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% $Header: /u/gcmpack/manual/part3/getting_started.tex,v 1.29 2004/10/14 19:11:47 edhill Exp $ |
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% $Name: $ |
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|
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%\section{Getting started} |
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|
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In this section, we describe how to use the model. In the first |
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section, we provide enough information to help you get started with |
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the model. We believe the best way to familiarize yourself with the |
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model is to run the case study examples provided with the base |
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version. Information on how to obtain, compile, and run the code is |
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found there as well as a brief description of the model structure |
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directory and the case study examples. The latter and the code |
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structure are described more fully in chapters |
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\ref{chap:discretization} and \ref{chap:sarch}, respectively. Here, in |
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this section, we provide information on how to customize the code when |
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you are ready to try implementing the configuration you have in mind. |
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1.30 |
|
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1.4 |
\section{Where to find information} |
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\label{sect:whereToFindInfo} |
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\begin{rawhtml} |
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<!-- CMIREDIR:whereToFindInfo: --> |
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\end{rawhtml} |
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|
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A web site is maintained for release 2 (``Pelican'') of MITgcm: |
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\begin{rawhtml} <A href=http://mitgcm.org/pelican/ target="idontexist"> \end{rawhtml} |
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1.4 |
\begin{verbatim} |
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1.15 |
http://mitgcm.org/pelican |
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1.4 |
\end{verbatim} |
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1.15 |
\begin{rawhtml} </A> \end{rawhtml} |
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Here you will find an on-line version of this document, a |
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``browsable'' copy of the code and a searchable database of the model |
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and site, as well as links for downloading the model and |
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1.15 |
documentation, to data-sources, and other related sites. |
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1.4 |
|
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1.15 |
There is also a web-archived support mailing list for the model that |
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you can email at \texttt{MITgcm-support@mitgcm.org} or browse at: |
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\begin{rawhtml} <A href=http://mitgcm.org/mailman/listinfo/mitgcm-support/ target="idontexist"> \end{rawhtml} |
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\begin{verbatim} |
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http://mitgcm.org/mailman/listinfo/mitgcm-support/ |
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http://mitgcm.org/pipermail/mitgcm-support/ |
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\end{verbatim} |
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\begin{rawhtml} </A> \end{rawhtml} |
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Essentially all of the MITgcm web pages can be searched using a |
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popular web crawler such as Google or through our own search facility: |
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\begin{rawhtml} <A href=http://mitgcm.org/mailman/htdig/ target="idontexist"> \end{rawhtml} |
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1.1 |
\begin{verbatim} |
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1.15 |
http://mitgcm.org/htdig/ |
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1.1 |
\end{verbatim} |
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\begin{rawhtml} </A> \end{rawhtml} |
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%%% http://www.google.com/search?q=hydrostatic+site%3Amitgcm.org |
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|
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\section{Obtaining the code} |
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\label{sect:obtainingCode} |
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\begin{rawhtml} |
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<!-- CMIREDIR:obtainingCode: --> |
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\end{rawhtml} |
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|
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MITgcm can be downloaded from our system by following |
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the instructions below. As a courtesy we ask that you send e-mail to us at |
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\begin{rawhtml} <A href=mailto:MITgcm-support@mitgcm.org> \end{rawhtml} |
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MITgcm-support@mitgcm.org |
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\begin{rawhtml} </A> \end{rawhtml} |
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to enable us to keep track of who's using the model and in what application. |
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You can download the model two ways: |
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|
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\begin{enumerate} |
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\item Using CVS software. CVS is a freely available source code management |
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tool. To use CVS you need to have the software installed. Many systems |
