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%{\large May 2001} |
%{\large May 2001} |
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%\end{center} |
%\end{center} |
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This is the first in a series of tutorials describing |
\section[Barotropic Gyre MITgcm Example]{Barotropic Ocean Gyre In Cartesian Coordinates} |
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example MITgcm numerical experiments. The example experiments |
\label{www:tutorials} |
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include both straightforward examples of idealized geophysical |
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fluid simulations and more involved cases encompassing |
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large scale modeling and |
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automatic differentiation. Both hydrostatic and non-hydrostatic |
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experiments are presented, as well as experiments employing |
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Cartesian, spherical-polar and cube-sphere coordinate systems. |
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These ``case study'' documents include information describing |
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the experimental configuration and detailed information on how to |
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configure the MITgcm code and input files for each experiment. |
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\section{Barotropic Ocean Gyre In Cartesian Coordinates} |
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\label{sect:eg-baro} |
\label{sect:eg-baro} |
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\begin{rawhtml} |
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<!-- CMIREDIR:eg-baro: --> |
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\end{rawhtml} |
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\begin{center} |
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(in directory: {\it verification/tutorial\_barotropic\_gyre/}) |
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\end{center} |
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This example experiment demonstrates using the MITgcm to simulate |
This example experiment demonstrates using the MITgcm to simulate |
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a Barotropic, wind-forced, ocean gyre circulation. The experiment |
a Barotropic, wind-forced, ocean gyre circulation. The files for this |
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is a numerical rendition of the gyre circulation problem similar |
experiment can be found in the verification directory tutorial\_barotropic\_gyre. |
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The experiment is a numerical rendition of the gyre circulation problem similar |
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to the problems described analytically by Stommel in 1966 |
to the problems described analytically by Stommel in 1966 |
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\cite{Stommel66} and numerically in Holland et. al \cite{Holland75}. |
\cite{Stommel66} and numerically in Holland et. al \cite{Holland75}. |
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Figure \ref{FIG:eg-baro-simulation_config} |
Figure \ref{FIG:eg-baro-simulation_config} |
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summarizes the configuration simulated. |
summarizes the configuration simulated. |
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%% === eh3 === |
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\begin{figure} |
\begin{figure} |
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\begin{center} |
%% \begin{center} |
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\resizebox{7.5in}{5.5in}{ |
%% \resizebox{7.5in}{5.5in}{ |
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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/barotropic_gyre/simulation_config.eps} } |
%% {s_examples/barotropic_gyre/simulation_config.eps} } |
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\end{center} |
%% \end{center} |
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\centerline{ |
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\scalefig{.95} |
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\epsfbox{s_examples/barotropic_gyre/simulation_config.eps} |
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} |
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\caption{Schematic of simulation domain and wind-stress forcing function |
\caption{Schematic of simulation domain and wind-stress forcing function |
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for barotropic gyre numerical experiment. The domain is enclosed bu solid |
for barotropic gyre numerical experiment. The domain is enclosed bu solid |
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walls at $x=$~0,1200km and at $y=$~0,1200km.} |
walls at $x=$~0,1200km and at $y=$~0,1200km.} |
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\end{figure} |
\end{figure} |
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\subsection{Equations Solved} |
\subsection{Equations Solved} |
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\label{www:tutorials} |
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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 |
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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. |
employed. |
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\subsection{Discrete Numerical Configuration} |
\subsection{Discrete Numerical Configuration} |
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\label{www:tutorials} |
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The domain is discretised with |
The domain is discretised with |
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a uniform grid spacing in the horizontal set to |
a uniform grid spacing in the horizontal set to |
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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. |
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\subsubsection{Numerical Stability Criteria} |
\subsubsection{Numerical Stability Criteria} |
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\label{www:tutorials} |
