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\end{figure} |
\end{figure} |
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\begin{rawhtml}MITGCM_INSERT_FIGURE_END\end{rawhtml} |
\begin{rawhtml}MITGCM_INSERT_FIGURE_END\end{rawhtml} |
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\begin{center} |
\begin{center} |
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\resizebox{10cm}{10cm}{ |
\resizebox{10cm}{10cm}{ |
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\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
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{part3/case_studies/doubly_periodic_convection/surfacesection.ps} } |
{s_examples/deep_convection/surfacesection.ps} } |
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\end{center} |
\end{center} |
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\caption{ |
\caption{ |
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} |
} |
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\label{FIG:eg-bconv-horizsection} |
\label{fig:eg-bconv-horizsection} |
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\label{fig:surf-convection-horizsection} |
\label{fig:surf-convection-horizsection} |
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\end{figure} |
\end{figure} |
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\begin{rawhtml}MITGCM_INSERT_FIGURE_END\end{rawhtml} |
\begin{rawhtml}MITGCM_INSERT_FIGURE_END\end{rawhtml} |
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in a binary data file generated using the Matlab script {\it input/gendata.m}. |
in a binary data file generated using the Matlab script {\it input/gendata.m}. |
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\subsection{Equations solved} |
\subsection{Equations solved} |
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\label{www:tutorials} |
%\label{www:tutorials} |
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|
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The model is configured in nonhydrostatic form, that is, all terms in the Navier |
The model is configured in nonhydrostatic form, that is, all terms in the Navier |
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Stokes equations are retained and the pressure field is found, subject to appropriate |
Stokes equations are retained and the pressure field is found, subject to appropriate |
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pressure equation described in Marshall et. al \cite{marshall:97a} is |
pressure equation described in Marshall et. al \cite{marshall:97a} is |
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employed. A horizontal Laplacian operator $\nabla_{h}^2$ provides viscous |
employed. A horizontal Laplacian operator $\nabla_{h}^2$ provides viscous |
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dissipation. The thermodynamic forcing appears as a sink in the potential temperature, |
dissipation. The thermodynamic forcing appears as a sink in the potential temperature, |
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$\theta$, equation (\ref{EQ:eg-bconv-global_forcing_ft}). This produces a set of equations |
$\theta$, equation (\ref{eq:eg-bconv-theta_equations}). |
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solved in this configuration as follows: |
This produces a set of equations solved in this configuration as follows: |
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|
134 |
\begin{eqnarray} |
\begin{eqnarray} |
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\label{EQ:eg-bconv-model_equations} |
\label{eq:eg-bconv-model_equations} |
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\frac{Du}{Dt} - fv + |
\frac{Du}{Dt} - fv + |
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\frac{1}{\rho}\frac{\partial p^{'}}{\partial x} - |
\frac{1}{\rho}\frac{\partial p^{'}}{\partial x} - |
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\nabla_{h}\cdot A_{h}\nabla_{h}u - |
\nabla_{h}\cdot A_{h}\nabla_{h}u - |
177 |
{\cal F}_\theta & \text{(surface)} \\ |
{\cal F}_\theta & \text{(surface)} \\ |
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0 & \text{(interior)} |
