Changeset 3104 for branches/2011/dev_LOCEAN_CMCC_INGV_MERCATOR_2011/DOC/TexFiles/Chapters

Timestamp:

2011-11-15T11:08:25+01:00 (13 years ago)

Author:

cetlod

Message:

dev_LOCEAN_CMCC_INGV_MERCATOR_2011:add in changes dev_MERCATOR_INGV_2011_MERGE into the new branch

Location:

branches/2011/dev_LOCEAN_CMCC_INGV_MERCATOR_2011/DOC/TexFiles/Chapters

Files:

• Chap_DIA.tex (modified) (3 diffs)
• Chap_SBC.tex (modified) (8 diffs)
• Chap_ZDF.tex (modified) (1 diff)

branches/2011/dev_LOCEAN_CMCC_INGV_MERCATOR_2011/DOC/TexFiles/Chapters/Chap_DIA.tex

@@ -681 +681 @@
 numeric of the code, so that the trajectories never intercept the bathymetry. 
 
+\subsubsection{ Input data: initial coordinates }
+
+Initial coordinates can be given with Ariane Tools convention ( IJK coordinates ,(\np{ln\_ariane}=true) )
+or with longitude and latitude.
+
+
+In case of Ariane convention, input filename is \np{"init\_float\_ariane"}. Its format is:
+
+\texttt{ I J K nisobfl itrash itrash }
+
+\noindent with: 
+
+ - I,J,K  : indexes of initial position
+
+ - nisobfl: 0 for an isobar float, 1 for a float following the w velocity  
+
+ - itrash : set to zero; it is a dummy variable to respect Ariane Tools convention
+
+ - itrash :set to zero; it is a dummy variable to respect Ariane Tools convention
+
+\noindent Example:\\
+\noindent \texttt{ 100.00000  90.00000  -1.50000 1.00000   0.00000}\\
+\texttt{ 102.00000  90.00000  -1.50000 1.00000   0.00000}\\
+\texttt{ 104.00000  90.00000  -1.50000 1.00000   0.00000}\\
+\texttt{ 106.00000  90.00000  -1.50000 1.00000   0.00000}\\
+\texttt{ 108.00000  90.00000  -1.50000 1.00000   0.00000}\\
+
+
+In the other case ( longitude and latitude ), input filename is \np{"init\_float"}. Its format is:
+
+\texttt{ Long Lat depth nisobfl ngrpfl itrash}
+
+\noindent with:
+
+ - Long, Lat, depth  : Longitude, latitude, depth
+
+ - nisobfl: 0 for an isobar float, 1 for a float following the w velocity
+
+ - ngrpfl : number to identify searcher group
+
+ - itrash :set to 1; it is a dummy variable.
+
+\noindent Example:
+
+\noindent\texttt{  20.0 0.0 0.0 0 1 1 }\\
+\texttt{ -21.0 0.0 0.0 0 1 1 }\\
+\texttt{ -22.0 0.0 0.0 0 1 1 }\\
+\texttt{ -23.0 0.0 0.0 0 1 1 }\\
+\texttt{ -24.0 0.0 0.0 0 1 1 }\\
+
+\np{jpnfl} is the total number of floats during the run.
+When initial positions are read in a restart file ( \np{ln\_rstflo= .TRUE.} ),  \np{jpnflnewflo}
+can be added in the initialization file. 
+
+\subsubsection{ Output data }
+
+\np{nn\_writefl} is the frequency of writing in float output file and \np{nn\_stockfl} 
+is the frequency of creation of the float restart file.
+
+Output data can be written in ascii files (\np{ln\_flo\_ascii = .TRUE.} ). In that case, 
+output filename is \np{is trajec\_float}.
+
+Another possiblity of writing format is Netcdf (\np{ln\_flo\_ascii = .FALSE.} ). There are 2 possibilities:
+
+ - if (\key{iomput}) is used, outputs are selected in  \np{iodef.xml}. Here it is an example of specification 
+   to put in files description section:
+
+\vspace{-30pt}
+\begin{alltt}  {{\scriptsize
+\begin{verbatim}
+
+     <group id="1d\_grid\_T" name="auto" description="ocean T grid variables" >   }
+       <file id="floats"  description="floats variables"> }\\
+           <field ref="traj\_lon"   name="floats\_longitude"   freq\_op="86400" />}
+           <field ref="traj\_lat"   name="floats\_latitude"    freq\_op="86400" />}
+           <field ref="traj\_dep"   name="floats\_depth"       freq\_op="86400" />}
+           <field ref="traj\_temp"  name="floats\_temperature" freq\_op="86400" />}
+           <field ref="traj\_salt"  name="floats\_salinity"    freq\_op="86400" />}
+           <field ref="traj\_dens"  name="floats\_density"     freq\_op="86400" />}
+           <field ref="traj\_group" name="floats\_group"       freq\_op="86400" />}
+       </file>}
+  </group>}
+
+\end{verbatim}
+}}\end{alltt}
+
+
