| 17 | 
  | 
  | 
| 18 | 
 \section{Where to find information} | 
 \section{Where to find information} | 
| 19 | 
 \label{sect:whereToFindInfo} | 
 \label{sect:whereToFindInfo} | 
| 20 | 
  | 
 \begin{rawhtml} | 
| 21 | 
 A web site is maintained for release 1 (Sealion) of MITgcm: | 
 <!-- CMIREDIR:whereToFindInfo: --> | 
| 22 | 
 \begin{verbatim} | 
 \end{rawhtml} | 
| 23 | 
 http://mitgcm.org/sealion | 
  | 
| 24 | 
 \end{verbatim} | 
 There is a web-archived support mailing list for the model that | 
| 25 | 
 Here you will find an on-line version of this document, a | 
 you can email at \texttt{MITgcm-support@mitgcm.org} or browse at: | 
| 26 | 
 ``browsable'' copy of the code and a searchable database of the model | 
 \begin{rawhtml} <A href=http://mitgcm.org/mailman/listinfo/mitgcm-support/ target="idontexist"> \end{rawhtml} | 
 | 
 and site, as well as links for downloading the model and | 
  | 
 | 
 documentation, to data-sources and other related sites. | 
  | 
 | 
  | 
  | 
 | 
 There is also a support news group for the model that you can email at | 
  | 
 | 
 \texttt{support@mitgcm.org} or browse at: | 
  | 
| 27 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 28 | 
 news://mitgcm.org/mitgcm.support | 
 http://mitgcm.org/mailman/listinfo/mitgcm-support/ | 
| 29 | 
  | 
 http://mitgcm.org/pipermail/mitgcm-support/ | 
| 30 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 31 | 
 A mail to the email list will reach all the developers and be archived | 
 \begin{rawhtml} </A> \end{rawhtml} | 
 | 
 on the newsgroup. A users email list will be established at some time | 
  | 
 | 
 in the future. | 
  | 
| 32 | 
  | 
  | 
| 33 | 
 \section{Obtaining the code} | 
 \section{Obtaining the code} | 
| 34 | 
 \label{sect:obtainingCode} | 
 \label{sect:obtainingCode} | 
| 35 | 
  | 
 \begin{rawhtml} | 
| 36 | 
  | 
 <!-- CMIREDIR:obtainingCode: --> | 
| 37 | 
  | 
 \end{rawhtml} | 
| 38 | 
  | 
  | 
| 39 | 
 MITgcm can be downloaded from our system by following | 
 MITgcm can be downloaded from our system by following | 
| 40 | 
 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 | 
| 41 | 
 \begin{rawhtml} <A href=mailto:support@mitgcm.org> \end{rawhtml} | 
 \begin{rawhtml} <A href=mailto:MITgcm-support@mitgcm.org> \end{rawhtml} | 
| 42 | 
 support@mitgcm.org | 
 MITgcm-support@mitgcm.org | 
| 43 | 
 \begin{rawhtml} </A> \end{rawhtml} | 
 \begin{rawhtml} </A> \end{rawhtml} | 
| 44 | 
 to enable us to keep track of who's using the model and in what application. | 
 to enable us to keep track of who's using the model and in what application. | 
| 45 | 
 You can download the model two ways: | 
 You can download the model two ways: | 
| 64 | 
  | 
  | 
| 65 | 
 \end{enumerate} | 
 \end{enumerate} | 
| 66 | 
  | 
  | 
| 67 | 
  | 
 \subsection{Method 1 - Checkout from CVS} | 
| 68 | 
  | 
 \label{sect:cvs_checkout} | 
| 69 | 
  | 
  | 
| 70 | 
 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 | 
| 71 | 
 provides an efficient and elegant way of organizing your code and keeping | 
 provides an efficient and elegant way of organizing your code and keeping | 
| 72 | 
 track of your changes. If CVS is not available on your machine, you can also | 
 track of your changes. If CVS is not available on your machine, you can also | 
| 73 | 
 download a tar file. | 
 download a tar file. | 
| 74 | 
  | 
  | 
| 75 | 
 Before you can use CVS, the following environment variable has to be set in | 
 Before you can use CVS, the following environment variable(s) should | 
| 76 | 
 your .cshrc or .tcshrc: | 
 be set within your shell.  For a csh or tcsh shell, put the following  | 
| 77 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 78 | 
 % setenv CVSROOT :pserver:cvsanon@mitgcm.org:/u/u0/gcmpack | 
 % setenv CVSROOT :pserver:cvsanon@mitgcm.org:/u/gcmpack | 
| 79 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 80 | 
  | 
 in your \texttt{.cshrc} or \texttt{.tcshrc} file.  For bash or sh | 
| 81 | 
  | 
 shells, put: | 
| 82 | 
  | 
 \begin{verbatim} | 
| 83 | 
  | 
 % export CVSROOT=':pserver:cvsanon@mitgcm.org:/u/gcmpack' | 
| 84 | 
  | 
 \end{verbatim} | 
| 85 | 
  | 
 in your \texttt{.profile} or \texttt{.bashrc} file. | 
| 86 | 
  | 
  | 
| 87 | 
  | 
  | 
| 88 | 
 To start using CVS, register with the MITgcm CVS server using command: | 
 To get MITgcm through CVS, first register with the MITgcm CVS server | 
| 89 | 
  | 
 using command: | 
| 90 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 91 | 
 % cvs login ( CVS password: cvsanon ) | 
 % cvs login ( CVS password: cvsanon ) | 
| 92 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 93 | 
 You only need to do ``cvs login'' once. | 
 You only need to do a ``cvs login'' once. | 
| 94 | 
  | 
  | 
| 95 | 
 To obtain the sources for release1 type: | 
 To obtain the latest sources type: | 
| 96 | 
  | 
 \begin{verbatim} | 
| 97 | 
  | 
 % cvs co MITgcm | 
| 98 | 
  | 
 \end{verbatim} | 
| 99 | 
  | 
 or to get a specific release type: | 
| 100 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 101 | 
 % cvs co -d directory -P -r release1 MITgcmUV | 
 % cvs co -P -r checkpoint52i_post  MITgcm | 
| 102 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 103 | 
  | 
 The MITgcm web site contains further directions concerning the source | 
| 104 | 
  | 
 code and CVS.  It also contains a web interface to our CVS archive so | 
| 105 | 
  | 
 that one may easily view the state of files, revisions, and other | 
| 106 | 
  | 
 development milestones: | 
| 107 | 
  | 
 \begin{rawhtml} <A href="http://mitgcm.org/download" target="idontexist"> \end{rawhtml} | 
| 108 | 
  | 
 \begin{verbatim} | 
| 109 | 
  | 
 http://mitgcm.org/source_code.html | 
| 110 | 
  | 
 \end{verbatim} | 
| 111 | 
  | 
 \begin{rawhtml} </A> \end{rawhtml} | 
| 112 | 
  | 
  | 
| 113 | 
 This creates a directory called \textit{directory}. If \textit{directory} | 
 As a convenience, the MITgcm CVS server contains aliases which are | 
| 114 | 
 exists this command updates your code based on the repository. Each | 
 named subsets of the codebase.  These aliases can be especially | 
| 115 | 
 directory in the source tree contains a directory \textit{CVS}. This | 
 helpful when used over slow internet connections or on machines with | 
| 116 | 
 information is required by CVS to keep track of your file versions with | 
 restricted storage space.  Table \ref{tab:cvsModules} contains a list | 
| 117 | 
 respect to the repository. Don't edit the files in \textit{CVS}! | 
 of CVS aliases | 
| 118 | 
 You can also use CVS to download code updates.  More extensive | 
 \begin{table}[htb] | 
| 119 | 
 information on using CVS for maintaining MITgcm code can be found  | 
   \centering | 
| 120 | 
 \begin{rawhtml} <A href=http://mitgcm.org/usingcvstoget.html target="idontexist"> \end{rawhtml} | 
   \begin{tabular}[htb]{|lp{3.25in}|}\hline | 
| 121 | 
  | 
     \textbf{Alias Name}    &  \textbf{Information (directories) Contained}  \\\hline | 
| 122 | 
  | 
     \texttt{MITgcm\_code}  &  Only the source code -- none of the verification examples.  \\ | 
| 123 | 
  | 
     \texttt{MITgcm\_verif\_basic} | 
| 124 | 
  | 
     &  Source code plus a small set of the verification examples  | 
| 125 | 
  | 
     (\texttt{global\_ocean.90x40x15}, \texttt{aim.5l\_cs}, \texttt{hs94.128x64x5},  | 
| 126 | 
  | 
     \texttt{front\_relax}, and \texttt{plume\_on\_slope}).  \\ | 
| 127 | 
  | 
     \texttt{MITgcm\_verif\_atmos}  &  Source code plus all of the atmospheric examples.  \\ | 
| 128 | 
  | 
     \texttt{MITgcm\_verif\_ocean}  &  Source code plus all of the oceanic examples.  \\ | 
| 129 | 
  | 
     \texttt{MITgcm\_verif\_all}    &  Source code plus all of the | 
| 130 | 
  | 
     verification examples. \\\hline | 
| 131 | 
  | 
   \end{tabular} | 
| 132 | 
  | 
   \caption{MITgcm CVS Modules} | 
| 133 | 
  | 
   \label{tab:cvsModules} | 
| 134 | 
  | 
 \end{table} | 
| 135 | 
  | 
  | 
| 136 | 
  | 
 The checkout process creates a directory called \texttt{MITgcm}. If | 
| 137 | 
  | 
 the directory \texttt{MITgcm} exists this command updates your code | 
| 138 | 
  | 
 based on the repository. Each directory in the source tree contains a | 
| 139 | 
  | 
 directory \texttt{CVS}. This information is required by CVS to keep | 
| 140 | 
  | 
 track of your file versions with respect to the repository. Don't edit | 
| 141 | 
  | 
 the files in \texttt{CVS}!  You can also use CVS to download code | 
| 142 | 
  | 
 updates.  More extensive information on using CVS for maintaining | 
| 143 | 
  | 
 MITgcm code can be found | 
| 144 | 
  | 
 \begin{rawhtml} <A href="http://mitgcm.org/usingcvstoget.html" target="idontexist"> \end{rawhtml} | 
| 145 | 
 here | 
 here | 
| 146 | 
 \begin{rawhtml} </A> \end{rawhtml}  | 
 \begin{rawhtml} </A> \end{rawhtml}  | 
| 147 | 
 . | 
 . | 
| 148 | 
  | 
 It is important to note that the CVS aliases in Table | 
| 149 | 
  | 
 \ref{tab:cvsModules} cannot be used in conjunction with the CVS | 
| 150 | 
  | 
 \texttt{-d DIRNAME} option.  However, the \texttt{MITgcm} directories | 
| 151 | 
  | 
 they create can be changed to a different name following the check-out: | 
| 152 | 
  | 
 \begin{verbatim} | 
| 153 | 
  | 
    %  cvs co MITgcm_verif_basic | 
| 154 | 
  | 
    %  mv MITgcm MITgcm_verif_basic | 
| 155 | 
  | 
 \end{verbatim} | 
| 156 | 
  | 
  | 
| 157 | 
  | 
 \subsubsection{Upgrading from an earlier version} | 
| 158 | 
  | 
  | 
| 159 | 
  | 
 If you already have an earlier version of the code you can ``upgrade'' | 
| 160 | 
  | 
 your copy instead of downloading the entire repository again. First, | 
| 161 | 
  | 
 ``cd'' (change directory) to the top of your working copy: | 
| 162 | 
  | 
 \begin{verbatim} | 
| 163 | 
  | 
 % cd MITgcm | 
| 164 | 
  | 
 \end{verbatim} | 
| 165 | 
  | 
 and then issue the cvs update command such as: | 
| 166 | 
  | 
 \begin{verbatim} | 
| 167 | 
  | 
 % cvs -q update -r checkpoint52i_post -d -P | 
| 168 | 
  | 
 \end{verbatim} | 
| 169 | 
  | 
 This will update the ``tag'' to ``checkpoint52i\_post'', add any new | 
| 170 | 
  | 
 directories (-d) and remove any empty directories (-P). The -q option | 
| 171 | 
  | 
 means be quiet which will reduce the number of messages you'll see in | 
| 172 | 
  | 
 the terminal. If you have modified the code prior to upgrading, CVS | 
| 173 | 
  | 
 will try to merge your changes with the upgrades. If there is a | 
| 174 | 
  | 
 conflict between your modifications and the upgrade, it will report | 
| 175 | 
  | 
 that file with a ``C'' in front, e.g.: | 
| 176 | 
  | 
 \begin{verbatim} | 
| 177 | 
  | 
 C model/src/ini_parms.F | 
| 178 | 
  | 
 \end{verbatim} | 
| 179 | 
  | 
 If the list of conflicts scrolled off the screen, you can re-issue the | 
| 180 | 
  | 
 cvs update command and it will report the conflicts. Conflicts are | 
| 181 | 
  | 
 indicated in the code by the delimites ``$<<<<<<<$'', ``======='' and | 
| 182 | 
  | 
 ``$>>>>>>>$''. For example, | 
| 183 | 
  | 
 {\small | 
| 184 | 
  | 
 \begin{verbatim} | 
| 185 | 
  | 
 <<<<<<< ini_parms.F | 
| 186 | 
  | 
      & bottomDragLinear,myOwnBottomDragCoefficient, | 
| 187 | 
  | 
 ======= | 
| 188 | 
  | 
