15 |
this section, we provide information on how to customize the code when |
this section, we provide information on how to customize the code when |
16 |
you are ready to try implementing the configuration you have in mind. |
you are ready to try implementing the configuration you have in mind. |
17 |
|
|
18 |
|
|
19 |
\section{Where to find information} |
\section{Where to find information} |
20 |
\label{sect:whereToFindInfo} |
\label{sect:whereToFindInfo} |
21 |
|
\begin{rawhtml} |
22 |
|
<!-- CMIREDIR:whereToFindInfo: --> |
23 |
|
\end{rawhtml} |
24 |
|
|
25 |
A web site is maintained for release 2 (``Pelican'') of MITgcm: |
A web site is maintained for release 2 (``Pelican'') of MITgcm: |
26 |
\begin{rawhtml} <A href=http://mitgcm.org/pelican/ target="idontexist"> \end{rawhtml} |
\begin{rawhtml} <A href=http://mitgcm.org/pelican/ target="idontexist"> \end{rawhtml} |
54 |
|
|
55 |
\section{Obtaining the code} |
\section{Obtaining the code} |
56 |
\label{sect:obtainingCode} |
\label{sect:obtainingCode} |
57 |
|
\begin{rawhtml} |
58 |
|
<!-- CMIREDIR:obtainingCode: --> |
59 |
|
\end{rawhtml} |
60 |
|
|
61 |
MITgcm can be downloaded from our system by following |
MITgcm can be downloaded from our system by following |
62 |
the instructions below. As a courtesy we ask that you send e-mail to us at |
the instructions below. As a courtesy we ask that you send e-mail to us at |
86 |
|
|
87 |
\end{enumerate} |
\end{enumerate} |
88 |
|
|
89 |
\subsubsection{Checkout from CVS} |
\subsection{Method 1 - Checkout from CVS} |
90 |
\label{sect:cvs_checkout} |
\label{sect:cvs_checkout} |
91 |
|
|
92 |
If CVS is available on your system, we strongly encourage you to use it. CVS |
If CVS is available on your system, we strongly encourage you to use it. CVS |
99 |
\begin{verbatim} |
\begin{verbatim} |
100 |
% setenv CVSROOT :pserver:cvsanon@mitgcm.org:/u/gcmpack |
% setenv CVSROOT :pserver:cvsanon@mitgcm.org:/u/gcmpack |
101 |
\end{verbatim} |
\end{verbatim} |
102 |
in your .cshrc or .tcshrc file. For bash or sh shells, put: |
in your \texttt{.cshrc} or \texttt{.tcshrc} file. For bash or sh |
103 |
|
shells, put: |
104 |
\begin{verbatim} |
\begin{verbatim} |
105 |
% export CVSROOT=':pserver:cvsanon@mitgcm.org:/u/gcmpack' |
% export CVSROOT=':pserver:cvsanon@mitgcm.org:/u/gcmpack' |
106 |
\end{verbatim} |
\end{verbatim} |
155 |
\label{tab:cvsModules} |
\label{tab:cvsModules} |
156 |
\end{table} |
\end{table} |
157 |
|
|
158 |
The checkout process creates a directory called \textit{MITgcm}. If |
The checkout process creates a directory called \texttt{MITgcm}. If |
159 |
the directory \textit{MITgcm} exists this command updates your code |
the directory \texttt{MITgcm} exists this command updates your code |
160 |
based on the repository. Each directory in the source tree contains a |
based on the repository. Each directory in the source tree contains a |
161 |
directory \textit{CVS}. This information is required by CVS to keep |
directory \texttt{CVS}. This information is required by CVS to keep |
162 |
track of your file versions with respect to the repository. Don't edit |
track of your file versions with respect to the repository. Don't edit |
163 |
the files in \textit{CVS}! You can also use CVS to download code |
the files in \texttt{CVS}! You can also use CVS to download code |
164 |
updates. More extensive information on using CVS for maintaining |
updates. More extensive information on using CVS for maintaining |
165 |
MITgcm code can be found |
MITgcm code can be found |
166 |
\begin{rawhtml} <A href=''http://mitgcm.org/usingcvstoget.html'' target="idontexist"> \end{rawhtml} |
\begin{rawhtml} <A href=''http://mitgcm.org/usingcvstoget.html'' target="idontexist"> \end{rawhtml} |
177 |
\end{verbatim} |
\end{verbatim} |
178 |
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|
179 |
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|
180 |
\subsubsection{Conventional download method} |
\subsection{Method 2 - Tar file download} |
181 |
\label{sect:conventionalDownload} |
\label{sect:conventionalDownload} |
182 |
|
|
183 |
If you do not have CVS on your system, you can download the model as a |
If you do not have CVS on your system, you can download the model as a |
264 |
with. So please be sure you understand what you're doing. |
with. So please be sure you understand what you're doing. |
265 |
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|
266 |
\section{Model and directory structure} |
\section{Model and directory structure} |
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|
\begin{rawhtml} |
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|
<!-- CMIREDIR:directory_structure: --> |
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\end{rawhtml} |
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|
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The ``numerical'' model is contained within a execution environment |
The ``numerical'' model is contained within a execution environment |
272 |
support wrapper. This wrapper is designed to provide a general |
support wrapper. This wrapper is designed to provide a general |
274 |
model that uses the framework. Under this structure the model is split |
model that uses the framework. Under this structure the model is split |
275 |
into execution environment support code and conventional numerical |
into execution environment support code and conventional numerical |
276 |
model code. The execution environment support code is held under the |
model code. The execution environment support code is held under the |
277 |
\textit{eesupp} directory. The grid point model code is held under the |
\texttt{eesupp} directory. The grid point model code is held under the |
278 |
\textit{model} directory. Code execution actually starts in the |
\texttt{model} directory. Code execution actually starts in the |
279 |
\textit{eesupp} routines and not in the \textit{model} routines. For |
\texttt{eesupp} routines and not in the \texttt{model} routines. For |
280 |
this reason the top-level \textit{MAIN.F} is in the |
this reason the top-level \texttt{MAIN.F} is in the |
281 |
\textit{eesupp/src} directory. In general, end-users should not need |
\texttt{eesupp/src} directory. In general, end-users should not need |
282 |
to worry about this level. The top-level routine for the numerical |
to worry about this level. The top-level routine for the numerical |
283 |
part of the code is in \textit{model/src/THE\_MODEL\_MAIN.F}. Here is |
part of the code is in \texttt{model/src/THE\_MODEL\_MAIN.F}. Here is |
284 |
a brief description of the directory structure of the model under the |
a brief description of the directory structure of the model under the |
285 |
root tree (a detailed description is given in section 3: Code |
root tree (a detailed description is given in section 3: Code |
286 |
structure). |
structure). |
287 |
|
|
288 |
\begin{itemize} |
\begin{itemize} |
289 |
|
|
290 |
\item \textit{bin}: this directory is initially empty. It is the |
\item \texttt{bin}: this directory is initially empty. It is the |
291 |
default directory in which to compile the code. |
default directory in which to compile the code. |
292 |
|
|
293 |
\item \textit{diags}: contains the code relative to time-averaged |
\item \texttt{diags}: contains the code relative to time-averaged |
294 |
diagnostics. It is subdivided into two subdirectories \textit{inc} |
diagnostics. It is subdivided into two subdirectories \texttt{inc} |
295 |
and \textit{src} that contain include files (*.\textit{h} files) and |
and \texttt{src} that contain include files (\texttt{*.h} files) and |
296 |
Fortran subroutines (*.\textit{F} files), respectively. |
Fortran subroutines (\texttt{*.F} files), respectively. |
297 |
|
|
298 |
\item \textit{doc}: contains brief documentation notes. |
\item \texttt{doc}: contains brief documentation notes. |
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|
300 |
\item \textit{eesupp}: contains the execution environment source code. |
\item \texttt{eesupp}: contains the execution environment source code. |
301 |
Also subdivided into two subdirectories \textit{inc} and |
Also subdivided into two subdirectories \texttt{inc} and |
302 |
\textit{src}. |
\texttt{src}. |
303 |
|
|
304 |
\item \textit{exe}: this directory is initially empty. It is the |
\item \texttt{exe}: this directory is initially empty. It is the |
305 |
default directory in which to execute the code. |
default directory in which to execute the code. |
306 |
|
|
307 |
\item \textit{model}: this directory contains the main source code. |
\item \texttt{model}: this directory contains the main source code. |
308 |
Also subdivided into two subdirectories \textit{inc} and |
Also subdivided into two subdirectories \texttt{inc} and |
309 |
\textit{src}. |
\texttt{src}. |
310 |
|
|
311 |
\item \textit{pkg}: contains the source code for the packages. Each |
\item \texttt{pkg}: contains the source code for the packages. Each |
312 |
package corresponds to a subdirectory. For example, \textit{gmredi} |
package corresponds to a subdirectory. For example, \texttt{gmredi} |
313 |
contains the code related to the Gent-McWilliams/Redi scheme, |
contains the code related to the Gent-McWilliams/Redi scheme, |
314 |
\textit{aim} the code relative to the atmospheric intermediate |
\texttt{aim} the code relative to the atmospheric intermediate |
315 |
physics. The packages are described in detail in section 3. |
physics. The packages are described in detail in section 3. |
316 |
|
|
317 |
\item \textit{tools}: this directory contains various useful tools. |
\item \texttt{tools}: this directory contains various useful tools. |
318 |
For example, \textit{genmake2} is a script written in csh (C-shell) |
For example, \texttt{genmake2} is a script written in csh (C-shell) |
319 |
that should be used to generate your makefile. The directory |
that should be used to generate your makefile. The directory |
320 |
\textit{adjoint} contains the makefile specific to the Tangent |
\texttt{adjoint} contains the makefile specific to the Tangent |
321 |
linear and Adjoint Compiler (TAMC) that generates the adjoint code. |
linear and Adjoint Compiler (TAMC) that generates the adjoint code. |
322 |
The latter is described in details in part V. |
The latter is described in details in part V. |
323 |
|
|
324 |
\item \textit{utils}: this directory contains various utilities. The |
\item \texttt{utils}: this directory contains various utilities. The |
325 |
subdirectory \textit{knudsen2} contains code and a makefile that |
subdirectory \texttt{knudsen2} contains code and a makefile that |
326 |
compute coefficients of the polynomial approximation to the knudsen |
compute coefficients of the polynomial approximation to the knudsen |
327 |
formula for an ocean nonlinear equation of state. The |
formula for an ocean nonlinear equation of state. The |
328 |
\textit{matlab} subdirectory contains matlab scripts for reading |
\texttt{matlab} subdirectory contains matlab scripts for reading |
329 |
model output directly into matlab. \textit{scripts} contains C-shell |
model output directly into matlab. \texttt{scripts} contains C-shell |
330 |
post-processing scripts for joining processor-based and tiled-based |
post-processing scripts for joining processor-based and tiled-based |