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come with CVS pre-installed, otherwise good places to look for |
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the software for a particular platform are |
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\begin{rawhtml} <A href=http://www.cvshome.org/ target="idontexist"> \end{rawhtml} |
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cvshome.org |
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\begin{rawhtml} </A> \end{rawhtml} |
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and |
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\begin{rawhtml} <A href=http://www.wincvs.org/ target="idontexist"> \end{rawhtml} |
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wincvs.org |
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\begin{rawhtml} </A> \end{rawhtml} |
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. |
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|
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\item Using a tar file. This method is simple and does not |
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require any special software. However, this method does not |
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provide easy support for maintenance updates. |
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|
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\end{enumerate} |
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|
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1.27 |
\subsection{Method 1 - Checkout from CVS} |
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\label{sect:cvs_checkout} |
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|
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If CVS is available on your system, we strongly encourage you to use it. CVS |
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provides an efficient and elegant way of organizing your code and keeping |
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track of your changes. If CVS is not available on your machine, you can also |
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download a tar file. |
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|
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1.15 |
Before you can use CVS, the following environment variable(s) should |
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be set within your shell. For a csh or tcsh shell, put the following |
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\begin{verbatim} |
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% setenv CVSROOT :pserver:cvsanon@mitgcm.org:/u/gcmpack |
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\end{verbatim} |
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in your .cshrc or .tcshrc file. For bash or sh shells, put: |
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1.1 |
\begin{verbatim} |
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1.15 |
% export CVSROOT=':pserver:cvsanon@mitgcm.org:/u/gcmpack' |
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1.6 |
\end{verbatim} |
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1.20 |
in your \texttt{.profile} or \texttt{.bashrc} file. |
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1.6 |
|
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1.15 |
|
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To get MITgcm through CVS, first register with the MITgcm CVS server |
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using command: |
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1.6 |
\begin{verbatim} |
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1.1 |
% cvs login ( CVS password: cvsanon ) |
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\end{verbatim} |
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1.15 |
You only need to do a ``cvs login'' once. |
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1.1 |
|
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1.15 |
To obtain the latest sources type: |
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\begin{verbatim} |
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% cvs co MITgcm |
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\end{verbatim} |
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or to get a specific release type: |
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1.1 |
\begin{verbatim} |
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1.16 |
% cvs co -P -r checkpoint52i_post MITgcm |
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1.1 |
\end{verbatim} |
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edhill |
1.15 |
The MITgcm web site contains further directions concerning the source |
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code and CVS. It also contains a web interface to our CVS archive so |
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that one may easily view the state of files, revisions, and other |
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development milestones: |
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\begin{rawhtml} <A href=''http://mitgcm.org/download'' target="idontexist"> \end{rawhtml} |
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edhill |
1.15 |
\begin{verbatim} |
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1.17 |
http://mitgcm.org/source_code.html |
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edhill |
1.15 |
\end{verbatim} |
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\begin{rawhtml} </A> \end{rawhtml} |
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1.1 |
|
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edhill |
1.19 |
As a convenience, the MITgcm CVS server contains aliases which are |
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named subsets of the codebase. These aliases can be especially |
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helpful when used over slow internet connections or on machines with |
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restricted storage space. Table \ref{tab:cvsModules} contains a list |
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of CVS aliases |
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\begin{table}[htb] |
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\centering |
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\begin{tabular}[htb]{|lp{3.25in}|}\hline |
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\textbf{Alias Name} & \textbf{Information (directories) Contained} \\\hline |
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\texttt{MITgcm\_code} & Only the source code -- none of the verification examples. \\ |