0 & \text{(interior)} |
179 |
\end{cases} |
\end{cases} |
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\label{eq:eg-bconv-theta_equations} |
181 |
\end{eqnarray} |
\end{eqnarray} |
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|
183 |
\noindent where $u=\frac{Dx}{Dt}$, $v=\frac{Dy}{Dt}$ and |
\noindent where $u=\frac{Dx}{Dt}$, $v=\frac{Dy}{Dt}$ and |
189 |
\\ |
\\ |
190 |
|
|
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\subsection{Discrete numerical configuration} |
\subsection{Discrete numerical configuration} |
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\label{www:tutorials} |
%\label{www:tutorials} |
193 |
|
|
194 |
The domain is discretised with a uniform grid spacing in each direction. There are 64 |
The domain is discretised with a uniform grid spacing in each direction. There are 64 |
195 |
grid cells in directions $x$ and $y$ and 20 vertical levels thus the domain |
grid cells in directions $x$ and $y$ and 20 vertical levels thus the domain |
196 |
comprises a total of just over 80 000 gridpoints. |
comprises a total of just over 80 000 gridpoints. |
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|
|
198 |
\subsection{Numerical stability criteria and other considerations} |
\subsection{Numerical stability criteria and other considerations} |
199 |
\label{www:tutorials} |
%\label{www:tutorials} |
200 |
|
|
201 |
For a heat flux of 800 Wm$^2$ and a rotation rate of $10^{-4}$ s$^{-1}$ the |
For a heat flux of 800 Wm$^2$ and a rotation rate of $10^{-4}$ s$^{-1}$ the |
202 |
plume-scale can be expected to be a few hundred meters guiding our choice of grid |
plume-scale can be expected to be a few hundred meters guiding our choice of grid |
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50 m, the implied maximum timestep for stability, $\delta t_u$ is |
50 m, the implied maximum timestep for stability, $\delta t_u$ is |
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|
212 |
\begin{eqnarray} |
\begin{eqnarray} |
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\label{EQ:eg-bconv-advectiveCFLcondition} |
\label{eq:eg-bconv-advectiveCFLcondition} |
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%\delta t_u = \frac{\Delta x}{| \vec{u} \} = 50 s |
%\delta t_u = \frac{\Delta x}{| \vec{u} \} = 50 s |
215 |
\end{eqnarray} |
\end{eqnarray} |
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correlated over 50 m. |
correlated over 50 m. |
223 |
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|
224 |
\subsection{Experiment configuration} |
\subsection{Experiment configuration} |
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\label{www:tutorials} |
%\label{www:tutorials} |
226 |
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|
227 |
The model configuration for this experiment resides under the directory |
The model configuration for this experiment resides under the directory |
228 |
{\it verification/convection/}. The experiment files |
{\it verification/convection/}. The experiment files |
239 |
experiment. Below we describe these experiment-specific customisations. |
experiment. Below we describe these experiment-specific customisations. |
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|
241 |
\subsubsection{File {\it code/CPP\_EEOPTIONS.h}} |
\subsubsection{File {\it code/CPP\_EEOPTIONS.h}} |
242 |
\label{www:tutorials} |
%\label{www:tutorials} |
243 |
|
|
244 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
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customisations for this experiment. |
customisations for this experiment. |
246 |
|
|
247 |
\subsubsection{File {\it code/CPP\_OPTIONS.h}} |
\subsubsection{File {\it code/CPP\_OPTIONS.h}} |
248 |
\label{www:tutorials} |
%\label{www:tutorials} |
249 |
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|
250 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
251 |
customisations for this experiment. |
customisations for this experiment. |
252 |
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|
253 |
\subsubsection{File {\it code/SIZE.h}} |
\subsubsection{File {\it code/SIZE.h}} |
254 |
\label{www:tutorials} |