331 |
model output. |
model output. |
332 |
|
|
333 |
\item \textit{verification}: this directory contains the model |
\item \texttt{verification}: this directory contains the model |
334 |
examples. See section \ref{sect:modelExamples}. |
examples. See section \ref{sect:modelExamples}. |
335 |
|
|
336 |
\end{itemize} |
\end{itemize} |
337 |
|
|
338 |
\section{Example experiments} |
\section[MITgcm Example Experiments]{Example experiments} |
339 |
\label{sect:modelExamples} |
\label{sect:modelExamples} |
340 |
|
\begin{rawhtml} |
341 |
|
<!-- CMIREDIR:modelExamples: --> |
342 |
|
\end{rawhtml} |
343 |
|
|
344 |
%% a set of twenty-four pre-configured numerical experiments |
%% a set of twenty-four pre-configured numerical experiments |
345 |
|
|
351 |
The other examples follow the same general structure as the tutorial |
The other examples follow the same general structure as the tutorial |
352 |
examples. However, they only include brief instructions in a text file |
examples. However, they only include brief instructions in a text file |
353 |
called {\it README}. The examples are located in subdirectories under |
called {\it README}. The examples are located in subdirectories under |
354 |
the directory \textit{verification}. Each example is briefly described |
the directory \texttt{verification}. Each example is briefly described |
355 |
below. |
below. |
356 |
|
|
357 |
\subsection{Full list of model examples} |
\subsection{Full list of model examples} |
358 |
|
|
359 |
\begin{enumerate} |
\begin{enumerate} |
360 |
|
|
361 |
\item \textit{exp0} - single layer, ocean double gyre (barotropic with |
\item \texttt{exp0} - single layer, ocean double gyre (barotropic with |
362 |
free-surface). This experiment is described in detail in section |
free-surface). This experiment is described in detail in section |
363 |
\ref{sect:eg-baro}. |
\ref{sect:eg-baro}. |
364 |
|
|
365 |
\item \textit{exp1} - Four layer, ocean double gyre. This experiment |
\item \texttt{exp1} - Four layer, ocean double gyre. This experiment |
366 |
is described in detail in section \ref{sect:eg-baroc}. |
is described in detail in section \ref{sect:eg-baroc}. |
367 |
|
|
368 |
\item \textit{exp2} - 4x4 degree global ocean simulation with steady |
\item \texttt{exp2} - 4x4 degree global ocean simulation with steady |
369 |
climatological forcing. This experiment is described in detail in |
climatological forcing. This experiment is described in detail in |
370 |
section \ref{sect:eg-global}. |
section \ref{sect:eg-global}. |
371 |
|
|
372 |
\item \textit{exp4} - Flow over a Gaussian bump in open-water or |
\item \texttt{exp4} - Flow over a Gaussian bump in open-water or |
373 |
channel with open boundaries. |
channel with open boundaries. |
374 |
|
|
375 |
\item \textit{exp5} - Inhomogenously forced ocean convection in a |
\item \texttt{exp5} - Inhomogenously forced ocean convection in a |
376 |
doubly periodic box. |
doubly periodic box. |
377 |
|
|
378 |
\item \textit{front\_relax} - Relaxation of an ocean thermal front (test for |
\item \texttt{front\_relax} - Relaxation of an ocean thermal front (test for |
379 |
Gent/McWilliams scheme). 2D (Y-Z). |
Gent/McWilliams scheme). 2D (Y-Z). |
380 |
|
|
381 |
\item \textit{internal wave} - Ocean internal wave forced by open |
\item \texttt{internal wave} - Ocean internal wave forced by open |
382 |
boundary conditions. |
boundary conditions. |
383 |
|
|
384 |
\item \textit{natl\_box} - Eastern subtropical North Atlantic with KPP |
\item \texttt{natl\_box} - Eastern subtropical North Atlantic with KPP |
385 |
scheme; 1 month integration |
scheme; 1 month integration |
386 |
|
|
387 |
\item \textit{hs94.1x64x5} - Zonal averaged atmosphere using Held and |
\item \texttt{hs94.1x64x5} - Zonal averaged atmosphere using Held and |
388 |
Suarez '94 forcing. |
Suarez '94 forcing. |
389 |
|
|
390 |
\item \textit{hs94.128x64x5} - 3D atmosphere dynamics using Held and |
\item \texttt{hs94.128x64x5} - 3D atmosphere dynamics using Held and |
391 |
Suarez '94 forcing. |
Suarez '94 forcing. |
392 |
|
|
393 |
\item \textit{hs94.cs-32x32x5} - 3D atmosphere dynamics using Held and |
\item \texttt{hs94.cs-32x32x5} - 3D atmosphere dynamics using Held and |
394 |
Suarez '94 forcing on the cubed sphere. |
Suarez '94 forcing on the cubed sphere. |
395 |
|
|
396 |
\item \textit{aim.5l\_zon-ave} - Intermediate Atmospheric physics. |
\item \texttt{aim.5l\_zon-ave} - Intermediate Atmospheric physics. |
397 |
Global Zonal Mean configuration, 1x64x5 resolution. |
Global Zonal Mean configuration, 1x64x5 resolution. |
398 |
|
|
399 |
\item \textit{aim.5l\_XZ\_Equatorial\_Slice} - Intermediate |
\item \texttt{aim.5l\_XZ\_Equatorial\_Slice} - Intermediate |
400 |
Atmospheric physics, equatorial Slice configuration. 2D (X-Z). |
Atmospheric physics, equatorial Slice configuration. 2D (X-Z). |
401 |
|
|
402 |
\item \textit{aim.5l\_Equatorial\_Channel} - Intermediate Atmospheric |
\item \texttt{aim.5l\_Equatorial\_Channel} - Intermediate Atmospheric |
403 |
physics. 3D Equatorial Channel configuration. |
physics. 3D Equatorial Channel configuration. |
404 |
|
|
405 |
\item \textit{aim.5l\_LatLon} - Intermediate Atmospheric physics. |
\item \texttt{aim.5l\_LatLon} - Intermediate Atmospheric physics. |
406 |
Global configuration, on latitude longitude grid with 128x64x5 grid |
Global configuration, on latitude longitude grid with 128x64x5 grid |
407 |
points ($2.8^\circ{\rm degree}$ resolution). |
points ($2.8^\circ{\rm degree}$ resolution). |
408 |
|
|
409 |
\item \textit{adjustment.128x64x1} Barotropic adjustment problem on |
\item \texttt{adjustment.128x64x1} Barotropic adjustment problem on |
410 |
latitude longitude grid with 128x64 grid points ($2.8^\circ{\rm |
latitude longitude grid with 128x64 grid points ($2.8^\circ{\rm |
411 |
degree}$ resolution). |
degree}$ resolution). |
412 |
|
|
413 |
\item \textit{adjustment.cs-32x32x1} Barotropic adjustment problem on |
\item \texttt{adjustment.cs-32x32x1} Barotropic adjustment problem on |
414 |
cube sphere grid with 32x32 points per face ( roughly $2.8^\circ{\rm |
cube sphere grid with 32x32 points per face ( roughly $2.8^\circ{\rm |
415 |
degree}$ resolution). |
degree}$ resolution). |
416 |
|
|
417 |
\item \textit{advect\_cs} Two-dimensional passive advection test on |
\item \texttt{advect\_cs} Two-dimensional passive advection test on |
418 |
cube sphere grid. |
cube sphere grid. |
419 |
|
|
420 |
\item \textit{advect\_xy} Two-dimensional (horizontal plane) passive |
\item \texttt{advect\_xy} Two-dimensional (horizontal plane) passive |
421 |
advection test on Cartesian grid. |
advection test on Cartesian grid. |
422 |
|
|
423 |
\item \textit{advect\_yz} Two-dimensional (vertical plane) passive |
\item \texttt{advect\_yz} Two-dimensional (vertical plane) passive |
424 |
advection test on Cartesian grid. |
advection test on Cartesian grid. |
425 |
|
|
426 |
\item \textit{carbon} Simple passive tracer experiment. Includes |
\item \texttt{carbon} Simple passive tracer experiment. Includes |
427 |
derivative calculation. Described in detail in section |
derivative calculation. Described in detail in section |
428 |
\ref{sect:eg-carbon-ad}. |
\ref{sect:eg-carbon-ad}. |
429 |
|
|
430 |
\item \textit{flt\_example} Example of using float package. |
\item \texttt{flt\_example} Example of using float package. |
431 |
|
|
432 |
\item \textit{global\_ocean.90x40x15} Global circulation with GM, flux |
\item \texttt{global\_ocean.90x40x15} Global circulation with GM, flux |
433 |
boundary conditions and poles. |
boundary conditions and poles. |
434 |
|
|
435 |
\item \textit{global\_ocean\_pressure} Global circulation in pressure |
\item \texttt{global\_ocean\_pressure} Global circulation in pressure |
436 |
coordinate (non-Boussinesq ocean model). Described in detail in |
coordinate (non-Boussinesq ocean model). Described in detail in |
437 |
section \ref{sect:eg-globalpressure}. |
section \ref{sect:eg-globalpressure}. |
438 |
|
|
439 |
\item \textit{solid-body.cs-32x32x1} Solid body rotation test for cube |
\item \texttt{solid-body.cs-32x32x1} Solid body rotation test for cube |
440 |
sphere grid. |
sphere grid. |
441 |
|
|
442 |
\end{enumerate} |
\end{enumerate} |
446 |
Each example directory has the following subdirectories: |
Each example directory has the following subdirectories: |
447 |
|
|
448 |
\begin{itemize} |
\begin{itemize} |
449 |
\item \textit{code}: contains the code particular to the example. At a |
\item \texttt{code}: contains the code particular to the example. At a |
450 |
minimum, this directory includes the following files: |
minimum, this directory includes the following files: |
451 |
|
|
452 |
\begin{itemize} |
\begin{itemize} |
453 |
\item \textit{code/CPP\_EEOPTIONS.h}: declares CPP keys relative to |
\item \texttt{code/packages.conf}: declares the list of packages or |
454 |
|
package groups to be used. If not included, the default version |
455 |
|
is located in \texttt{pkg/pkg\_default}. Package groups are |
456 |
|
simply convenient collections of commonly used packages which are |
457 |
|
defined in \texttt{pkg/pkg\_default}. Some packages may require |
458 |
|
other packages or may require their absence (that is, they are |
459 |
|
incompatible) and these package dependencies are listed in |
460 |
|
\texttt{pkg/pkg\_depend}. |
461 |
|
|
462 |
|
\item \texttt{code/CPP\_EEOPTIONS.h}: declares CPP keys relative to |
463 |
the ``execution environment'' part of the code. The default |
the ``execution environment'' part of the code. The default |
464 |
version is located in \textit{eesupp/inc}. |
version is located in \texttt{eesupp/inc}. |
465 |
|
|
466 |
\item \textit{code/CPP\_OPTIONS.h}: declares CPP keys relative to |
\item \texttt{code/CPP\_OPTIONS.h}: declares CPP keys relative to |
467 |
the ``numerical model'' part of the code. The default version is |
the ``numerical model'' part of the code. The default version is |
468 |
located in \textit{model/inc}. |
located in \texttt{model/inc}. |
469 |
|
|
470 |
\item \textit{code/SIZE.h}: declares size of underlying |
\item \texttt{code/SIZE.h}: declares size of underlying |
471 |
computational grid. The default version is located in |
computational grid. The default version is located in |
472 |
\textit{model/inc}. |
\texttt{model/inc}. |
473 |
\end{itemize} |
\end{itemize} |
474 |
|
|
475 |
In addition, other include files and subroutines might be present in |
In addition, other include files and subroutines might be present in |
476 |
\textit{code} depending on the particular experiment. See Section 2 |
\texttt{code} depending on the particular experiment. See Section 2 |
477 |
for more details. |
for more details. |
478 |
|
|
479 |
\item \textit{input}: contains the input data files required to run |
\item \texttt{input}: contains the input data files required to run |
480 |
the example. At a minimum, the \textit{input} directory contains the |
the example. At a minimum, the \texttt{input} directory contains the |
481 |
following files: |
following files: |
482 |
|
|
483 |
\begin{itemize} |
\begin{itemize} |
484 |
\item \textit{input/data}: this file, written as a namelist, |
\item \texttt{input/data}: this file, written as a namelist, |
485 |
specifies the main parameters for the experiment. |