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\texttt{MITgcm\_verif\_basic} |
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& Source code plus a small set of the verification examples |
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(\texttt{global\_ocean.90x40x15}, \texttt{aim.5l\_cs}, \texttt{hs94.128x64x5}, |
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\texttt{front\_relax}, and \texttt{plume\_on\_slope}). \\ |
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\texttt{MITgcm\_verif\_atmos} & Source code plus all of the atmospheric examples. \\ |
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\texttt{MITgcm\_verif\_ocean} & Source code plus all of the oceanic examples. \\ |
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\texttt{MITgcm\_verif\_all} & Source code plus all of the |
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verification examples. \\\hline |
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\end{tabular} |
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\caption{MITgcm CVS Modules} |
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\label{tab:cvsModules} |
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\end{table} |
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edhill |
1.15 |
|
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The checkout process creates a directory called \textit{MITgcm}. If |
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the directory \textit{MITgcm} exists this command updates your code |
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based on the repository. Each directory in the source tree contains a |
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directory \textit{CVS}. This information is required by CVS to keep |
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track of your file versions with respect to the repository. Don't edit |
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the files in \textit{CVS}! You can also use CVS to download code |
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updates. More extensive information on using CVS for maintaining |
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MITgcm code can be found |
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edhill |
1.17 |
\begin{rawhtml} <A href=''http://mitgcm.org/usingcvstoget.html'' target="idontexist"> \end{rawhtml} |
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cnh |
1.7 |
here |
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\begin{rawhtml} </A> \end{rawhtml} |
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. |
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edhill |
1.19 |
It is important to note that the CVS aliases in Table |
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\ref{tab:cvsModules} cannot be used in conjunction with the CVS |
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\texttt{-d DIRNAME} option. However, the \texttt{MITgcm} directories |
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they create can be changed to a different name following the check-out: |
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\begin{verbatim} |
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% cvs co MITgcm_verif_basic |
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% mv MITgcm MITgcm_verif_basic |
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\end{verbatim} |
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cnh |
1.7 |
|
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adcroft |
1.1 |
|
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cnh |
1.27 |
\subsection{Method 2 - Tar file download} |
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1.4 |
\label{sect:conventionalDownload} |
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1.1 |
|
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adcroft |
1.4 |
If you do not have CVS on your system, you can download the model as a |
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edhill |
1.15 |
tar file from the web site at: |
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cnh |
1.7 |
\begin{rawhtml} <A href=http://mitgcm.org/download target="idontexist"> \end{rawhtml} |
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adcroft |
1.1 |
\begin{verbatim} |
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http://mitgcm.org/download/ |
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\end{verbatim} |
188 |
cnh |
1.7 |
\begin{rawhtml} </A> \end{rawhtml} |
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adcroft |
1.4 |
The tar file still contains CVS information which we urge you not to |
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delete; even if you do not use CVS yourself the information can help |
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edhill |
1.15 |
us if you should need to send us your copy of the code. If a recent |
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tar file does not exist, then please contact the developers through |
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edhill |
1.17 |
the |
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\begin{rawhtml} <A href=''mailto:MITgcm-support@mitgcm.org"> \end{rawhtml} |
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MITgcm-support@mitgcm.org |
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\begin{rawhtml} </A> \end{rawhtml} |
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mailing list. |
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1.1 |
|
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edhill |
1.19 |
\subsubsection{Upgrading from an earlier version} |
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1.12 |
|
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If you already have an earlier version of the code you can ``upgrade'' |
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your copy instead of downloading the entire repository again. First, |
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``cd'' (change directory) to the top of your working copy: |
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\begin{verbatim} |
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% cd MITgcm |
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\end{verbatim} |
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edhill |
1.15 |
and then issue the cvs update command such as: |
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adcroft |
1.12 |
\begin{verbatim} |
209 |
edhill |
1.16 |
% cvs -q update -r checkpoint52i_post -d -P |
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1.12 |
\end{verbatim} |
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edhill |
1.16 |
