New URL for NEMO forge!   http://forge.nemo-ocean.eu

Since March 2022 along with NEMO 4.2 release, the code development moved to a self-hosted GitLab.
This present forge is now archived and remained online for history.
Changeset 11564 for NEMO/branches/2019/dev_r10973_AGRIF-01_jchanut_small_jpi_jpj/doc/latex/NEMO/subfiles/chap_TRA.tex – NEMO

Ignore:
Timestamp:
2019-09-18T16:11:52+02:00 (5 years ago)
Author:
jchanut
Message:

#2199, merged with trunk

Location:
NEMO/branches/2019/dev_r10973_AGRIF-01_jchanut_small_jpi_jpj/doc
Files:
4 edited

Legend:

Unmodified
Added
Removed
  • NEMO/branches/2019/dev_r10973_AGRIF-01_jchanut_small_jpi_jpj/doc

    • Property svn:ignore deleted
  • NEMO/branches/2019/dev_r10973_AGRIF-01_jchanut_small_jpi_jpj/doc/latex

    • Property svn:ignore
      •  

        old new  
        1 *.aux 
        2 *.bbl 
        3 *.blg 
        4 *.dvi 
        5 *.fdb* 
        6 *.fls 
        7 *.idx 
        8 *.ilg 
        9 *.ind 
        10 *.log 
        11 *.maf 
        12 *.mtc* 
        13 *.out 
        14 *.pdf 
        15 *.toc 
        16 _minted-* 
         1figures 
  • NEMO/branches/2019/dev_r10973_AGRIF-01_jchanut_small_jpi_jpj/doc/latex/NEMO

    • Property svn:ignore deleted
  • NEMO/branches/2019/dev_r10973_AGRIF-01_jchanut_small_jpi_jpj/doc/latex/NEMO/subfiles/chap_TRA.tex

    r10544 r11564  
    88\label{chap:TRA} 
    99 
    10 \minitoc 
    11  
    12 % missing/update  
     10\chaptertoc 
     11 
     12% missing/update 
    1313% traqsr: need to coordinate with SBC module 
    1414 
    15 %STEVEN :  is the use of the word "positive" to describe a scheme enough, or should it be "positive definite"? I added a comment to this effect on some instances of this below 
     15%STEVEN :  is the use of the word "positive" to describe a scheme enough, or should it be "positive definite"? 
     16%I added a comment to this effect on some instances of this below 
    1617 
    1718Using the representation described in \autoref{chap:DOM}, several semi -discrete space forms of 
     
    3536The terms QSR, BBC, BBL and DMP are optional. 
    3637The external forcings and parameterisations require complex inputs and complex calculations 
    37 (\eg bulk formulae, estimation of mixing coefficients) that are carried out in the SBC, 
     38(\eg\ bulk formulae, estimation of mixing coefficients) that are carried out in the SBC, 
    3839LDF and ZDF modules and described in \autoref{chap:SBC}, \autoref{chap:LDF} and 
    3940\autoref{chap:ZDF}, respectively. 
     
    4748associated modules \mdl{eosbn2} and \mdl{phycst}). 
    4849 
    49 The different options available to the user are managed by namelist logicals or CPP keys. 
     50The different options available to the user are managed by namelist logicals. 
    5051For each equation term \textit{TTT}, the namelist logicals are \textit{ln\_traTTT\_xxx}, 
    5152where \textit{xxx} is a 3 or 4 letter acronym corresponding to each optional scheme. 
    52 The CPP key (when it exists) is \key{traTTT}. 
    5353The equivalent code can be found in the \textit{traTTT} or \textit{traTTT\_xxx} module, 
    5454in the \path{./src/OCE/TRA} directory. 
    5555 
    5656The user has the option of extracting each tendency term on the RHS of the tracer equation for output 
    57 (\np{ln\_tra\_trd} or \np{ln\_tra\_mxl}~\forcode{= .true.}), as described in \autoref{chap:DIA}. 
     57(\np{ln\_tra\_trd} or \np{ln\_tra\_mxl}\forcode{=.true.}), as described in \autoref{chap:DIA}. 
    5858 
    5959% ================================================================ 
    6060% Tracer Advection 
    6161% ================================================================ 
    62 \section{Tracer advection (\protect\mdl{traadv})} 
     62\section[Tracer advection (\textit{traadv.F90})] 
     63{Tracer advection (\protect\mdl{traadv})} 
    6364\label{sec:TRA_adv} 
    6465%------------------------------------------namtra_adv----------------------------------------------------- 
    6566 
    66 \nlst{namtra_adv} 
     67\begin{listing} 
     68  \nlst{namtra_adv} 
     69  \caption{\texttt{namtra\_adv}} 
     70  \label{lst:namtra_adv} 
     71\end{listing} 
    6772%------------------------------------------------------------------------------------------------------------- 
    6873 
    69 When considered (\ie when \np{ln\_traadv\_NONE} is not set to \forcode{.true.}), 
     74When considered (\ie\ when \np{ln\_traadv\_OFF} is not set to \forcode{.true.}), 
    7075the advection tendency of a tracer is expressed in flux form, 
    71 \ie as the divergence of the advective fluxes. 
     76\ie\ as the divergence of the advective fluxes. 
    7277Its discrete expression is given by : 
    7378\begin{equation} 
    74   \label{eq:tra_adv} 
     79  \label{eq:TRA_adv} 
    7580  ADV_\tau = - \frac{1}{b_t} \Big(   \delta_i [ e_{2u} \, e_{3u} \; u \; \tau_u] 
    7681                                   + \delta_j [ e_{1v} \, e_{3v} \; v \; \tau_v] \Big) 
     
    7883\end{equation} 
    7984where $\tau$ is either T or S, and $b_t = e_{1t} \, e_{2t} \, e_{3t}$ is the volume of $T$-cells. 
    80 The flux form in \autoref{eq:tra_adv} implicitly requires the use of the continuity equation. 
     85The flux form in \autoref{eq:TRA_adv} implicitly requires the use of the continuity equation. 
    8186Indeed, it is obtained by using the following equality: $\nabla \cdot (\vect U \, T) = \vect U \cdot \nabla T$ which 
    8287results from the use of the continuity equation, $\partial_t e_3 + e_3 \; \nabla \cdot \vect U = 0$ 
    83 (which reduces to $\nabla \cdot \vect U = 0$ in linear free surface, \ie \np{ln\_linssh}~\forcode{= .true.}). 
     88(which reduces to $\nabla \cdot \vect U = 0$ in linear free surface, \ie\ \np{ln\_linssh}\forcode{=.true.}). 
    8489Therefore it is of paramount importance to design the discrete analogue of the advection tendency so that 
    8590it is consistent with the continuity equation in order to enforce the conservation properties of 
    8691the continuous equations. 
    87 In other words, by setting $\tau = 1$ in (\autoref{eq:tra_adv}) we recover the discrete form of 
     92In other words, by setting $\tau = 1$ in (\autoref{eq:TRA_adv}) we recover the discrete form of 
    8893the continuity equation which is used to calculate the vertical velocity. 
    8994%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    9095\begin{figure}[!t] 
    91   \begin{center} 
    92     \includegraphics[]{Fig_adv_scheme} 
    93     \caption{ 
    94       \protect\label{fig:adv_scheme} 
    95       Schematic representation of some ways used to evaluate the tracer value at $u$-point and 
    96       the amount of tracer exchanged between two neighbouring grid points. 
    97       Upsteam biased scheme (ups): 
    98       the upstream value is used and the black area is exchanged. 
    99       Piecewise parabolic method (ppm): 
    100       a parabolic interpolation is used and the black and dark grey areas are exchanged. 
    101       Monotonic upstream scheme for conservative laws (muscl): 
    102       a parabolic interpolation is used and black, dark grey and grey areas are exchanged. 
    103       Second order scheme (cen2): 
    104       the mean value is used and black, dark grey, grey and light grey areas are exchanged. 
    105       Note that this illustration does not include the flux limiter used in ppm and muscl schemes. 
    106     } 
    107   \end{center} 
     96  \centering 
     97  \includegraphics[width=\textwidth]{Fig_adv_scheme} 
     98  \caption[Ways to evaluate the tracer value and the amount of tracer exchanged]{ 
     99    Schematic representation of some ways used to evaluate the tracer value at $u$-point and 
     100    the amount of tracer exchanged between two neighbouring grid points. 
     101    Upsteam biased scheme (ups): 
     102    the upstream value is used and the black area is exchanged. 
     103    Piecewise parabolic method (ppm): 
     104    a parabolic interpolation is used and the black and dark grey areas are exchanged. 
     105    Monotonic upstream scheme for conservative laws (muscl): 
     106    a parabolic interpolation is used and black, dark grey and grey areas are exchanged. 
     107    Second order scheme (cen2): 
     108    the mean value is used and black, dark grey, grey and light grey areas are exchanged. 
     109    Note that this illustration does not include the flux limiter used in ppm and muscl schemes.} 
     110  \label{fig:TRA_adv_scheme} 
    108111\end{figure} 
    109112%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    110113 
    111 The key difference between the advection schemes available in \NEMO is the choice made in space and 
     114The key difference between the advection schemes available in \NEMO\ is the choice made in space and 
    112115time interpolation to define the value of the tracer at the velocity points 
    113 (\autoref{fig:adv_scheme}). 
     116(\autoref{fig:TRA_adv_scheme}). 
    114117 
    115118Along solid lateral and bottom boundaries a zero tracer flux is automatically specified, 
     
