13 |
%{\large May 2001} |
%{\large May 2001} |
14 |
%\end{center} |
%\end{center} |
15 |
|
|
16 |
This is the first in a series of tutorials describing |
\section[Barotropic Gyre MITgcm Example]{Barotropic Ocean Gyre In Cartesian Coordinates} |
|
example MITgcm numerical experiments. The example experiments |
|
|
include both straightforward examples of idealized geophysical |
|
|
fluid simulations and more involved cases encompassing |
|
|
large scale modeling and |
|
|
automatic differentiation. Both hydrostatic and non-hydrostatic |
|
|
experiments are presented, as well as experiments employing |
|
|
Cartesian, spherical-polar and cube-sphere coordinate systems. |
|
|
These ``case study'' documents include information describing |
|
|
the experimental configuration and detailed information on how to |
|
|
configure the MITgcm code and input files for each experiment. |
|
|
|
|
|
\section{Barotropic Ocean Gyre In Cartesian Coordinates} |
|
17 |
\label{sect:eg-baro} |
\label{sect:eg-baro} |
18 |
|
\label{www:tutorials} |
19 |
|
\begin{rawhtml} |
20 |
|
<!-- CMIREDIR:eg-baro: --> |
21 |
|
\end{rawhtml} |
22 |
|
|
23 |
|
|
24 |
This example experiment demonstrates using the MITgcm to simulate |
This example experiment demonstrates using the MITgcm to simulate |
25 |
a Barotropic, wind-forced, ocean gyre circulation. The experiment |
a Barotropic, wind-forced, ocean gyre circulation. The files for this |
26 |
is a numerical rendition of the gyre circulation problem similar |
experiment can be found in the verification directory tutorial\_barotropic\_gyre. |
27 |
|
The experiment is a numerical rendition of the gyre circulation problem similar |
28 |
to the problems described analytically by Stommel in 1966 |
to the problems described analytically by Stommel in 1966 |
29 |
\cite{Stommel66} and numerically in Holland et. al \cite{Holland75}. |
\cite{Stommel66} and numerically in Holland et. al \cite{Holland75}. |
30 |
|
|
60 |
Figure \ref{FIG:eg-baro-simulation_config} |
Figure \ref{FIG:eg-baro-simulation_config} |
61 |
summarizes the configuration simulated. |
summarizes the configuration simulated. |
62 |
|
|
63 |
|
%% === eh3 === |
64 |
\begin{figure} |
\begin{figure} |
65 |
\begin{center} |
%% \begin{center} |
66 |
\resizebox{7.5in}{5.5in}{ |
%% \resizebox{7.5in}{5.5in}{ |
67 |
\includegraphics*[0.2in,0.7in][10.5in,10.5in] |
%% \includegraphics*[0.2in,0.7in][10.5in,10.5in] |
68 |
{part3/case_studies/barotropic_gyre/simulation_config.eps} } |
%% {part3/case_studies/barotropic_gyre/simulation_config.eps} } |
69 |
\end{center} |
%% \end{center} |
70 |
|
\centerline{ |
71 |
|
\scalefig{.95} |
72 |
|
\epsfbox{part3/case_studies/barotropic_gyre/simulation_config.eps} |
73 |
|
} |
74 |
\caption{Schematic of simulation domain and wind-stress forcing function |
\caption{Schematic of simulation domain and wind-stress forcing function |
75 |
for barotropic gyre numerical experiment. The domain is enclosed bu solid |
for barotropic gyre numerical experiment. The domain is enclosed bu solid |
76 |
walls at $x=$~0,1200km and at $y=$~0,1200km.} |
walls at $x=$~0,1200km and at $y=$~0,1200km.} |
78 |
\end{figure} |
\end{figure} |
79 |
|
|
80 |
\subsection{Equations Solved} |
\subsection{Equations Solved} |
81 |
|
\label{www:tutorials} |
82 |
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 |
83 |
pressure equation described in Marshall et. al \cite{marshall:97a} is |
pressure equation described in Marshall et. al \cite{marshall:97a} is |
84 |
employed. |
employed. |
113 |
|
|
114 |
|
|
115 |
\subsection{Discrete Numerical Configuration} |
\subsection{Discrete Numerical Configuration} |
116 |
|
\label{www:tutorials} |
117 |
|
|
118 |
The domain is discretised with |
The domain is discretised with |
119 |
a uniform grid spacing in the horizontal set to |
a uniform grid spacing in the horizontal set to |
122 |
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. |
123 |
|
|