specifies the main parameters for the experiment. |
486 |
|
|
487 |
\item \textit{input/data.pkg}: contains parameters relative to the |
\item \texttt{input/data.pkg}: contains parameters relative to the |
488 |
packages used in the experiment. |
packages used in the experiment. |
489 |
|
|
490 |
\item \textit{input/eedata}: this file contains ``execution |
\item \texttt{input/eedata}: this file contains ``execution |
491 |
environment'' data. At present, this consists of a specification |
environment'' data. At present, this consists of a specification |
492 |
of the number of threads to use in $X$ and $Y$ under multithreaded |
of the number of threads to use in $X$ and $Y$ under multithreaded |
493 |
execution. |
execution. |
498 |
of the experiment. This varies from experiment to experiment. See |
of the experiment. This varies from experiment to experiment. See |
499 |
section 2 for more details. |
section 2 for more details. |
500 |
|
|
501 |
\item \textit{results}: this directory contains the output file |
\item \texttt{results}: this directory contains the output file |
502 |
\textit{output.txt} produced by the simulation example. This file is |
\texttt{output.txt} produced by the simulation example. This file is |
503 |
useful for comparison with your own output when you run the |
useful for comparison with your own output when you run the |
504 |
experiment. |
experiment. |
505 |
\end{itemize} |
\end{itemize} |
507 |
Once you have chosen the example you want to run, you are ready to |
Once you have chosen the example you want to run, you are ready to |
508 |
compile the code. |
compile the code. |
509 |
|
|
510 |
\section{Building the code} |
\section[Building MITgcm]{Building the code} |
511 |
\label{sect:buildingCode} |
\label{sect:buildingCode} |
512 |
|
\begin{rawhtml} |
513 |
To compile the code, we use the {\em make} program. This uses a file |
<!-- CMIREDIR:buildingCode: --> |
514 |
({\em Makefile}) that allows us to pre-process source files, specify |
\end{rawhtml} |
515 |
compiler and optimization options and also figures out any file |
|
516 |
dependencies. We supply a script ({\em genmake2}), described in |
To compile the code, we use the \texttt{make} program. This uses a |
517 |
section \ref{sect:genmake}, that automatically creates the {\em |
file (\texttt{Makefile}) that allows us to pre-process source files, |
518 |
Makefile} for you. You then need to build the dependencies and |
specify compiler and optimization options and also figures out any |
519 |
|
file dependencies. We supply a script (\texttt{genmake2}), described |
520 |
|
in section \ref{sect:genmake}, that automatically creates the |
521 |
|
\texttt{Makefile} for you. You then need to build the dependencies and |
522 |
compile the code. |
compile the code. |
523 |
|
|
524 |
As an example, let's assume that you want to build and run experiment |
As an example, assume that you want to build and run experiment |
525 |
\textit{verification/exp2}. The are multiple ways and places to |
\texttt{verification/exp2}. The are multiple ways and places to |
526 |
actually do this but here let's build the code in |
actually do this but here let's build the code in |
527 |
\textit{verification/exp2/input}: |
\texttt{verification/exp2/build}: |
528 |
\begin{verbatim} |
\begin{verbatim} |
529 |
% cd verification/exp2/input |
% cd verification/exp2/build |
530 |
\end{verbatim} |
\end{verbatim} |
531 |
First, build the {\em Makefile}: |
First, build the \texttt{Makefile}: |
532 |
\begin{verbatim} |
\begin{verbatim} |
533 |
% ../../../tools/genmake2 -mods=../code |
% ../../../tools/genmake2 -mods=../code |
534 |
\end{verbatim} |
\end{verbatim} |
535 |
The command line option tells {\em genmake} to override model source |
The command line option tells \texttt{genmake} to override model source |
536 |
code with any files in the directory {\em ./code/}. |
code with any files in the directory \texttt{../code/}. |
537 |
|
|
538 |
On many systems, the {\em genmake2} program will be able to |
On many systems, the \texttt{genmake2} program will be able to |
539 |
automatically recognize the hardware, find compilers and other tools |
automatically recognize the hardware, find compilers and other tools |
540 |
within the user's path (``echo \$PATH''), and then choose an |
within the user's path (``\texttt{echo \$PATH}''), and then choose an |
541 |
appropriate set of options from the files contained in the {\em |
appropriate set of options from the files (``optfiles'') contained in |
542 |
tools/build\_options} directory. Under some circumstances, a user |
the \texttt{tools/build\_options} directory. Under some |
543 |
may have to create a new ``optfile'' in order to specify the exact |
circumstances, a user may have to create a new ``optfile'' in order to |
544 |
combination of compiler, compiler flags, libraries, and other options |
specify the exact combination of compiler, compiler flags, libraries, |
545 |
necessary to build a particular configuration of MITgcm. In such |
and other options necessary to build a particular configuration of |
546 |
cases, it is generally helpful to read the existing ``optfiles'' and |
MITgcm. In such cases, it is generally helpful to read the existing |
547 |
mimic their syntax. |
``optfiles'' and mimic their syntax. |
548 |
|
|
549 |
Through the MITgcm-support list, the MITgcm developers are willing to |
Through the MITgcm-support list, the MITgcm developers are willing to |
550 |
provide help writing or modifing ``optfiles''. And we encourage users |
provide help writing or modifing ``optfiles''. And we encourage users |
555 |
\begin{rawhtml} </A> \end{rawhtml} |
\begin{rawhtml} </A> \end{rawhtml} |
556 |
list. |
list. |
557 |
|
|
558 |
To specify an optfile to {\em genmake2}, the syntax is: |
To specify an optfile to \texttt{genmake2}, the syntax is: |
559 |
\begin{verbatim} |
\begin{verbatim} |
560 |
% ../../../tools/genmake2 -mods=../code -of /path/to/optfile |
% ../../../tools/genmake2 -mods=../code -of /path/to/optfile |
561 |
\end{verbatim} |
\end{verbatim} |
562 |
|
|
563 |
Once a {\em Makefile} has been generated, we create the dependencies: |
Once a \texttt{Makefile} has been generated, we create the |
564 |
|
dependencies with the command: |
565 |
\begin{verbatim} |
\begin{verbatim} |
566 |
% make depend |
% make depend |
567 |
\end{verbatim} |
\end{verbatim} |
568 |
This modifies the {\em Makefile} by attaching a [long] list of files |
This modifies the \texttt{Makefile} by attaching a (usually, long) |
569 |
upon which other files depend. The purpose of this is to reduce |
list of files upon which other files depend. The purpose of this is to |
570 |
re-compilation if and when you start to modify the code. The {\tt make |
reduce re-compilation if and when you start to modify the code. The |
571 |
depend} command also creates links from the model source to this |
{\tt make depend} command also creates links from the model source to |
572 |
directory. |
this directory. It is important to note that the {\tt make depend} |
573 |
|
stage will occasionally produce warnings or errors since the |
574 |
|
dependency parsing tool is unable to find all of the necessary header |
575 |
|
files (\textit{eg.} \texttt{netcdf.inc}). In these circumstances, it |
576 |
|
is usually OK to ignore the warnings/errors and proceed to the next |
577 |
|
step. |
578 |
|
|
579 |
Next compile the code: |
Next one can compile the code using: |
580 |
\begin{verbatim} |
\begin{verbatim} |
581 |
% make |
% make |
582 |
\end{verbatim} |
\end{verbatim} |
583 |
The {\tt make} command creates an executable called \textit{mitgcmuv}. |
The {\tt make} command creates an executable called \texttt{mitgcmuv}. |
584 |
Additional make ``targets'' are defined within the makefile to aid in |
Additional make ``targets'' are defined within the makefile to aid in |
585 |
the production of adjoint and other versions of MITgcm. |
the production of adjoint and other versions of MITgcm. On SMP |
586 |
|
(shared multi-processor) systems, the build process can often be sped |
587 |
Now you are ready to run the model. General instructions for doing so are |
up appreciably using the command: |
|
given in section \ref{sect:runModel}. Here, we can run the model with: |
|
|
\begin{verbatim} |
|
|
./mitgcmuv > output.txt |
|
|
\end{verbatim} |
|
|
where we are re-directing the stream of text output to the file {\em |
|
|
output.txt}. |
|
|
|
|
|
|
|
|
\subsection{Building/compiling the code elsewhere} |
|
|
|
|
|
In the example above (section \ref{sect:buildingCode}) we built the |
|
|
executable in the {\em input} directory of the experiment for |
|
|
convenience. You can also configure and compile the code in other |
|
|
locations, for example on a scratch disk with out having to copy the |
|
|
entire source tree. The only requirement to do so is you have {\tt |
|
|
genmake2} in your path or you know the absolute path to {\tt |
|
|
genmake2}. |
|
|
|
|
|
The following sections outline some possible methods of organizing |
|
|
your source and data. |
|
|
|
|
|
\subsubsection{Building from the {\em ../code directory}} |
|
|
|
|
|
This is just as simple as building in the {\em input/} directory: |
|
588 |
\begin{verbatim} |
\begin{verbatim} |
589 |
% cd verification/exp2/code |
% make -j 2 |
|
% ../../../tools/genmake2 |
|
|
% make depend |
|
|
% make |
|
|
\end{verbatim} |
|
|
However, to run the model the executable ({\em mitgcmuv}) and input |
|
|
files must be in the same place. If you only have one calculation to make: |
|
|
\begin{verbatim} |
|
|
% cd ../input |
|
|
% cp ../code/mitgcmuv ./ |
|
|
% ./mitgcmuv > output.txt |
|
|
\end{verbatim} |
|
|
or if you will be making multiple runs with the same executable: |
|
|
\begin{verbatim} |
|
|
% cd ../ |
|
|
% cp -r input run1 |
|
|
% cp code/mitgcmuv run1 |
|
|
% cd run1 |
|
|
% ./mitgcmuv > output.txt |
|
590 |
\end{verbatim} |
\end{verbatim} |
591 |
|
where the ``2'' can be replaced with a number that corresponds to the |
592 |
|
number of CPUs available. |
593 |
|
|
594 |
\subsubsection{Building from a new directory} |
Now you are ready to run the model. General instructions for doing so are |
595 |
|
given in section \ref{sect:runModel}. Here, we can run the model by |
596 |
Since the {\em input} directory contains input files it is often more |
first creating links to all the input files: |
|
useful to keep {\em input} pristine and build in a new directory |
|
|
within {\em verification/exp2/}: |
|
|
\begin{verbatim} |
|
|
% cd verification/exp2 |
|
|
% mkdir build |
|
|
% cd build |
|
|
% ../../../tools/genmake2 -mods=../code |
|
|
% make depend |
|
|
% make |
|
|
\end{verbatim} |
|
|
This builds the code exactly as before but this time you need to copy |
|
|
either the executable or the input files or both in order to run the |
|
|
model. For example, |
|
|
\begin{verbatim} |
|
|
% cp ../input/* ./ |
|
|
% ./mitgcmuv > output.txt |
|
|
\end{verbatim} |
|
|
or if you tend to make multiple runs with the same executable then |
|
|
running in a new directory each time might be more appropriate: |
|
|
\begin{verbatim} |
|
|
% cd ../ |
|
|
% mkdir run1 |
|
|
% cp build/mitgcmuv run1/ |
|
|
% cp input/* run1/ |
|
|
% cd run1 |
|
|
% ./mitgcmuv > output.txt |
|
|
\end{verbatim} |
|
|