    119122\begin{description} 
    120123\item[linear free surface:] 
    121   (\np{ln\_linssh}~\forcode{= .true.}) 
     124  (\np{ln\_linssh}\forcode{=.true.}) 
    122125  the first level thickness is constant in time: 
    123126  the vertical boundary condition is applied at the fixed surface $z = 0$ rather than on 
    124127  the moving surface $z = \eta$. 
    125128  There is a non-zero advective flux which is set for all advection schemes as 
    126   $\tau_w|_{k = 1/2} = T_{k = 1}$, \ie the product of surface velocity (at $z = 0$) by 
     129  $\tau_w|_{k = 1/2} = T_{k = 1}$, \ie\ the product of surface velocity (at $z = 0$) by 
    127130  the first level tracer value. 
    128131\item[non-linear free surface:] 
    129   (\np{ln\_linssh}~\forcode{= .false.}) 
     132  (\np{ln\_linssh}\forcode{=.false.}) 
    130133  convergence/divergence in the first ocean level moves the free surface up/down. 
    131134  There is no tracer advection through it so that the advective fluxes through the surface are also zero. 
     
    136139Nevertheless, in the latter case, it is achieved to a good approximation since 
    137140the non-conservative term is the product of the time derivative of the tracer and the free surface height, 
    138 two quantities that are not correlated \citep{Roullet_Madec_JGR00, Griffies_al_MWR01, Campin2004}. 
    139  
    140 The velocity field that appears in (\autoref{eq:tra_adv} and \autoref{eq:tra_adv_zco}) is 
    141 the centred (\textit{now}) \textit{effective} ocean velocity, \ie the \textit{eulerian} velocity 
     141two quantities that are not correlated \citep{roullet.madec_JGR00, griffies.pacanowski.ea_MWR01, campin.adcroft.ea_OM04}. 
     142 
     143The velocity field that appears in (\autoref{eq:TRA_adv} is 
     144the centred (\textit{now}) \textit{effective} ocean velocity, \ie\ the \textit{eulerian} velocity 
    142145(see \autoref{chap:DYN}) plus the eddy induced velocity (\textit{eiv}) and/or 
    143146the mixed layer eddy induced velocity (\textit{eiv}) when those parameterisations are used 
     
    148151Conservative Laws scheme (MUSCL), a $3^{rd}$ Upstream Biased Scheme (UBS, also often called UP3), 
    149152and a Quadratic Upstream Interpolation for Convective Kinematics with Estimated Streaming Terms scheme (QUICKEST). 
    150 The choice is made in the \ngn{namtra\_adv} namelist, by setting to \forcode{.true.} one of 
     153The choice is made in the \nam{tra\_adv} namelist, by setting to \forcode{.true.} one of 
    151154the logicals \textit{ln\_traadv\_xxx}. 
    152155The corresponding code can be found in the \textit{traadv\_xxx.F90} module, where 
    153156\textit{xxx} is a 3 or 4 letter acronym corresponding to each scheme. 
    154 By default (\ie in the reference namelist, \textit{namelist\_ref}), all the logicals are set to \forcode{.false.}. 
     157By default (\ie\ in the reference namelist, \textit{namelist\_ref}), all the logicals are set to \forcode{.false.}. 
    155158If the user does not select an advection scheme in the configuration namelist (\textit{namelist\_cfg}), 
    156159the tracers will \textit{not} be advected! 
     
    183186%        2nd and 4th order centred schemes 
    184187% ------------------------------------------------------------------------------------------------------------- 
    185 \subsection{CEN: Centred scheme (\protect\np{ln\_traadv\_cen}~\forcode{= .true.})} 
     188\subsection[CEN: Centred scheme (\forcode{ln_traadv_cen=.true.})] 
     189{CEN: Centred scheme (\protect\np{ln\_traadv\_cen}\forcode{=.true.})} 
    186190\label{subsec:TRA_adv_cen} 
    187191 
    188 %        2nd order centred scheme   
    189  
    190 The centred advection scheme (CEN) is used when \np{ln\_traadv\_cen}~\forcode{= .true.}. 
     192%        2nd order centred scheme 
     193 
     194The centred advection scheme (CEN) is used when \np{ln\_traadv\_cen}\forcode{=.true.}. 
    191195Its order ($2^{nd}$ or $4^{th}$) can be chosen independently on horizontal (iso-level) and vertical direction by 
    192196setting \np{nn\_cen\_h} and \np{nn\_cen\_v} to $2$ or $4$. 
     
    197201For example, in the $i$-direction : 
    198202\begin{equation} 
    199   \label{eq:tra_adv_cen2} 
     203  \label{eq:TRA_adv_cen2} 
    200204  \tau_u^{cen2} = \overline T ^{i + 1/2} 
    201205\end{equation} 
    202206 
    203 CEN2 is non diffusive (\ie it conserves the tracer variance, $\tau^2$) but dispersive 
    204 (\ie it may create false extrema). 
     207CEN2 is non diffusive (\ie\ it conserves the tracer variance, $\tau^2$) but dispersive 
     208(\ie\ it may create false extrema). 
    205209It is therefore notoriously noisy and must be used in conjunction with an explicit diffusion operator to 
    206210produce a sensible solution. 
    207211The associated time-stepping is performed using a leapfrog scheme in conjunction with an Asselin time-filter, 
    208 so $T$ in (\autoref{eq:tra_adv_cen2}) is the \textit{now} tracer value. 
     212so $T$ in (\autoref{eq:TRA_adv_cen2}) is the \textit{now} tracer value. 
    209213 
    210214Note that using the CEN2, the overall tracer advection is of second order accuracy since 
    211 both (\autoref{eq:tra_adv}) and (\autoref{eq:tra_adv_cen2}) have this order of accuracy. 
    212  
    213 %        4nd order centred scheme   
     215both (\autoref{eq:TRA_adv}) and (\autoref{eq:TRA_adv_cen2}) have this order of accuracy. 
     216 
     217%        4nd order centred scheme 
    214218 
    215219In the $4^{th}$ order formulation (CEN4), tracer values are evaluated at u- and v-points as 
     
    217221For example, in the $i$-direction: 
    218222\begin{equation} 
    219   \label{eq:tra_adv_cen4} 
     223  \label{eq:TRA_adv_cen4} 
    220224  \tau_u^{cen4} = \overline{T - \frac{1}{6} \, \delta_i \Big[ \delta_{i + 1/2}[T] \, \Big]}^{\,i + 1/2} 
    221225\end{equation} 
    222 In the vertical direction (\np{nn\_cen\_v}~\forcode{= 4}), 
    223 a $4^{th}$ COMPACT interpolation has been prefered \citep{Demange_PhD2014}. 
     226In the vertical direction (\np{nn\_cen\_v}\forcode{=4}), 
     227a $4^{th}$ COMPACT interpolation has been prefered \citep{demange_phd14}. 
    224228In the COMPACT scheme, both the field and its derivative are interpolated, which leads, after a matrix inversion, 
    225 spectral characteristics similar to schemes of higher order \citep{Lele_JCP1992}.  
     229spectral characteristics similar to schemes of higher order \citep{lele_JCP92}. 
    226230 
    227231Strictly speaking, the CEN4 scheme is not a $4^{th}$ order advection scheme but 
    228232a $4^{th}$ order evaluation of advective fluxes, 
    229 since the divergence of advective fluxes \autoref{eq:tra_adv} is kept at $2^{nd}$ order. 
     233since the divergence of advective fluxes \autoref{eq:TRA_adv} is kept at $2^{nd}$ order. 
    230234The expression \textit{$4^{th}$ order scheme} used in oceanographic literature is usually associated with 
    231235the scheme presented here. 
     