+ -  if (\key{iomput}) is not used, a file called \np{trajec\_float.nc} will be created by IOIPSL library.
+
+
+
 See also \href{http://stockage.univ-brest.fr/~grima/Ariane/}{here} the web site describing 
 the off-line use of this marvellous diagnostic tool.
+
+
+% -------------------------------------------------------------------------------------------------------------
+%       Harmonic analysis of tidal constituents
+% -------------------------------------------------------------------------------------------------------------
+\section{Harmonic analysis of tidal constituents (\key{diaharm}) }
+\label{DIA_diag_harm}
+
+A module is available to compute the amplitude and phase for tidal waves. 
+This diagnostic is actived with \key{diaharm}.
+
+%------------------------------------------namdia_harm----------------------------------------------------
+\namdisplay{namdia_harm}
+%----------------------------------------------------------------------------------------------------------
+
+Concerning the on-line Harmonic analysis, some parameters are available in namelist:
+
+- \texttt{nit000\_han} is the first time step used for harmonic analysis
+
+- \texttt{nitend\_han} is the last time step used for harmonic analysis
+
+- \texttt{nstep\_han} is the time step frequency for harmonic analysis
+
+- \texttt{nb\_ana} is the number of harmonics to analyse
+
+- \texttt{tname} is an array with names of tidal constituents to analyse
+
+\texttt{nit000\_han} and \texttt{nitend\_han} must be between \texttt{nit000} and \texttt{nitend} of the simulation.
+The restart capability is not implemented.
+
+The Harmonic analysis solve this equation:
+\begin{equation}
+h_{i} - A_{0} + \sum^{nb\_ana}_{j=1}[A_{j}cos(\nu_{j}t_{j}-\phi_{j})] = e_{i}
+\end{equation}
+
+With $A_{j}$,$\nu_{j}$,$\phi_{j}$, the amplitude, frequency and phase for each wave and $e_{i}$ the error.
+$h_{i}$ is the sea level for the time $t_{i}$ and $A_{0}$ is the mean sea level. \\
+We can rewrite this equation:
+\begin{equation}
+h_{i} - A_{0} + \sum^{nb\_ana}_{j=1}[C_{j}cos(\nu_{j}t_{j})+S_{j}sin(\nu_{j}t_{j})] = e_{i}
+\end{equation}
+with $A_{j}=\sqrt{C^{2}_{j}+S^{2}_{j}}$ et $\phi_{j}=arctan(S_{j}/C_{j})$.
+
+We obtain in output $C_{j}$ and $S_{j}$ for each tidal wave.
+
+% -------------------------------------------------------------------------------------------------------------
+%       Sections transports
+% -------------------------------------------------------------------------------------------------------------
+\section{Transports across sections (\key{diadct}) }
+\label{DIA_diag_dct}
+
+A module is available to compute the transport of volume, heat and salt through sections. This diagnostic
+is actived with \key{diadct}.
+
+Each section is defined by the coordinates of its 2 extremities. The pathways between them are contructed
+using tools which can be found in  \texttt{NEMOGCM/TOOLS/SECTIONS\_DIADCT} and are written in a binary file
+ \texttt{section\_ijglobal.diadct\_ORCA2\_LIM} which is later read in by NEMO to compute on-line transports.
+
+The on-line transports module creates three output ascii files: 
+
+- \texttt{volume\_transport} for volume transports (  unit: $10^{6} m^{3} s^{-1}$ )
+
+- \texttt{heat\_transport}   for heat transports   (  unit: $10^{15} W $ )
+
+- \texttt{salt\_transport}   for salt transports   (  unit: $10^{9}g s^{-1}$ )\\
+
+
+Namelist parameters control how frequently the flows are summed and the time scales over which
+ they are averaged, as well as the level of output for debugging:
+
+%------------------------------------------namdct----------------------------------------------------
+\namdisplay{namdct}
+%-------------------------------------------------------------------------------------------------------------
+
+\texttt{nn\_dct}: frequency of instantaneous transports computing
+
+\texttt{nn\_dctwri}: frequency of writing ( mean of instantaneous transports )
+
+\texttt{nn\_debug}: debugging of the section
+