%\label{www:tutorials} |
255 |
|
|
256 |
Three lines are customized in this file. These prescribe the domain grid dimensions. |
Three lines are customized in this file. These prescribe the domain grid dimensions. |
257 |
\begin{itemize} |
\begin{itemize} |
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|
275 |
\begin{rawhtml}<PRE>\end{rawhtml} |
\begin{rawhtml}<PRE>\end{rawhtml} |
276 |
\begin{small} |
\begin{small} |
277 |
\input{part3/case_studies/doubly_periodic_convection/code/SIZE.h} |
\input{s_examples/deep_convection/code/SIZE.h} |
278 |
\end{small} |
\end{small} |
279 |
\begin{rawhtml}</PRE>\end{rawhtml} |
\begin{rawhtml}</PRE>\end{rawhtml} |
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|
|
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\subsubsection{File {\it input/data}} |
\subsubsection{File {\it input/data}} |
282 |
\label{www:tutorials} |
%\label{www:tutorials} |
283 |
|
|
284 |
This file, reproduced completely below, specifies the main parameters |
This file, reproduced completely below, specifies the main parameters |
285 |
for the experiment. The parameters that are significant for this configuration |
for the experiment. The parameters that are significant for this configuration |
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|
|
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\item Line 4, |
\item Line 4, |
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\begin{verbatim} |
\begin{verbatim} |
292 |
4 tRef=20*20.0, |
4 tRef=20*20.0, |
293 |
\end{verbatim} |
\end{verbatim} |
294 |
this line sets |
this line sets |
295 |
the initial and reference values of potential temperature at each model |
the initial and reference values of potential temperature at each model |
296 |
level in units of $^{\circ}$C. Here the value is arbitrary since, in this case, the |
level in units of $^{\circ}\mathrm{C}$. Here the value is arbitrary since, in this case, the |
297 |
flow evolves independently of the absolute magnitude of the reference temperature. |
flow evolves independently of the absolute magnitude of the reference temperature. |
298 |
For each depth level the initial and reference profiles will be uniform in |
For each depth level the initial and reference profiles will be uniform in |
299 |
$x$ and $y$. The values specified are read into the |
$x$ and $y$. The values specified are read into the |
319 |
|
|
320 |
\item Line 5, |
\item Line 5, |
321 |
\begin{verbatim} |
\begin{verbatim} |
322 |
5 sRef=20*35.0, |
5 sRef=20*35.0, |
323 |
\end{verbatim} |
\end{verbatim} |
324 |
this line sets the initial and reference values of salinity at each model |
this line sets the initial and reference values of salinity at each model |
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level in units of ppt. In this case salinity is set to an (arbitrary) uniform value of |
level in units of ppt. In this case salinity is set to an (arbitrary) uniform value of |
349 |
|
|
350 |
\item Line 6, |
\item Line 6, |
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\begin{verbatim} |
\begin{verbatim} |
352 |
6 viscAh=0.1, |
6 viscAh=0.1, |
353 |
\end{verbatim} |
\end{verbatim} |
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this line sets the horizontal laplacian dissipation coefficient to |
this line sets the horizontal laplacian dissipation coefficient to |
355 |
0.1 ${\rm m^{2}s^{-1}}$. Boundary conditions |
0.1 ${\rm m^{2}s^{-1}}$. Boundary conditions |
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|
|
381 |
\item Line 7, |
\item Line 7, |
382 |
\begin{verbatim} |
\begin{verbatim} |
383 |
7 viscAz=0.1, |
7 viscAz=0.1, |
384 |
\end{verbatim} |
\end{verbatim} |
385 |
this line sets the vertical laplacian frictional dissipation coefficient to |
this line sets the vertical laplacian frictional dissipation coefficient to |
386 |
0.1 ${\rm m^{2}s^{-1}}$. Boundary conditions |
0.1 ${\rm m^{2}s^{-1}}$. Boundary conditions |
694 |
\end{verbatim} |
\end{verbatim} |
695 |
Sets the tolerance which the three-dimensional, conjugate |
Sets the tolerance which the three-dimensional, conjugate |
696 |
gradient solver will use to test for convergence in equation |