|
|
|
\subsubsection{Building on a scratch disk} |
|
|
|
|
|
Model object files and output data can use up large amounts of disk |
|
|
space so it is often the case that you will be operating on a large |
|
|
scratch disk. Assuming the model source is in {\em ~/MITgcm} then the |
|
|
following commands will build the model in {\em /scratch/exp2-run1}: |
|
|
\begin{verbatim} |
|
|
% cd /scratch/exp2-run1 |
|
|
% ~/MITgcm/tools/genmake2 -rootdir=~/MITgcm \ |
|
|
-mods=~/MITgcm/verification/exp2/code |
|
|
% make depend |
|
|
% make |
|
|
\end{verbatim} |
|
|
To run the model here, you'll need the input files: |
|
597 |
\begin{verbatim} |
\begin{verbatim} |
598 |
% cp ~/MITgcm/verification/exp2/input/* ./ |
ln -s ../input/* . |
|
% ./mitgcmuv > output.txt |
|
599 |
\end{verbatim} |
\end{verbatim} |
600 |
|
and then calling the executable with: |
|
As before, you could build in one directory and make multiple runs of |
|
|
the one experiment: |
|
601 |
\begin{verbatim} |
\begin{verbatim} |
602 |
% cd /scratch/exp2 |
./mitgcmuv > output.txt |
|
% mkdir build |
|
|
% cd build |
|
|
% ~/MITgcm/tools/genmake2 -rootdir=~/MITgcm \ |
|
|
-mods=~/MITgcm/verification/exp2/code |
|
|
% make depend |
|
|
% make |
|
|
% cd ../ |
|
|
% cp -r ~/MITgcm/verification/exp2/input run2 |
|
|
% cd run2 |
|
|
% ./mitgcmuv > output.txt |
|
603 |
\end{verbatim} |
\end{verbatim} |
604 |
|
where we are re-directing the stream of text output to the file |
605 |
|
\texttt{output.txt}. |
606 |
|
|
607 |
|
|
608 |
\subsection{Using \texttt{genmake2}} |
\section[Running MITgcm]{Running the model in prognostic mode} |
|
\label{sect:genmake} |
|
|
|
|
|
To compile the code, first use the program \texttt{genmake2} (located |
|
|
in the \texttt{tools} directory) to generate a Makefile. |
|
|
\texttt{genmake2} is a shell script written to work with all |
|
|
``sh''--compatible shells including bash v1, bash v2, and Bourne. |
|
|
Internally, \texttt{genmake2} determines the locations of needed |
|
|
files, the compiler, compiler options, libraries, and Unix tools. It |
|
|
relies upon a number of ``optfiles'' located in the |
|
|
\texttt{tools/build\_options} directory. |
|
|
|
|
|
The purpose of the optfiles is to provide all the compilation options |
|
|
for particular ``platforms'' (where ``platform'' roughly means the |
|
|
combination of the hardware and the compiler) and code configurations. |
|
|
Given the combinations of possible compilers and library dependencies |
|
|
({\it eg.} MPI and NetCDF) there may be numerous optfiles available |
|
|
for a single machine. The naming scheme for the majority of the |
|
|
optfiles shipped with the code is |
|
|
\begin{center} |
|
|
{\bf OS\_HARDWARE\_COMPILER } |
|
|
\end{center} |
|
|
where |
|
|
\begin{description} |
|
|
\item[OS] is the name of the operating system (generally the |
|
|
lower-case output of the {\tt 'uname'} command) |
|
|
\item[HARDWARE] is a string that describes the CPU type and |
|
|
corresponds to output from the {\tt 'uname -m'} command: |
|
|
\begin{description} |
|
|
\item[ia32] is for ``x86'' machines such as i386, i486, i586, i686, |
|
|
and athlon |
|
|
\item[ia64] is for Intel IA64 systems (eg. Itanium, Itanium2) |
|
|
\item[amd64] is AMD x86\_64 systems |
|
|
\item[ppc] is for Mac PowerPC systems |
|
|
\end{description} |
|
|
\item[COMPILER] is the compiler name (generally, the name of the |
|
|
FORTRAN executable) |
|
|
\end{description} |
|
|
|
|
|
In many cases, the default optfiles are sufficient and will result in |
|
|
usable Makefiles. However, for some machines or code configurations, |
|
|
new ``optfiles'' must be written. To create a new optfile, it is |
|
|
generally best to start with one of the defaults and modify it to suit |
|
|
your needs. Like \texttt{genmake2}, the optfiles are all written |
|
|
using a simple ``sh''--compatible syntax. While nearly all variables |
|
|
used within \texttt{genmake2} may be specified in the optfiles, the |
|
|
critical ones that should be defined are: |
|
|
|
|
|
\begin{description} |
|
|
\item[FC] the FORTRAN compiler (executable) to use |
|
|
\item[DEFINES] the command-line DEFINE options passed to the compiler |
|
|
\item[CPP] the C pre-processor to use |
|
|
\item[NOOPTFLAGS] options flags for special files that should not be |
|
|
optimized |
|
|
\end{description} |
|
|
|
|
|
For example, the optfile for a typical Red Hat Linux machine (``ia32'' |
|
|
architecture) using the GCC (g77) compiler is |
|
|
\begin{verbatim} |
|
|
FC=g77 |
|
|
DEFINES='-D_BYTESWAPIO -DWORDLENGTH=4' |
|
|
CPP='cpp -traditional -P' |
|
|
NOOPTFLAGS='-O0' |
|
|
# For IEEE, use the "-ffloat-store" option |
|
|
if test "x$IEEE" = x ; then |
|
|
FFLAGS='-Wimplicit -Wunused -Wuninitialized' |
|
|
FOPTIM='-O3 -malign-double -funroll-loops' |
|
|
else |
|
|
FFLAGS='-Wimplicit -Wunused -ffloat-store' |
|
|
FOPTIM='-O0 -malign-double' |
|
|
fi |
|
|
\end{verbatim} |
|
|
|
|
|
If you write an optfile for an unrepresented machine or compiler, you |
|
|
are strongly encouraged to submit the optfile to the MITgcm project |
|
|
for inclusion. Please send the file to the |
|
|
\begin{rawhtml} <A href="mail-to:MITgcm-support@mitgcm.org"> \end{rawhtml} |
|
|
\begin{center} |
|
|
MITgcm-support@mitgcm.org |
|
|
\end{center} |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
|
|
mailing list. |
|
|
|
|
|
In addition to the optfiles, \texttt{genmake2} supports a number of |
|
|
helpful command-line options. A complete list of these options can be |
|
|
obtained from: |
|
|
\begin{verbatim} |
|
|
% genmake2 -h |
|
|
\end{verbatim} |
|
|
|
|
|
The most important command-line options are: |
|
|
\begin{description} |
|
|
|
|
|
\item[\texttt{--optfile=/PATH/FILENAME}] specifies the optfile that |
|
|
should be used for a particular build. |
|
|
|
|
|
If no "optfile" is specified (either through the command line or the |
|
|
MITGCM\_OPTFILE environment variable), genmake2 will try to make a |
|
|
reasonable guess from the list provided in {\em |
|
|
tools/build\_options}. The method used for making this guess is |
|
|
to first determine the combination of operating system and hardware |
|
|
(eg. "linux\_ia32") and then find a working FORTRAN compiler within |
|
|
the user's path. When these three items have been identified, |
|
|
genmake2 will try to find an optfile that has a matching name. |
|
|
|
|
|
\item[\texttt{--pdefault='PKG1 PKG2 PKG3 ...'}] specifies the default |
|
|
set of packages to be used. The normal order of precedence for |
|
|
packages is as follows: |
|
|
\begin{enumerate} |
|
|
\item If available, the command line (\texttt{--pdefault}) settings |
|
|
over-rule any others. |
|
|
|
|
|
\item Next, \texttt{genmake2} will look for a file named |
|
|
``\texttt{packages.conf}'' in the local directory or in any of the |
|
|
directories specified with the \texttt{--mods} option. |
|
|
|
|
|
\item Finally, if neither of the above are available, |
|
|
\texttt{genmake2} will use the \texttt{/pkg/pkg\_default} file. |
|
|
\end{enumerate} |
|
|
|
|
|
\item[\texttt{--pdepend=/PATH/FILENAME}] specifies the dependency file |
|
|
used for packages. |
|
|
|
|
|
If not specified, the default dependency file {\em pkg/pkg\_depend} |
|
|
is used. The syntax for this file is parsed on a line-by-line basis |
|
|
where each line containes either a comment ("\#") or a simple |
|
|
"PKGNAME1 (+|-)PKGNAME2" pairwise rule where the "+" or "-" symbol |
|
|
specifies a "must be used with" or a "must not be used with" |
|
|
relationship, respectively. If no rule is specified, then it is |
|
|
assumed that the two packages are compatible and will function |
|
|
either with or without each other. |
|
|
|
|
|
\item[\texttt{--adof=/path/to/file}] specifies the "adjoint" or |
|
|
automatic differentiation options file to be used. The file is |
|
|
analogous to the ``optfile'' defined above but it specifies |
|
|
information for the AD build process. |
|
|
|
|
|
The default file is located in {\em |
|
|
tools/adjoint\_options/adjoint\_default} and it defines the "TAF" |
|
|
and "TAMC" compilers. An alternate version is also available at |
|
|
{\em tools/adjoint\_options/adjoint\_staf} that selects the newer |
|
|
"STAF" compiler. As with any compilers, it is helpful to have their |
|
|
directories listed in your {\tt \$PATH} environment variable. |
|
|
|
|
|
\item[\texttt{--mods='DIR1 DIR2 DIR3 ...'}] specifies a list of |
|
|
directories containing ``modifications''. These directories contain |
|
|
files with names that may (or may not) exist in the main MITgcm |
|
|
source tree but will be overridden by any identically-named sources |
|
|
within the ``MODS'' directories. |
|
|
|
|
|
The order of precedence for this "name-hiding" is as follows: |
|
|
\begin{itemize} |
|
|
\item ``MODS'' directories (in the order given) |
|
|
\item Packages either explicitly specified or provided by default |
|
|
(in the order given) |
|
|
\item Packages included due to package dependencies (in the order |
|
|
that that package dependencies are parsed) |
|
|
\item The "standard dirs" (which may have been specified by the |
|
|
``-standarddirs'' option) |
|
|
\end{itemize} |
|
|
|
|
|
\item[\texttt{--mpi}] This option enables certain MPI features (using |
|
|
CPP \texttt{\#define}s) within the code and is necessary for MPI |
|
|
builds (see Section \ref{sect:mpi-build}). |
|
|
|
|
|
\item[\texttt{--make=/path/to/gmake}] Due to the poor handling of |
|
|
soft-links and other bugs common with the \texttt{make} versions |
|
|
provided by commercial Unix vendors, GNU \texttt{make} (sometimes |
|
|
called \texttt{gmake}) should be preferred. This option provides a |
|
|
means for specifying the make executable to be used. |
|
|
|
|
|
\item[\texttt{--bash=/path/to/sh}] On some (usually older UNIX) |
|
|
machines, the ``bash'' shell is unavailable. To run on these |
|
|
systems, \texttt{genmake2} can be invoked using an ``sh'' (that is, |
|
|
a Bourne, POSIX, or compatible) shell. The syntax in these |
|
|
circumstances is: |
|
|
\begin{center} |
|
|
\texttt{\% /bin/sh genmake2 -bash=/bin/sh [...options...]} |
|
|
\end{center} |
|
|
where \texttt{/bin/sh} can be replaced with the full path and name |
|
|
of the desired shell. |
|
|
|
|
|
\end{description} |
|
|
|
|
|
|
|
|
\subsection{Building with MPI} |
|
|
\label{sect:mpi-build} |
|
|
|
|
|
Building MITgcm to use MPI libraries can be complicated due to the |
|
|
variety of different MPI implementations available, their dependencies |
|
|
or interactions with different compilers, and their often ad-hoc |
|
|
locations within file systems. For these reasons, its generally a |
|
|
good idea to start by finding and reading the documentation for your |
|
|
machine(s) and, if necessary, seeking help from your local systems |
|
|
administrator. |
|
|
|
|
|
The steps for building MITgcm with MPI support are: |
|
|
\begin{enumerate} |
|
|
|
|
|
\item Determine the locations of your MPI-enabled compiler and/or MPI |
|
|
libraries and put them into an options file as described in Section |
|
|
\ref{sect:genmake}. One can start with one of the examples in: |
|
|
\begin{rawhtml} <A |
|
|
href="http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm/tools/build_options/"> |
|
|
\end{rawhtml} |
|
|
\begin{center} |
|
|
\texttt{MITgcm/tools/build\_options/} |
|