+\subsubsection{ To create a binary file containing the pathway of each section }
+
+In \texttt{NEMOGCM/TOOLS/SECTIONS\_DIADCT/run}, the file \texttt{ {list\_sections.ascii\_global}}
+contains a list of all the sections that are to be computed (this list of sections is based on MERSEA project metrics).
+
+Another file is available for the GYRE configuration (\texttt{ {list\_sections.ascii\_GYRE}}). 
+
+Each section is defined by:
+
+\noindent \texttt{ long1 lat1 long2 lat2 nclass (ok/no)strpond (no)ice section\_name }\\
+with:
+
+- \texttt{long1 lat1} , coordinates of the first extremity of the section;
+
+- \texttt{long2 lat2} , coordinates of the second extremity of the section;
+
+- \texttt{nclass} the number of bounds of your classes (e.g. 3 bounds for 2 classes);
+
+- \texttt{okstrpond} to compute heat and salt transport, \texttt{nostrpond} if no;
+
+- \texttt{ice}  to compute surface and volume ice transports, \texttt{noice} if no. \\
+
+
+\noindent The results of the computing of transports, and the directions of positive
+ and negative flow do not depend on the order of the 2 extremities in this file.\\ 
+
+
+\noindent If nclass =/ 0,the next lines contain the class type and the nclass bounds:
+
+\texttt{long1 lat1 long2 lat2 nclass (ok/no)strpond (no)ice section\_name}
+
+\texttt{classtype}
+
+\texttt{zbound1}
+
+\texttt{zbound2}
+
+\texttt{.}
+
+\texttt{.}
+
+\texttt{nclass-1}
+
+\texttt{nclass}
+
+\noindent where \texttt{classtype} can be:
+
+- \texttt{zsal} for salinity classes
+
+- \texttt{ztem} for temperature classes
+
+- \texttt{zlay} for depth classes
+
+- \texttt{zsigi} for insitu density classes
+
+- \texttt{zsigp} for potential density classes \\
+
+  
+The script \texttt{job.ksh} computes the pathway for each section and creates a binary file 
+\texttt{section\_ijglobal.diadct\_ORCA2\_LIM} which is read by NEMO. \\
+
+It is possible to use this tools for new configuations: \texttt{job.ksh} has to be updated 
+with the coordinates file name and path. \\
+
+
+Examples of two sections, the ACC\_Drake\_Passage with no classes, and the
+ ATL\_Cuba\_Florida with 4 temperature clases (5 class bounds), are shown:
+
+\noindent \texttt{ -68.    -54.5   -60.    -64.7  00 okstrpond noice ACC\_Drake\_Passage}
+
+\noindent \texttt{ -80.5    22.5   -80.5    25.5  05 nostrpond noice ATL\_Cuba\_Florida}
+
+\noindent \texttt{ztem}
+
+\noindent \texttt{-2.0}
+
+\noindent \texttt{ 4.5}
+
+\noindent \texttt{ 7.0}
+
+\noindent \texttt{12.0}
+
+\noindent \texttt{40.0}
+
+
+\subsubsection{ To read the output files }
+
+The output format is :
+ 
+\small{\texttt{date, time-step number, section number, section name, section slope coefficient, class number, 
+class name, class bound 1 , classe bound2, transport\_direction1 ,  transport\_direction2, transport\_total}}\\
+
+
+For sections with classes, the first \texttt{nclass-1} lines correspond to the transport for each class 
+and the last line corresponds to the total transport summed over all classes. For sections with no classes, class number
+\texttt{ 1 } corresponds to \texttt{ total class } and this class is called  \texttt{N}, meaning \texttt{none}.\\
+
+
+\noindent \texttt{ transport\_direction1 } is the positive part of the transport ( \texttt{ > = 0 } ).
+
+\noindent \texttt{ transport\_direction2 } is the negative part of the transport ( \texttt{ < = 0 } ).\\
+
+
+\noindent The \texttt{section slope coefficient} gives information about the significance of transports signs and direction:\\
+
+
+
+\begin{tabular}{|c|c|c|c|p{4cm}|}
+\hline
+section slope coefficient & section type & direction 1 & direction 2 & total transport \\ \hline
+0.    &  horizontal & northward & southward & postive: northward  \\ \hline
+1000. &  vertical   & eastward  & westward  & postive: eastward  \\ \hline                
+\texttt{=/0, =/ 1000.}   &  diagonal   & eastward  & westward  & postive: eastward  \\ \hline                
+\end{tabular}
+
+
 
