Changeset 5965 for branches/2014/dev_r4650_UKMO14.5_SST_BIAS_CORRECTION/DOC/TexFiles/Chapters/Chap_TRA.tex

Timestamp:

2015-12-01T16:35:30+01:00 (8 years ago)

Author:

timgraham

Message:

Upgraded branch to r5518 of trunk (v3.6 stable revision)

File:

• branches/2014/dev_r4650_UKMO14.5_SST_BIAS_CORRECTION/DOC/TexFiles/Chapters/Chap_TRA.tex (modified) (3 diffs)

branches/2014/dev_r4650_UKMO14.5_SST_BIAS_CORRECTION/DOC/TexFiles/Chapters/Chap_TRA.tex

@@ -1077 +1077 @@
 correctly set  ($i.e.$ that $T_o$ and $S_o$ are provided in input files and read 
 using \mdl{fldread}, see \S\ref{SBC_fldread}). 
-The restoring coefficient $\gamma$ is a three-dimensional array initialized by the 
-user in routine \rou{dtacof} also located in module \mdl{tradmp}. 
+The restoring coefficient $\gamma$ is a three-dimensional array read in during the \rou{tra\_dmp\_init} routine. The file name is specified by the namelist variable \np{cn\_resto}. The DMP\_TOOLS tool is provided to allow users to generate the netcdf file.
 
 The two main cases in which \eqref{Eq_tra_dmp} is used are \textit{(a)} 
@@ -1092 +1091 @@
 diagnostic method \citep{Sarmiento1982}. It allows us to find the velocity 
 field consistent with the model dynamics whilst having a $T$, $S$ field 
-close to a given climatological field ($T_o$, $S_o$). The time scale 
-associated with $S_o$ is generally not a constant but spatially varying 
-in order to respect other properties. For example, it is usually set to zero 
-in the mixed layer (defined either on a density or $S_o$ criterion) 
-\citep{Madec_al_JPO96} and in the equatorial region 
-\citep{Reverdin1991, Fujio1991, Marti_PhD92} since these two regions 
-have a short time scale of adjustment; while smaller $\gamma$ are used 
-in the deep ocean where the typical time scale is long \citep{Sarmiento1982}. 
-In addition the time scale is reduced (even to zero) along the western 
-boundary to allow the model to reconstruct its own western boundary 
-structure in equilibrium with its physics. 
-The choice of the shape of the Newtonian damping is controlled by two 
-namelist parameters \np{nn\_hdmp} and \np{nn\_zdmp}. The former allows us to specify: the 
-width of the equatorial band in which no damping is applied; a decrease 
-in the vicinity of the coast; and a damping everywhere in the Red and Med Seas.
-The latter sets whether damping should act in the mixed layer or not. 
-The time scale associated with the damping depends on the depth as
-a hyperbolic tangent, with \np{rn\_surf} as surface value, \np{rn\_bot} as 
-bottom value and a transition depth of \np{rn\_dep}.  
+close to a given climatological field ($T_o$, $S_o$). 
 
 The robust diagnostic method is very efficient in preventing temperature 
@@ -1118 +1099 @@
 by stabilising the water column too much.
 
-An example of the computation of $\gamma$ for a robust diagnostic experiment 
-with the ORCA2 model is provided in the \mdl{tradmp} module 
-(subroutines \rou{dtacof} and \rou{cofdis} which compute the coefficient 
-and the distance to the bathymetry, respectively). These routines are 
-provided as examples and can be customised by the user. 
+The namelist parameter \np{nn\_zdmp} sets whether the damping should be applied in the whole water column or only below the mixed layer (defined either on a density or $S_o$ criterion). It is common to set the damping to zero in the mixed layer as the adjustment time scale is short here \citep{Madec_al_JPO96}.
+
+\subsection[DMP\_TOOLS]{Generating resto.nc using DMP\_TOOLS}
+
+DMP\_TOOLS can be used to generate a netcdf file containing the restoration coefficient $\gamma$. Note that in order to maintain bit comparison with previous NEMO versions DMP\_TOOLS must be compiled and run on the same machine as the NEMO model. A mesh\_mask.nc file for the model configuration is required as an input. This can be generated by carrying out a short model run with the namelist parameter \np{nn\_msh} set to 1. The namelist parameter \np{ln\_tradmp} will also need to be set to .false. for this to work. The \nl{nam\_dmp\_create} namelist in the DMP\_TOOLS directory is used to specify options for the restoration coefficient.
+
+%--------------------------------------------nam_dmp_create-------------------------------------------------
+\namdisplay{nam_dmp_create}
+%-------------------------------------------------------------------------------------------------------
+
+\np{cp\_cfg}, \np{cp\_cpz}, \np{jp\_cfg} and \np{jperio} specify the model configuration being used and should be the same as specified in \nl{namcfg}. The variable \nl{lzoom} is used to specify that the damping is being used as in case \textit{a} above to provide boundary conditions to a zoom configuration. In the case of the arctic or antarctic zoom configurations this includes some specific treatment. Otherwise damping is applied to the 6 grid points along the ocean boundaries. The open boundaries are specified by the variables \np{lzoom\_n}, \np{lzoom\_e}, \np{lzoom\_s}, \np{lzoom\_w} in the \nl{nam\_zoom\_dmp} name list.
+
+The remaining switch namelist variables determine the spatial variation of the restoration coefficient in non-zoom configurations. \np{ln\_full\_field} specifies that newtonian damping should be applied to the whole model domain. \np{ln\_med\_red\_seas} specifies grid specific restoration coefficients in the Mediterranean Sea for the ORCA4, ORCA2 and ORCA05 configurations. If \np{ln\_old\_31\_lev\_code} is set then the depth variation of the coeffients will be specified as a function of the model number. This option is included to allow backwards compatability of the ORCA2 reference configurations with previous model versions. \np{ln\_coast} specifies that the restoration coefficient should be reduced near to coastlines. This option only has an effect if \np{ln\_full\_field} is true. \np{ln\_zero\_top\_layer} specifies that the restoration coefficient should be zero in the surface layer. Finally \np{ln\_custom} specifies that the custom module will be called. This module is contained in the file custom.F90 and can be edited by users. For example damping could be applied in a specific region.
+
+The restoration coefficient can be set to zero in equatorial regions by specifying a positive value of \np{nn\_hdmp}. Equatorward of this latitude the restoration coefficient will be zero with a smooth transition to the full values of a 10$^{\circ}$ latitud band. This is often used because of the short adjustment time scale in the equatorial region \citep{Reverdin1991, Fujio1991, Marti_PhD92}. The time scale associated with the damping depends on the depth as a hyperbolic tangent, with \np{rn\_surf} as surface value, \np{rn\_bot} as bottom value and a transition depth of \np{rn\_dep}.  
 
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