124 |
\subsubsection{Numerical Stability Criteria} |
\subsubsection{Numerical Stability Criteria} |
125 |
|
\label{www:tutorials} |
126 |
|
|
127 |
The Laplacian dissipation coefficient, $A_{h}$, is set to $400 m s^{-1}$. |
The Laplacian dissipation coefficient, $A_{h}$, is set to $400 m s^{-1}$. |
128 |
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}, |
176 |
of 0.5 and limits $\delta t$ to $1200s$. |
of 0.5 and limits $\delta t$ to $1200s$. |
177 |
|
|
178 |
\subsection{Code Configuration} |
\subsection{Code Configuration} |
179 |
|
\label{www:tutorials} |
180 |
\label{SEC:eg-baro-code_config} |
\label{SEC:eg-baro-code_config} |
181 |
|
|
182 |
The model configuration for this experiment resides under the |
The model configuration for this experiment resides under the |
196 |
to these files associated with this experiment. |
to these files associated with this experiment. |
197 |
|
|
198 |
\subsubsection{File {\it input/data}} |
\subsubsection{File {\it input/data}} |
199 |
|
\label{www:tutorials} |
200 |
|
|
201 |
This file, reproduced completely below, specifies the main parameters |
This file, reproduced completely below, specifies the main parameters |
202 |
for the experiment. The parameters that are significant for this configuration |
for the experiment. The parameters that are significant for this configuration |
308 |
\end{small} |
\end{small} |
309 |
|
|
310 |
\subsubsection{File {\it input/data.pkg}} |
\subsubsection{File {\it input/data.pkg}} |
311 |
|
\label{www:tutorials} |
312 |
|
|
313 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
314 |
customizations for this experiment. |
customizations for this experiment. |
315 |
|
|
316 |
\subsubsection{File {\it input/eedata}} |
\subsubsection{File {\it input/eedata}} |
317 |
|
\label{www:tutorials} |
318 |
|
|
319 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
320 |
customizations for this experiment. |
customizations for this experiment. |
321 |
|
|
322 |
\subsubsection{File {\it input/windx.sin\_y}} |
\subsubsection{File {\it input/windx.sin\_y}} |
323 |
|
\label{www:tutorials} |
324 |
|
|
325 |
The {\it input/windx.sin\_y} file specifies a two-dimensional ($x,y$) |
The {\it input/windx.sin\_y} file specifies a two-dimensional ($x,y$) |
326 |
map of wind stress ,$\tau_{x}$, values. The units used are $Nm^{-2}$. |
map of wind stress ,$\tau_{x}$, values. The units used are $Nm^{-2}$. |
331 |
code for creating the {\it input/windx.sin\_y} file. |
code for creating the {\it input/windx.sin\_y} file. |
332 |
|
|
333 |
\subsubsection{File {\it input/topog.box}} |
\subsubsection{File {\it input/topog.box}} |
334 |
|
\label{www:tutorials} |
335 |
|
|
336 |
|
|
337 |
The {\it input/topog.box} file specifies a two-dimensional ($x,y$) |
The {\it input/topog.box} file specifies a two-dimensional ($x,y$) |
343 |
code for creating the {\it input/topog.box} file. |
code for creating the {\it input/topog.box} file. |
344 |
|
|
345 |
\subsubsection{File {\it code/SIZE.h}} |
\subsubsection{File {\it code/SIZE.h}} |
346 |
|
\label{www:tutorials} |
347 |
|
|
348 |
Two lines are customized in this file for the current experiment |
Two lines are customized in this file for the current experiment |
349 |
|
|
366 |
\end{small} |
\end{small} |
367 |
|
|
368 |
\subsubsection{File {\it code/CPP\_OPTIONS.h}} |
\subsubsection{File {\it code/CPP\_OPTIONS.h}} |
369 |
|
\label{www:tutorials} |
370 |
|
|
371 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
372 |
customizations for this experiment. |
customizations for this experiment. |
373 |
|
|
374 |
|
|
375 |
\subsubsection{File {\it code/CPP\_EEOPTIONS.h}} |
\subsubsection{File {\it code/CPP\_EEOPTIONS.h}} |
376 |
|
\label{www:tutorials} |
377 |
|
|
378 |
This file uses standard default values and does not contain |
This file uses standard default values and does not contain |
379 |
customizations for this experiment. |
customizations for this experiment. |