|
\end{center} |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
|
|
such as \texttt{linux\_ia32\_g77+mpi\_cg01} or |
|
|
\texttt{linux\_ia64\_efc+mpi} and then edit it to suit the machine at |
|
|
hand. You may need help from your user guide or local systems |
|
|
administrator to determine the exact location of the MPI libraries. |
|
|
If libraries are not installed, MPI implementations and related |
|
|
tools are available including: |
|
|
\begin{itemize} |
|
|
\item \begin{rawhtml} <A |
|
|
href="http://www-unix.mcs.anl.gov/mpi/mpich/"> |
|
|
\end{rawhtml} |
|
|
MPICH |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
|
|
|
|
|
\item \begin{rawhtml} <A |
|
|
href="http://www.lam-mpi.org/"> |
|
|
\end{rawhtml} |
|
|
LAM/MPI |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
|
|
|
|
|
\item \begin{rawhtml} <A |
|
|
href="http://www.osc.edu/~pw/mpiexec/"> |
|
|
\end{rawhtml} |
|
|
MPIexec |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
|
|
\end{itemize} |
|
|
|
|
|
\item Build the code with the \texttt{genmake2} \texttt{-mpi} option |
|
|
(see Section \ref{sect:genmake}) using commands such as: |
|
|
{\footnotesize \begin{verbatim} |
|
|
% ../../../tools/genmake2 -mods=../code -mpi -of=YOUR_OPTFILE |
|
|
% make depend |
|
|
% make |
|
|
\end{verbatim} } |
|
|
|
|
|
\item Run the code with the appropriate MPI ``run'' or ``exec'' |
|
|
program provided with your particular implementation of MPI. |
|
|
Typical MPI packages such as MPICH will use something like: |
|
|
\begin{verbatim} |
|
|
% mpirun -np 4 -machinefile mf ./mitgcmuv |
|
|
\end{verbatim} |
|
|
Sightly more complicated scripts may be needed for many machines |
|
|
since execution of the code may be controlled by both the MPI |
|
|
library and a job scheduling and queueing system such as PBS, |
|
|
LoadLeveller, Condor, or any of a number of similar tools. A few |
|
|
example scripts (those used for our \begin{rawhtml} <A |
|
|
href="http://mitgcm.org/testing.html"> \end{rawhtml}regular |
|
|
verification runs\begin{rawhtml} </A> \end{rawhtml}) are available |
|
|
at: |
|
|
\begin{rawhtml} <A |
|
|
href="http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm_contrib/test_scripts/"> |
|
|
\end{rawhtml} |
|
|
{\footnotesize \tt |
|
|
http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm\_contrib/test\_scripts/ } |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
|
|
|
|
|
\end{enumerate} |
|
|
|
|
|
|
|
|
|
|
|
\section{Running the model} |
|
609 |
\label{sect:runModel} |
\label{sect:runModel} |
610 |
|
\begin{rawhtml} |
611 |
|
<!-- CMIREDIR:runModel: --> |
612 |
|
\end{rawhtml} |
613 |
|
|
614 |
If compilation finished succesfuully (section \ref{sect:buildingCode}) |
If compilation finished succesfully (section \ref{sect:buildingCode}) |
615 |
then an executable called \texttt{mitgcmuv} will now exist in the |
then an executable called \texttt{mitgcmuv} will now exist in the |
616 |
local directory. |
local directory. |
617 |
|
|
618 |
To run the model as a single process (ie. not in parallel) simply |
To run the model as a single process (\textit{ie.} not in parallel) |
619 |
type: |
simply type: |
620 |
\begin{verbatim} |
\begin{verbatim} |
621 |
% ./mitgcmuv |
% ./mitgcmuv |
622 |
\end{verbatim} |
\end{verbatim} |
626 |
your screen. This output contains details such as parameter values as |
your screen. This output contains details such as parameter values as |
627 |
well as diagnostics such as mean Kinetic energy, largest CFL number, |
well as diagnostics such as mean Kinetic energy, largest CFL number, |
628 |
etc. It is worth keeping this text output with the binary output so we |
etc. It is worth keeping this text output with the binary output so we |
629 |
normally re-direct the {\em stdout} stream as follows: |
normally re-direct the \texttt{stdout} stream as follows: |
630 |
\begin{verbatim} |
\begin{verbatim} |
631 |
% ./mitgcmuv > output.txt |
% ./mitgcmuv > output.txt |
632 |
\end{verbatim} |
\end{verbatim} |
633 |
|
In the event that the model encounters an error and stops, it is very |
634 |
For the example experiments in {\em verification}, an example of the |
helpful to include the last few line of this \texttt{output.txt} file |
635 |
output is kept in {\em results/output.txt} for comparison. You can compare |
along with the (\texttt{stderr}) error message within any bug reports. |
636 |
your {\em output.txt} with this one to check that the set-up works. |
|
637 |
|
For the example experiments in \texttt{verification}, an example of the |
638 |
|
output is kept in \texttt{results/output.txt} for comparison. You can |
639 |
|
compare your \texttt{output.txt} with the corresponding one for that |
640 |
|
experiment to check that the set-up works. |
641 |
|
|
642 |
|
|
643 |
|
|
644 |
\subsection{Output files} |
\subsection{Output files} |
645 |
|
|
646 |
The model produces various output files. At a minimum, the instantaneous |
The model produces various output files and, when using \texttt{mnc}, |
647 |
``state'' of the model is written out, which is made of the following files: |
sometimes even directories. Depending upon the I/O package(s) |
648 |
|
selected at compile time (either \texttt{mdsio} or \texttt{mnc} or |
649 |
|
both as determined by \texttt{code/packages.conf}) and the run-time |
650 |
|
flags set (in \texttt{input/data.pkg}), the following output may |
651 |
|
appear. |
652 |
|
|
653 |
|
|
654 |
|
\subsubsection{MDSIO output files} |
655 |
|
|
656 |
|
The ``traditional'' output files are generated by the \texttt{mdsio} |
657 |
|
package. At a minimum, the instantaneous ``state'' of the model is |
658 |
|
written out, which is made of the following files: |
659 |
|
|
660 |
\begin{itemize} |
\begin{itemize} |
661 |
\item \textit{U.00000nIter} - zonal component of velocity field (m/s and $> |
\item \texttt{U.00000nIter} - zonal component of velocity field (m/s and $> |
662 |
0 $ eastward). |
0 $ eastward). |
663 |
|
|
664 |
\item \textit{V.00000nIter} - meridional component of velocity field (m/s |
\item \texttt{V.00000nIter} - meridional component of velocity field (m/s |
665 |
and $> 0$ northward). |
and $> 0$ northward). |
666 |
|
|
667 |
\item \textit{W.00000nIter} - vertical component of velocity field (ocean: |
\item \texttt{W.00000nIter} - vertical component of velocity field (ocean: |
668 |
m/s and $> 0$ upward, atmosphere: Pa/s and $> 0$ towards increasing pressure |
m/s and $> 0$ upward, atmosphere: Pa/s and $> 0$ towards increasing pressure |
669 |
i.e. downward). |
i.e. downward). |
670 |
|
|
671 |
\item \textit{T.00000nIter} - potential temperature (ocean: $^{0}$C, |
\item \texttt{T.00000nIter} - potential temperature (ocean: $^{0}$C, |
672 |
atmosphere: $^{0}$K). |
atmosphere: $^{0}$K). |
673 |
|
|
674 |
\item \textit{S.00000nIter} - ocean: salinity (psu), atmosphere: water vapor |
\item \texttt{S.00000nIter} - ocean: salinity (psu), atmosphere: water vapor |
675 |
(g/kg). |
(g/kg). |
676 |
|
|
677 |
\item \textit{Eta.00000nIter} - ocean: surface elevation (m), atmosphere: |
\item \texttt{Eta.00000nIter} - ocean: surface elevation (m), atmosphere: |
678 |
surface pressure anomaly (Pa). |
surface pressure anomaly (Pa). |
679 |
\end{itemize} |
\end{itemize} |
680 |
|
|
681 |
The chain \textit{00000nIter} consists of ten figures that specify the |
The chain \texttt{00000nIter} consists of ten figures that specify the |
682 |
iteration number at which the output is written out. For example, \textit{% |
iteration number at which the output is written out. For example, \texttt{% |
683 |
U.0000000300} is the zonal velocity at iteration 300. |
U.0000000300} is the zonal velocity at iteration 300. |
684 |
|
|
685 |
In addition, a ``pickup'' or ``checkpoint'' file called: |
In addition, a ``pickup'' or ``checkpoint'' file called: |
686 |
|
|
687 |
\begin{itemize} |
\begin{itemize} |
688 |
\item \textit{pickup.00000nIter} |
\item \texttt{pickup.00000nIter} |
689 |
\end{itemize} |
\end{itemize} |
690 |
|
|
691 |
is written out. This file represents the state of the model in a condensed |
is written out. This file represents the state of the model in a condensed |
693 |
there is an additional ``pickup'' file: |
there is an additional ``pickup'' file: |
694 |
|
|
695 |
\begin{itemize} |
\begin{itemize} |
696 |
\item \textit{pickup\_cd.00000nIter} |
\item \texttt{pickup\_cd.00000nIter} |
697 |
\end{itemize} |
\end{itemize} |
698 |
|
|
699 |
containing the D-grid velocity data and that has to be written out as well |
containing the D-grid velocity data and that has to be written out as well |
700 |
in order to restart the integration. Rolling checkpoint files are the same |
in order to restart the integration. Rolling checkpoint files are the same |
701 |
as the pickup files but are named differently. Their name contain the chain |
as the pickup files but are named differently. Their name contain the chain |
702 |
\textit{ckptA} or \textit{ckptB} instead of \textit{00000nIter}. They can be |
\texttt{ckptA} or \texttt{ckptB} instead of \texttt{00000nIter}. They can be |
703 |
used to restart the model but are overwritten every other time they are |
used to restart the model but are overwritten every other time they are |
704 |
output to save disk space during long integrations. |
output to save disk space during long integrations. |
705 |
|
|
706 |
|
|
707 |
|
|
708 |
|
\subsubsection{MNC output files} |
709 |
|
|
710 |
|
Unlike the \texttt{mdsio} output, the \texttt{mnc}--generated output |
711 |
|
is usually (though not necessarily) placed within a subdirectory with |
712 |
|
a name such as \texttt{mnc\_test\_\${DATE}\_\${SEQ}}. The files |
713 |
|
within this subdirectory are all in the ``self-describing'' netCDF |
714 |
|
format and can thus be browsed and/or plotted using tools such as: |
715 |
|
\begin{itemize} |
716 |
|
\item \texttt{ncdump} is a utility which is typically included |
717 |
|
with every netCDF install: |
718 |
|
\begin{rawhtml} <A href="http://www.unidata.ucar.edu/packages/netcdf/"> \end{rawhtml} |
719 |
|
\begin{verbatim} |
720 |
|
http://www.unidata.ucar.edu/packages/netcdf/ |
721 |
|
\end{verbatim} |
722 |
|
\begin{rawhtml} </A> \end{rawhtml} and it converts the netCDF |
723 |
|
binaries into formatted ASCII text files. |
724 |
|
|
725 |
|
\item \texttt{ncview} utility is a very convenient and quick way |
726 |
|
to plot netCDF data and it runs on most OSes: |
727 |
|
\begin{rawhtml} <A href="http://meteora.ucsd.edu/~pierce/ncview_home_page.html"> \end{rawhtml} |
728 |
|
\begin{verbatim} |
729 |
|
http://meteora.ucsd.edu/~pierce/ncview_home_page.html |
730 |
|
\end{verbatim} |
731 |
|
\begin{rawhtml} </A> \end{rawhtml} |
732 |
|
|
733 |
|
\item MatLAB(c) and other common post-processing environments provide |
734 |
|
various netCDF interfaces including: |
735 |
|
\begin{rawhtml} <A href="http://woodshole.er.usgs.gov/staffpages/cdenham/public_html/MexCDF/nc4ml5.html"> \end{rawhtml} |
736 |
|
\begin{verbatim} |
737 |
|
http://woodshole.er.usgs.gov/staffpages/cdenham/public_html/MexCDF/nc4ml5.html |
738 |
|
\end{verbatim} |
739 |
|
\begin{rawhtml} </A> \end{rawhtml} |
740 |
|
\end{itemize} |
741 |
|
|
742 |
|
|
743 |
\subsection{Looking at the output} |
\subsection{Looking at the output} |
744 |
|
|
745 |
All the model data are written according to a ``meta/data'' file format. |