    235239 
    236240A direct consequence of the pseudo-fourth order nature of the scheme is that it is not non-diffusive, 
    237 \ie the global variance of a tracer is not preserved using CEN4. 
     241\ie\ the global variance of a tracer is not preserved using CEN4. 
    238242Furthermore, it must be used in conjunction with an explicit diffusion operator to produce a sensible solution. 
    239243As in CEN2 case, the time-stepping is performed using a leapfrog scheme in conjunction with an Asselin time-filter, 
    240 so $T$ in (\autoref{eq:tra_adv_cen4}) is the \textit{now} tracer. 
     244so $T$ in (\autoref{eq:TRA_adv_cen4}) is the \textit{now} tracer. 
    241245 
    242246At a $T$-grid cell adjacent to a boundary (coastline, bottom and surface), 
     
    248252 
    249253% ------------------------------------------------------------------------------------------------------------- 
    250 %        FCT scheme   
    251 % ------------------------------------------------------------------------------------------------------------- 
    252 \subsection{FCT: Flux Corrected Transport scheme (\protect\np{ln\_traadv\_fct}~\forcode{= .true.})} 
     254%        FCT scheme 
     255% ------------------------------------------------------------------------------------------------------------- 
     256\subsection[FCT: Flux Corrected Transport scheme (\forcode{ln_traadv_fct=.true.})] 
     257{FCT: Flux Corrected Transport scheme (\protect\np{ln\_traadv\_fct}\forcode{=.true.})} 
    253258\label{subsec:TRA_adv_tvd} 
    254259 
    255 The Flux Corrected Transport schemes (FCT) is used when \np{ln\_traadv\_fct}~\forcode{= .true.}. 
     260The Flux Corrected Transport schemes (FCT) is used when \np{ln\_traadv\_fct}\forcode{=.true.}. 
    256261Its order ($2^{nd}$ or $4^{th}$) can be chosen independently on horizontal (iso-level) and vertical direction by 
    257262setting \np{nn\_fct\_h} and \np{nn\_fct\_v} to $2$ or $4$. 
     
    262267For example, in the $i$-direction : 
    263268\begin{equation} 
    264   \label{eq:tra_adv_fct} 
     269  \label{eq:TRA_adv_fct} 
    265270  \begin{split} 
    266271    \tau_u^{ups} &= 
     
    275280where $c_u$ is a flux limiter function taking values between 0 and 1. 
    276281The FCT order is the one of the centred scheme used 
    277 (\ie it depends on the setting of \np{nn\_fct\_h} and \np{nn\_fct\_v}). 
     282(\ie\ it depends on the setting of \np{nn\_fct\_h} and \np{nn\_fct\_v}). 
    278283There exist many ways to define $c_u$, each corresponding to a different FCT scheme. 
    279 The one chosen in \NEMO is described in \citet{Zalesak_JCP79}. 
     284The one chosen in \NEMO\ is described in \citet{zalesak_JCP79}. 
    280285$c_u$ only departs from $1$ when the advective term produces a local extremum in the tracer field. 
    281286The resulting scheme is quite expensive but \textit{positive}. 
    282287It can be used on both active and passive tracers. 
    283 A comparison of FCT-2 with MUSCL and a MPDATA scheme can be found in \citet{Levy_al_GRL01}. 
    284  
    285 An additional option has been added controlled by \np{nn\_fct\_zts}. 
    286 By setting this integer to a value larger than zero, 
    287 a $2^{nd}$ order FCT scheme is used on both horizontal and vertical direction, but on the latter, 
    288 a split-explicit time stepping is used, with a number of sub-timestep equals to \np{nn\_fct\_zts}. 
    289 This option can be useful when the size of the timestep is limited by vertical advection \citep{Lemarie_OM2015}. 
    290 Note that in this case, a similar split-explicit time stepping should be used on vertical advection of momentum to 
    291 insure a better stability (see \autoref{subsec:DYN_zad}). 
    292  
    293 For stability reasons (see \autoref{chap:STP}), 
    294 $\tau_u^{cen}$ is evaluated in (\autoref{eq:tra_adv_fct}) using the \textit{now} tracer while 
     288A comparison of FCT-2 with MUSCL and a MPDATA scheme can be found in \citet{levy.estublier.ea_GRL01}. 
     289 
     290 
     291For stability reasons (see \autoref{chap:TD}), 
     292$\tau_u^{cen}$ is evaluated in (\autoref{eq:TRA_adv_fct}) using the \textit{now} tracer while 
    295293$\tau_u^{ups}$ is evaluated using the \textit{before} tracer. 
    296294In other words, the advective part of the scheme is time stepped with a leap-frog scheme 
     
    298296 
    299297% ------------------------------------------------------------------------------------------------------------- 
    300 %        MUSCL scheme   
    301 % ------------------------------------------------------------------------------------------------------------- 
    302 \subsection{MUSCL: Monotone Upstream Scheme for Conservative Laws (\protect\np{ln\_traadv\_mus}~\forcode{= .true.})} 
     298%        MUSCL scheme 
     299% ------------------------------------------------------------------------------------------------------------- 
     300\subsection[MUSCL: Monotone Upstream Scheme for Conservative Laws (\forcode{ln_traadv_mus=.true.})] 
     301{MUSCL: Monotone Upstream Scheme for Conservative Laws (\protect\np{ln\_traadv\_mus}\forcode{=.true.})} 
    303302\label{subsec:TRA_adv_mus} 
    304303 
    305 The Monotone Upstream Scheme for Conservative Laws (MUSCL) is used when \np{ln\_traadv\_mus}~\forcode{= .true.}. 
     304The Monotone Upstream Scheme for Conservative Laws (MUSCL) is used when \np{ln\_traadv\_mus}\forcode{=.true.}. 
    306305MUSCL implementation can be found in the \mdl{traadv\_mus} module. 
    307306 
    308 MUSCL has been first implemented in \NEMO by \citet{Levy_al_GRL01}. 
     307MUSCL has been first implemented in \NEMO\ by \citet{levy.estublier.ea_GRL01}. 
    309308In its formulation, the tracer at velocity points is evaluated assuming a linear tracer variation between 
    310 two $T$-points (\autoref{fig:adv_scheme}). 
     309two $T$-points (\autoref{fig:TRA_adv_scheme}). 
    311310For example, in the $i$-direction : 
    312311\begin{equation} 
    313   % \label{eq:tra_adv_mus} 
     312  % \label{eq:TRA_adv_mus} 
    314313  \tau_u^{mus} = \lt\{ 
    315314  \begin{split} 
     
    331330This choice ensure the \textit{positive} character of the scheme. 
    332331In addition, fluxes round a grid-point where a runoff is applied can optionally be computed using upstream fluxes 
    333 (\np{ln\_mus\_ups}~\forcode{= .true.}). 
    334  
    335 % ------------------------------------------------------------------------------------------------------------- 
    336 %        UBS scheme   
    337 % ------------------------------------------------------------------------------------------------------------- 
    338 \subsection{UBS a.k.a. UP3: Upstream-Biased Scheme (\protect\np{ln\_traadv\_ubs}~\forcode{= .true.})} 
     332(\np{ln\_mus\_ups}\forcode{=.true.}). 
     333 
     334% ------------------------------------------------------------------------------------------------------------- 
     335%        UBS scheme 
     336% ------------------------------------------------------------------------------------------------------------- 
     337\subsection[UBS a.k.a. UP3: Upstream-Biased Scheme (\forcode{ln_traadv_ubs=.true.})] 
     338{UBS a.k.a. UP3: Upstream-Biased Scheme (\protect\np{ln\_traadv\_ubs}\forcode{=.true.})} 
    339339\label{subsec:TRA_adv_ubs} 
    340340 
    341 The Upstream-Biased Scheme (UBS) is used when \np{ln\_traadv\_ubs}~\forcode{= .true.}. 
     341The Upstream-Biased Scheme (UBS) is used when \np{ln\_traadv\_ubs}\forcode{=.true.}. 
    342342UBS implementation can be found in the \mdl{traadv\_mus} module. 
    343343 
     