This will update the ``tag'' to ``checkpoint52i\_post'', add any new |
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adcroft |
1.12 |
directories (-d) and remove any empty directories (-P). The -q option |
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means be quiet which will reduce the number of messages you'll see in |
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the terminal. If you have modified the code prior to upgrading, CVS |
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will try to merge your changes with the upgrades. If there is a |
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conflict between your modifications and the upgrade, it will report |
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that file with a ``C'' in front, e.g.: |
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\begin{verbatim} |
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C model/src/ini_parms.F |
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\end{verbatim} |
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If the list of conflicts scrolled off the screen, you can re-issue the |
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cvs update command and it will report the conflicts. Conflicts are |
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edhill |
1.15 |
indicated in the code by the delimites ``$<<<<<<<$'', ``======='' and |
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``$>>>>>>>$''. For example, |
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edhill |
1.17 |
{\small |
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1.12 |
\begin{verbatim} |
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<<<<<<< ini_parms.F |
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& bottomDragLinear,myOwnBottomDragCoefficient, |
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======= |
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& bottomDragLinear,bottomDragQuadratic, |
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>>>>>>> 1.18 |
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\end{verbatim} |
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edhill |
1.17 |
} |
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adcroft |
1.12 |
means that you added ``myOwnBottomDragCoefficient'' to a namelist at |
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the same time and place that we added ``bottomDragQuadratic''. You |
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need to resolve this conflict and in this case the line should be |
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changed to: |
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edhill |
1.17 |
{\small |
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adcroft |
1.12 |
\begin{verbatim} |
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& bottomDragLinear,bottomDragQuadratic,myOwnBottomDragCoefficient, |
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\end{verbatim} |
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edhill |
1.17 |
} |
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edhill |
1.15 |
and the lines with the delimiters ($<<<<<<$,======,$>>>>>>$) be deleted. |
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adcroft |
1.12 |
Unless you are making modifications which exactly parallel |
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developments we make, these types of conflicts should be rare. |
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|
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\paragraph*{Upgrading to the current pre-release version} |
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|
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We don't make a ``release'' for every little patch and bug fix in |
250 |
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order to keep the frequency of upgrades to a minimum. However, if you |
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have run into a problem for which ``we have already fixed in the |
252 |
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latest code'' and we haven't made a ``tag'' or ``release'' since that |
253 |
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patch then you'll need to get the latest code: |
254 |
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\begin{verbatim} |
255 |
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% cvs -q update -A -d -P |
256 |
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\end{verbatim} |
257 |
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Unlike, the ``check-out'' and ``update'' procedures above, there is no |
258 |
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``tag'' or release name. The -A tells CVS to upgrade to the |
259 |
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very latest version. As a rule, we don't recommend this since you |
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might upgrade while we are in the processes of checking in the code so |
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that you may only have part of a patch. Using this method of updating |
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also means we can't tell what version of the code you are working |
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with. So please be sure you understand what you're doing. |
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|
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adcroft |
1.4 |
\section{Model and directory structure} |
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1.30 |
\begin{rawhtml} |
267 |
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<!-- CMIREDIR:directory_structure: --> |
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\end{rawhtml} |
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1.1 |
|
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adcroft |
1.12 |
The ``numerical'' model is contained within a execution environment |
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support wrapper. This wrapper is designed to provide a general |
272 |
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framework for grid-point models. MITgcmUV is a specific numerical |
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model that uses the framework. Under this structure the model is split |
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into execution environment support code and conventional numerical |
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model code. The execution environment support code is held under the |
276 |
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\textit{eesupp} directory. The grid point model code is held under the |