 % -------------------------------------------------------------------------------------------------------------
@@ -726 +1013 @@
 are removed from the sub-basins. Note also that the Arctic Ocean has been split 
 into Atlantic and Pacific basins along the North fold line.  }
-\end{center}   \end{figure}
+\end{center}   \end{figure}  
 %>>>>>>>>>>>>>>>>>>>>>>>>>>>>
 
@@ -733 +1020 @@
 (see Section \ref{MISC_steric} below for one of them). 
 Activating those outputs requires to define the \key{diaar5} CPP key.
+\\
+\\
 
 

branches/2011/dev_LOCEAN_CMCC_INGV_MERCATOR_2011/DOC/TexFiles/Chapters/Chap_SBC.tex

@@ -24 +24 @@
 \end{itemize}
 
-Four different ways to provide the first six fields to the ocean are available which 
+Five different ways to provide the first six fields to the ocean are available which 
 are controlled by namelist variables: an analytical formulation (\np{ln\_ana}~=~true), 
 a flux formulation (\np{ln\_flx}~=~true), a bulk formulae formulation (CORE 
-(\np{ln\_core}~=~true) or CLIO (\np{ln\_clio}~=~true) bulk formulae) and a coupled 
+(\np{ln\_core}~=~true), CLIO (\np{ln\_clio}~=~true) or MFS
+\footnote { Note that MFS bulk formulae compute fluxes only for the ocean component}
+(\np{ln\_ecmwf}~=~true) bulk formulae) and a coupled 
 formulation (exchanges with a atmospheric model via the OASIS coupler) 
 (\np{ln\_cpl}~=~true). When used, the atmospheric pressure forces both 
-ocean and ice dynamics (\np{ln\_apr\_dyn}~=~true)
-\footnote{The surface pressure field could be use in bulk formulae, nevertheless 
-none of the current bulk formulea (CLIO and CORE) uses the it.}. 
+ocean and ice dynamics (\np{ln\_apr\_dyn}~=~true).
 The frequency at which the six or seven fields have to be updated is the \np{nn\_fsbc} 
 namelist parameter. 
@@ -46 +46 @@
 (\np{nn\_ice}~=~0,1, 2 or 3); the addition of river runoffs as surface freshwater 
 fluxes or lateral inflow (\np{ln\_rnf}~=~true); the addition of a freshwater flux adjustment 
-in order to avoid a mean sea-level drift (\np{nn\_fwb}~=~0,~1~or~2); and the 
+in order to avoid a mean sea-level drift (\np{nn\_fwb}~=~0,~1~or~2); the 
 transformation of the solar radiation (if provided as daily mean) into a diurnal 
-cycle (\np{ln\_dm2dc}~=~true).
+cycle (\np{ln\_dm2dc}~=~true); and a neutral drag coefficient can be read from an external wave 
+model (\np{ln\_cdgw}~=~true). The latter option is possible only in case core or ecmwf bulk formulas are selected.
 
