Changeset 6808 for branches/NERC/dev_r5549_BDY_ZEROGRAD/DOC/TexFiles/Chapters/Chap_DIA.tex

Timestamp:

2016-07-19T10:38:35+02:00 (8 years ago)

Author:

jamesharle

Message:

merge with trunk@6232 for consistency with SSB code

File:

• branches/NERC/dev_r5549_BDY_ZEROGRAD/DOC/TexFiles/Chapters/Chap_DIA.tex (modified) (5 diffs, 1 prop)

branches/NERC/dev_r5549_BDY_ZEROGRAD/DOC/TexFiles/Chapters/Chap_DIA.tex

@@ -2 +2 @@
 % Chapter I/O & Diagnostics
 % ================================================================
-\chapter{Ouput and Diagnostics (IOM, DIA, TRD, FLO)}
+\chapter{Output and Diagnostics (IOM, DIA, TRD, FLO)}
 \label{DIA}
 \minitoc
 
 \newpage
-$\ $\newline    % force a new ligne
+$\ $\newline    % force a new line
 
 % ================================================================
@@ -33 +33 @@
 "\textit{grep -i numout}" in the source code directory.
 
-By default, diagnostic output files are written in NetCDF format but an IEEE binary output format, called DIMG, can be choosen by defining \key{dimgout}. 
+By default, diagnostic output files are written in NetCDF format but an IEEE binary output format, called DIMG, can be chosen by defining \key{dimgout}. 
 
 Since version 3.2, when defining \key{iomput}, an I/O server has been added which provides more flexibility in the choice of the fields to be written as well as how the writing work is distributed over the processors in massively parallel computing. The complete description of the use of this I/O server is presented in the next section. 
@@ -57 +57 @@
 \item The choice of output frequencies that can be different for each file (including real months and years).
 \item The choice of file contents; includes complete flexibility over which data are written in which files (the same data can be written in different files). 
-\item The possibility to split output files at a choosen frequency.
+\item The possibility to split output files at a chosen frequency.
 \item The possibility to extract a vertical or an horizontal subdomain.
 \item The choice of the temporal operation to perform, e.g.: average, accumulate, instantaneous, min, max and once.
@@ -1319 +1319 @@
 
 % -------------------------------------------------------------------------------------------------------------
+%       25 hour mean and hourly Surface, Mid and Bed 
+% -------------------------------------------------------------------------------------------------------------
+\section{25 hour mean output for tidal models }
+
+A module is available to compute a crudely detided M2 signal by obtaining a 25 hour mean.
+The 25 hour mean is available for daily runs by summing up the 25 hourly instantananeous hourly values from
+midnight at the start of the day to midight at the day end.
+This diagnostic is actived with the logical  $ln\_dia25h$
+
+%------------------------------------------nam_dia25h------------------------------------------------------
+\namdisplay{nam_dia25h}
+%----------------------------------------------------------------------------------------------------------
+
+\section{Top Middle and Bed hourly output }
+
+A module is available to output the surface (top), mid water and bed diagnostics of a set of standard variables. 
+This can be a useful diagnostic when hourly or sub-hourly output is required in high resolution tidal outputs.
+The tidal signal is retained but the overall data usage is cut to just three vertical levels. Also the bottom level 
+is calculated for each cell.
+This diagnostic is actived with the logical  $ln\_diatmb$
+
+%------------------------------------------nam_diatmb-----------------------------------------------------
+\namdisplay{nam_diatmb}
+%----------------------------------------------------------------------------------------------------------
+
+% -------------------------------------------------------------------------------------------------------------
 %       Sections transports
 % -------------------------------------------------------------------------------------------------------------
@@ -1522 +1548 @@
 \\
 
+\section{Courant numbers}
+Courant numbers provide a theoretical indication of the model's numerical stability. The advective Courant numbers can be calculated according to
+\begin{equation}
+\label{eq:CFL}
+C_u = |u|\frac{\rdt}{e_{1u}}, \quad C_v = |v|\frac{\rdt}{e_{2v}}, \quad C_w = |w|\frac{\rdt}{e_{3w}}
+\end{equation}
+in the zonal, meridional and vertical directions respectively. The vertical component is included although it is not strictly valid as the vertical velocity is calculated from the continuity equation rather than as a prognostic variable. Physically this represents the rate at which information is propogated across a grid cell. Values greater than 1 indicate that information is propagated across more than one grid cell in a single time step.
+
+The variables can be activated by setting the \np{nn\_diacfl} namelist parameter to 1 in the \ngn{namctl} namelist. The diagnostics will be written out to an ascii file named cfl\_diagnostics.ascii. In this file the maximum value of $C_u$, $C_v$, and $C_w$ are printed at each timestep along with the coordinates of where the maximum value occurs. At the end of the model run the maximum value of $C_u$, $C_v$, and $C_w$ for the whole model run is printed along with the coordinates of each. The maximum values from the run are also copied to the ocean.output file.