The ``traditional'' or mdsio model data are written according to a |
746 |
Each variable is associated with two files with suffix names \textit{.data} |
``meta/data'' file format. Each variable is associated with two files |
747 |
and \textit{.meta}. The \textit{.data} file contains the data written in |
with suffix names \texttt{.data} and \texttt{.meta}. The |
748 |
binary form (big\_endian by default). The \textit{.meta} file is a |
\texttt{.data} file contains the data written in binary form |
749 |
``header'' file that contains information about the size and the structure |
(big\_endian by default). The \texttt{.meta} file is a ``header'' file |
750 |
of the \textit{.data} file. This way of organizing the output is |
that contains information about the size and the structure of the |
751 |
particularly useful when running multi-processors calculations. The base |
\texttt{.data} file. This way of organizing the output is particularly |
752 |
version of the model includes a few matlab utilities to read output files |
useful when running multi-processors calculations. The base version of |
753 |
written in this format. The matlab scripts are located in the directory |
the model includes a few matlab utilities to read output files written |
754 |
\textit{utils/matlab} under the root tree. The script \textit{rdmds.m} reads |
in this format. The matlab scripts are located in the directory |
755 |
the data. Look at the comments inside the script to see how to use it. |
\texttt{utils/matlab} under the root tree. The script \texttt{rdmds.m} |
756 |
|
reads the data. Look at the comments inside the script to see how to |
757 |
|
use it. |
758 |
|
|
759 |
Some examples of reading and visualizing some output in {\em Matlab}: |
Some examples of reading and visualizing some output in {\em Matlab}: |
760 |
\begin{verbatim} |
\begin{verbatim} |
771 |
>> for n=1:11; imagesc(eta(:,:,n)');axis ij;colorbar;pause(.5);end |
>> for n=1:11; imagesc(eta(:,:,n)');axis ij;colorbar;pause(.5);end |
772 |
\end{verbatim} |
\end{verbatim} |
773 |
|
|
774 |
\section{Doing it yourself: customizing the code} |
Similar scripts for netCDF output (\texttt{rdmnc.m}) are available and |
775 |
|
they are described in Section \ref{sec:pkg:mnc}. |
776 |
|
|
|
When you are ready to run the model in the configuration you want, the |
|
|
easiest thing is to use and adapt the setup of the case studies |
|
|
experiment (described previously) that is the closest to your |
|
|
configuration. Then, the amount of setup will be minimized. In this |
|
|
section, we focus on the setup relative to the ``numerical model'' |
|
|
part of the code (the setup relative to the ``execution environment'' |
|
|
part is covered in the parallel implementation section) and on the |
|
|
variables and parameters that you are likely to change. |
|
|
|
|
|
\subsection{Configuration and setup} |
|
|
|
|
|
The CPP keys relative to the ``numerical model'' part of the code are |
|
|
all defined and set in the file \textit{CPP\_OPTIONS.h }in the |
|
|
directory \textit{ model/inc }or in one of the \textit{code |
|
|
}directories of the case study experiments under |
|
|
\textit{verification.} The model parameters are defined and declared |
|
|
in the file \textit{model/inc/PARAMS.h }and their default values are |
|
|
set in the routine \textit{model/src/set\_defaults.F. }The default |
|
|
values can be modified in the namelist file \textit{data }which needs |
|
|
to be located in the directory where you will run the model. The |
|
|
parameters are initialized in the routine |
|
|
\textit{model/src/ini\_parms.F}. Look at this routine to see in what |
|
|
part of the namelist the parameters are located. |
|
|
|
|
|
In what follows the parameters are grouped into categories related to |
|
|
the computational domain, the equations solved in the model, and the |
|
|
simulation controls. |
|
|
|
|
|
\subsection{Computational domain, geometry and time-discretization} |
|
|
|
|
|
\begin{description} |
|
|
\item[dimensions] \ |
|
|
|
|
|
The number of points in the x, y, and r directions are represented |
|
|
by the variables \textbf{sNx}, \textbf{sNy} and \textbf{Nr} |
|
|
respectively which are declared and set in the file |
|
|
\textit{model/inc/SIZE.h}. (Again, this assumes a mono-processor |
|
|
calculation. For multiprocessor calculations see the section on |
|
|
parallel implementation.) |
|
|
|
|
|
\item[grid] \ |
|
|
|
|
|
Three different grids are available: cartesian, spherical polar, and |
|
|
curvilinear (which includes the cubed sphere). The grid is set |
|
|
through the logical variables \textbf{usingCartesianGrid}, |
|
|
\textbf{usingSphericalPolarGrid}, and \textbf{usingCurvilinearGrid}. |
|
|
In the case of spherical and curvilinear grids, the southern |
|
|
boundary is defined through the variable \textbf{phiMin} which |
|
|
corresponds to the latitude of the southern most cell face (in |
|
|
degrees). The resolution along the x and y directions is controlled |
|
|
by the 1D arrays \textbf{delx} and \textbf{dely} (in meters in the |
|
|
case of a cartesian grid, in degrees otherwise). The vertical grid |
|
|
spacing is set through the 1D array \textbf{delz} for the ocean (in |
|
|
meters) or \textbf{delp} for the atmosphere (in Pa). The variable |
|
|
\textbf{Ro\_SeaLevel} represents the standard position of Sea-Level |
|
|
in ``R'' coordinate. This is typically set to 0m for the ocean |
|
|
(default value) and 10$^{5}$Pa for the atmosphere. For the |
|
|
atmosphere, also set the logical variable \textbf{groundAtK1} to |
|
|
\texttt{'.TRUE.'} which puts the first level (k=1) at the lower |
|
|
boundary (ground). |
|
|
|
|
|
For the cartesian grid case, the Coriolis parameter $f$ is set |
|
|
through the variables \textbf{f0} and \textbf{beta} which correspond |
|
|
to the reference Coriolis parameter (in s$^{-1}$) and |
|
|
$\frac{\partial f}{ \partial y}$(in m$^{-1}$s$^{-1}$) respectively. |
|
|
If \textbf{beta } is set to a nonzero value, \textbf{f0} is the |
|
|
value of $f$ at the southern edge of the domain. |
|
|
|
|
|
\item[topography - full and partial cells] \ |
|
|
|
|
|
The domain bathymetry is read from a file that contains a 2D (x,y) |
|
|
map of depths (in m) for the ocean or pressures (in Pa) for the |
|
|
atmosphere. The file name is represented by the variable |
|
|
\textbf{bathyFile}. The file is assumed to contain binary numbers |
|
|
giving the depth (pressure) of the model at each grid cell, ordered |
|
|
with the x coordinate varying fastest. The points are ordered from |
|
|
low coordinate to high coordinate for both axes. The model code |
|
|
applies without modification to enclosed, periodic, and double |
|
|
periodic domains. Periodicity is assumed by default and is |
|
|
suppressed by setting the depths to 0m for the cells at the limits |
|
|
of the computational domain (note: not sure this is the case for the |
|
|
atmosphere). The precision with which to read the binary data is |
|
|
controlled by the integer variable \textbf{readBinaryPrec} which can |
|
|
take the value \texttt{32} (single precision) or \texttt{64} (double |
|
|
precision). See the matlab program \textit{gendata.m} in the |
|
|
\textit{input} directories under \textit{verification} to see how |
|
|
the bathymetry files are generated for the case study experiments. |
|
|
|
|
|
To use the partial cell capability, the variable \textbf{hFacMin} |
|
|
needs to be set to a value between 0 and 1 (it is set to 1 by |
|
|
default) corresponding to the minimum fractional size of the cell. |
|
|
For example if the bottom cell is 500m thick and \textbf{hFacMin} is |
|
|
set to 0.1, the actual thickness of the cell (i.e. used in the code) |
|
|
can cover a range of discrete values 50m apart from 50m to 500m |
|
|
depending on the value of the bottom depth (in \textbf{bathyFile}) |
|
|
at this point. |
|
|
|
|
|
Note that the bottom depths (or pressures) need not coincide with |
|
|
the models levels as deduced from \textbf{delz} or \textbf{delp}. |
|
|
The model will interpolate the numbers in \textbf{bathyFile} so that |
|
|
they match the levels obtained from \textbf{delz} or \textbf{delp} |
|
|
and \textbf{hFacMin}. |
|
|
|
|
|
(Note: the atmospheric case is a bit more complicated than what is |
|
|
written here I think. To come soon...) |
|
|
|
|
|
\item[time-discretization] \ |
|
|
|
|
|
The time steps are set through the real variables \textbf{deltaTMom} |
|
|
and \textbf{deltaTtracer} (in s) which represent the time step for |
|
|
the momentum and tracer equations, respectively. For synchronous |
|
|
integrations, simply set the two variables to the same value (or you |
|
|
can prescribe one time step only through the variable |
|
|
\textbf{deltaT}). The Adams-Bashforth stabilizing parameter is set |
|
|
through the variable \textbf{abEps} (dimensionless). The stagger |
|
|
baroclinic time stepping can be activated by setting the logical |
|
|
variable \textbf{staggerTimeStep} to \texttt{'.TRUE.'}. |
|
|
|
|
|
\end{description} |
|
|
|
|
|
|
|
|
\subsection{Equation of state} |
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First, because the model equations are written in terms of |
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perturbations, a reference thermodynamic state needs to be specified. |
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This is done through the 1D arrays \textbf{tRef} and \textbf{sRef}. |
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\textbf{tRef} specifies the reference potential temperature profile |
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(in $^{o}$C for the ocean and $^{o}$K for the atmosphere) starting |
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from the level k=1. Similarly, \textbf{sRef} specifies the reference |
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salinity profile (in ppt) for the ocean or the reference specific |
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humidity profile (in g/kg) for the atmosphere. |
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The form of the equation of state is controlled by the character |
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variables \textbf{buoyancyRelation} and \textbf{eosType}. |
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\textbf{buoyancyRelation} is set to \texttt{'OCEANIC'} by default and |
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needs to be set to \texttt{'ATMOSPHERIC'} for atmosphere simulations. |
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In this case, \textbf{eosType} must be set to \texttt{'IDEALGAS'}. |
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For the ocean, two forms of the equation of state are available: |
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linear (set \textbf{eosType} to \texttt{'LINEAR'}) and a polynomial |
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approximation to the full nonlinear equation ( set \textbf{eosType} to |
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\texttt{'POLYNOMIAL'}). In the linear case, you need to specify the |
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thermal and haline expansion coefficients represented by the variables |