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\textit{model} directory. Code execution actually starts in the |
278 |
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\textit{eesupp} routines and not in the \textit{model} routines. For |
279 |
edhill |
1.17 |
this reason the top-level \textit{MAIN.F} is in the |
280 |
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\textit{eesupp/src} directory. In general, end-users should not need |
281 |
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to worry about this level. The top-level routine for the numerical |
282 |
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part of the code is in \textit{model/src/THE\_MODEL\_MAIN.F}. Here is |
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a brief description of the directory structure of the model under the |
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root tree (a detailed description is given in section 3: Code |
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structure). |
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adcroft |
1.1 |
|
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\begin{itemize} |
288 |
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|
289 |
edhill |
1.17 |
\item \textit{bin}: this directory is initially empty. It is the |
290 |
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default directory in which to compile the code. |
291 |
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|
|
292 |
adcroft |
1.1 |
\item \textit{diags}: contains the code relative to time-averaged |
293 |
edhill |
1.17 |
diagnostics. It is subdivided into two subdirectories \textit{inc} |
294 |
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and \textit{src} that contain include files (*.\textit{h} files) and |
295 |
|
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Fortran subroutines (*.\textit{F} files), respectively. |
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adcroft |
1.1 |
|
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\item \textit{doc}: contains brief documentation notes. |
298 |
edhill |
1.17 |
|
299 |
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\item \textit{eesupp}: contains the execution environment source code. |
300 |
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Also subdivided into two subdirectories \textit{inc} and |
301 |
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\textit{src}. |
302 |
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|
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\item \textit{exe}: this directory is initially empty. It is the |
304 |
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|
default directory in which to execute the code. |
305 |
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|
306 |
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\item \textit{model}: this directory contains the main source code. |
307 |
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|
Also subdivided into two subdirectories \textit{inc} and |
308 |
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\textit{src}. |
309 |
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|
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\item \textit{pkg}: contains the source code for the packages. Each |
311 |
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package corresponds to a subdirectory. For example, \textit{gmredi} |
312 |
|
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contains the code related to the Gent-McWilliams/Redi scheme, |
313 |
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|
\textit{aim} the code relative to the atmospheric intermediate |
314 |
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|
physics. The packages are described in detail in section 3. |
315 |
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|
316 |
|
|
\item \textit{tools}: this directory contains various useful tools. |
317 |
|
|
For example, \textit{genmake2} is a script written in csh (C-shell) |
318 |
|
|
that should be used to generate your makefile. The directory |
319 |
|
|
\textit{adjoint} contains the makefile specific to the Tangent |
320 |
|
|
linear and Adjoint Compiler (TAMC) that generates the adjoint code. |
321 |
|
|
The latter is described in details in part V. |
322 |
|
|
|
323 |
adcroft |
1.1 |
\item \textit{utils}: this directory contains various utilities. The |
324 |
edhill |
1.17 |
subdirectory \textit{knudsen2} contains code and a makefile that |
325 |
|
|
compute coefficients of the polynomial approximation to the knudsen |
326 |
|
|
formula for an ocean nonlinear equation of state. The |
327 |
|
|
\textit{matlab} subdirectory contains matlab scripts for reading |
328 |
|
|
model output directly into matlab. \textit{scripts} contains C-shell |
329 |
|
|
post-processing scripts for joining processor-based and tiled-based |
330 |
|
|
model output. |
331 |
|
|
|
332 |
|
|
\item \textit{verification}: this directory contains the model |
333 |
|
|
examples. See section \ref{sect:modelExamples}. |
334 |
adcroft |
1.1 |
|
335 |
|
|
\end{itemize} |
336 |
|
|
|
337 |
cnh |
1.26 |
\section[MITgcm Example Experiments]{Example experiments} |
338 |
adcroft |
1.4 |
\label{sect:modelExamples} |
339 |
edhill |
1.30 |
\begin{rawhtml} |
340 |
|
|
<!-- CMIREDIR:modelExamples: --> |
341 |
|
|
\end{rawhtml} |
342 |
adcroft |
1.1 |
|
343 |
edhill |
1.15 |
%% a set of twenty-four pre-configured numerical experiments |
344 |
|
|
|
345 |
|
|
The MITgcm distribution comes with more than a dozen pre-configured |
346 |
|
|
numerical experiments. Some of these example experiments are tests of |
347 |
|
|
individual parts of the model code, but many are fully fledged |
348 |
|
|
numerical simulations. A few of the examples are used for tutorial |
349 |
|
|
documentation in sections \ref{sect:eg-baro} - \ref{sect:eg-global}. |
350 |
|
|
The other examples follow the same general structure as the tutorial |
351 |
|
|
examples. However, they only include brief instructions in a text file |
352 |
|
|
called {\it README}. The examples are located in subdirectories under |
353 |
|
|
the directory \textit{verification}. Each example is briefly described |
354 |
|
|
below. |
355 |
adcroft |
1.1 |
|
356 |
cnh |
1.8 |
\subsection{Full list of model examples} |
357 |
adcroft |
1.1 |
|
358 |
cnh |
1.8 |
\begin{enumerate} |
359 |
edhill |
1.17 |
|
360 |
adcroft |
1.1 |
\item \textit{exp0} - single layer, ocean double gyre (barotropic with |
361 |
edhill |
1.15 |
free-surface). This experiment is described in detail in section |
362 |
|
|
\ref{sect:eg-baro}. |
363 |
adcroft |
1.1 |
|
364 |
edhill |
1.15 |
\item \textit{exp1} - Four layer, ocean double gyre. This experiment |
365 |