      & bottomDragLinear,bottomDragQuadratic, | 
| 189 | 
  | 
 >>>>>>> 1.18 | 
| 190 | 
  | 
 \end{verbatim} | 
| 191 | 
  | 
 } | 
| 192 | 
  | 
 means that you added ``myOwnBottomDragCoefficient'' to a namelist at | 
| 193 | 
  | 
 the same time and place that we added ``bottomDragQuadratic''. You | 
| 194 | 
  | 
 need to resolve this conflict and in this case the line should be | 
| 195 | 
  | 
 changed to: | 
| 196 | 
  | 
 {\small | 
| 197 | 
  | 
 \begin{verbatim} | 
| 198 | 
  | 
      & bottomDragLinear,bottomDragQuadratic,myOwnBottomDragCoefficient, | 
| 199 | 
  | 
 \end{verbatim} | 
| 200 | 
  | 
 } | 
| 201 | 
  | 
 and the lines with the delimiters ($<<<<<<$,======,$>>>>>>$) be deleted. | 
| 202 | 
  | 
 Unless you are making modifications which exactly parallel | 
| 203 | 
  | 
 developments we make, these types of conflicts should be rare. | 
| 204 | 
  | 
  | 
| 205 | 
  | 
 \paragraph*{Upgrading to the current pre-release version} | 
| 206 | 
  | 
  | 
| 207 | 
  | 
 We don't make a ``release'' for every little patch and bug fix in | 
| 208 | 
  | 
 order to keep the frequency of upgrades to a minimum. However, if you | 
| 209 | 
  | 
 have run into a problem for which ``we have already fixed in the | 
| 210 | 
  | 
 latest code'' and we haven't made a ``tag'' or ``release'' since that | 
| 211 | 
  | 
 patch then you'll need to get the latest code: | 
| 212 | 
  | 
 \begin{verbatim} | 
| 213 | 
  | 
 % cvs -q update -A -d -P | 
| 214 | 
  | 
 \end{verbatim} | 
| 215 | 
  | 
 Unlike, the ``check-out'' and ``update'' procedures above, there is no | 
| 216 | 
  | 
 ``tag'' or release name. The -A tells CVS to upgrade to the | 
| 217 | 
  | 
 very latest version. As a rule, we don't recommend this since you | 
| 218 | 
  | 
 might upgrade while we are in the processes of checking in the code so | 
| 219 | 
  | 
 that you may only have part of a patch. Using this method of updating | 
| 220 | 
  | 
 also means we can't tell what version of the code you are working | 
| 221 | 
  | 
 with. So please be sure you understand what you're doing. | 
| 222 | 
  | 
  | 
| 223 | 
  | 
 \subsection{Method 2 - Tar file download} | 
 | 
 \paragraph*{Conventional download method} | 
  | 
| 224 | 
 \label{sect:conventionalDownload} | 
 \label{sect:conventionalDownload} | 
| 225 | 
  | 
  | 
| 226 | 
 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 | 
| 227 | 
 tar file from the reference web site at: | 
 tar file from the web site at: | 
| 228 | 
 \begin{rawhtml} <A href=http://mitgcm.org/download target="idontexist"> \end{rawhtml} | 
 \begin{rawhtml} <A href=http://mitgcm.org/download target="idontexist"> \end{rawhtml} | 
| 229 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 230 | 
 http://mitgcm.org/download/ | 
 http://mitgcm.org/download/ | 
| 232 | 
 \begin{rawhtml} </A> \end{rawhtml} | 
 \begin{rawhtml} </A> \end{rawhtml} | 
| 233 | 
 The tar file still contains CVS information which we urge you not to | 
 The tar file still contains CVS information which we urge you not to | 
| 234 | 
 delete; even if you do not use CVS yourself the information can help | 
 delete; even if you do not use CVS yourself the information can help | 
| 235 | 
 us if you should need to send us your copy of the code. | 
 us if you should need to send us your copy of the code.  If a recent | 
| 236 | 
  | 
 tar file does not exist, then please contact the developers through | 
| 237 | 
  | 
 the  | 
| 238 | 
  | 
 \begin{rawhtml} <A href="mailto:MITgcm-support@mitgcm.org"> \end{rawhtml} | 
| 239 | 
  | 
 MITgcm-support@mitgcm.org | 
| 240 | 
  | 
 \begin{rawhtml} </A> \end{rawhtml} | 
| 241 | 
  | 
 mailing list. | 
| 242 | 
  | 
  | 
| 243 | 
 \section{Model and directory structure} | 
 \section{Model and directory structure} | 
| 244 | 
  | 
 \begin{rawhtml} | 
| 245 | 
 The ``numerical'' model is contained within a execution environment support | 
 <!-- CMIREDIR:directory_structure: --> | 
| 246 | 
 wrapper. This wrapper is designed to provide a general framework for | 
 \end{rawhtml} | 
| 247 | 
 grid-point models. MITgcmUV is a specific numerical model that uses the | 
  | 
| 248 | 
 framework. Under this structure the model is split into execution | 
 The ``numerical'' model is contained within a execution environment | 
| 249 | 
 environment support code and conventional numerical model code. The | 
 support wrapper. This wrapper is designed to provide a general | 
| 250 | 
 execution environment support code is held under the \textit{eesupp} | 
 framework for grid-point models. MITgcmUV is a specific numerical | 
| 251 | 
 directory. The grid point model code is held under the \textit{model} | 
 model that uses the framework. Under this structure the model is split | 
| 252 | 
 directory. Code execution actually starts in the \textit{eesupp} routines | 
 into execution environment support code and conventional numerical | 
| 253 | 
 and not in the \textit{model} routines. For this reason the top-level  | 
 model code. The execution environment support code is held under the | 
| 254 | 
 \textit{MAIN.F} is in the \textit{eesupp/src} directory. In general, | 
 \texttt{eesupp} directory. The grid point model code is held under the | 
| 255 | 
 end-users should not need to worry about this level. The top-level routine | 
 \texttt{model} directory. Code execution actually starts in the | 
| 256 | 
 for the numerical part of the code is in \textit{model/src/THE\_MODEL\_MAIN.F% | 
 \texttt{eesupp} routines and not in the \texttt{model} routines. For | 
| 257 | 
 }. Here is a brief description of the directory structure of the model under | 
 this reason the top-level \texttt{MAIN.F} is in the | 
| 258 | 
 the root tree (a detailed description is given in section 3: Code structure). | 
 \texttt{eesupp/src} directory. In general, end-users should not need | 
| 259 | 
  | 
 to worry about this level. The top-level routine for the numerical | 
| 260 | 
 \begin{itemize} | 
 part of the code is in \texttt{model/src/THE\_MODEL\_MAIN.F}. Here is | 
| 261 | 
 \item \textit{bin}: this directory is initially empty. It is the default | 
 a brief description of the directory structure of the model under the | 
| 262 | 
 directory in which to compile the code. | 
 root tree (a detailed description is given in section 3: Code | 
| 263 | 
  | 
 structure). | 
| 264 | 
 \item \textit{diags}: contains the code relative to time-averaged | 
  | 
| 265 | 
 diagnostics. It is subdivided into two subdirectories \textit{inc} and  | 
 \begin{itemize} | 
| 266 | 
 \textit{src} that contain include files (*.\textit{h} files) and Fortran | 
  | 
| 267 | 
 subroutines (*.\textit{F} files), respectively. | 
 \item \texttt{doc}: contains brief documentation notes. | 
| 268 | 
  | 
    | 
| 269 | 
 \item \textit{doc}: contains brief documentation notes. | 
 \item \texttt{eesupp}: contains the execution environment source code. | 
| 270 | 
  | 
   Also subdivided into two subdirectories \texttt{inc} and | 
| 271 | 
 \item \textit{eesupp}: contains the execution environment source code. Also | 
   \texttt{src}. | 
| 272 | 
 subdivided into two subdirectories \textit{inc} and \textit{src}. | 
    | 
| 273 | 
  | 
 \item \texttt{model}: this directory contains the main source code. | 
| 274 | 
 \item \textit{exe}: this directory is initially empty. It is the default | 
   Also subdivided into two subdirectories \texttt{inc} and | 
| 275 | 
 directory in which to execute the code. | 
   \texttt{src}. | 
| 276 | 
  | 
    | 
| 277 | 
 \item \textit{model}: this directory contains the main source code. Also | 
 \item \texttt{pkg}: contains the source code for the packages. Each | 
| 278 | 
 subdivided into two subdirectories \textit{inc} and \textit{src}. | 
   package corresponds to a subdirectory. For example, \texttt{gmredi} | 
| 279 | 
  | 
   contains the code related to the Gent-McWilliams/Redi scheme, | 
| 280 | 
 \item \textit{pkg}: contains the source code for the packages. Each package | 
   \texttt{aim} the code relative to the atmospheric intermediate | 
| 281 | 
 corresponds to a subdirectory. For example, \textit{gmredi} contains the | 
   physics. The packages are described in detail in chapter \ref{chap.packagesI}. | 
| 282 | 
 code related to the Gent-McWilliams/Redi scheme, \textit{aim} the code | 
    | 
| 283 | 
 relative to the atmospheric intermediate physics. The packages are described | 
 \item \texttt{tools}: this directory contains various useful tools. | 
| 284 | 
 in detail in section 3. | 
   For example, \texttt{genmake2} is a script written in csh (C-shell) | 
| 285 | 
  | 
   that should be used to generate your makefile. The directory | 
| 286 | 
 \item \textit{tools}: this directory contains various useful tools. For | 
   \texttt{adjoint} contains the makefile specific to the Tangent | 
| 287 | 
 example, \textit{genmake} is a script written in csh (C-shell) that should | 
   linear and Adjoint Compiler (TAMC) that generates the adjoint code. | 
| 288 | 
 be used to generate your makefile. The directory \textit{adjoint} contains | 
   The latter is described in detail in part \ref{chap.ecco}. | 
| 289 | 
 the makefile specific to the Tangent linear and Adjoint Compiler (TAMC) that | 
   This directory also contains the subdirectory build\_options, which | 
| 290 | 
 generates the adjoint code. The latter is described in details in part V. | 
   contains the `optfiles' with the compiler options for the different | 
| 291 | 
  | 
   compilers and machines that can run MITgcm. | 
| 292 | 
 \item \textit{utils}: this directory contains various utilities. The | 
    | 
| 293 | 
 subdirectory \textit{knudsen2} contains code and a makefile that | 
 \item \texttt{utils}: this directory contains various utilities. The | 
| 294 | 
 compute coefficients of the polynomial approximation to the knudsen | 
   subdirectory \texttt{knudsen2} contains code and a makefile that | 
| 295 | 
 formula for an ocean nonlinear equation of state. The \textit{matlab} | 
   compute coefficients of the polynomial approximation to the knudsen | 
| 296 | 
 subdirectory contains matlab scripts for reading model output directly | 
   formula for an ocean nonlinear equation of state. The | 
| 297 | 
 into matlab. \textit{scripts} contains C-shell post-processing | 
   \texttt{matlab} subdirectory contains matlab scripts for reading | 
| 298 | 
 scripts for joining processor-based and tiled-based model output. | 
   model output directly into matlab. \texttt{scripts} contains C-shell | 
| 299 | 
  | 
   post-processing scripts for joining processor-based and tiled-based | 
| 300 | 
 \item \textit{verification}: this directory contains the model examples. See | 
   model output. The subdirectory exch2 contains the code needed for | 
| 301 | 
 section \ref{sect:modelExamples}. | 
   the exch2 package to work with different combinations of domain | 
| 302 | 
 \end{itemize} | 
   decompositions. | 
| 303 | 
  | 
    | 
| 304 | 
 \section{Example experiments} | 
 \item \texttt{verification}: this directory contains the model | 
| 305 | 
 \label{sect:modelExamples} | 
   examples. See section \ref{sect:modelExamples}. | 
| 306 | 
  | 
  | 
| 307 | 