    347347For example, in the $i$-direction: 
    348348\begin{equation} 
    349   \label{eq:tra_adv_ubs} 
     349  \label{eq:TRA_adv_ubs} 
    350350  \tau_u^{ubs} = \overline T ^{i + 1/2} - \frac{1}{6} 
    351351    \begin{cases} 
     
    358358 
    359359This results in a dissipatively dominant (i.e. hyper-diffusive) truncation error 
    360 \citep{Shchepetkin_McWilliams_OM05}. 
    361 The overall performance of the advection scheme is similar to that reported in \cite{Farrow1995}. 
     360\citep{shchepetkin.mcwilliams_OM05}. 
     361The overall performance of the advection scheme is similar to that reported in \cite{farrow.stevens_JPO95}. 
    362362It is a relatively good compromise between accuracy and smoothness. 
    363363Nevertheless the scheme is not \textit{positive}, meaning that false extrema are permitted, 
     
    367367The intrinsic diffusion of UBS makes its use risky in the vertical direction where 
    368368the control of artificial diapycnal fluxes is of paramount importance 
    369 \citep{Shchepetkin_McWilliams_OM05, Demange_PhD2014}. 
     369\citep{shchepetkin.mcwilliams_OM05, demange_phd14}. 
    370370Therefore the vertical flux is evaluated using either a $2^nd$ order FCT scheme or a $4^th$ order COMPACT scheme 
    371 (\np{nn\_cen\_v}~\forcode{= 2 or 4}). 
    372  
    373 For stability reasons (see \autoref{chap:STP}), the first term  in \autoref{eq:tra_adv_ubs} 
     371(\np{nn\_ubs\_v}\forcode{=2 or 4}). 
     372 
     373For stability reasons (see \autoref{chap:TD}), the first term  in \autoref{eq:TRA_adv_ubs} 
    374374(which corresponds to a second order centred scheme) 
    375375is evaluated using the \textit{now} tracer (centred in time) while the second term 
    376376(which is the diffusive part of the scheme), 
    377377is evaluated using the \textit{before} tracer (forward in time). 
    378 This choice is discussed by \citet{Webb_al_JAOT98} in the context of the QUICK advection scheme. 
     378This choice is discussed by \citet{webb.de-cuevas.ea_JAOT98} in the context of the QUICK advection scheme. 
    379379UBS and QUICK schemes only differ by one coefficient. 
    380 Replacing 1/6 with 1/8 in \autoref{eq:tra_adv_ubs} leads to the QUICK advection scheme \citep{Webb_al_JAOT98}. 
     380Replacing 1/6 with 1/8 in \autoref{eq:TRA_adv_ubs} leads to the QUICK advection scheme \citep{webb.de-cuevas.ea_JAOT98}. 
    381381This option is not available through a namelist parameter, since the 1/6 coefficient is hard coded. 
    382382Nevertheless it is quite easy to make the substitution in the \mdl{traadv\_ubs} module and obtain a QUICK scheme. 
    383383 
    384 Note that it is straightforward to rewrite \autoref{eq:tra_adv_ubs} as follows: 
     384Note that it is straightforward to rewrite \autoref{eq:TRA_adv_ubs} as follows: 
    385385\begin{gather} 
    386   \label{eq:traadv_ubs2} 
     386  \label{eq:TRA_adv_ubs2} 
    387387  \tau_u^{ubs} = \tau_u^{cen4} + \frac{1}{12} 
    388388    \begin{cases} 
     
    391391    \end{cases} 
    392392  \intertext{or equivalently} 
    393   % \label{eq:traadv_ubs2b} 
     393  % \label{eq:TRA_adv_ubs2b} 
    394394  u_{i + 1/2} \ \tau_u^{ubs} = u_{i + 1/2} \, \overline{T - \frac{1}{6} \, \delta_i \Big[ \delta_{i + 1/2}[T] \Big]}^{\,i + 1/2} 
    395395                             - \frac{1}{2} |u|_{i + 1/2} \, \frac{1}{6} \, \delta_{i + 1/2} [\tau"_i] \nonumber 
    396396\end{gather} 
    397397 
    398 \autoref{eq:traadv_ubs2} has several advantages. 
     398\autoref{eq:TRA_adv_ubs2} has several advantages. 
    399399Firstly, it clearly reveals that the UBS scheme is based on the fourth order scheme to which 
    400400an upstream-biased diffusion term is added. 
    401401Secondly, this emphasises that the $4^{th}$ order part (as well as the $2^{nd}$ order part as stated above) has to 
    402 be evaluated at the \textit{now} time step using \autoref{eq:tra_adv_ubs}. 
     402be evaluated at the \textit{now} time step using \autoref{eq:TRA_adv_ubs}. 
    403403Thirdly, the diffusion term is in fact a biharmonic operator with an eddy coefficient which 
    404404is simply proportional to the velocity: $A_u^{lm} = \frac{1}{12} \, {e_{1u}}^3 \, |u|$. 
    405 Note the current version of NEMO uses the computationally more efficient formulation \autoref{eq:tra_adv_ubs}. 
    406  
    407 % ------------------------------------------------------------------------------------------------------------- 
    408 %        QCK scheme   
    409 % ------------------------------------------------------------------------------------------------------------- 
    410 \subsection{QCK: QuiCKest scheme (\protect\np{ln\_traadv\_qck}~\forcode{= .true.})} 
     405Note the current version of \NEMO\ uses the computationally more efficient formulation \autoref{eq:TRA_adv_ubs}. 
     406 
     407% ------------------------------------------------------------------------------------------------------------- 
     408%        QCK scheme 
     409% ------------------------------------------------------------------------------------------------------------- 
     410\subsection[QCK: QuiCKest scheme (\forcode{ln_traadv_qck=.true.})] 
     411{QCK: QuiCKest scheme (\protect\np{ln\_traadv\_qck}\forcode{=.true.})} 
    411412\label{subsec:TRA_adv_qck} 
    412413 
    413414The Quadratic Upstream Interpolation for Convective Kinematics with Estimated Streaming Terms (QUICKEST) scheme 
    414 proposed by \citet{Leonard1979} is used when \np{ln\_traadv\_qck}~\forcode{= .true.}. 
     415proposed by \citet{leonard_CMAME79} is used when \np{ln\_traadv\_qck}\forcode{=.true.}. 
    415416QUICKEST implementation can be found in the \mdl{traadv\_qck} module. 
    416417 
    417418QUICKEST is the third order Godunov scheme which is associated with the ULTIMATE QUICKEST limiter 
    418 \citep{Leonard1991}. 
    419 It has been implemented in NEMO by G. Reffray (MERCATOR-ocean) and can be found in the \mdl{traadv\_qck} module. 
     419\citep{leonard_CMAME91}. 
     420It has been implemented in \NEMO\ by G. Reffray (MERCATOR-ocean) and can be found in the \mdl{traadv\_qck} module. 
    420421The resulting scheme is quite expensive but \textit{positive}. 
    421422It can be used on both active and passive tracers. 
     