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The Laplacian dissipation coefficient, $A_{h}$, is set to $400 m s^{-1}$. |
The Laplacian dissipation coefficient, $A_{h}$, is set to $400 m s^{-1}$. |
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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}, |
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of 0.5 and limits $\delta t$ to $1200s$. |
of 0.5 and limits $\delta t$ to $1200s$. |
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\subsection{Code Configuration} |
\subsection{Code Configuration} |
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\label{www:tutorials} |
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\label{SEC:eg-baro-code_config} |
\label{SEC:eg-baro-code_config} |
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The model configuration for this experiment resides under the |
The model configuration for this experiment resides under the |
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directory {\it verification/exp0/}. The experiment files |
directory {\it verification/tutorial\_barotropic\_gyre/}. |
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The experiment files |
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\begin{itemize} |
\begin{itemize} |
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\item {\it input/data} |
\item {\it input/data} |
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\item {\it input/data.pkg} |
\item {\it input/data.pkg} |
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to these files associated with this experiment. |
to these files associated with this experiment. |
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\subsubsection{File {\it input/data}} |
\subsubsection{File {\it input/data}} |
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\label{www:tutorials} |
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This file, reproduced completely below, specifies the main parameters |
This file, reproduced completely below, specifies the main parameters |
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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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notes. |
notes. |
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\begin{small} |
\begin{small} |
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\input{part3/case_studies/barotropic_gyre/input/data} |
\input{s_examples/barotropic_gyre/input/data} |
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\end{small} |
\end{small} |
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\subsubsection{File {\it input/data.pkg}} |
\subsubsection{File {\it input/data.pkg}} |
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\label{www:tutorials} |
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This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
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customizations for this experiment. |
customizations for this experiment. |
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\subsubsection{File {\it input/eedata}} |
\subsubsection{File {\it input/eedata}} |
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|
\label{www:tutorials} |
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This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
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customizations for this experiment. |
customizations for this experiment. |
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\subsubsection{File {\it input/windx.sin\_y}} |
\subsubsection{File {\it input/windx.sin\_y}} |
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|
\label{www:tutorials} |
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The {\it input/windx.sin\_y} file specifies a two-dimensional ($x,y$) |
The {\it input/windx.sin\_y} file specifies a two-dimensional ($x,y$) |
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map of wind stress ,$\tau_{x}$, values. The units used are $Nm^{-2}$. |
map of wind stress ,$\tau_{x}$, values. The units used are $Nm^{-2}$. |
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code for creating the {\it input/windx.sin\_y} file. |
code for creating the {\it input/windx.sin\_y} file. |
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\subsubsection{File {\it input/topog.box}} |
\subsubsection{File {\it input/topog.box}} |
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\label{www:tutorials} |
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| 339 |
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The {\it input/topog.box} file specifies a two-dimensional ($x,y$) |
The {\it input/topog.box} file specifies a two-dimensional ($x,y$) |
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code for creating the {\it input/topog.box} file. |
code for creating the {\it input/topog.box} file. |
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\subsubsection{File {\it code/SIZE.h}} |
\subsubsection{File {\it code/SIZE.h}} |
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\label{www:tutorials} |
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Two lines are customized in this file for the current experiment |
Two lines are customized in this file for the current experiment |
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\end{itemize} |
\end{itemize} |
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\begin{small} |
\begin{small} |
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\input{part3/case_studies/barotropic_gyre/code/SIZE.h} |
\input{s_examples/barotropic_gyre/code/SIZE.h} |
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\end{small} |
\end{small} |
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\subsubsection{File {\it code/CPP\_OPTIONS.h}} |
\subsubsection{File {\it code/CPP\_OPTIONS.h}} |
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|
\label{www:tutorials} |
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This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
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customizations for this experiment. |
customizations for this experiment. |
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| 377 |
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\subsubsection{File {\it code/CPP\_EEOPTIONS.h}} |
\subsubsection{File {\it code/CPP\_EEOPTIONS.h}} |
| 379 |
|
\label{www:tutorials} |
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|
| 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. |