 The MITgcm distribution comes with a set of twenty-four pre-configured | 
 \item \texttt{jobs}: contains sample job scripts for running MITgcm. | 
| 308 | 
 numerical experiments. Some of these examples experiments are tests of  | 
    | 
| 309 | 
 individual parts of the model code, but many are fully fledged numerical | 
 \item \texttt{lsopt}: Line search code used for optimization. | 
| 310 | 
 simulations. A few of the examples are used for tutorial documentation | 
    | 
| 311 | 
 in sections \ref{sect:eg-baro} - \ref{sect:eg-global}. The other examples | 
 \item \texttt{optim}: Interface between MITgcm and line search code. | 
| 312 | 
 follow the same general structure as the tutorial examples. However, | 
    | 
 | 
 they only include brief instructions in a text file called {\it README}. | 
  | 
 | 
 The examples are located in subdirectories under | 
  | 
 | 
 the directory \textit{verification}. Each | 
  | 
 | 
 example is briefly described below. | 
  | 
 | 
  | 
  | 
 | 
 \subsection{Full list of model examples} | 
  | 
 | 
  | 
  | 
 | 
 \begin{enumerate} | 
  | 
 | 
 \item \textit{exp0} - single layer, ocean double gyre (barotropic with | 
  | 
 | 
 free-surface). This experiment is described in detail in section | 
  | 
 | 
 \ref{sect:eg-baro}. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{exp1} - Four layer, ocean double gyre. This experiment is described in detail in section | 
  | 
 | 
 \ref{sect:eg-baroc}. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{exp2} - 4x4 degree global ocean simulation with steady | 
  | 
 | 
 climatological forcing. This experiment is described in detail in section | 
  | 
 | 
 \ref{sect:eg-global}. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{exp4} - Flow over a Gaussian bump in open-water or channel | 
  | 
 | 
 with open boundaries. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{exp5} - Inhomogenously forced ocean convection in a doubly | 
  | 
 | 
 periodic box. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{front\_relax} - Relaxation of an ocean thermal front (test for | 
  | 
 | 
 Gent/McWilliams scheme). 2D (Y-Z). | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{internal wave} - Ocean internal wave forced by open boundary | 
  | 
 | 
 conditions. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{natl\_box} - Eastern subtropical North Atlantic with KPP | 
  | 
 | 
 scheme; 1 month integration | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{hs94.1x64x5} - Zonal averaged atmosphere using Held and Suarez | 
  | 
 | 
 '94 forcing. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{hs94.128x64x5} - 3D atmosphere dynamics using Held and Suarez | 
  | 
 | 
 '94 forcing. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{hs94.cs-32x32x5} - 3D atmosphere dynamics using Held and | 
  | 
 | 
 Suarez '94 forcing on the cubed sphere. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{aim.5l\_zon-ave} - Intermediate Atmospheric physics. Global  | 
  | 
 | 
 Zonal Mean configuration, 1x64x5 resolution. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{aim.5l\_XZ\_Equatorial\_Slice} - Intermediate Atmospheric | 
  | 
 | 
 physics, equatorial Slice configuration. | 
  | 
 | 
 2D (X-Z). | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{aim.5l\_Equatorial\_Channel} - Intermediate Atmospheric | 
  | 
 | 
 physics. 3D Equatorial Channel configuration. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{aim.5l\_LatLon} - Intermediate Atmospheric physics. | 
  | 
 | 
 Global configuration, on latitude longitude grid with 128x64x5 grid points | 
  | 
 | 
 ($2.8^\circ{\rm degree}$ resolution). | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{adjustment.128x64x1} Barotropic adjustment | 
  | 
 | 
 problem on latitude longitude grid with 128x64 grid points ($2.8^\circ{\rm degree}$ resolution). | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{adjustment.cs-32x32x1} | 
  | 
 | 
 Barotropic adjustment | 
  | 
 | 
 problem on cube sphere grid with 32x32 points per face ( roughly | 
  | 
 | 
 $2.8^\circ{\rm degree}$ resolution). | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{advect\_cs} Two-dimensional passive advection test on | 
  | 
 | 
 cube sphere grid. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{advect\_xy} Two-dimensional (horizontal plane) passive advection  | 
  | 
 | 
 test on Cartesian grid. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{advect\_yz} Two-dimensional (vertical plane) passive advection test on Cartesian grid. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{carbon} Simple passive tracer experiment. Includes derivative | 
  | 
 | 
 calculation. Described in detail in section \ref{sect:eg-carbon-ad}. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{flt\_example} Example of using float package. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{global\_ocean.90x40x15} Global circulation with | 
  | 
 | 
 GM, flux boundary conditions and poles. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{solid-body.cs-32x32x1} Solid body rotation test for cube sphere | 
  | 
 | 
 grid. | 
  | 
 | 
  | 
  | 
 | 
 \end{enumerate} | 
  | 
 | 
  | 
  | 
 | 
 \subsection{Directory structure of model examples} | 
  | 
 | 
  | 
  | 
 | 
 Each example directory has the following subdirectories: | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item \textit{code}: contains the code particular to the example. At a | 
  | 
 | 
 minimum, this directory includes the following files: | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item \textit{code/CPP\_EEOPTIONS.h}: declares CPP keys relative to the | 
  | 
 | 
 ``execution environment'' part of the code. The default version is located | 
  | 
 | 
 in \textit{eesupp/inc}. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{code/CPP\_OPTIONS.h}: declares CPP keys relative to the | 
  | 
 | 
 ``numerical model'' part of the code. The default version is located in  | 
  | 
 | 
 \textit{model/inc}. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{code/SIZE.h}: declares size of underlying computational grid. | 
  | 
 | 
 The default version is located in \textit{model/inc}. | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 In addition, other include files and subroutines might be present in \textit{% | 
  | 
 | 
 code} depending on the particular experiment. See section 2 for more details. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{input}: contains the input data files required to run the | 
  | 
 | 
 example. At a minimum, the \textit{input} directory contains the following | 
  | 
 | 
 files: | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item \textit{input/data}: this file, written as a namelist, specifies the | 
  | 
 | 
 main parameters for the experiment. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{input/data.pkg}: contains parameters relative to the packages | 
  | 
 | 
 used in the experiment. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{input/eedata}: this file contains ``execution environment'' | 
  | 
 | 
 data. At present, this consists of a specification of the number of threads | 
  | 
 | 
 to use in $X$ and $Y$ under multithreaded execution. | 
  | 
| 313 | 
 \end{itemize} | 
 \end{itemize} | 
| 314 | 
  | 
  | 
| 315 | 
 In addition, you will also find in this directory the forcing and topography | 
 \section[Building MITgcm]{Building the code} | 
 | 
 files as well as the files describing the initial state of the experiment. | 
  | 
 | 
 This varies from experiment to experiment. See section 2 for more details. | 
  | 
 | 
  | 
  | 
 | 
 \item \textit{results}: this directory contains the output file \textit{% | 
  | 
 | 
 output.txt} produced by the simulation example. This file is useful for | 
  | 
 | 
 comparison with your own output when you run the experiment. | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 Once you have chosen the example you want to run, you are ready to compile | 
  | 
 | 
 the code. | 
  | 
 | 
  | 
  | 
 | 
 \section{Building the code} | 
  | 
| 316 | 
 \label{sect:buildingCode} | 
 \label{sect:buildingCode} | 
| 317 | 
  | 
 \begin{rawhtml} | 
| 318 | 
  | 
 <!-- CMIREDIR:buildingCode: --> | 
| 319 | 
  | 
 \end{rawhtml} | 
| 320 | 
  | 
  | 
| 321 | 
  | 
 To compile the code, we use the \texttt{make} program. This uses a | 
| 322 | 
  | 
 file (\texttt{Makefile}) that allows us to pre-process source files, | 
| 323 | 
  | 
 specify compiler and optimization options and also figures out any | 
| 324 | 
  | 
 file dependencies. We supply a script (\texttt{genmake2}), described | 
| 325 | 
  | 
 in section \ref{sect:genmake}, that automatically creates the | 
| 326 | 
  | 
 \texttt{Makefile} for you. You then need to build the dependencies and | 
| 327 | 
  | 
 compile the code. | 
| 328 | 
  | 
  | 
| 329 | 
  | 
 As an example, assume that you want to build and run experiment | 
| 330 | 
  | 
 \texttt{verification/exp2}. The are multiple ways and places to | 
| 331 | 
  | 
 actually do this but here let's build the code in | 
| 332 | 
  | 
 \texttt{verification/exp2/build}: | 
| 333 | 
  | 
 \begin{verbatim} | 
| 334 | 
  | 
 % cd verification/exp2/build | 
| 335 | 
  | 
 \end{verbatim} | 
| 336 | 
  | 
 First, build the \texttt{Makefile}: | 
| 337 | 
  | 
 \begin{verbatim} | 
| 338 | 
  | 
 % ../../../tools/genmake2 -mods=../code | 
| 339 | 
  | 
 \end{verbatim} | 
| 340 | 
  | 
 The command line option tells \texttt{genmake} to override model source | 
| 341 | 
  | 
 code with any files in the directory \texttt{../code/}. | 
| 342 | 
  | 
  | 
| 343 | 
  | 
 On many systems, the \texttt{genmake2} program will be able to | 
| 344 | 
  | 
 automatically recognize the hardware, find compilers and other tools | 
| 345 | 
  | 
 within the user's path (``\texttt{echo \$PATH}''), and then choose an | 
| 346 | 
  | 
 appropriate set of options from the files (``optfiles'') contained in | 
| 347 | 
  | 
 the \texttt{tools/build\_options} directory.  Under some | 
| 348 | 
  | 
 circumstances, a user may have to create a new ``optfile'' in order to | 
| 349 | 
  | 
 specify the exact combination of compiler, compiler flags, libraries, | 
| 350 | 
  | 
 and other options necessary to build a particular configuration of | 
| 351 | 
  | 
 MITgcm.  In such cases, it is generally helpful to read the existing | 
| 352 | 
  | 
 ``optfiles'' and mimic their syntax. | 
| 353 | 
  | 
  | 
| 354 | 
  | 
 Through the MITgcm-support list, the MITgcm developers are willing to | 
| 355 | 
  | 
 provide help writing or modifing ``optfiles''.  And we encourage users | 
| 356 | 
  | 
 to post new ``optfiles'' (particularly ones for new machines or | 
| 357 | 
  | 
 architectures) to the  | 
| 358 | 
  | 
 \begin{rawhtml} <A href="mailto:MITgcm-support@mitgcm.org"> \end{rawhtml} | 
| 359 | 
  | 
 MITgcm-support@mitgcm.org | 
| 360 | 
  | 
 \begin{rawhtml} </A> \end{rawhtml} | 
| 361 | 
  | 
 list. | 
| 362 | 
  | 
  | 
| 363 | 
 To compile the code, we use the {\em make} program. This uses a file | 
 To specify an optfile to \texttt{genmake2}, the syntax is: | 
 | 
 ({\em Makefile}) that allows us to pre-process source files, specify | 
  | 
 | 