    431432% Tracer Lateral Diffusion 
    432433% ================================================================ 
    433 \section{Tracer lateral diffusion (\protect\mdl{traldf})} 
     434\section[Tracer lateral diffusion (\textit{traldf.F90})] 
     435{Tracer lateral diffusion (\protect\mdl{traldf})} 
    434436\label{sec:TRA_ldf} 
    435437%-----------------------------------------nam_traldf------------------------------------------------------ 
    436438 
    437 \nlst{namtra_ldf} 
     439\begin{listing} 
     440  \nlst{namtra_ldf} 
     441  \caption{\texttt{namtra\_ldf}} 
     442  \label{lst:namtra_ldf} 
     443\end{listing} 
    438444%------------------------------------------------------------------------------------------------------------- 
    439   
    440 Options are defined through the \ngn{namtra\_ldf} namelist variables. 
    441 They are regrouped in four items, allowing to specify  
     445 
     446Options are defined through the \nam{tra\_ldf} namelist variables. 
     447They are regrouped in four items, allowing to specify 
    442448$(i)$   the type of operator used (none, laplacian, bilaplacian), 
    443449$(ii)$  the direction along which the operator acts (iso-level, horizontal, iso-neutral), 
    444 $(iii)$ some specific options related to the rotated operators (\ie non-iso-level operator), and 
     450$(iii)$ some specific options related to the rotated operators (\ie\ non-iso-level operator), and 
    445451$(iv)$  the specification of eddy diffusivity coefficient (either constant or variable in space and time). 
    446452Item $(iv)$ will be described in \autoref{chap:LDF}. 
     
    450456 
    451457The lateral diffusion of tracers is evaluated using a forward scheme, 
    452 \ie the tracers appearing in its expression are the \textit{before} tracers in time, 
     458\ie\ the tracers appearing in its expression are the \textit{before} tracers in time, 
    453459except for the pure vertical component that appears when a rotation tensor is used. 
    454 This latter component is solved implicitly together with the vertical diffusion term (see \autoref{chap:STP}). 
    455 When \np{ln\_traldf\_msc}~\forcode{= .true.}, a Method of Stabilizing Correction is used in which 
    456 the pure vertical component is split into an explicit and an implicit part \citep{Lemarie_OM2012}. 
     460This latter component is solved implicitly together with the vertical diffusion term (see \autoref{chap:TD}). 
     461When \np{ln\_traldf\_msc}\forcode{=.true.}, a Method of Stabilizing Correction is used in which 
     462the pure vertical component is split into an explicit and an implicit part \citep{lemarie.debreu.ea_OM12}. 
    457463 
    458464% ------------------------------------------------------------------------------------------------------------- 
    459465%        Type of operator 
    460466% ------------------------------------------------------------------------------------------------------------- 
    461 \subsection[Type of operator (\protect\np{ln\_traldf}\{\_NONE,\_lap,\_blp\}\})]{Type of operator (\protect\np{ln\_traldf\_NONE}, \protect\np{ln\_traldf\_lap}, or \protect\np{ln\_traldf\_blp}) }  
     467\subsection[Type of operator (\texttt{ln\_traldf}\{\texttt{\_OFF,\_lap,\_blp}\})] 
     468{Type of operator (\protect\np{ln\_traldf\_OFF}, \protect\np{ln\_traldf\_lap}, or \protect\np{ln\_traldf\_blp}) } 
    462469\label{subsec:TRA_ldf_op} 
    463470 
     
    465472 
    466473\begin{description} 
    467 \item[\np{ln\_traldf\_NONE}~\forcode{= .true.}:] 
     474\item[\np{ln\_traldf\_OFF}\forcode{=.true.}:] 
    468475  no operator selected, the lateral diffusive tendency will not be applied to the tracer equation. 
    469476  This option can be used when the selected advection scheme is diffusive enough (MUSCL scheme for example). 
    470 \item[\np{ln\_traldf\_lap}~\forcode{= .true.}:] 
     477\item[\np{ln\_traldf\_lap}\forcode{=.true.}:] 
    471478  a laplacian operator is selected. 
    472   This harmonic operator takes the following expression:  $\mathpzc{L}(T) = \nabla \cdot A_{ht} \; \nabla T $, 
     479  This harmonic operator takes the following expression:  $\mathcal{L}(T) = \nabla \cdot A_{ht} \; \nabla T $, 
    473480  where the gradient operates along the selected direction (see \autoref{subsec:TRA_ldf_dir}), 
    474481  and $A_{ht}$ is the eddy diffusivity coefficient expressed in $m^2/s$ (see \autoref{chap:LDF}). 
    475 \item[\np{ln\_traldf\_blp}~\forcode{= .true.}]: 
     482\item[\np{ln\_traldf\_blp}\forcode{=.true.}]: 
    476483  a bilaplacian operator is selected. 
    477484  This biharmonic operator takes the following expression: 
    478   $\mathpzc{B} = - \mathpzc{L}(\mathpzc{L}(T)) = - \nabla \cdot b \nabla (\nabla \cdot b \nabla T)$ 
     485  $\mathcal{B} = - \mathcal{L}(\mathcal{L}(T)) = - \nabla \cdot b \nabla (\nabla \cdot b \nabla T)$ 
    479486  where the gradient operats along the selected direction, 
    480487  and $b^2 = B_{ht}$ is the eddy diffusivity coefficient expressed in $m^4/s$ (see \autoref{chap:LDF}). 
     
    486493minimizing the impact on the larger scale features. 
    487494The main difference between the two operators is the scale selectiveness. 
    488 The bilaplacian damping time (\ie its spin down time) scales like $\lambda^{-4}$ for 
     495The bilaplacian damping time (\ie\ its spin down time) scales like $\lambda^{-4}$ for 
    489496disturbances of wavelength $\lambda$ (so that short waves damped more rapidelly than long ones), 
    490497whereas the laplacian damping time scales only like $\lambda^{-2}$. 
     
    493500%        Direction of action 
    494501% ------------------------------------------------------------------------------------------------------------- 
    495 \subsection[Action direction (\protect\np{ln\_traldf}\{\_lev,\_hor,\_iso,\_triad\})]{Direction of action (\protect\np{ln\_traldf\_lev}, \protect\np{ln\_traldf\_hor}, \protect\np{ln\_traldf\_iso}, or \protect\np{ln\_traldf\_triad}) }  
     502\subsection[Action direction (\texttt{ln\_traldf}\{\texttt{\_lev,\_hor,\_iso,\_triad}\})] 
     503{Direction of action (\protect\np{ln\_traldf\_lev}, \protect\np{ln\_traldf\_hor}, \protect\np{ln\_traldf\_iso}, or \protect\np{ln\_traldf\_triad}) } 
    496504\label{subsec:TRA_ldf_dir} 
    497505 
    498506The choice of a direction of action determines the form of operator used. 
    499507The operator is a simple (re-entrant) laplacian acting in the (\textbf{i},\textbf{j}) plane when 
    500 iso-level option is used (\np{ln\_traldf\_lev}~\forcode{= .true.}) or 
    501 when a horizontal (\ie geopotential) operator is demanded in \textit{z}-coordinate 
    502 (\np{ln\_traldf\_hor} and \np{ln\_zco} equal \forcode{.true.}). 
     508iso-level option is used (\np{ln\_traldf\_lev}\forcode{=.true.}) or 
     509when a horizontal (\ie\ geopotential) operator is demanded in \textit{z}-coordinate 
     510(\np{ln\_traldf\_hor} and \np{ln\_zco}\forcode{=.true.}). 
    503511The associated code can be found in the \mdl{traldf\_lap\_blp} module. 
    504512The operator is a rotated (re-entrant) laplacian when 
    505513the direction along which it acts does not coincide with the iso-level surfaces, 
    506514that is when standard or triad iso-neutral option is used 
    507 (\np{ln\_traldf\_iso} or \np{ln\_traldf\_triad} equals \forcode{.true.}, 
     515(\np{ln\_traldf\_iso} or \np{ln\_traldf\_triad} = \forcode{.true.}, 
    508516see \mdl{traldf\_iso} or \mdl{traldf\_triad} module, resp.), or 
    509 when a horizontal (\ie geopotential) operator is demanded in \textit{s}-coordinate 
    510 (\np{ln\_traldf\_hor} and \np{ln\_sco} equal \forcode{.true.}) 
     517when a horizontal (\ie\ geopotential) operator is demanded in \textit{s}-coordinate 
     518(\np{ln\_traldf\_hor} and \np{ln\_sco} = \forcode{.true.}) 
    511519\footnote{In this case, the standard iso-neutral operator will be automatically selected}. 
    512520In that case, a rotation is applied to the gradient(s) that appears in the operator so that 
     