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\textbf{tAlpha} (in K$^{-1}$) and \textbf{sBeta} (in ppt$^{-1}$). For |
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the nonlinear case, you need to generate a file of polynomial |
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coefficients called \textit{POLY3.COEFFS}. To do this, use the program |
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\textit{utils/knudsen2/knudsen2.f} under the model tree (a Makefile is |
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available in the same directory and you will need to edit the number |
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and the values of the vertical levels in \textit{knudsen2.f} so that |
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they match those of your configuration). |
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There there are also higher polynomials for the equation of state: |
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\begin{description} |
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\item[\texttt{'UNESCO'}:] The UNESCO equation of state formula of |
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Fofonoff and Millard \cite{fofonoff83}. This equation of state |
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assumes in-situ temperature, which is not a model variable; {\em its |
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use is therefore discouraged, and it is only listed for |
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completeness}. |
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\item[\texttt{'JMD95Z'}:] A modified UNESCO formula by Jackett and |
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McDougall \cite{jackett95}, which uses the model variable potential |
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temperature as input. The \texttt{'Z'} indicates that this equation |
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of state uses a horizontally and temporally constant pressure |
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$p_{0}=-g\rho_{0}z$. |
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\item[\texttt{'JMD95P'}:] A modified UNESCO formula by Jackett and |
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McDougall \cite{jackett95}, which uses the model variable potential |
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temperature as input. The \texttt{'P'} indicates that this equation |
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of state uses the actual hydrostatic pressure of the last time |
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step. Lagging the pressure in this way requires an additional pickup |
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file for restarts. |
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\item[\texttt{'MDJWF'}:] The new, more accurate and less expensive |
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equation of state by McDougall et~al. \cite{mcdougall03}. It also |
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requires lagging the pressure and therefore an additional pickup |
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file for restarts. |
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\end{description} |
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For none of these options an reference profile of temperature or |
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salinity is required. |
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\subsection{Momentum equations} |
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In this section, we only focus for now on the parameters that you are |
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likely to change, i.e. the ones relative to forcing and dissipation |
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for example. The details relevant to the vector-invariant form of the |
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equations and the various advection schemes are not covered for the |
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moment. We assume that you use the standard form of the momentum |
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equations (i.e. the flux-form) with the default advection scheme. |
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Also, there are a few logical variables that allow you to turn on/off |
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various terms in the momentum equation. These variables are called |
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\textbf{momViscosity, momAdvection, momForcing, useCoriolis, |
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momPressureForcing, momStepping} and \textbf{metricTerms }and are |
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assumed to be set to \texttt{'.TRUE.'} here. Look at the file |
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\textit{model/inc/PARAMS.h }for a precise definition of these |
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variables. |
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\begin{description} |
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\item[initialization] \ |
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The velocity components are initialized to 0 unless the simulation |
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is starting from a pickup file (see section on simulation control |
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parameters). |
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\item[forcing] \ |
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This section only applies to the ocean. You need to generate |
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wind-stress data into two files \textbf{zonalWindFile} and |
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\textbf{meridWindFile} corresponding to the zonal and meridional |
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components of the wind stress, respectively (if you want the stress |
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|
to be along the direction of only one of the model horizontal axes, |
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|
you only need to generate one file). The format of the files is |
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|
similar to the bathymetry file. The zonal (meridional) stress data |
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|
are assumed to be in Pa and located at U-points (V-points). As for |
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the bathymetry, the precision with which to read the binary data is |
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|
controlled by the variable \textbf{readBinaryPrec}. See the matlab |
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|
program \textit{gendata.m} in the \textit{input} directories under |
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\textit{verification} to see how simple analytical wind forcing data |
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|
are generated for the case study experiments. |
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There is also the possibility of prescribing time-dependent periodic |
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forcing. To do this, concatenate the successive time records into a |
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single file (for each stress component) ordered in a (x,y,t) fashion |
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|
and set the following variables: \textbf{periodicExternalForcing }to |
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|
\texttt{'.TRUE.'}, \textbf{externForcingPeriod }to the period (in s) |
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|
of which the forcing varies (typically 1 month), and |
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|
\textbf{externForcingCycle} to the repeat time (in s) of the forcing |
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|
(typically 1 year -- note: \textbf{ externForcingCycle} must be a |
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|
multiple of \textbf{externForcingPeriod}). With these variables set |
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up, the model will interpolate the forcing linearly at each |
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iteration. |
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\item[dissipation] \ |
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The lateral eddy viscosity coefficient is specified through the |
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variable \textbf{viscAh} (in m$^{2}$s$^{-1}$). The vertical eddy |
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|
viscosity coefficient is specified through the variable |
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\textbf{viscAz} (in m$^{2}$s$^{-1}$) for the ocean and |
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|
\textbf{viscAp} (in Pa$^{2}$s$^{-1}$) for the atmosphere. The |
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|
vertical diffusive fluxes can be computed implicitly by setting the |
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logical variable \textbf{implicitViscosity }to \texttt{'.TRUE.'}. |
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In addition, biharmonic mixing can be added as well through the |
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|
variable \textbf{viscA4} (in m$^{4}$s$^{-1}$). On a spherical polar |
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|
grid, you might also need to set the variable \textbf{cosPower} |
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|
which is set to 0 by default and which represents the power of |
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|
cosine of latitude to multiply viscosity. Slip or no-slip conditions |
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|
at lateral and bottom boundaries are specified through the logical |
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|
variables \textbf{no\_slip\_sides} and \textbf{no\_slip\_bottom}. If |
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|
set to \texttt{'.FALSE.'}, free-slip boundary conditions are |
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|
applied. If no-slip boundary conditions are applied at the bottom, a |
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|
bottom drag can be applied as well. Two forms are available: linear |
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|
(set the variable \textbf{bottomDragLinear} in s$ ^{-1}$) and |
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|
quadratic (set the variable \textbf{bottomDragQuadratic} in |
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m$^{-1}$). |
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The Fourier and Shapiro filters are described elsewhere. |
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\item[C-D scheme] \ |
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If you run at a sufficiently coarse resolution, you will need the |
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|
C-D scheme for the computation of the Coriolis terms. The |