 compiler and optimization options and also figures out any file | 
  | 
 | 
 dependencies. We supply a script ({\em genmake}), described in section | 
  | 
 | 
 \ref{sect:genmake}, that automatically creates the {\em Makefile} for | 
  | 
 | 
 you. You then need to build the dependencies and compile the code. | 
  | 
 | 
  | 
  | 
 | 
 As an example, let's assume that you want to build and run experiment | 
  | 
 | 
 \textit{verification/exp2}. The are multiple ways and places to actually | 
  | 
 | 
 do this but here let's build the code in | 
  | 
 | 
 \textit{verification/exp2/input}: | 
  | 
 | 
 \begin{verbatim} | 
  | 
 | 
 % cd verification/exp2/input | 
  | 
 | 
 \end{verbatim} | 
  | 
 | 
 First, build the {\em Makefile}: | 
  | 
 | 
 \begin{verbatim} | 
  | 
 | 
 % ../../../tools/genmake -mods=../code | 
  | 
 | 
 \end{verbatim} | 
  | 
 | 
 The command line option tells {\em genmake} to override model source | 
  | 
 | 
 code with any files in the directory {\em ./code/}. | 
  | 
 | 
  | 
  | 
 | 
 If there is no \textit{.genmakerc} in the \textit{input} directory, you have | 
  | 
 | 
 to use the following options when invoking \textit{genmake}: | 
  | 
| 364 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 365 | 
 % ../../../tools/genmake  -mods=../code | 
 % ../../../tools/genmake2 -mods=../code -of /path/to/optfile | 
| 366 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 367 | 
  | 
  | 
| 368 | 
 Next, create the dependencies: | 
 Once a \texttt{Makefile} has been generated, we create the | 
| 369 | 
  | 
 dependencies with the command: | 
| 370 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 371 | 
 % make depend | 
 % make depend | 
| 372 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 373 | 
 This modifies {\em Makefile} by attaching a [long] list of files on | 
 This modifies the \texttt{Makefile} by attaching a (usually, long) | 
| 374 | 
 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 | 
| 375 | 
 re-compilation if and when you start to modify the code. {\tt make | 
 reduce re-compilation if and when you start to modify the code. The | 
| 376 | 
 depend} also created links from the model source to this directory. | 
 {\tt make depend} command also creates links from the model source to | 
| 377 | 
  | 
 this directory.  It is important to note that the {\tt make depend} | 
| 378 | 
  | 
 stage will occasionally produce warnings or errors since the | 
| 379 | 
  | 
 dependency parsing tool is unable to find all of the necessary header | 
| 380 | 
  | 
 files (\textit{eg.}  \texttt{netcdf.inc}).  In these circumstances, it | 
| 381 | 
  | 
 is usually OK to ignore the warnings/errors and proceed to the next | 
| 382 | 
  | 
 step. | 
| 383 | 
  | 
  | 
| 384 | 
 Now compile the code: | 
 Next one can compile the code using: | 
| 385 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 386 | 
 % make | 
 % make | 
| 387 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 388 | 
 The {\tt make} command creates an executable called \textit{mitgcmuv}. | 
 The {\tt make} command creates an executable called \texttt{mitgcmuv}. | 
| 389 | 
  | 
 Additional make ``targets'' are defined within the makefile to aid in | 
| 390 | 
  | 
 the production of adjoint and other versions of MITgcm.  On SMP | 
| 391 | 
  | 
 (shared multi-processor) systems, the build process can often be sped | 
| 392 | 
  | 
 up appreciably using the command: | 
| 393 | 
  | 
 \begin{verbatim} | 
| 394 | 
  | 
 % make -j 2 | 
| 395 | 
  | 
 \end{verbatim} | 
| 396 | 
  | 
 where the ``2'' can be replaced with a number that corresponds to the | 
| 397 | 
  | 
 number of CPUs available. | 
| 398 | 
  | 
  | 
| 399 | 
 Now you are ready to run the model. General instructions for doing so are | 
 Now you are ready to run the model. General instructions for doing so are | 
| 400 | 
 given in section \ref{sect:runModel}. Here, we can run the model with: | 
 given in section \ref{sect:runModel}. Here, we can run the model by | 
| 401 | 
  | 
 first creating links to all the input files: | 
| 402 | 
  | 
 \begin{verbatim} | 
| 403 | 
  | 
 ln -s ../input/* . | 
| 404 | 
  | 
 \end{verbatim} | 
| 405 | 
  | 
 and then calling the executable with: | 
| 406 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 407 | 
 ./mitgcmuv > output.txt | 
 ./mitgcmuv > output.txt | 
| 408 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 409 | 
 where we are re-directing the stream of text output to the file {\em | 
 where we are re-directing the stream of text output to the file | 
| 410 | 
 output.txt}. | 
 \texttt{output.txt}. | 
 | 
  | 
  | 
| 411 | 
  | 
  | 
| 412 | 
 \subsection{Building/compiling the code elsewhere} | 
 \subsection{Building/compiling the code elsewhere} | 
| 413 | 
  | 
  | 
| 416 | 
 convenience. You can also configure and compile the code in other | 
 convenience. You can also configure and compile the code in other | 
| 417 | 
 locations, for example on a scratch disk with out having to copy the | 
 locations, for example on a scratch disk with out having to copy the | 
| 418 | 
 entire source tree. The only requirement to do so is you have {\tt | 
 entire source tree. The only requirement to do so is you have {\tt | 
| 419 | 
 genmake} in your path or you know the absolute path to {\tt genmake}. | 
   genmake2} in your path or you know the absolute path to {\tt | 
| 420 | 
  | 
   genmake2}. | 
| 421 | 
  | 
  | 
| 422 | 
 The following sections outline some possible methods of organizing you | 
 The following sections outline some possible methods of organizing | 
| 423 | 
 source and data. | 
 your source and data. | 
| 424 | 
  | 
  | 
| 425 | 
 \subsubsection{Building from the {\em ../code directory}} | 
 \subsubsection{Building from the {\em ../code directory}} | 
| 426 | 
  | 
  | 
| 427 | 
 This is just as simple as building in the {\em input/} directory: | 
 This is just as simple as building in the {\em input/} directory: | 
| 428 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 429 | 
 % cd verification/exp2/code | 
 % cd verification/exp2/code | 
| 430 | 
 % ../../../tools/genmake | 
 % ../../../tools/genmake2 | 
| 431 | 
 % make depend | 
 % make depend | 
| 432 | 
 % make | 
 % make | 
| 433 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 456 | 
 % cd verification/exp2 | 
 % cd verification/exp2 | 
| 457 | 
 % mkdir build | 
 % mkdir build | 
| 458 | 
 % cd build | 
 % cd build | 
| 459 | 
 % ../../../tools/genmake -mods=../code | 
 % ../../../tools/genmake2 -mods=../code | 
| 460 | 
 % make depend | 
 % make depend | 
| 461 | 
 % make | 
 % make | 
| 462 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 478 | 
 % ./mitgcmuv > output.txt | 
 % ./mitgcmuv > output.txt | 
| 479 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 480 | 
  | 
  | 
| 481 | 
 \subsubsection{Building from on a scratch disk} | 
 \subsubsection{Building on a scratch disk} | 
| 482 | 
  | 
  | 
| 483 | 
 Model object files and output data can use up large amounts of disk | 
 Model object files and output data can use up large amounts of disk | 
| 484 | 
 space so it is often the case that you will be operating on a large | 
 space so it is often the case that you will be operating on a large | 
| 486 | 
 following commands will build the model in {\em /scratch/exp2-run1}: | 
 following commands will build the model in {\em /scratch/exp2-run1}: | 
| 487 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 488 | 
 % cd /scratch/exp2-run1 | 
 % cd /scratch/exp2-run1 | 
| 489 | 
 % ~/MITgcm/tools/genmake -rootdir=~/MITgcm -mods=~/MITgcm/verification/exp2/code | 
 % ~/MITgcm/tools/genmake2 -rootdir=~/MITgcm \ | 
| 490 | 
  | 
   -mods=~/MITgcm/verification/exp2/code | 
| 491 | 
 % make depend | 
 % make depend | 
| 492 | 
 % make | 
 % make | 
| 493 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 503 | 
 % cd /scratch/exp2 | 
 % cd /scratch/exp2 | 
| 504 | 
 % mkdir build | 
 % mkdir build | 
| 505 | 
 % cd build | 
 % cd build | 
| 506 | 
 % ~/MITgcm/tools/genmake -rootdir=~/MITgcm -mods=~/MITgcm/verification/exp2/code | 
 % ~/MITgcm/tools/genmake2 -rootdir=~/MITgcm \ | 
| 507 | 
  | 
   -mods=~/MITgcm/verification/exp2/code | 
| 508 | 
 % make depend | 
 % make depend | 
| 509 | 
 % make | 
 % make | 
| 510 | 
 % cd ../ | 
 % cd ../ | 
| 514 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 515 | 
  | 
  | 
| 516 | 
  | 
  | 
| 517 | 
  | 
 \subsection{Using \texttt{genmake2}} | 
 | 
 \subsection{\textit{genmake}} | 
  | 
| 518 | 
 \label{sect:genmake} | 
 \label{sect:genmake} | 
| 519 | 
  | 
  | 
| 520 | 
 To compile the code, use the script \textit{genmake} located in the \textit{% | 
 To compile the code, first use the program \texttt{genmake2} (located | 
| 521 | 
 tools} directory. \textit{genmake} is a script that generates the makefile. | 
 in the \texttt{tools} directory) to generate a Makefile. | 
| 522 | 
 It has been written so that the code can be compiled on a wide diversity of | 
 \texttt{genmake2} is a shell script written to work with all | 
| 523 | 
 machines and systems. However, if it doesn't work the first time on your | 
 ``sh''--compatible shells including bash v1, bash v2, and Bourne. | 
| 524 | 
 platform, you might need to edit certain lines of \textit{genmake} in the | 
 Internally, \texttt{genmake2} determines the locations of needed | 
| 525 | 
 section containing the setups for the different machines. The file is | 
 files, the compiler, compiler options, libraries, and Unix tools.  It | 
| 526 | 
 structured like this: | 
 relies upon a number of ``optfiles'' located in the | 
| 527 | 
 \begin{verbatim} | 
 \texttt{tools/build\_options} directory. | 
| 528 | 
         . | 
  | 
| 529 | 
         . | 
 The purpose of the optfiles is to provide all the compilation options | 
| 530 | 
         . | 
 for particular ``platforms'' (where ``platform'' roughly means the | 
| 531 | 
 general instructions (machine independent) | 
 combination of the hardware and the compiler) and code configurations. | 
| 532 | 
         . | 
 Given the combinations of possible compilers and library dependencies | 
| 533 | 
         . | 
 ({\it eg.}  MPI and NetCDF) there may be numerous optfiles available | 
| 534 | 
         . | 
 for a single machine.  The naming scheme for the majority of the | 
| 535 | 
     - setup machine 1 | 
 optfiles shipped with the code is | 
| 536 | 
     - setup machine 2 | 
 \begin{center} | 
| 537 | 
     - setup machine 3 | 
   {\bf OS\_HARDWARE\_COMPILER } | 
| 538 | 
     - setup machine 4 | 
 \end{center} | 
| 539 | 
        etc | 
 where | 
| 540 | 
         . | 
 \begin{description} | 
| 541 | 
         . | 
 \item[OS] is the name of the operating system (generally the | 
| 542 | 
         . | 
   lower-case output of the {\tt 'uname'} command) | 
| 543 | 
 \end{verbatim} | 
 \item[HARDWARE] is a string that describes the CPU type and | 
| 544 | 
  | 
   corresponds to output from the  {\tt 'uname -m'} command: | 
| 545 | 
 For example, the setup corresponding to a DEC alpha machine is reproduced | 
   \begin{description} | 
| 546 | 
 here: | 
   \item[ia32] is for ``x86'' machines such as i386, i486, i586, i686, | 
| 547 | 
 \begin{verbatim} | 