|
|
is described in detail in section \ref{sect:eg-baroc}. |
366 |
|
|
|
367 |
adcroft |
1.1 |
\item \textit{exp2} - 4x4 degree global ocean simulation with steady |
368 |
edhill |
1.15 |
climatological forcing. This experiment is described in detail in |
369 |
|
|
section \ref{sect:eg-global}. |
370 |
|
|
|
371 |
|
|
\item \textit{exp4} - Flow over a Gaussian bump in open-water or |
372 |
|
|
channel with open boundaries. |
373 |
|
|
|
374 |
|
|
\item \textit{exp5} - Inhomogenously forced ocean convection in a |
375 |
|
|
doubly periodic box. |
376 |
adcroft |
1.1 |
|
377 |
cnh |
1.8 |
\item \textit{front\_relax} - Relaxation of an ocean thermal front (test for |
378 |
adcroft |
1.1 |
Gent/McWilliams scheme). 2D (Y-Z). |
379 |
|
|
|
380 |
edhill |
1.15 |
\item \textit{internal wave} - Ocean internal wave forced by open |
381 |
|
|
boundary conditions. |
382 |
|
|
|
383 |
cnh |
1.8 |
\item \textit{natl\_box} - Eastern subtropical North Atlantic with KPP |
384 |
edhill |
1.15 |
scheme; 1 month integration |
385 |
|
|
|
386 |
|
|
\item \textit{hs94.1x64x5} - Zonal averaged atmosphere using Held and |
387 |
|
|
Suarez '94 forcing. |
388 |
|
|
|
389 |
|
|
\item \textit{hs94.128x64x5} - 3D atmosphere dynamics using Held and |
390 |
|
|
Suarez '94 forcing. |
391 |
|
|
|
392 |
adcroft |
1.1 |
\item \textit{hs94.cs-32x32x5} - 3D atmosphere dynamics using Held and |
393 |
edhill |
1.15 |
Suarez '94 forcing on the cubed sphere. |
394 |
|
|
|
395 |
|
|
\item \textit{aim.5l\_zon-ave} - Intermediate Atmospheric physics. |
396 |
|
|
Global Zonal Mean configuration, 1x64x5 resolution. |
397 |
|
|
|
398 |
|
|
\item \textit{aim.5l\_XZ\_Equatorial\_Slice} - Intermediate |
399 |
|
|
Atmospheric physics, equatorial Slice configuration. 2D (X-Z). |
400 |
|
|
|
401 |
adcroft |
1.1 |
\item \textit{aim.5l\_Equatorial\_Channel} - Intermediate Atmospheric |
402 |
edhill |
1.15 |
physics. 3D Equatorial Channel configuration. |
403 |
|
|
|
404 |
cnh |
1.8 |
\item \textit{aim.5l\_LatLon} - Intermediate Atmospheric physics. |
405 |
edhill |
1.15 |
Global configuration, on latitude longitude grid with 128x64x5 grid |
406 |
|
|
points ($2.8^\circ{\rm degree}$ resolution). |
407 |
|
|
|
408 |
|
|
\item \textit{adjustment.128x64x1} Barotropic adjustment problem on |
409 |
|
|
latitude longitude grid with 128x64 grid points ($2.8^\circ{\rm |
410 |
|
|
degree}$ resolution). |
411 |
|
|
|
412 |
|
|
\item \textit{adjustment.cs-32x32x1} Barotropic adjustment problem on |
413 |
|
|
cube sphere grid with 32x32 points per face ( roughly $2.8^\circ{\rm |
414 |
|
|
degree}$ resolution). |
415 |
|
|
|
416 |
cnh |
1.8 |
\item \textit{advect\_cs} Two-dimensional passive advection test on |
417 |
edhill |
1.15 |
cube sphere grid. |
418 |
|
|
|
419 |
|
|
\item \textit{advect\_xy} Two-dimensional (horizontal plane) passive |
420 |
|
|
advection test on Cartesian grid. |
421 |
|
|
|
422 |
|
|
\item \textit{advect\_yz} Two-dimensional (vertical plane) passive |
423 |
|
|
advection test on Cartesian grid. |
424 |
|
|
|
425 |
|
|
\item \textit{carbon} Simple passive tracer experiment. Includes |
426 |
|
|
derivative calculation. Described in detail in section |
427 |
|
|
\ref{sect:eg-carbon-ad}. |
428 |
cnh |
1.8 |
|
429 |
|
|
\item \textit{flt\_example} Example of using float package. |
430 |
edhill |
1.15 |
|
431 |
|
|
\item \textit{global\_ocean.90x40x15} Global circulation with GM, flux |
432 |
|
|
boundary conditions and poles. |
433 |
cnh |
1.8 |
|
434 |
mlosch |
1.13 |
\item \textit{global\_ocean\_pressure} Global circulation in pressure |
435 |
|
|
coordinate (non-Boussinesq ocean model). Described in detail in |
436 |
|
|
section \ref{sect:eg-globalpressure}. |
437 |
edhill |
1.15 |
|
438 |
|
|
\item \textit{solid-body.cs-32x32x1} Solid body rotation test for cube |
439 |
|
|
sphere grid. |
440 |
cnh |
1.8 |
|
441 |
|
|
\end{enumerate} |
442 |
adcroft |
1.1 |
|
443 |
adcroft |
1.4 |
\subsection{Directory structure of model examples} |
444 |
adcroft |
1.1 |
|
445 |
|
|
Each example directory has the following subdirectories: |
446 |
|
|
|
447 |
|
|
\begin{itemize} |
448 |
|
|
\item \textit{code}: contains the code particular to the example. At a |
449 |
edhill |
1.16 |
minimum, this directory includes the following files: |
450 |
adcroft |
1.1 |
|
451 |
edhill |
1.16 |
\begin{itemize} |
452 |
|
|
\item \textit{code/CPP\_EEOPTIONS.h}: declares CPP keys relative to |
453 |
|
|
the ``execution environment'' part of the code. The default |
454 |
|
|
version is located in \textit{eesupp/inc}. |
455 |
|
|
|
456 |
|
|
\item \textit{code/CPP\_OPTIONS.h}: declares CPP keys relative to |
457 |
|
|
the ``numerical model'' part of the code. The default version is |
458 |
|
|
located in \textit{model/inc}. |
459 |
|
|
|
460 |
|
|
\item \textit{code/SIZE.h}: declares size of underlying |
461 |
|
|
computational grid. The default version is located in |
462 |
|
|
\textit{model/inc}. |
463 |
|
|
\end{itemize} |
464 |
|
|
|
465 |
|
|
In addition, other include files and subroutines might be present in |
466 |
|
|
\textit{code} depending on the particular experiment. See Section 2 |
467 |
|
|
for more details. |
468 |
edhill |
1.15 |
|
469 |
|
|
\item \textit{input}: contains the input data files required to run |
470 |
|
|
the example. At a minimum, the \textit{input} directory contains the |
471 |
|
|
following files: |
472 |
adcroft |
1.1 |
|
473 |
edhill |
1.16 |
\begin{itemize} |
474 |
|
|
\item \textit{input/data}: this file, written as a namelist, |
475 |
|
|
specifies the main parameters for the experiment. |
476 |
|
|
|
477 |
|
|
\item \textit{input/data.pkg}: contains parameters relative to the |
478 |
|
|
packages used in the experiment. |
479 |
|
|
|
480 |
|
|
\item \textit{input/eedata}: this file contains ``execution |
481 |
|
|
environment'' data. At present, this consists of a specification |
482 |
|
|
of the number of threads to use in $X$ and $Y$ under multithreaded |
483 |
|
|
execution. |
484 |
|
|
\end{itemize} |
485 |
edhill |
1.17 |
|
486 |
|
|
In addition, you will also find in this directory the forcing and |
487 |
|
|
topography files as well as the files describing the initial state |
488 |
|
|
of the experiment. This varies from experiment to experiment. See |
489 |
|
|
section 2 for more details. |
490 |
edhill |
1.16 |
|
491 |
|
|
\item \textit{results}: this directory contains the output file |
492 |
|
|
\textit{output.txt} produced by the simulation example. This file is |
493 |
|
|
useful for comparison with your own output when you run the |
494 |
|
|
experiment. |
495 |
adcroft |
1.1 |
\end{itemize} |
496 |
|
|
|
497 |
edhill |
1.17 |
Once you have chosen the example you want to run, you are ready to |
498 |
|
|
compile the code. |
499 |
adcroft |