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|
variable\textbf{\ tauCD}, which represents the C-D scheme coupling |
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timescale (in s) needs to be set. |
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\item[calculation of pressure/geopotential] \ |
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First, to run a non-hydrostatic ocean simulation, set the logical |
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|
variable \textbf{nonHydrostatic} to \texttt{'.TRUE.'}. The pressure |
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|
field is then inverted through a 3D elliptic equation. (Note: this |
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|
capability is not available for the atmosphere yet.) By default, a |
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|
hydrostatic simulation is assumed and a 2D elliptic equation is used |
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|
to invert the pressure field. The parameters controlling the |
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|
behaviour of the elliptic solvers are the variables |
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|
\textbf{cg2dMaxIters} and \textbf{cg2dTargetResidual } for |
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|
the 2D case and \textbf{cg3dMaxIters} and |
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|
\textbf{cg3dTargetResidual} for the 3D case. You probably won't need to |
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|
alter the default values (are we sure of this?). |
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For the calculation of the surface pressure (for the ocean) or |
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|
surface geopotential (for the atmosphere) you need to set the |
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|
logical variables \textbf{rigidLid} and \textbf{implicitFreeSurface} |
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(set one to \texttt{'.TRUE.'} and the other to \texttt{'.FALSE.'} |
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|
depending on how you want to deal with the ocean upper or atmosphere |
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lower boundary). |
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\end{description} |
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\subsection{Tracer equations} |
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This section covers the tracer equations i.e. the potential |
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|
temperature equation and the salinity (for the ocean) or specific |
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|
humidity (for the atmosphere) equation. As for the momentum equations, |
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|
we only describe for now the parameters that you are likely to change. |
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|
The logical variables \textbf{tempDiffusion} \textbf{tempAdvection} |
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|
\textbf{tempForcing}, and \textbf{tempStepping} allow you to turn |
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|
on/off terms in the temperature equation (same thing for salinity or |
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|
specific humidity with variables \textbf{saltDiffusion}, |
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|
\textbf{saltAdvection} etc.). These variables are all assumed here to |
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|
be set to \texttt{'.TRUE.'}. Look at file \textit{model/inc/PARAMS.h} |
|
|
for a precise definition. |
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|
|
|
\begin{description} |
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|
\item[initialization] \ |
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The initial tracer data can be contained in the binary files |
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|
\textbf{hydrogThetaFile} and \textbf{hydrogSaltFile}. These files |
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|
should contain 3D data ordered in an (x,y,r) fashion with k=1 as the |
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|
first vertical level. If no file names are provided, the tracers |
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|
are then initialized with the values of \textbf{tRef} and |
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|
\textbf{sRef} mentioned above (in the equation of state section). In |
|
|
this case, the initial tracer data are uniform in x and y for each |
|
|
depth level. |
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|
\item[forcing] \ |
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This part is more relevant for the ocean, the procedure for the |
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|
atmosphere not being completely stabilized at the moment. |
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A combination of fluxes data and relaxation terms can be used for |
|
|
driving the tracer equations. For potential temperature, heat flux |
|
|
data (in W/m$ ^{2}$) can be stored in the 2D binary file |
|
|
\textbf{surfQfile}. Alternatively or in addition, the forcing can |
|
|
be specified through a relaxation term. The SST data to which the |
|
|
model surface temperatures are restored to are supposed to be stored |
|
|
in the 2D binary file \textbf{thetaClimFile}. The corresponding |
|
|
relaxation time scale coefficient is set through the variable |
|
|
\textbf{tauThetaClimRelax} (in s). The same procedure applies for |
|
|
salinity with the variable names \textbf{EmPmRfile}, |
|
|
\textbf{saltClimFile}, and \textbf{tauSaltClimRelax} for freshwater |
|
|
flux (in m/s) and surface salinity (in ppt) data files and |
|
|
relaxation time scale coefficient (in s), respectively. Also for |
|
|
salinity, if the CPP key \textbf{USE\_NATURAL\_BCS} is turned on, |
|
|
natural boundary conditions are applied i.e. when computing the |
|
|
surface salinity tendency, the freshwater flux is multiplied by the |
|
|
model surface salinity instead of a constant salinity value. |
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|
As for the other input files, the precision with which to read the |
|
|
data is controlled by the variable \textbf{readBinaryPrec}. |
|
|
Time-dependent, periodic forcing can be applied as well following |
|
|
the same procedure used for the wind forcing data (see above). |
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|
|
\item[dissipation] \ |
|
|
|
|
|
Lateral eddy diffusivities for temperature and salinity/specific |
|
|
humidity are specified through the variables \textbf{diffKhT} and |
|
|
\textbf{diffKhS} (in m$^{2}$/s). Vertical eddy diffusivities are |
|
|
specified through the variables \textbf{diffKzT} and |
|
|
\textbf{diffKzS} (in m$^{2}$/s) for the ocean and \textbf{diffKpT |
|
|
}and \textbf{diffKpS} (in Pa$^{2}$/s) for the atmosphere. The |
|
|
vertical diffusive fluxes can be computed implicitly by setting the |
|
|
logical variable \textbf{implicitDiffusion} to \texttt{'.TRUE.'}. |
|
|
In addition, biharmonic diffusivities can be specified as well |
|
|
through the coefficients \textbf{diffK4T} and \textbf{diffK4S} (in |
|
|
m$^{4}$/s). Note that the cosine power scaling (specified through |
|
|
\textbf{cosPower}---see the momentum equations section) is applied to |
|
|
the tracer diffusivities (Laplacian and biharmonic) as well. The |
|
|
Gent and McWilliams parameterization for oceanic tracers is |
|
|
described in the package section. Finally, note that tracers can be |
|
|
also subject to Fourier and Shapiro filtering (see the corresponding |
|
|
section on these filters). |
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|
\item[ocean convection] \ |
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|
|
|
Two options are available to parameterize ocean convection: one is |
|
|
to use the convective adjustment scheme. In this case, you need to |
|
|
set the variable \textbf{cadjFreq}, which represents the frequency |
|
|
(in s) with which the adjustment algorithm is called, to a non-zero |
|
|
value (if set to a negative value by the user, the model will set it |
|
|
to the tracer time step). The other option is to parameterize |
|
|
convection with implicit vertical diffusion. To do this, set the |
|
|
logical variable \textbf{implicitDiffusion} to \texttt{'.TRUE.'} |
|
|
and the real variable \textbf{ivdc\_kappa} to a value (in m$^{2}$/s) |
|
|
you wish the tracer vertical diffusivities to have when mixing |
|
|
tracers vertically due to static instabilities. Note that |
|
|
\textbf{cadjFreq} and \textbf{ivdc\_kappa}can not both have non-zero |
|
|
value. |
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\end{description} |
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|
\subsection{Simulation controls} |
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|
|
|
The model ''clock'' is defined by the variable \textbf{deltaTClock} |
|
|
(in s) which determines the IO frequencies and is used in tagging |
|
|
output. Typically, you will set it to the tracer time step for |
|
|
accelerated runs (otherwise it is simply set to the default time step |
|
|
\textbf{deltaT}). Frequency of checkpointing and dumping of the model |
|
|
state are referenced to this clock (see below). |
|
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|
|
|
\begin{description} |
|
|
\item[run duration] \ |
|
|
|
|
|
The beginning of a simulation is set by specifying a start time (in |
|
|
s) through the real variable \textbf{startTime} or by specifying an |
|
|
initial iteration number through the integer variable |
|
|
\textbf{nIter0}. If these variables are set to nonzero values, the |
|
|
model will look for a ''pickup'' file \textit{pickup.0000nIter0} to |
|
|
restart the integration. The end of a simulation is set through the |
|
|
real variable \textbf{endTime} (in s). Alternatively, you can |
|
|
specify instead the number of time steps to execute through the |
|
|
integer variable \textbf{nTimeSteps}. |
|
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|
|
\item[frequency of output] \ |
|
|
|
|
|
Real variables defining frequencies (in s) with which output files |
|
|
are written on disk need to be set up. \textbf{dumpFreq} controls |
|
|
the frequency with which the instantaneous state of the model is |
|
|
saved. \textbf{chkPtFreq} and \textbf{pchkPtFreq} control the output |
|
|
frequency of rolling and permanent checkpoint files, respectively. |
|
|
See section 1.5.1 Output files for the definition of model state and |
|
|
checkpoint files. In addition, time-averaged fields can be written |
|
|
out by setting the variable \textbf{taveFreq} (in s). The precision |
|
|
with which to write the binary data is controlled by the integer |
|
|
variable w\textbf{riteBinaryPrec} (set it to \texttt{32} or |
|
|
\texttt{64}). |
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|
|
\end{description} |
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|
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%%% Local Variables: |
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