     and athlon | 
| 548 | 
   case OSF1+mpi: | 
   \item[ia64] is for Intel IA64 systems (eg. Itanium, Itanium2) | 
| 549 | 
     echo "Configuring for DEC Alpha" | 
   \item[amd64] is AMD x86\_64 systems | 
| 550 | 
     set CPP        = ( '/usr/bin/cpp -P' ) | 
   \item[ppc] is for Mac PowerPC systems | 
| 551 | 
     set DEFINES    = ( ${DEFINES}  '-DTARGET_DEC -DWORDLENGTH=1' ) | 
   \end{description} | 
| 552 | 
     set KPP        = ( 'kapf' ) | 
 \item[COMPILER] is the compiler name (generally, the name of the | 
| 553 | 
     set KPPFILES   = ( 'main.F' ) | 
   FORTRAN executable) | 
| 554 | 
     set KFLAGS1    = ( '-scan=132 -noconc -cmp=' ) | 
 \end{description} | 
| 555 | 
     set FC         = ( 'f77' ) | 
  | 
| 556 | 
     set FFLAGS     = ( '-convert big_endian -r8 -extend_source -automatic -call_shared -notransform_loops -align dcommons' ) | 
 In many cases, the default optfiles are sufficient and will result in | 
| 557 | 
     set FOPTIM     = ( '-O5 -fast -tune host -inline all' ) | 
 usable Makefiles.  However, for some machines or code configurations, | 
| 558 | 
     set NOOPTFLAGS = ( '-O0' ) | 
 new ``optfiles'' must be written. To create a new optfile, it is | 
| 559 | 
     set LIBS       = ( '-lfmpi -lmpi -lkmp_osfp10 -pthread' ) | 
 generally best to start with one of the defaults and modify it to suit | 
| 560 | 
     set NOOPTFILES = ( 'barrier.F different_multiple.F external_fields_load.F') | 
 your needs.  Like \texttt{genmake2}, the optfiles are all written | 
| 561 | 
     set RMFILES    = ( '*.p.out' ) | 
 using a simple ``sh''--compatible syntax.  While nearly all variables | 
| 562 | 
     breaksw | 
 used within \texttt{genmake2} may be specified in the optfiles, the | 
| 563 | 
 \end{verbatim} | 
 critical ones that should be defined are: | 
| 564 | 
  | 
  | 
| 565 | 
 Typically, these are the lines that you might need to edit to make \textit{% | 
 \begin{description} | 
| 566 | 
 genmake} work on your platform if it doesn't work the first time. \textit{% | 
 \item[FC] the FORTRAN compiler (executable) to use | 
| 567 | 
 genmake} understands several options that are described here: | 
 \item[DEFINES] the command-line DEFINE options passed to the compiler | 
| 568 | 
  | 
 \item[CPP] the C pre-processor to use | 
| 569 | 
 \begin{itemize} | 
 \item[NOOPTFLAGS] options flags for special files that should not be | 
| 570 | 
 \item -rootdir=dir | 
   optimized | 
| 571 | 
  | 
 \end{description} | 
| 572 | 
 indicates where the model root directory is relative to the directory where | 
  | 
| 573 | 
 you are compiling. This option is not needed if you compile in the \textit{% | 
 For example, the optfile for a typical Red Hat Linux machine (``ia32'' | 
| 574 | 
 bin} directory (which is the default compilation directory) or within the  | 
 architecture) using the GCC (g77) compiler is | 
| 575 | 
 \textit{verification} tree. | 
 \begin{verbatim} | 
| 576 | 
  | 
 FC=g77 | 
| 577 | 
 \item -mods=dir1,dir2,... | 
 DEFINES='-D_BYTESWAPIO -DWORDLENGTH=4' | 
| 578 | 
  | 
 CPP='cpp  -traditional -P' | 
| 579 | 
 indicates the relative or absolute paths directories where the sources | 
 NOOPTFLAGS='-O0' | 
| 580 | 
 should take precedence over the default versions (located in \textit{model},  | 
 #  For IEEE, use the "-ffloat-store" option | 
| 581 | 
 \textit{eesupp},...). Typically, this option is used when running the | 
 if test "x$IEEE" = x ; then | 
| 582 | 
 examples, see below. | 
     FFLAGS='-Wimplicit -Wunused -Wuninitialized' | 
| 583 | 
  | 
     FOPTIM='-O3 -malign-double -funroll-loops' | 
| 584 | 
 \item -enable=pkg1,pkg2,... | 
 else | 
| 585 | 
  | 
     FFLAGS='-Wimplicit -Wunused -ffloat-store' | 
| 586 | 
 enables packages source code \textit{pkg1}, \textit{pkg2},... when creating | 
     FOPTIM='-O0 -malign-double' | 
| 587 | 
 the makefile. | 
 fi | 
| 588 | 
  | 
 \end{verbatim} | 
| 589 | 
 \item -disable=pkg1,pkg2,... | 
  | 
| 590 | 
  | 
 If you write an optfile for an unrepresented machine or compiler, you | 
| 591 | 
 disables packages source code \textit{pkg1}, \textit{pkg2},... when creating | 
 are strongly encouraged to submit the optfile to the MITgcm project | 
| 592 | 
 the makefile. | 
 for inclusion.  Please send the file to the | 
| 593 | 
  | 
 \begin{rawhtml} <A href="mail-to:MITgcm-support@mitgcm.org"> \end{rawhtml} | 
| 594 | 
 \item -platform=machine | 
 \begin{center} | 
| 595 | 
  | 
   MITgcm-support@mitgcm.org | 
| 596 | 
 specifies the platform for which you want the makefile. In general, you | 
 \end{center} | 
| 597 | 
 won't need this option. \textit{genmake} will select the right machine for | 
 \begin{rawhtml} </A> \end{rawhtml} | 
| 598 | 
 you (the one you're working on!). However, this option is useful if you have | 
 mailing list. | 
 | 
 a choice of several compilers on one machine and you want to use the one | 
  | 
 | 
 that is not the default (ex: \texttt{pgf77} instead of \texttt{f77} under | 
  | 
 | 
 Linux). | 
  | 
 | 
  | 
  | 
 | 
 \item -mpi | 
  | 
| 599 | 
  | 
  | 
| 600 | 
 this is used when you want to run the model in parallel processing mode | 
 In addition to the optfiles, \texttt{genmake2} supports a number of | 
| 601 | 
 under mpi (see section on parallel computation for more details). | 
 helpful command-line options.  A complete list of these options can be | 
| 602 | 
  | 
 obtained from: | 
| 603 | 
  | 
 \begin{verbatim} | 
| 604 | 
  | 
 % genmake2 -h | 
| 605 | 
  | 
 \end{verbatim} | 
| 606 | 
  | 
  | 
| 607 | 
  | 
 The most important command-line options are: | 
| 608 | 
  | 
 \begin{description} | 
| 609 | 
  | 
    | 
| 610 | 
  | 
 \item[\texttt{--optfile=/PATH/FILENAME}] specifies the optfile that | 
| 611 | 
  | 
   should be used for a particular build. | 
| 612 | 
  | 
    | 
| 613 | 
  | 
   If no "optfile" is specified (either through the command line or the | 
| 614 | 
  | 
   MITGCM\_OPTFILE environment variable), genmake2 will try to make a | 
| 615 | 
  | 
   reasonable guess from the list provided in {\em | 
| 616 | 
  | 
     tools/build\_options}.  The method used for making this guess is | 
| 617 | 
  | 
   to first determine the combination of operating system and hardware | 
| 618 | 
  | 
   (eg. "linux\_ia32") and then find a working FORTRAN compiler within | 
| 619 | 
  | 
   the user's path.  When these three items have been identified, | 
| 620 | 
  | 
   genmake2 will try to find an optfile that has a matching name. | 
| 621 | 
  | 
    | 
| 622 | 
  | 
 \item[\texttt{--pdefault='PKG1 PKG2 PKG3 ...'}] specifies the default | 
| 623 | 
  | 
   set of packages to be used.  The normal order of precedence for | 
| 624 | 
  | 
   packages is as follows: | 
| 625 | 
  | 
   \begin{enumerate} | 
| 626 | 
  | 
   \item If available, the command line (\texttt{--pdefault}) settings | 
| 627 | 
  | 
     over-rule any others. | 
| 628 | 
  | 
  | 
| 629 | 
  | 
   \item Next, \texttt{genmake2} will look for a file named | 
| 630 | 
  | 
     ``\texttt{packages.conf}'' in the local directory or in any of the | 
| 631 | 
  | 
     directories specified with the \texttt{--mods} option. | 
| 632 | 
  | 
      | 
| 633 | 
  | 
   \item Finally, if neither of the above are available, | 
| 634 | 
  | 
     \texttt{genmake2} will use the \texttt{/pkg/pkg\_default} file. | 
| 635 | 
  | 
   \end{enumerate} | 
| 636 | 
  | 
    | 
| 637 | 
  | 
 \item[\texttt{--pdepend=/PATH/FILENAME}] specifies the dependency file | 
| 638 | 
  | 
   used for packages. | 
| 639 | 
  | 
    | 
| 640 | 
  | 
   If not specified, the default dependency file {\em pkg/pkg\_depend} | 
| 641 | 
  | 
   is used.  The syntax for this file is parsed on a line-by-line basis | 
| 642 | 
  | 
   where each line containes either a comment ("\#") or a simple | 
| 643 | 
  | 
   "PKGNAME1 (+|-)PKGNAME2" pairwise rule where the "+" or "-" symbol | 
| 644 | 
  | 
   specifies a "must be used with" or a "must not be used with" | 
| 645 | 
  | 
   relationship, respectively.  If no rule is specified, then it is | 
| 646 | 
  | 
   assumed that the two packages are compatible and will function | 
| 647 | 
  | 
   either with or without each other. | 
| 648 | 
  | 
    | 
| 649 | 
  | 
 \item[\texttt{--adof=/path/to/file}] specifies the "adjoint" or | 
| 650 | 
  | 
   automatic differentiation options file to be used.  The file is | 
| 651 | 
  | 
   analogous to the ``optfile'' defined above but it specifies | 
| 652 | 
  | 
   information for the AD build process. | 
| 653 | 
  | 
    | 
| 654 | 
  | 
   The default file is located in {\em | 
| 655 | 
  | 
     tools/adjoint\_options/adjoint\_default} and it defines the "TAF" | 
| 656 | 
  | 
   and "TAMC" compilers.  An alternate version is also available at | 
| 657 | 
  | 
   {\em tools/adjoint\_options/adjoint\_staf} that selects the newer | 
| 658 | 
  | 
   "STAF" compiler.  As with any compilers, it is helpful to have their | 
| 659 | 
  | 
   directories listed in your {\tt \$PATH} environment variable. | 
| 660 | 
  | 
    | 
| 661 | 
  | 
 \item[\texttt{--mods='DIR1 DIR2 DIR3 ...'}] specifies a list of | 
| 662 | 
  | 
   directories containing ``modifications''.  These directories contain | 
| 663 | 
  | 
   files with names that may (or may not) exist in the main MITgcm | 
| 664 | 
  | 
   source tree but will be overridden by any identically-named sources | 
| 665 | 
  | 
   within the ``MODS'' directories. | 
| 666 | 
  | 
    | 
| 667 | 
  | 
   The order of precedence for this "name-hiding" is as follows: | 
| 668 | 
  | 
   \begin{itemize} | 
| 669 | 
  | 
   \item ``MODS'' directories (in the order given) | 
| 670 | 
  | 
   \item Packages either explicitly specified or provided by default | 
| 671 | 
  | 
     (in the order given) | 
| 672 | 
  | 
   \item Packages included due to package dependencies (in the order | 
| 673 | 
  | 
     that that package dependencies are parsed) | 
| 674 | 
  | 
   \item The "standard dirs" (which may have been specified by the | 
| 675 | 
  | 
     ``-standarddirs'' option) | 
| 676 | 
  | 
   \end{itemize} | 
| 677 | 
  | 
    | 
| 678 | 
  | 
 \item[\texttt{--mpi}] This option enables certain MPI features (using | 
| 679 | 
  | 
   CPP \texttt{\#define}s) within the code and is necessary for MPI | 
| 680 | 
  | 
   builds (see Section \ref{sect:mpi-build}). | 
| 681 | 
  | 
    | 
| 682 | 
  | 
 \item[\texttt{--make=/path/to/gmake}] Due to the poor handling of | 
| 683 | 
  | 
   soft-links and other bugs common with the \texttt{make} versions | 
| 684 | 
  | 
   provided by commercial Unix vendors, GNU \texttt{make} (sometimes | 
| 685 | 
  | 
   called \texttt{gmake}) should be preferred.  This option provides a | 
| 686 | 
  | 
   means for specifying the make executable to be used. | 
| 687 | 
  | 
    | 
| 688 | 
  | 
 \item[\texttt{--bash=/path/to/sh}] On some (usually older UNIX) | 
| 689 | 
  | 
   machines, the ``bash'' shell is unavailable.  To run on these | 
| 690 | 
  | 
   systems, \texttt{genmake2} can be invoked using an ``sh'' (that is, | 
| 691 | 
  | 
   a Bourne, POSIX, or compatible) shell.  The syntax in these | 
| 692 | 
  | 
   circumstances is: | 
| 693 | 
  | 
   \begin{center} | 