    519527%       iso-level operator 
    520528% ------------------------------------------------------------------------------------------------------------- 
    521 \subsection{Iso-level (bi -)laplacian operator ( \protect\np{ln\_traldf\_iso}) } 
     529\subsection[Iso-level (bi-)laplacian operator (\texttt{ln\_traldf\_iso})] 
     530{Iso-level (bi-)laplacian operator ( \protect\np{ln\_traldf\_iso})} 
    522531\label{subsec:TRA_ldf_lev} 
    523532 
    524 The laplacian diffusion operator acting along the model (\textit{i,j})-surfaces is given by:  
    525 \begin{equation} 
    526   \label{eq:tra_ldf_lap} 
     533The laplacian diffusion operator acting along the model (\textit{i,j})-surfaces is given by: 
     534\begin{equation} 
     535  \label{eq:TRA_ldf_lap} 
    527536  D_t^{lT} = \frac{1}{b_t} \Bigg(   \delta_{i} \lt[ A_u^{lT} \; \frac{e_{2u} \, e_{3u}}{e_{1u}} \; \delta_{i + 1/2} [T] \rt] 
    528537                                  + \delta_{j} \lt[ A_v^{lT} \; \frac{e_{1v} \, e_{3v}}{e_{2v}} \; \delta_{j + 1/2} [T] \rt] \Bigg) 
     
    531540where zero diffusive fluxes is assumed across solid boundaries, 
    532541first (and third in bilaplacian case) horizontal tracer derivative are masked. 
    533 It is implemented in the \rou{traldf\_lap} subroutine found in the \mdl{traldf\_lap} module. 
    534 The module also contains \rou{traldf\_blp}, the subroutine calling twice \rou{traldf\_lap} in order to 
     542It is implemented in the \rou{tra\_ldf\_lap} subroutine found in the \mdl{traldf\_lap\_blp} module. 
     543The module also contains \rou{tra\_ldf\_blp}, the subroutine calling twice \rou{tra\_ldf\_lap} in order to 
    535544compute the iso-level bilaplacian operator. 
    536545 
    537546It is a \textit{horizontal} operator (\ie acting along geopotential surfaces) in 
    538547the $z$-coordinate with or without partial steps, but is simply an iso-level operator in the $s$-coordinate. 
    539 It is thus used when, in addition to \np{ln\_traldf\_lap} or \np{ln\_traldf\_blp}~\forcode{= .true.}, 
    540 we have \np{ln\_traldf\_lev}~\forcode{= .true.} or \np{ln\_traldf\_hor}~=~\np{ln\_zco}~\forcode{= .true.}. 
     548It is thus used when, in addition to \np{ln\_traldf\_lap} or \np{ln\_traldf\_blp}\forcode{=.true.}, 
     549we have \np{ln\_traldf\_lev}\forcode{=.true.} or \np{ln\_traldf\_hor}~=~\np{ln\_zco}\forcode{=.true.}. 
    541550In both cases, it significantly contributes to diapycnal mixing. 
    542551It is therefore never recommended, even when using it in the bilaplacian case. 
    543552 
    544 Note that in the partial step $z$-coordinate (\np{ln\_zps}~\forcode{= .true.}), 
     553Note that in the partial step $z$-coordinate (\np{ln\_zps}\forcode{=.true.}), 
    545554tracers in horizontally adjacent cells are located at different depths in the vicinity of the bottom. 
    546 In this case, horizontal derivatives in (\autoref{eq:tra_ldf_lap}) at the bottom level require a specific treatment. 
     555In this case, horizontal derivatives in (\autoref{eq:TRA_ldf_lap}) at the bottom level require a specific treatment. 
    547556They are calculated in the \mdl{zpshde} module, described in \autoref{sec:TRA_zpshde}. 
    548557 
     
    550559%         Rotated laplacian operator 
    551560% ------------------------------------------------------------------------------------------------------------- 
    552 \subsection{Standard and triad (bi -)laplacian operator} 
     561\subsection{Standard and triad (bi-)laplacian operator} 
    553562\label{subsec:TRA_ldf_iso_triad} 
    554563 
    555 %&&    Standard rotated (bi -)laplacian operator 
     564%&&    Standard rotated (bi-)laplacian operator 
    556565%&& ---------------------------------------------- 
    557 \subsubsection{Standard rotated (bi -)laplacian operator (\protect\mdl{traldf\_iso})} 
     566\subsubsection[Standard rotated (bi-)laplacian operator (\textit{traldf\_iso.F90})] 
     567{Standard rotated (bi-)laplacian operator (\protect\mdl{traldf\_iso})} 
    558568\label{subsec:TRA_ldf_iso} 
    559 The general form of the second order lateral tracer subgrid scale physics (\autoref{eq:PE_zdf}) 
     569The general form of the second order lateral tracer subgrid scale physics (\autoref{eq:MB_zdf}) 
    560570takes the following semi -discrete space form in $z$- and $s$-coordinates: 
    561571\begin{equation} 
    562   \label{eq:tra_ldf_iso} 
     572  \label{eq:TRA_ldf_iso} 
    563573  \begin{split} 
    564574    D_T^{lT} = \frac{1}{b_t} \Bigg[ \quad &\delta_i A_u^{lT} \lt( \frac{e_{2u} e_{3u}}{e_{1u}}                      \, \delta_{i + 1/2} [T] 
     
    573583where $b_t = e_{1t} \, e_{2t} \, e_{3t}$  is the volume of $T$-cells, 
    574584$r_1$ and $r_2$ are the slopes between the surface of computation ($z$- or $s$-surfaces) and 
    575 the surface along which the diffusion operator acts (\ie horizontal or iso-neutral surfaces). 
    576 It is thus used when, in addition to \np{ln\_traldf\_lap}~\forcode{= .true.}, 
    577 we have \np{ln\_traldf\_iso}~\forcode{= .true.}, 
    578 or both \np{ln\_traldf\_hor}~\forcode{= .true.} and \np{ln\_zco}~\forcode{= .true.}. 
     585the surface along which the diffusion operator acts (\ie\ horizontal or iso-neutral surfaces). 
     586It is thus used when, in addition to \np{ln\_traldf\_lap}\forcode{=.true.}, 
     587we have \np{ln\_traldf\_iso}\forcode{=.true.}, 
     588or both \np{ln\_traldf\_hor}\forcode{=.true.} and \np{ln\_zco}\forcode{=.true.}. 
    579589The way these slopes are evaluated is given in \autoref{sec:LDF_slp}. 
    580590At the surface, bottom and lateral boundaries, the turbulent fluxes of heat and salt are set to zero using 
    581591the mask technique (see \autoref{sec:LBC_coast}). 
    582592 
    583 The operator in \autoref{eq:tra_ldf_iso} involves both lateral and vertical derivatives. 
     593The operator in \autoref{eq:TRA_ldf_iso} involves both lateral and vertical derivatives. 
    584594For numerical stability, the vertical second derivative must be solved using the same implicit time scheme as that 
    585595used in the vertical physics (see \autoref{sec:TRA_zdf}). 
     