1.1 |
|
500 |
cnh |
1.26 |
\section[Building MITgcm]{Building the code} |
501 |
adcroft |
1.4 |
\label{sect:buildingCode} |
502 |
edhill |
1.30 |
\begin{rawhtml} |
503 |
|
|
<!-- CMIREDIR:buildingCode: --> |
504 |
|
|
\end{rawhtml} |
505 |
adcroft |
1.4 |
|
506 |
|
|
To compile the code, we use the {\em make} program. This uses a file |
507 |
|
|
({\em Makefile}) that allows us to pre-process source files, specify |
508 |
|
|
compiler and optimization options and also figures out any file |
509 |
edhill |
1.16 |
dependencies. We supply a script ({\em genmake2}), described in |
510 |
|
|
section \ref{sect:genmake}, that automatically creates the {\em |
511 |
|
|
Makefile} for you. You then need to build the dependencies and |
512 |
|
|
compile the code. |
513 |
adcroft |
1.4 |
|
514 |
|
|
As an example, let's assume that you want to build and run experiment |
515 |
edhill |
1.16 |
\textit{verification/exp2}. The are multiple ways and places to |
516 |
|
|
actually do this but here let's build the code in |
517 |
adcroft |
1.4 |
\textit{verification/exp2/input}: |
518 |
|
|
\begin{verbatim} |
519 |
|
|
% cd verification/exp2/input |
520 |
|
|
\end{verbatim} |
521 |
|
|
First, build the {\em Makefile}: |
522 |
|
|
\begin{verbatim} |
523 |
edhill |
1.16 |
% ../../../tools/genmake2 -mods=../code |
524 |
adcroft |
1.4 |
\end{verbatim} |
525 |
|
|
The command line option tells {\em genmake} to override model source |
526 |
edhill |
1.29 |
code with any files in the directory {\em ../code/}. |
527 |
adcroft |
1.4 |
|
528 |
edhill |
1.16 |
On many systems, the {\em genmake2} program will be able to |
529 |
|
|
automatically recognize the hardware, find compilers and other tools |
530 |
|
|
within the user's path (``echo \$PATH''), and then choose an |
531 |
edhill |
1.29 |
appropriate set of options from the files (``optfiles'') contained in |
532 |
|
|
the {\em tools/build\_options} directory. Under some circumstances, a |
533 |
|
|
user may have to create a new ``optfile'' in order to specify the |
534 |
|
|
exact combination of compiler, compiler flags, libraries, and other |
535 |
|
|
options necessary to build a particular configuration of MITgcm. In |
536 |
|
|
such cases, it is generally helpful to read the existing ``optfiles'' |
537 |
|
|
and mimic their syntax. |
538 |
edhill |
1.16 |
|
539 |
|
|
Through the MITgcm-support list, the MITgcm developers are willing to |
540 |
|
|
provide help writing or modifing ``optfiles''. And we encourage users |
541 |
|
|
to post new ``optfiles'' (particularly ones for new machines or |
542 |
edhill |
1.17 |
architectures) to the |
543 |
|
|
\begin{rawhtml} <A href=''mailto:MITgcm-support@mitgcm.org"> \end{rawhtml} |
544 |
|
|
MITgcm-support@mitgcm.org |
545 |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
546 |
|
|
list. |
547 |
edhill |
1.16 |
|
548 |
|
|
To specify an optfile to {\em genmake2}, the syntax is: |
549 |
adcroft |
1.4 |
\begin{verbatim} |
550 |
edhill |
1.16 |
% ../../../tools/genmake2 -mods=../code -of /path/to/optfile |
551 |
adcroft |
1.4 |
\end{verbatim} |
552 |
|
|
|
553 |
edhill |
1.16 |
Once a {\em Makefile} has been generated, we create the dependencies: |
554 |
adcroft |
1.4 |
\begin{verbatim} |
555 |
|
|
% make depend |
556 |
|
|
\end{verbatim} |
557 |
edhill |
1.16 |
This modifies the {\em Makefile} by attaching a [long] list of files |
558 |
|
|
upon which other files depend. The purpose of this is to reduce |
559 |
|
|
re-compilation if and when you start to modify the code. The {\tt make |
560 |
|
|
depend} command also creates links from the model source to this |
561 |
edhill |
1.29 |
directory. It is important to note that the {\tt make depend} stage |
562 |
|
|
will occasionally produce warnings or errors since the dependency |
563 |
|
|
parsing tool is unable to find all of the necessary header files |
564 |
|
|
(\textit{eg.} \texttt{netcdf.inc}). In these circumstances, it is |
565 |
|
|
usually OK to ignore the warnings/errors and proceed to the next step. |
566 |
adcroft |
1.1 |
|
567 |
edhill |
1.16 |
Next compile the code: |
568 |
adcroft |
1.4 |
\begin{verbatim} |
569 |
|
|
% make |
570 |
|
|
\end{verbatim} |
571 |
|
|
The {\tt make} command creates an executable called \textit{mitgcmuv}. |
572 |
edhill |
1.16 |
Additional make ``targets'' are defined within the makefile to aid in |
573 |
|
|
the production of adjoint and other versions of MITgcm. |
574 |
adcroft |
1.4 |
|
575 |
|
|
Now you are ready to run the model. General instructions for doing so are |
576 |
|
|
given in section \ref{sect:runModel}. Here, we can run the model with: |
577 |
|
|
\begin{verbatim} |
578 |
|
|
./mitgcmuv > output.txt |
579 |
|
|
\end{verbatim} |
580 |
|
|
where we are re-directing the stream of text output to the file {\em |
581 |
|
|
output.txt}. |
582 |
|
|
|
583 |
|
|
|
584 |
cnh |
1.26 |
\section[Running MITgcm]{Running the model in prognostic mode} |
585 |
adcroft |
1.4 |
\label{sect:runModel} |
586 |
edhill |
1.30 |
\begin{rawhtml} |
587 |
|
|
<!-- CMIREDIR:runModel: --> |
588 |
|
|
\end{rawhtml} |
589 |
adcroft |
1.4 |
|
590 |
edhill |
1.23 |
If compilation finished succesfuully (section \ref{sect:buildingCode}) |
591 |
|
|
then an executable called \texttt{mitgcmuv} will now exist in the |
592 |
|
|
local directory. |
593 |
adcroft |
1.1 |
|
594 |
edhill |
1.29 |
To run the model as a single process (\textit{ie.} not in parallel) |
595 |
|
|
simply type: |
596 |
adcroft |
1.1 |
\begin{verbatim} |
597 |
adcroft |
1.4 |
% ./mitgcmuv |
598 |
adcroft |
1.1 |
\end{verbatim} |
599 |
adcroft |
1.4 |
The ``./'' is a safe-guard to make sure you use the local executable |
600 |
|
|
in case you have others that exist in your path (surely odd if you |
601 |
|
|
do!). The above command will spew out many lines of text output to |
602 |
|
|
your screen. This output contains details such as parameter values as |
603 |
|
|
well as diagnostics such as mean Kinetic energy, largest CFL number, |
604 |
|
|
etc. It is worth keeping this text output with the binary output so we |
605 |
|
|
normally re-direct the {\em stdout} stream as follows: |
606 |
adcroft |
1.1 |
\begin{verbatim} |
607 |
adcroft |
1.4 |
% ./mitgcmuv > output.txt |
608 |
adcroft |
1.1 |
\end{verbatim} |
609 |
edhill |
1.29 |
In the event that the model encounters an error and stops, it is very |
610 |
|
|
helpful to include the last few line of this \texttt{output.txt} file |
611 |
|
|
along with the (\texttt{stderr}) error message within any bug reports. |
612 |
adcroft |
1.1 |
|
613 |
edhill |
1.17 |
For the example experiments in {\em verification}, an example of the |
614 |
edhill |
1.29 |
output is kept in {\em results/output.txt} for comparison. You can |
615 |
|
|