| 694 | 
  | 
     \texttt{\%  /bin/sh genmake2 -bash=/bin/sh [...options...]} | 
| 695 | 
  | 
   \end{center} | 
| 696 | 
  | 
   where \texttt{/bin/sh} can be replaced with the full path and name | 
| 697 | 
  | 
   of the desired shell. | 
| 698 | 
  | 
  | 
| 699 | 
  | 
 \end{description} | 
| 700 | 
  | 
  | 
| 701 | 
  | 
  | 
| 702 | 
  | 
 \subsection{Building with MPI} | 
| 703 | 
  | 
 \label{sect:mpi-build} | 
| 704 | 
  | 
  | 
| 705 | 
  | 
 Building MITgcm to use MPI libraries can be complicated due to the | 
| 706 | 
  | 
 variety of different MPI implementations available, their dependencies | 
| 707 | 
  | 
 or interactions with different compilers, and their often ad-hoc | 
| 708 | 
  | 
 locations within file systems.  For these reasons, its generally a | 
| 709 | 
  | 
 good idea to start by finding and reading the documentation for your | 
| 710 | 
  | 
 machine(s) and, if necessary, seeking help from your local systems | 
| 711 | 
  | 
 administrator. | 
| 712 | 
  | 
  | 
| 713 | 
 \item -jam | 
 The steps for building MITgcm with MPI support are: | 
| 714 | 
  | 
 \begin{enumerate} | 
| 715 | 
  | 
    | 
| 716 | 
  | 
 \item Determine the locations of your MPI-enabled compiler and/or MPI | 
| 717 | 
  | 
   libraries and put them into an options file as described in Section | 
| 718 | 
  | 
   \ref{sect:genmake}.  One can start with one of the examples in: | 
| 719 | 
  | 
   \begin{rawhtml} <A | 
| 720 | 
  | 
     href="http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm/tools/build_options/"> | 
| 721 | 
  | 
   \end{rawhtml} | 
| 722 | 
  | 
   \begin{center} | 
| 723 | 
  | 
     \texttt{MITgcm/tools/build\_options/} | 
| 724 | 
  | 
   \end{center} | 
| 725 | 
  | 
   \begin{rawhtml} </A> \end{rawhtml} | 
| 726 | 
  | 
   such as \texttt{linux\_ia32\_g77+mpi\_cg01} or | 
| 727 | 
  | 
   \texttt{linux\_ia64\_efc+mpi} and then edit it to suit the machine at | 
| 728 | 
  | 
   hand.  You may need help from your user guide or local systems | 
| 729 | 
  | 
   administrator to determine the exact location of the MPI libraries. | 
| 730 | 
  | 
   If libraries are not installed, MPI implementations and related | 
| 731 | 
  | 
   tools are available including: | 
| 732 | 
  | 
   \begin{itemize} | 
| 733 | 
  | 
   \item \begin{rawhtml} <A | 
| 734 | 
  | 
       href="http://www-unix.mcs.anl.gov/mpi/mpich/"> | 
| 735 | 
  | 
     \end{rawhtml} | 
| 736 | 
  | 
     MPICH | 
| 737 | 
  | 
     \begin{rawhtml} </A> \end{rawhtml} | 
| 738 | 
  | 
  | 
| 739 | 
  | 
   \item \begin{rawhtml} <A | 
| 740 | 
  | 
       href="http://www.lam-mpi.org/"> | 
| 741 | 
  | 
     \end{rawhtml} | 
| 742 | 
  | 
     LAM/MPI | 
| 743 | 
  | 
     \begin{rawhtml} </A> \end{rawhtml} | 
| 744 | 
  | 
  | 
| 745 | 
  | 
   \item \begin{rawhtml} <A | 
| 746 | 
  | 
       href="http://www.osc.edu/~pw/mpiexec/"> | 
| 747 | 
  | 
     \end{rawhtml} | 
| 748 | 
  | 
     MPIexec | 
| 749 | 
  | 
     \begin{rawhtml} </A> \end{rawhtml} | 
| 750 | 
  | 
   \end{itemize} | 
| 751 | 
  | 
    | 
| 752 | 
  | 
 \item Build the code with the \texttt{genmake2} \texttt{-mpi} option | 
| 753 | 
  | 
   (see Section \ref{sect:genmake}) using commands such as: | 
| 754 | 
  | 
 {\footnotesize \begin{verbatim} | 
| 755 | 
  | 
   %  ../../../tools/genmake2 -mods=../code -mpi -of=YOUR_OPTFILE | 
| 756 | 
  | 
   %  make depend | 
| 757 | 
  | 
   %  make | 
| 758 | 
  | 
 \end{verbatim} } | 
| 759 | 
  | 
    | 
| 760 | 
  | 
 \item Run the code with the appropriate MPI ``run'' or ``exec'' | 
| 761 | 
  | 
   program provided with your particular implementation of MPI. | 
| 762 | 
  | 
   Typical MPI packages such as MPICH will use something like: | 
| 763 | 
  | 
 \begin{verbatim} | 
| 764 | 
  | 
   %  mpirun -np 4 -machinefile mf ./mitgcmuv | 
| 765 | 
  | 
 \end{verbatim} | 
| 766 | 
  | 
   Sightly more complicated scripts may be needed for many machines | 
| 767 | 
  | 
   since execution of the code may be controlled by both the MPI | 
| 768 | 
  | 
   library and a job scheduling and queueing system such as PBS, | 
| 769 | 
  | 
   LoadLeveller, Condor, or any of a number of similar tools.  A few | 
| 770 | 
  | 
   example scripts (those used for our \begin{rawhtml} <A | 
| 771 | 
  | 
     href="http://mitgcm.org/testing.html"> \end{rawhtml}regular | 
| 772 | 
  | 
   verification runs\begin{rawhtml} </A> \end{rawhtml}) are available | 
| 773 | 
  | 
   at: | 
| 774 | 
  | 
   \begin{rawhtml} <A | 
| 775 | 
  | 
     href="http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm_contrib/test_scripts/"> | 
| 776 | 
  | 
   \end{rawhtml} | 
| 777 | 
  | 
   {\footnotesize \tt | 
| 778 | 
  | 
     http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm\_contrib/test\_scripts/ } | 
| 779 | 
  | 
   \begin{rawhtml} </A> \end{rawhtml} | 
| 780 | 
  | 
  | 
| 781 | 
 this is used when you want to run the model in parallel processing mode | 
 \end{enumerate} | 
 | 
 under jam (see section on parallel computation for more details). | 
  | 
 | 
 \end{itemize} | 
  | 
| 782 | 
  | 
  | 
| 783 | 
 For some of the examples, there is a file called \textit{.genmakerc} in the  | 
 An example of the above process on the MITgcm cluster (``cg01'') using | 
| 784 | 
 \textit{input} directory that has the relevant \textit{genmake} options for | 
 the GNU g77 compiler and the mpich MPI library is: | 
 | 
 that particular example. In this way you don't need to type the options when | 
  | 
 | 
 invoking \textit{genmake}. | 
  | 
| 785 | 
  | 
  | 
| 786 | 
  | 
 {\footnotesize \begin{verbatim} | 
| 787 | 
  | 
   %  cd MITgcm/verification/exp5 | 
| 788 | 
  | 
   %  mkdir build | 
| 789 | 
  | 
   %  cd build | 
| 790 | 
  | 
   %  ../../../tools/genmake2 -mpi -mods=../code \ | 
| 791 | 
  | 
        -of=../../../tools/build_options/linux_ia32_g77+mpi_cg01 | 
| 792 | 
  | 
   %  make depend | 
| 793 | 
  | 
   %  make | 
| 794 | 
  | 
   %  cd ../input | 
| 795 | 
  | 
   %  /usr/local/pkg/mpi/mpi-1.2.4..8a-gm-1.5/g77/bin/mpirun.ch_gm \ | 
| 796 | 
  | 
        -machinefile mf --gm-kill 5 -v -np 2  ../build/mitgcmuv | 
| 797 | 
  | 
 \end{verbatim} } | 
| 798 | 
  | 
  | 
| 799 | 
 \section{Running the model} | 
 \section[Running MITgcm]{Running the model in prognostic mode} | 
| 800 | 
 \label{sect:runModel} | 
 \label{sect:runModel} | 
| 801 | 
  | 
 \begin{rawhtml} | 
| 802 | 
  | 
 <!-- CMIREDIR:runModel: --> | 
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  | 
 \end{rawhtml} | 
| 804 | 
  | 
  | 
| 805 | 
  | 
 If compilation finished succesfully (section \ref{sect:buildingCode}) | 
| 806 | 
  | 
 then an executable called \texttt{mitgcmuv} will now exist in the | 
| 807 | 
  | 
 local directory. | 
| 808 | 
  | 
  | 
| 809 | 
 If compilation finished succesfuully (section \ref{sect:buildModel}) | 
 To run the model as a single process (\textit{ie.} not in parallel) | 
| 810 | 
 then an executable called {\em mitgcmuv} will now exist in the local | 
 simply type: | 
 | 
 directory. | 
  | 
 | 
  | 
  | 
 | 
 To run the model as a single process (ie. not in parallel) simply | 
  | 
 | 
 type: | 
  | 
| 811 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 812 | 
 % ./mitgcmuv | 
 % ./mitgcmuv | 
| 813 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 817 | 
 your screen.  This output contains details such as parameter values as | 
 your screen.  This output contains details such as parameter values as | 
| 818 | 
 well as diagnostics such as mean Kinetic energy, largest CFL number, | 
 well as diagnostics such as mean Kinetic energy, largest CFL number, | 
| 819 | 
 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 | 
| 820 | 
 normally re-direct the {\em stdout} stream as follows: | 
 normally re-direct the \texttt{stdout} stream as follows: | 
| 821 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 822 | 
 % ./mitgcmuv > output.txt | 
 % ./mitgcmuv > output.txt | 
| 823 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 824 | 
  | 
 In the event that the model encounters an error and stops, it is very | 
| 825 | 
 For the example experiments in {\em vericication}, an example of the | 
 helpful to include the last few line of this \texttt{output.txt} file | 
| 826 | 
 output is kept in {\em results/output.txt} for comparison. You can compare | 
 along with the (\texttt{stderr}) error message within any bug reports. | 
| 827 | 
 your {\em output.txt} with this one to check that the set-up works. | 
  | 
| 828 | 
  | 
 For the example experiments in \texttt{verification}, an example of the | 
| 829 | 
  | 
 output is kept in \texttt{results/output.txt} for comparison. You can | 
| 830 | 
  | 
 compare your \texttt{output.txt} with the corresponding one for that | 
| 831 | 
  | 
 experiment to check that the set-up works. | 
| 832 | 
  | 
  | 
| 833 | 
  | 
  | 
| 834 | 
  | 
  | 
| 835 | 
 \subsection{Output files} | 
 \subsection{Output files} | 
| 836 | 
  | 
  | 
| 837 | 
 The model produces various output files. At a minimum, the instantaneous | 
 The model produces various output files and, when using \texttt{mnc}, | 
| 838 | 
 ``state'' of the model is written out, which is made of the following files: | 
 sometimes even directories.  Depending upon the I/O package(s) | 
| 839 | 
  | 
 selected at compile time (either \texttt{mdsio} or \texttt{mnc} or | 
| 840 | 
  | 
 both as determined by \texttt{code/packages.conf}) and the run-time | 
| 841 | 
  | 
 flags set (in \texttt{input/data.pkg}), the following output may | 
| 842 | 
  | 
 appear. | 
| 843 | 
  | 
  | 
| 844 | 
  | 
  | 
| 845 | 
  | 
 \subsubsection{MDSIO output files} | 
| 846 | 
  | 
  | 
| 847 | 
  | 
 The ``traditional'' output files are generated by the \texttt{mdsio} | 
| 848 | 
  | 
 package.  At a minimum, the instantaneous ``state'' of the model is | 
| 849 | 
  | 
 written out, which is made of the following files: | 
| 850 | 
  | 
  | 
| 851 | 
 \begin{itemize} | 
 \begin{itemize} | 
| 852 | 
 \item \textit{U.00000nIter} - zonal component of velocity field (m/s and $> | 
 \item \texttt{U.00000nIter} - zonal component of velocity field (m/s | 
| 853 | 
 0 $ eastward). | 
   and positive eastward). | 
| 854 | 
  | 
  | 
| 855 | 
 \item \textit{V.00000nIter} - meridional component of velocity field (m/s | 
 \item \texttt{V.00000nIter} - meridional component of velocity field | 
| 856 | 
 and $> 0$ northward). | 
   (m/s and positive northward). | 
| 857 | 
  | 
  | 
| 858 | 
 \item \textit{W.00000nIter} - vertical component of velocity field (ocean: | 
 \item \texttt{W.00000nIter} - vertical component of velocity field | 
| 859 | 
 m/s and $> 0$ upward, atmosphere: Pa/s and $> 0$ towards increasing pressure | 
   (ocean: m/s and positive upward, atmosphere: Pa/s and positive | 
| 860 | 
 i.e. downward). | 
   towards increasing pressure i.e. downward). | 
| 861 | 
  | 
  | 
| 862 | 
 \item \textit{T.00000nIter} - potential temperature (ocean: $^{0}$C, | 
 \item \texttt{T.00000nIter} - potential temperature (ocean: | 
| 863 | 
 atmosphere: $^{0}$K). | 
   $^{\circ}\mathrm{C}$, atmosphere: $^{\circ}\mathrm{K}$). | 
| 864 | 
  | 
  | 
| 865 | 
 \item \textit{S.00000nIter} - ocean: salinity (psu), atmosphere: water vapor | 