    590600This formulation conserves the tracer but does not ensure the decrease of the tracer variance. 
    591601Nevertheless the treatment performed on the slopes (see \autoref{chap:LDF}) allows the model to run safely without 
    592 any additional background horizontal diffusion \citep{Guilyardi_al_CD01}. 
    593  
    594 Note that in the partial step $z$-coordinate (\np{ln\_zps}~\forcode{= .true.}), 
    595 the horizontal derivatives at the bottom level in \autoref{eq:tra_ldf_iso} require a specific treatment. 
     602any additional background horizontal diffusion \citep{guilyardi.madec.ea_CD01}. 
     603 
     604Note that in the partial step $z$-coordinate (\np{ln\_zps}\forcode{=.true.}), 
     605the horizontal derivatives at the bottom level in \autoref{eq:TRA_ldf_iso} require a specific treatment. 
    596606They are calculated in module zpshde, described in \autoref{sec:TRA_zpshde}. 
    597607 
    598 %&&     Triad rotated (bi -)laplacian operator 
     608%&&     Triad rotated (bi-)laplacian operator 
    599609%&&  ------------------------------------------- 
    600 \subsubsection{Triad rotated (bi -)laplacian operator (\protect\np{ln\_traldf\_triad})} 
     610\subsubsection[Triad rotated (bi-)laplacian operator (\textit{ln\_traldf\_triad})] 
     611{Triad rotated (bi-)laplacian operator (\protect\np{ln\_traldf\_triad})} 
    601612\label{subsec:TRA_ldf_triad} 
    602613 
    603 If the Griffies triad scheme is employed (\np{ln\_traldf\_triad}~\forcode{= .true.}; see \autoref{apdx:triad}) 
    604  
    605 An alternative scheme developed by \cite{Griffies_al_JPO98} which ensures tracer variance decreases 
    606 is also available in \NEMO (\np{ln\_traldf\_grif}~\forcode{= .true.}). 
    607 A complete description of the algorithm is given in \autoref{apdx:triad}. 
    608  
    609 The lateral fourth order bilaplacian operator on tracers is obtained by applying (\autoref{eq:tra_ldf_lap}) twice. 
     614An alternative scheme developed by \cite{griffies.gnanadesikan.ea_JPO98} which ensures tracer variance decreases 
     615is also available in \NEMO\ (\np{ln\_traldf\_triad}\forcode{=.true.}). 
     616A complete description of the algorithm is given in \autoref{apdx:TRIADS}. 
     617 
     618The lateral fourth order bilaplacian operator on tracers is obtained by applying (\autoref{eq:TRA_ldf_lap}) twice. 
    610619The operator requires an additional assumption on boundary conditions: 
    611620both first and third derivative terms normal to the coast are set to zero. 
    612621 
    613 The lateral fourth order operator formulation on tracers is obtained by applying (\autoref{eq:tra_ldf_iso}) twice. 
     622The lateral fourth order operator formulation on tracers is obtained by applying (\autoref{eq:TRA_ldf_iso}) twice. 
    614623It requires an additional assumption on boundary conditions: 
    615624first and third derivative terms normal to the coast, 
     
    625634\item \np{rn\_slpmax} = slope limit (both operators) 
    626635\item \np{ln\_triad\_iso} = pure horizontal mixing in ML (triad only) 
    627 \item \np{rn\_sw\_triad} $= 1$ switching triad; $= 0$ all 4 triads used (triad only)  
     636\item \np{rn\_sw\_triad} $= 1$ switching triad; $= 0$ all 4 triads used (triad only) 
    628637\item \np{ln\_botmix\_triad} = lateral mixing on bottom (triad only) 
    629638\end{itemize} 
     
    632641% Tracer Vertical Diffusion 
    633642% ================================================================ 
    634 \section{Tracer vertical diffusion (\protect\mdl{trazdf})} 
     643\section[Tracer vertical diffusion (\textit{trazdf.F90})] 
     644{Tracer vertical diffusion (\protect\mdl{trazdf})} 
    635645\label{sec:TRA_zdf} 
    636646%--------------------------------------------namzdf--------------------------------------------------------- 
    637647 
    638 \nlst{namzdf} 
    639648%-------------------------------------------------------------------------------------------------------------- 
    640649 
    641 Options are defined through the \ngn{namzdf} namelist variables. 
     650Options are defined through the \nam{zdf} namelist variables. 
    642651The formulation of the vertical subgrid scale tracer physics is the same for all the vertical coordinates, 
    643652and is based on a laplacian operator. 
    644 The vertical diffusion operator given by (\autoref{eq:PE_zdf}) takes the following semi -discrete space form: 
     653The vertical diffusion operator given by (\autoref{eq:MB_zdf}) takes the following semi -discrete space form: 
    645654\begin{gather*} 
    646   % \label{eq:tra_zdf} 
     655  % \label{eq:TRA_zdf} 
    647656    D^{vT}_T = \frac{1}{e_{3t}} \, \delta_k \lt[ \, \frac{A^{vT}_w}{e_{3w}} \delta_{k + 1/2}[T] \, \rt] \\ 
    648657    D^{vS}_T = \frac{1}{e_{3t}} \; \delta_k \lt[ \, \frac{A^{vS}_w}{e_{3w}} \delta_{k + 1/2}[S] \, \rt] 
     
    651660respectively. 
    652661Generally, $A_w^{vT} = A_w^{vS}$ except when double diffusive mixing is parameterised 
    653 (\ie \key{zdfddm} is defined). 
     662(\ie\ \np{ln\_zdfddm}\forcode{=.true.},). 
    654663The way these coefficients are evaluated is given in \autoref{chap:ZDF} (ZDF). 
    655664Furthermore, when iso-neutral mixing is used, both mixing coefficients are increased by 
    656665$\frac{e_{1w} e_{2w}}{e_{3w} }({r_{1w}^2 + r_{2w}^2})$ to account for the vertical second derivative of 
    657 \autoref{eq:tra_ldf_iso}. 
     666\autoref{eq:TRA_ldf_iso}. 
    658667 
    659668At the surface and bottom boundaries, the turbulent fluxes of heat and salt must be specified. 
     
    663672 
    664673The large eddy coefficient found in the mixed layer together with high vertical resolution implies that 
    665 in the case of explicit time stepping (\np{ln\_zdfexp}~\forcode{= .true.}) 
    666 there would be too restrictive a constraint on the time step. 
    667 Therefore, the default implicit time stepping is preferred for the vertical diffusion since 
     674there would be too restrictive constraint on the time step if we use explicit time stepping. 
     675Therefore an implicit time stepping is preferred for the vertical diffusion since 
    668676it overcomes the stability constraint. 
    669 A forward time differencing scheme (\np{ln\_zdfexp}~\forcode{= .true.}) using 
    670 a time splitting technique (\np{nn\_zdfexp} $> 1$) is provided as an alternative. 
    671 Namelist variables \np{ln\_zdfexp} and \np{nn\_zdfexp} apply to both tracers and dynamics. 
    672677 
    673678% ================================================================ 
     
    680685%        surface boundary condition 
    681686% ------------------------------------------------------------------------------------------------------------- 
    682 \subsection{Surface boundary condition (\protect\mdl{trasbc})} 
     687\subsection[Surface boundary condition (\textit{trasbc.F90})] 
     688{Surface boundary condition (\protect\mdl{trasbc})} 
    683689\label{subsec:TRA_sbc} 
    684690 
     
    690696 
    691697Due to interactions and mass exchange of water ($F_{mass}$) with other Earth system components 
    692 (\ie atmosphere, sea-ice, land), the change in the heat and salt content of the surface layer of the ocean is due 
     698(\ie\ atmosphere, sea-ice, land), the change in the heat and salt content of the surface layer of the ocean is due 
    693699both to the heat and salt fluxes crossing the sea surface (not linked with $F_{mass}$) and 
    694700to the heat and salt content of the mass exchange. 
     
    702708\item 
    703709  $Q_{ns}$, the non-solar part of the net surface heat flux that crosses the sea surface 
    704   (\ie the difference between the total surface heat flux and the fraction of the short wave flux that 
     710  (\ie\ the difference between the total surface heat flux and the fraction of the short wave flux that 
    705711  penetrates into the water column, see \autoref{subsec:TRA_qsr}) 
    706712  plus the heat content associated with of the mass exchange with the atmosphere and lands. 
     
    720726The surface boundary condition on temperature and salinity is applied as follows: 
    721727\begin{equation} 
    722   \label{eq:tra_sbc} 
     728  \label{eq:TRA_sbc} 
    723729  \begin{alignedat}{2} 
    724730    F^T &= \frac{1}{C_p} &\frac{1}{\rho_o \lt. e_{3t} \rt|_{k = 1}} &\overline{Q_{ns}      }^t \\ 
     
    728734where $\overline x^t$ means that $x$ is averaged over two consecutive time steps 
    729735($t - \rdt / 2$ and $t + \rdt / 2$). 
    730 Such time averaging prevents the divergence of odd and even time step (see \autoref{chap:STP}). 
    731  
    732 In the linear free surface case (\np{ln\_linssh}~\forcode{= .true.}), an additional term has to be added on 
     736Such time averaging prevents the divergence of odd and even time step (see \autoref{chap:TD}). 
     737 
     738In the linear free surface case (\np{ln\_linssh}\forcode{=.true.}), an additional term has to be added on 
    733739both temperature and salinity. 
    734740On temperature, this term remove the heat content associated with mass exchange that has been added to $Q_{ns}$. 
     