 In this chapter, we first discuss where the surface boundary condition appears in the
-model equations. Then we present the four ways of providing the surface boundary condition, 
+model equations. Then we present the five ways of providing the surface boundary condition, 
 followed by the description of the atmospheric pressure and the river runoff. 
 Next the scheme for interpolation on the fly is described.
@@ -480 +481 @@
 % Bulk formulation
 % ================================================================
-\section  [Bulk formulation (\textit{sbcblk\_core} or \textit{sbcblk\_clio}) ]
-      {Bulk formulation \small{(\mdl{sbcblk\_core} or \mdl{sbcblk\_clio} module)} }
+\section  [Bulk formulation (\textit{sbcblk\_core}, \textit{sbcblk\_clio} or \textit{sbcblk\_ecmwf}) ]
+      {Bulk formulation \small{(\mdl{sbcblk\_core} \mdl{sbcblk\_clio} \mdl{sbcblk\_ecmwf} modules)} }
 \label{SBC_blk}
 
@@ -487 +488 @@
 using bulk formulae and atmospheric fields and ocean (and ice) variables. 
 
-The atmospheric fields used depend on the bulk formulae used. Two bulk formulations 
-are available : the CORE and CLIO bulk formulea. The choice is made by setting to true
-one of the following namelist variable : \np{ln\_core} and \np{ln\_clio}.
-
-Note : in forced mode, when a sea-ice model is used, a bulk formulation have to be used. 
-Therefore the two bulk formulea provided include the computation of the fluxes over both 
+The atmospheric fields used depend on the bulk formulae used. Three bulk formulations 
+are available : the CORE, the CLIO and the MFS bulk formulea. The choice is made by setting to true
+one of the following namelist variable : \np{ln\_core} ; \np{ln\_clio} or  \np{ln\_ecmwf}.
+
+Note : in forced mode, when a sea-ice model is used, a bulk formulation (CLIO or CORE) have to be used. 
+Therefore the two bulk (CLIO and CORE) formulea include the computation of the fluxes over both 
 an ocean and an ice surface. 
 
@@ -583 +584 @@
 namelist (see \S\ref{SBC_fldread}). 
 