compare your {\em output.txt} with the corresponding one for that |
616 |
|
|
experiment to check that the set-up works. |
617 |
adcroft |
1.1 |
|
618 |
|
|
|
619 |
|
|
|
620 |
adcroft |
1.4 |
\subsection{Output files} |
621 |
adcroft |
1.1 |
|
622 |
edhill |
1.29 |
The model produces various output files. Depending upon the I/O |
623 |
|
|
package selected (either \texttt{mdsio} or \texttt{mnc} or both as |
624 |
|
|
determined by both the compile-time settings and the run-time flags in |
625 |
|
|
\texttt{data.pkg}), the following output may appear. |
626 |
|
|
|
627 |
|
|
|
628 |
|
|
\subsubsection{MDSIO output files} |
629 |
|
|
|
630 |
|
|
The ``traditional'' output files are generated by the \texttt{mdsio} |
631 |
|
|
package. At a minimum, the instantaneous ``state'' of the model is |
632 |
|
|
written out, which is made of the following files: |
633 |
adcroft |
1.1 |
|
634 |
|
|
\begin{itemize} |
635 |
|
|
\item \textit{U.00000nIter} - zonal component of velocity field (m/s and $> |
636 |
|
|
0 $ eastward). |
637 |
|
|
|
638 |
|
|
\item \textit{V.00000nIter} - meridional component of velocity field (m/s |
639 |
|
|
and $> 0$ northward). |
640 |
|
|
|
641 |
|
|
\item \textit{W.00000nIter} - vertical component of velocity field (ocean: |
642 |
|
|
m/s and $> 0$ upward, atmosphere: Pa/s and $> 0$ towards increasing pressure |
643 |
|
|
i.e. downward). |
644 |
|
|
|
645 |
|
|
\item \textit{T.00000nIter} - potential temperature (ocean: $^{0}$C, |
646 |
|
|
atmosphere: $^{0}$K). |
647 |
|
|
|
648 |
|
|
\item \textit{S.00000nIter} - ocean: salinity (psu), atmosphere: water vapor |
649 |
|
|
(g/kg). |
650 |
|
|
|
651 |
|
|
\item \textit{Eta.00000nIter} - ocean: surface elevation (m), atmosphere: |
652 |
|
|
surface pressure anomaly (Pa). |
653 |
|
|
\end{itemize} |
654 |
|
|
|
655 |
|
|
The chain \textit{00000nIter} consists of ten figures that specify the |
656 |
|
|
iteration number at which the output is written out. For example, \textit{% |
657 |
|
|
U.0000000300} is the zonal velocity at iteration 300. |
658 |
|
|
|
659 |
|
|
In addition, a ``pickup'' or ``checkpoint'' file called: |
660 |
|
|
|
661 |
|
|
\begin{itemize} |
662 |
|
|
\item \textit{pickup.00000nIter} |
663 |
|
|
\end{itemize} |
664 |
|
|
|
665 |
|
|
is written out. This file represents the state of the model in a condensed |
666 |
|
|
form and is used for restarting the integration. If the C-D scheme is used, |
667 |
|
|
there is an additional ``pickup'' file: |
668 |
|
|
|
669 |
|
|
\begin{itemize} |
670 |
|
|
\item \textit{pickup\_cd.00000nIter} |
671 |
|
|
\end{itemize} |
672 |
|
|
|
673 |
|
|
containing the D-grid velocity data and that has to be written out as well |
674 |
|
|
in order to restart the integration. Rolling checkpoint files are the same |
675 |
|
|
as the pickup files but are named differently. Their name contain the chain |
676 |
|
|
\textit{ckptA} or \textit{ckptB} instead of \textit{00000nIter}. They can be |
677 |
|
|
used to restart the model but are overwritten every other time they are |
678 |
|
|
output to save disk space during long integrations. |
679 |
|
|
|
680 |
edhill |
1.29 |
|
681 |
|
|
|
682 |
|
|
\subsubsection{MNC output files} |
683 |
|
|
|
684 |
|
|
Unlike the \texttt{mdsio} output, the \texttt{mnc}--generated output |
685 |
|
|
is usually (though not necessarily) placed within a subdirectory with |
686 |
|
|
a name such as \texttt{mnc\_test\_\${DATE}\_\${SEQ}}. The files |
687 |
|
|
within this subdirectory are all in the ``self-describing'' netCDF |
688 |
|
|
format and can thus be browsed and/or plotted using tools such as: |
689 |
|
|
\begin{itemize} |
690 |
|
|
\item At a minimum, the \texttt{ncdump} utility is typically included |
691 |
|
|
with every netCDF install: |
692 |
|
|
\begin{rawhtml} <A href="http://www.unidata.ucar.edu/packages/netcdf/"> \end{rawhtml} |
693 |
|
|
\begin{verbatim} |
694 |
|
|
http://www.unidata.ucar.edu/packages/netcdf/ |
695 |
|
|
\end{verbatim} |
696 |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
697 |
|
|
|
698 |
|
|
\item The \texttt{ncview} utility is a very convenient and quick way |
699 |
|
|
to plot netCDF data and it runs on most OSes: |
700 |
|
|
\begin{rawhtml} <A href="http://meteora.ucsd.edu/~pierce/ncview_home_page.html"> \end{rawhtml} |
701 |
|
|
\begin{verbatim} |
702 |
|
|
http://meteora.ucsd.edu/~pierce/ncview_home_page.html |
703 |
|
|
\end{verbatim} |
704 |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
705 |
|
|
|
706 |
|
|
\item MatLAB(c) and other common post-processing environments provide |
707 |
|
|
various netCDF interfaces including: |
708 |
|
|
\begin{rawhtml} <A href="http://woodshole.er.usgs.gov/staffpages/cdenham/public_html/MexCDF/nc4ml5.html"> \end{rawhtml} |
709 |
|
|
\begin{verbatim} |
710 |
|
|
http://woodshole.er.usgs.gov/staffpages/cdenham/public_html/MexCDF/nc4ml5.html |
711 |
|
|
\end{verbatim} |
712 |
|
|
\begin{rawhtml} </A> \end{rawhtml} |
713 |
|
|
|
714 |
|
|
\end{itemize} |
715 |
|
|
|
716 |
|
|
|
717 |
adcroft |
1.4 |
\subsection{Looking at the output} |
718 |
adcroft |
1.1 |
|
719 |
edhill |
1.29 |
The ``traditional'' or mdsio model data are written according to a |
720 |
|
|
``meta/data'' file format. Each variable is associated with two files |
721 |
|
|
with suffix names \textit{.data} and \textit{.meta}. The |
722 |
|
|
\textit{.data} file contains the data written in binary form |
723 |
|
|
(big\_endian by default). The \textit{.meta} file is a ``header'' file |
724 |
|
|
that contains information about the size and the structure of the |
725 |
|
|
\textit{.data} file. This way of organizing the output is particularly |
726 |
|
|
useful when running multi-processors calculations. The base version of |
727 |
|
|
the model includes a few matlab utilities to read output files written |
728 |
|
|
in this format. The matlab scripts are located in the directory |
729 |
|
|
\textit{utils/matlab} under the root tree. The script \textit{rdmds.m} |
730 |
|
|
reads the data. Look at the comments inside the script to see how to |
731 |
|
|
use it. |
732 |
adcroft |
1.1 |
|
733 |
adcroft |
1.4 |
Some examples of reading and visualizing some output in {\em Matlab}: |
734 |
|
|
\begin{verbatim} |
735 |
|
|
% matlab |
736 |
|
|
>> H=rdmds('Depth'); |
737 |
|
|
>> contourf(H');colorbar; |
738 |
|
|
>> title('Depth of fluid as used by model'); |
739 |
|
|
|
740 |
|
|
>> eta=rdmds('Eta',10); |
741 |
|
|
>> imagesc(eta');axis ij;colorbar; |
742 |
|
|
>> title('Surface height at iter=10'); |
743 |
|
|
|
744 |
|
|
>> eta=rdmds('Eta',[0:10:100]); |
745 |
|
|
>> for n=1:11; imagesc(eta(:,:,n)');axis ij;colorbar;pause(.5);end |
746 |
|
|
\end{verbatim} |
747 |
adcroft |
1.1 |
|
748 |
edhill |
1.29 |
Similar scripts for netCDF output (\texttt{rdmnc.m}) are available. |