 \item \texttt{S.00000nIter} - ocean: salinity (psu), atmosphere: water | 
| 866 | 
 (g/kg). | 
   vapor (g/kg). | 
| 867 | 
  | 
  | 
| 868 | 
 \item \textit{Eta.00000nIter} - ocean: surface elevation (m), atmosphere: | 
 \item \texttt{Eta.00000nIter} - ocean: surface elevation (m), | 
| 869 | 
 surface pressure anomaly (Pa). | 
   atmosphere: surface pressure anomaly (Pa). | 
| 870 | 
 \end{itemize} | 
 \end{itemize} | 
| 871 | 
  | 
  | 
| 872 | 
 The chain \textit{00000nIter} consists of ten figures that specify the | 
 The chain \texttt{00000nIter} consists of ten figures that specify the | 
| 873 | 
 iteration number at which the output is written out. For example, \textit{% | 
 iteration number at which the output is written out. For example, | 
| 874 | 
 U.0000000300} is the zonal velocity at iteration 300. | 
 \texttt{U.0000000300} is the zonal velocity at iteration 300. | 
| 875 | 
  | 
  | 
| 876 | 
 In addition, a ``pickup'' or ``checkpoint'' file called: | 
 In addition, a ``pickup'' or ``checkpoint'' file called: | 
| 877 | 
  | 
  | 
| 878 | 
 \begin{itemize} | 
 \begin{itemize} | 
| 879 | 
 \item \textit{pickup.00000nIter} | 
 \item \texttt{pickup.00000nIter} | 
| 880 | 
 \end{itemize} | 
 \end{itemize} | 
| 881 | 
  | 
  | 
| 882 | 
 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 | 
| 884 | 
 there is an additional ``pickup'' file: | 
 there is an additional ``pickup'' file: | 
| 885 | 
  | 
  | 
| 886 | 
 \begin{itemize} | 
 \begin{itemize} | 
| 887 | 
 \item \textit{pickup\_cd.00000nIter} | 
 \item \texttt{pickup\_cd.00000nIter} | 
| 888 | 
 \end{itemize} | 
 \end{itemize} | 
| 889 | 
  | 
  | 
| 890 | 
 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 | 
| 891 | 
 in order to restart the integration. Rolling checkpoint files are the same | 
 in order to restart the integration. Rolling checkpoint files are the same | 
| 892 | 
 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  | 
| 893 | 
 \textit{ckptA} or \textit{ckptB} instead of \textit{00000nIter}. They can be | 
 \texttt{ckptA} or \texttt{ckptB} instead of \texttt{00000nIter}. They can be | 
| 894 | 
 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 | 
| 895 | 
 output to save disk space during long integrations. | 
 output to save disk space during long integrations. | 
| 896 | 
  | 
  | 
| 897 | 
  | 
 \subsubsection{MNC output files} | 
| 898 | 
  | 
  | 
| 899 | 
  | 
 Unlike the \texttt{mdsio} output, the \texttt{mnc}--generated output | 
| 900 | 
  | 
 is usually (though not necessarily) placed within a subdirectory with | 
| 901 | 
  | 
 a name such as \texttt{mnc\_test\_\${DATE}\_\${SEQ}}.   | 
| 902 | 
  | 
  | 
| 903 | 
 \subsection{Looking at the output} | 
 \subsection{Looking at the output} | 
| 904 | 
  | 
  | 
| 905 | 
 All the model data are written according to a ``meta/data'' file format. | 
 The ``traditional'' or mdsio model data are written according to a | 
| 906 | 
 Each variable is associated with two files with suffix names \textit{.data} | 
 ``meta/data'' file format.  Each variable is associated with two files | 
| 907 | 
 and \textit{.meta}. The \textit{.data} file contains the data written in | 
 with suffix names \texttt{.data} and \texttt{.meta}. The | 
| 908 | 
 binary form (big\_endian by default). The \textit{.meta} file is a | 
 \texttt{.data} file contains the data written in binary form | 
| 909 | 
 ``header'' file that contains information about the size and the structure | 
 (big\_endian by default). The \texttt{.meta} file is a ``header'' file | 
| 910 | 
 of the \textit{.data} file. This way of organizing the output is | 
 that contains information about the size and the structure of the | 
| 911 | 
 particularly useful when running multi-processors calculations. The base | 
 \texttt{.data} file. This way of organizing the output is particularly | 
| 912 | 
 version of the model includes a few matlab utilities to read output files | 
 useful when running multi-processors calculations. The base version of | 
| 913 | 
 written in this format. The matlab scripts are located in the directory  | 
 the model includes a few matlab utilities to read output files written | 
| 914 | 
 \textit{utils/matlab} under the root tree. The script \textit{rdmds.m} reads | 
 in this format. The matlab scripts are located in the directory | 
| 915 | 
 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} | 
| 916 | 
  | 
 reads the data. Look at the comments inside the script to see how to | 
| 917 | 
  | 
 use it. | 
| 918 | 
  | 
  | 
| 919 | 
 Some examples of reading and visualizing some output in {\em Matlab}: | 
 Some examples of reading and visualizing some output in {\em Matlab}: | 
| 920 | 
 \begin{verbatim} | 
 \begin{verbatim} | 
| 931 | 
 >> 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 | 
| 932 | 
 \end{verbatim} | 
 \end{verbatim} | 
| 933 | 
  | 
  | 
| 934 | 
 \section{Doing it yourself: customizing the code} | 
 Similar scripts for netCDF output (\texttt{rdmnc.m}) are available and | 
| 935 | 
  | 
 they are described in Section \ref{sec:pkg:mnc}. | 
 | 
 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{itemize} | 
  | 
 | 
 \item dimensions | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 The number of points in the x, y,\textit{\ }and r\textit{\ }directions are | 
  | 
 | 
 represented by the variables \textbf{sNx}\textit{, }\textbf{sNy}\textit{, }% | 
  | 
 | 
 and \textbf{Nr}\textit{\ }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 section on parallel | 
  | 
 | 
 implementation.) | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item grid | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 Three different grids are available: cartesian, spherical polar, and | 
  | 
 | 
 curvilinear (including the cubed sphere). The grid is set through the | 
  | 
 | 
 logical variables \textbf{usingCartesianGrid}\textit{, }\textbf{% | 
  | 
 | 
 usingSphericalPolarGrid}\textit{, }and \textit{\ }\textbf{% | 
  | 
 | 
 usingCurvilinearGrid}\textit{. }In the case of spherical and curvilinear | 
  | 
 | 
 grids, the southern boundary is defined through the variable \textbf{phiMin}% | 
  | 
 | 
 \textit{\ }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}\textit{\ }and \textbf{dely}\textit{\ }(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}\textit{\ }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 put 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}\textit{\ }and \textbf{beta}\textit{\ }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 }\textit{\ }% | 
  | 
 | 
 is set to a nonzero value, \textbf{f0}\textit{\ }is the value of $f$ at the | 
  | 
 | 
 southern edge of the domain. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item topography - full and partial cells | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 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}\textit{. }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}\textit{\ }% | 
  | 
 | 
 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}\textit{\ }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}\textit{\ }or\textit{\ }\textbf{delp}% | 
  | 
 | 
 \textit{. }The model will interpolate the numbers in \textbf{bathyFile}% | 
  | 
 | 
 \textit{\ }so that they match the levels obtained from \textbf{delz}\textit{% | 
  | 
 | 
 \ }or\textit{\ }\textbf{delp}\textit{\ }and \textbf{hFacMin}\textit{. } | 
  | 
 | 
  | 
  | 
 | 
 (Note: the atmospheric case is a bit more complicated than what is written | 
  | 
 | 
 here I think. To come soon...) | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item time-discretization | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 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}.'. | 
  | 
 | 
  | 
  | 
 | 
 \subsection{Equation of state} | 
  | 
 | 
  | 
  | 
 | 
 First, because the model equations are written in terms of perturbations, a | 
  | 
 | 
 reference thermodynamic state needs to be specified. This is done through | 
  | 
 | 
 the 1D arrays \textbf{tRef}\textit{\ }and \textbf{sRef}. \textbf{tRef }% | 
  | 
 | 
 specifies the reference potential temperature profile (in $^{o}$C for | 
  | 
 | 
 the ocean and $^{o}$K for the atmosphere) starting from the level | 
  | 
 | 
 k=1. Similarly, \textbf{sRef}\textit{\ }specifies the reference salinity | 
  | 
 | 
 profile (in ppt) for the ocean or the reference specific humidity profile | 
  | 
 | 
 (in g/kg) for the atmosphere. | 
  | 
 | 
  | 
  | 
 | 
 The form of the equation of state is controlled by the character variables  | 
  | 
 | 
 \textbf{buoyancyRelation}\textit{\ }and \textbf{eosType}\textit{. }\textbf{% | 
  | 
 | 
 buoyancyRelation}\textit{\ }is set to '\texttt{OCEANIC}' by default and | 
  | 
 | 
 needs to be set to '\texttt{ATMOSPHERIC}' for atmosphere simulations. In | 
  | 
 | 
 this case, \textbf{eosType}\textit{\ }must be set to '\texttt{IDEALGAS}'. | 
  | 
 | 
 For the ocean, two forms of the equation of state are available: linear (set  | 
  | 
 | 
 \textbf{eosType}\textit{\ }to '\texttt{LINEAR}') and a polynomial | 
  | 
 | 
 approximation to the full nonlinear equation ( set \textbf{eosType}\textit{\  | 
  | 
 | 
 }to '\texttt{POLYNOMIAL}'). In the linear case, you need to specify the | 
  | 
 | 
 thermal and haline expansion coefficients represented by the variables  | 
  | 
 | 
 \textbf{tAlpha}\textit{\ }(in K$^{-1}$) and \textbf{sBeta}\textit{\ }(in ppt$% | 
  | 
 | 
 ^{-1}$). For the nonlinear case, you need to generate a file of polynomial | 
  | 
 | 
 coefficients called \textit{POLY3.COEFFS. }To do this, use the program  | 
  | 
 | 
 \textit{utils/knudsen2/knudsen2.f }under the model tree (a Makefile is | 
  | 
 | 
 available in the same directory and you will need to edit the number and the | 
  | 
 | 
 values of the vertical levels in \textit{knudsen2.f }so that they match | 
  | 
 | 
 those of your configuration). \textit{\ } | 
  | 
 | 
  | 
  | 
 | 
 \subsection{Momentum equations} | 
  | 
 | 
  | 
  | 
 | 
 In this section, we only focus for now on the parameters that you are likely | 
  | 
 | 
 to change, i.e. the ones relative to forcing and dissipation for example. | 
  | 
 | 
 The details relevant to the vector-invariant form of the equations and the | 
  | 
 | 
 various advection schemes are not covered for the moment. We assume that you | 
  | 
 | 
 use the standard form of the momentum equations (i.e. the flux-form) with | 
  | 
 | 
 the default advection scheme. Also, there are a few logical variables that | 
  | 
 | 
 allow you to turn on/off various terms in the momentum equation. These | 
  | 
 | 
 variables are called \textbf{momViscosity, momAdvection, momForcing, | 
  | 
 | 
 useCoriolis, momPressureForcing, momStepping}\textit{, }and \textit{\ }% | 
  | 
 | 
 \textbf{metricTerms }and are assumed to be set to '.\texttt{TRUE}.' here. | 
  | 
 | 
 Look at the file \textit{model/inc/PARAMS.h }for a precise definition of | 
  | 
 | 
 these variables. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item initialization | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 The velocity components are initialized to 0 unless the simulation is | 
  | 
 | 