+% -------------------------------------------------------------------------------------------------------------
+%        ECMWF Bulk formulea
+% -------------------------------------------------------------------------------------------------------------
+\subsection    [MFS Bulk formulea (\np{ln\_ecmwf}=true)]
+            {MFS Bulk formulea (\np{ln\_ecmwf}=true, \mdl{sbcblk\_ecmwf})}
+\label{SBC_blk_ecmwf}
+%------------------------------------------namsbc_ecmwf----------------------------------------------------
+\namdisplay{namsbc_ecmwf} 
+%----------------------------------------------------------------------------------------------------------
+
+The MFS (Mediterranean Forecasting System) bulk formulae have been developed by
+ \citet{Castellari_al_JMS1998}. 
+They have been designed to handle the ECMWF operational data and are currently 
+in use in the MFS operational system \citep{Tonani_al_OS08}, \citep{Oddo_al_OS09}.
+The wind stress computation uses a drag coefficient computed according to \citet{Hellerman_Rosenstein_JPO83}.
+The surface boundary condition for temperature involves the balance between surface solar radiation,
+net long-wave radiation, the latent and sensible heat fluxes.
+Solar radiation is dependent on cloud cover and is computed by means of
+an astronomical formula \citep{Reed_JPO77}. Albedo monthly values are from \citet{Payne_JAS72} 
+as means of the values at $40^{o}N$ and $30^{o}N$ for the Atlantic Ocean (hence the same latitudinal
+band of the Mediterranean Sea). The net long-wave radiation flux
+\citep{Bignami_al_JGR95} is a function of
+air temperature, sea-surface temperature, cloud cover and relative humidity.
+Sensible heat and latent heat fluxes are computed by classical
+bulk formulae parameterized according to \citet{Kondo1975}.
+Details on the bulk formulae used can be found in \citet{Maggiore_al_PCE98} and \citet{Castellari_al_JMS1998}.
+
+The required 7 input fields must be provided on the model Grid-T and  are:
+\begin{itemize}
+\item          Zonal Component of the 10m wind ($ms^{-1}$)  (\np{sn\_windi})
+\item          Meridional Component of the 10m wind ($ms^{-1}$)  (\np{sn\_windj})
+\item          Total Claud Cover (\%)  (\np{sn\_clc})
+\item          2m Air Temperature ($K$) (\np{sn\_tair})
+\item          2m Dew Point Temperature ($K$)  (\np{sn\_rhm})
+\item          Total Precipitation ${Kg} m^{-2} s^{-1}$ (\np{sn\_prec})
+\item          Mean Sea Level Pressure (${Pa}) (\np{sn\_msl})
+\end{itemize}
+% -------------------------------------------------------------------------------------------------------------
 % ================================================================
 % Coupled formulation
@@ -643 +682 @@
 $\eta_{ib}$ can be set in the output. This can simplify altimetry data and model comparison 
 as inverse barometer sea surface height is usually removed from these date prior to their distribution.
+
+% ================================================================
+%        Tidal Potential
+% ================================================================
+\section   [Tidal Potential (\textit{sbctide})]
+                        {Tidal Potential (\mdl{sbctide})}
+\label{SBC_tide}
+
+A module is available to use the tidal potential forcing and is activated with with \key{tide}.
+
+
+%------------------------------------------nam_tide----------------------------------------------------
+\namdisplay{nam_tide}
+%-------------------------------------------------------------------------------------------------------------
+
+Concerning the tidal potential, some parameters are available in namelist:
+
+- \texttt{ln\_tide\_pot} activate the tidal potential forcing
+
+- \texttt{nb\_harmo} is the number of constituent used
+
+- \texttt{clname} is the name of constituent
+
+
+The tide is generated by the forces of gravity ot the Earth-Moon and Earth-Sun sytem;
+they are expressed as the gradient of the astronomical potential ($\vec{\nabla}\Pi_{a}$). \\
+
+The potential astronomical expressed, for the three types of tidal frequencies
+following, by : \\
+Tide long period :
+\begin{equation}
+\Pi_{a}=gA_{k}(\frac{1}{2}-\frac{3}{2}sin^{2}\phi)cos(\omega_{k}t+V_{0k})
+\end{equation}
+diurnal Tide :
+\begin{equation}
+\Pi_{a}=gA_{k}(sin 2\phi)cos(\omega_{k}t+\lambda+V_{0k})
+\end{equation}
+Semi-diurnal tide:
+\begin{equation}
+\Pi_{a}=gA_{k}(cos^{2}\phi)cos(\omega_{k}t+2\lambda+V_{0k})
+\end{equation}
+
+
+$A_{k}$ is the amplitude of the wave k, $\omega_{k}$ the pulsation of the wave k, $V_{0k}$ the astronomical phase of the wave
+$k$ to Greenwich.
+
+We make corrections to the astronomical potential.
+We obtain : 
+\begin{equation}
+\Pi-g\delta = (1+k-h) \Pi_{A}(\lambda,\phi)
+\end{equation}
+with $k$ a number of Love estimated to 0.6 which parametrized the astronomical tidal land,
+and $h$ a number of Love to 0.3 which parametrized the parametrization due to the astronomical tidal land.
 