gradient solver will use to test for convergence in equation |
697 |
\ref{EQ:eg-bconv-congrad_3d_resid} to $1 \times 10^{-9}$. |
%- note: Description of Conjugate gradient method (& related params) is missing |
698 |
The solver will iterate until the |
% in the mean time, substitute this eq ref: |
699 |
tolerance falls below this value or until the maximum number of |
\ref{eq:phi-nh} %\ref{eq:eg-bconv-congrad_3d_resid} |
700 |
solver iterations is reached. Used in routine |
to $1 \times 10^{-9}$. |
701 |
|
The solver will iterate until the tolerance falls below this value |
702 |
|
or until the maximum number of solver iterations is reached. |
703 |
|
Used in routine |
704 |
{\it |
{\it |
705 |
\begin{rawhtml} <A href=../code_reference/vdb/code/94.htm> \end{rawhtml} |
\begin{rawhtml} <A href=../code_reference/vdb/code/94.htm> \end{rawhtml} |
706 |
S/R CG3D ({\it cg3d.F}) |
S/R CG3D ({\it cg3d.F}) |
794 |
|
|
795 |
\begin{rawhtml}<PRE>\end{rawhtml} |
\begin{rawhtml}<PRE>\end{rawhtml} |
796 |
\begin{small} |
\begin{small} |
797 |
\input{part3/case_studies/doubly_periodic_convection/input/data} |
\input{s_examples/deep_convection/input/data} |
798 |
\end{small} |
\end{small} |
799 |
\begin{rawhtml}</PRE>\end{rawhtml} |
\begin{rawhtml}</PRE>\end{rawhtml} |
800 |
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801 |
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|
802 |
\subsubsection{File {\it input/data.pkg}} |
\subsubsection{File {\it input/data.pkg}} |
803 |
\label{www:tutorials} |
%\label{www:tutorials} |
804 |
|
|
805 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
806 |
customisations for this experiment. |
customisations for this experiment. |
807 |
|
|
808 |
\subsubsection{File {\it input/eedata}} |
\subsubsection{File {\it input/eedata}} |
809 |
\label{www:tutorials} |
%\label{www:tutorials} |
810 |
|
|
811 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
812 |
customisations for this experiment. |
customisations for this experiment. |
813 |
|
|
814 |
|
|
815 |
\subsubsection{File {\it input/Qsurf.bin}} |
\subsubsection{File {\it input/Qsurf.bin}} |
816 |
\label{www:tutorials} |
%\label{www:tutorials} |
817 |
|
|
818 |
The file {\it input/Qsurf.bin} specifies a two-dimensional ($x,y$) |
The file {\it input/Qsurf.bin} specifies a two-dimensional ($x,y$) |
819 |
map of heat flux values where |
map of heat flux values where |
828 |
\begin{center} |
\begin{center} |
829 |
% \resizebox{15cm}{10cm}{ |
% \resizebox{15cm}{10cm}{ |
830 |
% \includegraphics*[0.2in,0.7in][10.5in,10.5in] |
% \includegraphics*[0.2in,0.7in][10.5in,10.5in] |
831 |
% {part3/case_studies/doubly_periodic_convection/Qsurf.ps} } |
% {s_examples/deep_convection/Qsurf.ps} } |
832 |
\end{center} |
\end{center} |
833 |
\caption{ |
\caption{ |
834 |
} |
} |
835 |
\label{FIG:eg-bconv-Qsurf} |
\label{fig:eg-bconv-Qsurf} |
836 |
\end{figure} |
\end{figure} |
837 |
|
|
838 |
\subsection{Running the example} |
\subsection{Running the example} |
839 |
\label{www:tutorials} |
%\label{www:tutorials} |
840 |
|
|
841 |
\subsubsection{Code download} |
\subsubsection{Code download} |
842 |
\label{www:tutorials} |
%\label{www:tutorials} |
843 |
|
|
844 |
In order to run the examples you must first download the code distribution. |
In order to run the examples you must first download the code distribution. |
845 |
Instructions for downloading the code can be found in \ref{sect:obtainingCode}. |
Instructions for downloading the code can be found in \ref{sec:obtainingCode}. |
846 |
|
|
847 |
\subsubsection{Experiment Location} |
\subsubsection{Experiment Location} |
848 |
\label{www:tutorials} |
%\label{www:tutorials} |
849 |
|
|
850 |
This example experiments is located under the release sub-directory |
This example experiments is located under the release sub-directory |
851 |
|
|
853 |
{\it verification/convection/ } |
{\it verification/convection/ } |
854 |
|
|
855 |
\subsubsection{Running the Experiment} |
\subsubsection{Running the Experiment} |
856 |
\label{www:tutorials} |
%\label{www:tutorials} |
857 |
|
|
858 |
To run the experiment |
To run the experiment |
859 |
|
|