 starting from a pickup file (see section on simulation control parameters). | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item forcing | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 This section only applies to the ocean. You need to generate wind-stress | 
  | 
 | 
 data into two files \textbf{zonalWindFile}\textit{\ }and \textbf{% | 
  | 
 | 
 meridWindFile }corresponding to the zonal and meridional components of the | 
  | 
 | 
 wind stress, respectively (if you want the stress to be along the direction | 
  | 
 | 
 of only one of the model horizontal axes, you only need to generate one | 
  | 
 | 
 file). The format of the files is similar to the bathymetry file. The zonal | 
  | 
 | 
 (meridional) stress data are assumed to be in Pa and located at U-points | 
  | 
 | 
 (V-points). As for the bathymetry, the precision with which to read the | 
  | 
 | 
 binary data is controlled by the variable \textbf{readBinaryPrec}.\textbf{\ } | 
  | 
 | 
 See the matlab program \textit{gendata.m }in the \textit{input }directories | 
  | 
 | 
 under \textit{verification }to see how simple analytical wind forcing data | 
  | 
 | 
 are generated for the case study experiments.  | 
  | 
 | 
  | 
  | 
 | 
 There is also the possibility of prescribing time-dependent periodic | 
  | 
 | 
 forcing. To do this, concatenate the successive time records into a single | 
  | 
 | 
 file (for each stress component) ordered in a (x, y, t) fashion and set the | 
  | 
 | 
 following variables: \textbf{periodicExternalForcing }to '.\texttt{TRUE}.',  | 
  | 
 | 
 \textbf{externForcingPeriod }to the period (in s) of which the forcing | 
  | 
 | 
 varies (typically 1 month), and \textbf{externForcingCycle }to the repeat | 
  | 
 | 
 time (in s) of the forcing (typically 1 year -- note: \textbf{% | 
  | 
 | 
 externForcingCycle }must be a multiple of \textbf{externForcingPeriod}). | 
  | 
 | 
 With these variables set up, the model will interpolate the forcing linearly | 
  | 
 | 
 at each iteration. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item dissipation | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 The lateral eddy viscosity coefficient is specified through the variable  | 
  | 
 | 
 \textbf{viscAh}\textit{\ }(in m$^{2}$s$^{-1}$). The vertical eddy viscosity | 
  | 
 | 
 coefficient is specified through the variable \textbf{viscAz }(in m$^{2}$s$% | 
  | 
 | 
 ^{-1}$) for the ocean and \textbf{viscAp}\textit{\ }(in Pa$^{2}$s$^{-1}$) | 
  | 
 | 
 for the atmosphere. The vertical diffusive fluxes can be computed implicitly | 
  | 
 | 
 by setting the logical variable \textbf{implicitViscosity }to '.\texttt{TRUE}% | 
  | 
 | 
 .'. In addition, biharmonic mixing can be added as well through the variable  | 
  | 
 | 
 \textbf{viscA4}\textit{\ }(in m$^{4}$s$^{-1}$). On a spherical polar grid, | 
  | 
 | 
 you might also need to set the variable \textbf{cosPower} which is set to 0 | 
  | 
 | 
 by default and which represents the power of cosine of latitude to multiply | 
  | 
 | 
 viscosity. Slip or no-slip conditions at lateral and bottom boundaries are | 
  | 
 | 
 specified through the logical variables \textbf{no\_slip\_sides}\textit{\ }% | 
  | 
 | 
 and \textbf{no\_slip\_bottom}. If set to '\texttt{.FALSE.}', free-slip | 
  | 
 | 
 boundary conditions are applied. If no-slip boundary conditions are applied | 
  | 
 | 
 at the bottom, a bottom drag can be applied as well. Two forms are | 
  | 
 | 
 available: linear (set the variable \textbf{bottomDragLinear}\textit{\ }in s$% | 
  | 
 | 
 ^{-1}$) and quadratic (set the variable \textbf{bottomDragQuadratic}\textit{% | 
  | 
 | 
 \ }in m$^{-1}$). | 
  | 
 | 
  | 
  | 
 | 
 The Fourier and Shapiro filters are described elsewhere. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item C-D scheme | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 If you run at a sufficiently coarse resolution, you will need the C-D scheme | 
  | 
 | 
 for the computation of the Coriolis terms. The variable\textbf{\ tauCD}, | 
  | 
 | 
 which represents the C-D scheme coupling timescale (in s) needs to be set. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize}  | 
  | 
 | 
 \item calculation of pressure/geopotential | 
  | 
 | 
 \end{itemize}  | 
  | 
 | 
  | 
  | 
 | 
 First, to run a non-hydrostatic ocean simulation, set the logical variable  | 
  | 
 | 
 \textbf{nonHydrostatic} to '.\texttt{TRUE}.'. The pressure field is then | 
  | 
 | 
 inverted through a 3D elliptic equation. (Note: this capability is not | 
  | 
 | 
 available for the atmosphere yet.) By default, a hydrostatic simulation is | 
  | 
 | 
 assumed and a 2D elliptic equation is used to invert the pressure field. The | 
  | 
 | 
 parameters controlling the behaviour of the elliptic solvers are the | 
  | 
 | 
 variables \textbf{cg2dMaxIters}\textit{\ }and \textbf{cg2dTargetResidual }% | 
  | 
 | 
 for the 2D case and \textbf{cg3dMaxIters}\textit{\ }and \textbf{% | 
  | 
 | 
 cg3dTargetResidual }for the 3D case. You probably won't need to alter the | 
  | 
 | 
 default values (are we sure of this?). | 
  | 
 | 
  | 
  | 
 | 
 For the calculation of the surface pressure (for the ocean) or surface | 
  | 
 | 
 geopotential (for the atmosphere) you need to set the logical variables  | 
  | 
 | 
 \textbf{rigidLid} and \textbf{implicitFreeSurface}\textit{\ }(set one to '.% | 
  | 
 | 
 \texttt{TRUE}.' and the other to '.\texttt{FALSE}.' depending on how you | 
  | 
 | 
 want to deal with the ocean upper or atmosphere lower boundary). | 
  | 
 | 
  | 
  | 
 | 
 \subsection{Tracer equations} | 
  | 
 | 
  | 
  | 
 | 
 This section covers the tracer equations i.e. the potential temperature | 
  | 
 | 
 equation and the salinity (for the ocean) or specific humidity (for the | 
  | 
 | 
 atmosphere) equation. As for the momentum equations, we only describe for | 
  | 
 | 
 now the parameters that you are likely to change. The logical variables  | 
  | 
 | 
 \textbf{tempDiffusion}\textit{, }\textbf{tempAdvection}\textit{, }\textbf{% | 
  | 
 | 
 tempForcing}\textit{,} and \textbf{tempStepping} allow you to turn on/off | 
  | 
 | 
 terms in the temperature equation (same thing for salinity or specific | 
  | 
 | 
 humidity with variables \textbf{saltDiffusion}\textit{, }\textbf{% | 
  | 
 | 
 saltAdvection}\textit{\ }etc). These variables are all assumed here to be | 
  | 
 | 
 set to '.\texttt{TRUE}.'. Look at file \textit{model/inc/PARAMS.h }for a | 
  | 
 | 
 precise definition. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item initialization | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 The initial tracer data can be contained in the binary files \textbf{% | 
  | 
 | 
 hydrogThetaFile }and \textbf{hydrogSaltFile}. These files should contain 3D | 
  | 
 | 
 data ordered in an (x, y, r) fashion with k=1 as the first vertical level. | 
  | 
 | 
 If no file names are provided, the tracers are then initialized with the | 
  | 
 | 
 values of \textbf{tRef }and \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. | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize}  | 
  | 
 | 
 \item forcing | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 This part is more relevant for the ocean, the procedure for the atmosphere | 
  | 
 | 
 not being completely stabilized at the moment. | 
  | 
 | 
  | 
  | 
 | 
 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}\textit{. }% | 
  | 
 | 
 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}\textit{. }The corresponding relaxation time scale coefficient | 
  | 
 | 
 is set through the variable \textbf{tauThetaClimRelax}\textit{\ }(in s). The | 
  | 
 | 
 same procedure applies for salinity with the variable names \textbf{EmPmRfile% | 
  | 
 | 
 }\textit{, }\textbf{saltClimFile}\textit{, }and \textbf{tauSaltClimRelax}% | 
  | 
 | 
 \textit{\ }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. | 
  | 
 | 
  | 
  | 
 | 
 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). | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item dissipation | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 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). | 
  | 
| 936 | 
  | 
  | 
| 937 | 
  | 
 The MNC output files are all in the ``self-describing'' netCDF | 
| 938 | 
  | 
 format and can thus be browsed and/or plotted using tools such as: | 
| 939 | 
 \begin{itemize} | 
 \begin{itemize} | 
| 940 | 
 \item ocean convection | 
 \item \texttt{ncdump} is a utility which is typically included | 
| 941 | 
 \end{itemize} | 
   with every netCDF install: | 
| 942 | 
  | 
   \begin{rawhtml} <A href="http://www.unidata.ucar.edu/packages/netcdf/"> \end{rawhtml} | 
| 943 | 
 Two options are available to parameterize ocean convection: one is to use | 
 \begin{verbatim} | 
| 944 | 
 the convective adjustment scheme. In this case, you need to set the variable  | 
 http://www.unidata.ucar.edu/packages/netcdf/ | 
| 945 | 
 \textbf{cadjFreq}, which represents the frequency (in s) with which the | 
 \end{verbatim} | 
| 946 | 
 adjustment algorithm is called, to a non-zero value (if set to a negative | 
   \begin{rawhtml} </A> \end{rawhtml} and it converts the netCDF | 
| 947 | 
 value by the user, the model will set it to the tracer time step). The other | 
   binaries into formatted ASCII text files. | 
 | 
 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. | 
  | 
 | 
  | 
  | 
 | 
 \subsection{Simulation controls} | 
  | 
 | 
  | 
  | 
 | 
 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). | 
  | 
 | 
  | 
  | 
 | 
 \begin{itemize} | 
  | 
 | 
 \item run duration | 
  | 
 | 
 \end{itemize} | 
  | 
 | 
  | 
  | 
 | 
 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\textit{. }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}.  | 
  | 
| 948 | 
  | 
  | 
| 949 | 
 \begin{itemize} | 
 \item \texttt{ncview} utility is a very convenient and quick way | 
| 950 | 
 \item frequency of output | 
   to plot netCDF data and it runs on most OSes: | 
| 951 | 
  | 
   \begin{rawhtml} <A href="http://meteora.ucsd.edu/~pierce/ncview_home_page.html"> \end{rawhtml} | 
| 952 | 
  | 
 \begin{verbatim} | 
| 953 | 
  | 
 http://meteora.ucsd.edu/~pierce/ncview_home_page.html | 
| 954 | 
  | 
 \end{verbatim} | 
| 955 | 
  | 
   \begin{rawhtml} </A> \end{rawhtml} | 
| 956 | 
  | 
    | 
| 957 | 
  | 
 \item MatLAB(c) and other common post-processing environments provide | 
| 958 | 
  | 
   various netCDF interfaces including: | 
| 959 | 
  | 
   \begin{rawhtml} <A href="http://mexcdf.sourceforge.net/"> \end{rawhtml} | 
| 960 | 
  | 
 \begin{verbatim} | 
| 961 | 
  | 
 http://mexcdf.sourceforge.net/ | 
| 962 | 
  | 
 \end{verbatim} | 
| 963 | 
  | 
   \begin{rawhtml} </A> \end{rawhtml} | 
| 964 | 
  | 
   \begin{rawhtml} <A href="http://woodshole.er.usgs.gov/staffpages/cdenham/public_html/MexCDF/nc4ml5.html"> \end{rawhtml} | 
| 965 | 
  | 
 \begin{verbatim} | 
| 966 | 
  | 
 http://woodshole.er.usgs.gov/staffpages/cdenham/public_html/MexCDF/nc4ml5.html | 
| 967 | 
  | 
 \end{verbatim} | 
| 968 | 
  | 
   \begin{rawhtml} </A> \end{rawhtml} | 
| 969 | 
 \end{itemize} | 
 \end{itemize} | 
| 970 | 
  | 
  | 
 | 
 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}). | 
  |