 % ================================================================
@@ -938 +1030 @@
 \end{description}
 
+% -------------------------------------------------------------------------------------------------------------
+%        Neutral Drag Coefficient from external wave model
+% -------------------------------------------------------------------------------------------------------------
+\subsection   [Neutral drag coefficient from external wave model (\textit{sbcwave})]
+                        {Neutral drag coefficient from external wave model (\mdl{sbcwave})}
+\label{SBC_wave}
+%------------------------------------------namwave----------------------------------------------------
+\namdisplay{namsbc_wave}
+%-------------------------------------------------------------------------------------------------------------
+\begin{description}
+
+In order to read a neutral drag coeff, from an external data source (i.e. a wave model), the 
+logical variable \np{ln\_cdgw}
+ in $namsbc$ namelist must be defined ${.true.}$. 
+The \mdl{sbcwave} module containing the routine \np{sbc\_wave} reads the
+namelist ${namsbc\_wave}$ (for external data names, locations, frequency, interpolation and all 
+the miscellanous options allowed by Input Data generic Interface see \S\ref{SBC_input}) 
+and a 2D field of neutral drag coefficient. Then using the routine 
+TURB\_CORE\_1Z or TURB\_CORE\_2Z, and starting from the neutral drag coefficent provided, the drag coefficient is computed according 
+to stable/unstable conditions of the air-sea interface following \citet{Large_Yeager_Rep04}.
+
+\end{description}
+
 % Griffies doc:
 % When running ocean-ice simulations, we are not explicitly representing land processes, such as rivers, catchment areas, snow accumulation, etc. However, to reduce model drift, it is important to balance the hydrological cycle in ocean-ice models. We thus need to prescribe some form of global normalization to the precipitation minus evaporation plus river runoff. The result of the normalization should be a global integrated zero net water input to the ocean-ice system over a chosen time scale. 
@@ -944 +1059 @@
 
 
-

branches/2011/dev_LOCEAN_CMCC_INGV_MERCATOR_2011/DOC/TexFiles/Chapters/Chap_ZDF.tex

@@ -100 +100 @@
 $a=5$ and $n=2$. The last three values can be modified by setting the 
 \np{rn\_avmri}, \np{rn\_alp} and \np{nn\_ric} namelist parameters, respectively.
+
+A simple mixing-layer model to transfer and dissipate the atmospheric
+ forcings (wind-stress and buoyancy fluxes) can be activated setting 
+the \np{ln\_mldw} =.true. in the namelist.
+
+In this case, the local depth of turbulent wind-mixing or "Ekman depth"
+ $h_{e}(x,y,t)$ is evaluated and the vertical eddy coefficients prescribed within this layer.
+
+This depth is assumed proportional to the "depth of frictional influence" that is limited by rotation:
+\begin{equation}
+         h_{e} = Ek \frac {u^{*}} {f_{0}}    \\
+\end{equation}
+where, $Ek$ is an empirical parameter, $u^{*}$ is the friction velocity and $f_{0}$ is the Coriolis 
+parameter.
+
+In this similarity height relationship, the turbulent friction velocity:
+\begin{equation}
+         u^{*} = \sqrt \frac {|\tau|} {\rho_o}     \\
+\end{equation}
+
+is computed from the wind stress vector $|\tau|$ and the reference dendity $ \rho_o$.
+The final $h_{e}$ is further constrained by the adjustable bounds \np{rn\_mldmin} and \np{rn\_mldmax}.
+Once $h_{e}$ is computed, the vertical eddy coefficients within $h_{e}$ are set to 
+the empirical values \np{rn\_wtmix} and \np{rn\_wvmix} \citep{Lermusiaux2001}.
 
 % -------------------------------------------------------------------------------------------------------------