    737743The resulting surface boundary condition is applied as follows: 
    738744\begin{equation} 
    739   \label{eq:tra_sbc_lin} 
     745  \label{eq:TRA_sbc_lin} 
    740746  \begin{alignedat}{2} 
    741747    F^T &= \frac{1}{C_p} &\frac{1}{\rho_o \lt. e_{3t} \rt|_{k = 1}} 
     
    744750          &\overline{(\textit{sfx} -        \textit{emp} \lt. S \rt|_{k = 1})}^t 
    745751  \end{alignedat} 
    746 \end{equation}  
     752\end{equation} 
    747753Note that an exact conservation of heat and salt content is only achieved with non-linear free surface. 
    748754In the linear free surface case, there is a small imbalance. 
    749 The imbalance is larger than the imbalance associated with the Asselin time filter \citep{Leclair_Madec_OM09}. 
    750 This is the reason why the modified filter is not applied in the linear free surface case (see \autoref{chap:STP}). 
    751  
    752 % ------------------------------------------------------------------------------------------------------------- 
    753 %        Solar Radiation Penetration  
    754 % ------------------------------------------------------------------------------------------------------------- 
    755 \subsection{Solar radiation penetration (\protect\mdl{traqsr})} 
     755The imbalance is larger than the imbalance associated with the Asselin time filter \citep{leclair.madec_OM09}. 
     756This is the reason why the modified filter is not applied in the linear free surface case (see \autoref{chap:TD}). 
     757 
     758% ------------------------------------------------------------------------------------------------------------- 
     759%        Solar Radiation Penetration 
     760% ------------------------------------------------------------------------------------------------------------- 
     761\subsection[Solar radiation penetration (\textit{traqsr.F90})] 
     762{Solar radiation penetration (\protect\mdl{traqsr})} 
    756763\label{subsec:TRA_qsr} 
    757764%--------------------------------------------namqsr-------------------------------------------------------- 
    758765 
    759 \nlst{namtra_qsr} 
     766\begin{listing} 
     767  \nlst{namtra_qsr} 
     768  \caption{\texttt{namtra\_qsr}} 
     769  \label{lst:namtra_qsr} 
     770\end{listing} 
    760771%-------------------------------------------------------------------------------------------------------------- 
    761772 
    762 Options are defined through the \ngn{namtra\_qsr} namelist variables. 
    763 When the penetrative solar radiation option is used (\np{ln\_flxqsr}~\forcode{= .true.}), 
     773Options are defined through the \nam{tra\_qsr} namelist variables. 
     774When the penetrative solar radiation option is used (\np{ln\_traqsr}\forcode{=.true.}), 
    764775the solar radiation penetrates the top few tens of meters of the ocean. 
    765 If it is not used (\np{ln\_flxqsr}~\forcode{= .false.}) all the heat flux is absorbed in the first ocean level. 
    766 Thus, in the former case a term is added to the time evolution equation of temperature \autoref{eq:PE_tra_T} and 
    767 the surface boundary condition is modified to take into account only the non-penetrative part of the surface  
     776If it is not used (\np{ln\_traqsr}\forcode{=.false.}) all the heat flux is absorbed in the first ocean level. 
     777Thus, in the former case a term is added to the time evolution equation of temperature \autoref{eq:MB_PE_tra_T} and 
     778the surface boundary condition is modified to take into account only the non-penetrative part of the surface 
    768779heat flux: 
    769780\begin{equation} 
    770   \label{eq:PE_qsr} 
     781  \label{eq:TRA_PE_qsr} 
    771782  \begin{gathered} 
    772783    \pd[T]{t} = \ldots + \frac{1}{\rho_o \, C_p \, e_3} \; \pd[I]{k} \\ 
     
    774785  \end{gathered} 
    775786\end{equation} 
    776 where $Q_{sr}$ is the penetrative part of the surface heat flux (\ie the shortwave radiation) and 
     787where $Q_{sr}$ is the penetrative part of the surface heat flux (\ie\ the shortwave radiation) and 
    777788$I$ is the downward irradiance ($\lt. I \rt|_{z = \eta} = Q_{sr}$). 
    778 The additional term in \autoref{eq:PE_qsr} is discretized as follows: 
    779 \begin{equation} 
    780   \label{eq:tra_qsr} 
     789The additional term in \autoref{eq:TRA_PE_qsr} is discretized as follows: 
     790\begin{equation} 
     791  \label{eq:TRA_qsr} 
    781792  \frac{1}{\rho_o \, C_p \, e_3} \, \pd[I]{k} \equiv \frac{1}{\rho_o \, C_p \, e_{3t}} \delta_k [I_w] 
    782793\end{equation} 
     
    788799(specified through namelist parameter \np{rn\_abs}). 
    789800It is assumed to penetrate the ocean with a decreasing exponential profile, with an e-folding depth scale, $\xi_0$, 
    790 of a few tens of centimetres (typically $\xi_0 = 0.35~m$ set as \np{rn\_si0} in the \ngn{namtra\_qsr} namelist). 
     801of a few tens of centimetres (typically $\xi_0 = 0.35~m$ set as \np{rn\_si0} in the \nam{tra\_qsr} namelist). 
    791802For shorter wavelengths (400-700~nm), the ocean is more transparent, and solar energy propagates to 
    792803larger depths where it contributes to local heating. 
    793804The way this second part of the solar energy penetrates into the ocean depends on which formulation is chosen. 
    794 In the simple 2-waveband light penetration scheme (\np{ln\_qsr\_2bd}~\forcode{= .true.}) 
     805In the simple 2-waveband light penetration scheme (\np{ln\_qsr\_2bd}\forcode{=.true.}) 
    795806a chlorophyll-independent monochromatic formulation is chosen for the shorter wavelengths, 
    796 leading to the following expression \citep{Paulson1977}: 
     807leading to the following expression \citep{paulson.simpson_JPO77}: 
    797808\[ 
    798   % \label{eq:traqsr_iradiance} 
     809  % \label{eq:TRA_qsr_iradiance} 
    799810  I(z) = Q_{sr} \lt[ Re^{- z / \xi_0} + (1 - R) e^{- z / \xi_1} \rt] 
    800811\] 
     
    805816 
    806817Such assumptions have been shown to provide a very crude and simplistic representation of 
    807 observed light penetration profiles (\cite{Morel_JGR88}, see also \autoref{fig:traqsr_irradiance}). 
     818observed light penetration profiles (\cite{morel_JGR88}, see also \autoref{fig:TRA_qsr_irradiance}). 
    808819Light absorption in the ocean depends on particle concentration and is spectrally selective. 
    809 \cite{Morel_JGR88} has shown that an accurate representation of light penetration can be provided by 
     820\cite{morel_JGR88} has shown that an accurate representation of light penetration can be provided by 
    810821a 61 waveband formulation. 
    811822Unfortunately, such a model is very computationally expensive. 
    812 Thus, \cite{Lengaigne_al_CD07} have constructed a simplified version of this formulation in which 
     823Thus, \cite{lengaigne.menkes.ea_CD07} have constructed a simplified version of this formulation in which 
    813824visible light is split into three wavebands: blue (400-500 nm), green (500-600 nm) and red (600-700nm). 
    814825For each wave-band, the chlorophyll-dependent attenuation coefficient is fitted to the coefficients computed from 
    815 the full spectral model of \cite{Morel_JGR88} (as modified by \cite{Morel_Maritorena_JGR01}), 
     826the full spectral model of \cite{morel_JGR88} (as modified by \cite{morel.maritorena_JGR01}), 
    816827assuming the same power-law relationship. 
    817 As shown in \autoref{fig:traqsr_irradiance}, this formulation, called RGB (Red-Green-Blue), 
     828As shown in \autoref{fig:TRA_qsr_irradiance}, this formulation, called RGB (Red-Green-Blue), 
    818829reproduces quite closely the light penetration profiles predicted by the full spectal model, 
    819830but with much greater computational efficiency. 
    820831The 2-bands formulation does not reproduce the full model very well. 
    821832 
    822 The RGB formulation is used when \np{ln\_qsr\_rgb}~\forcode{= .true.}. 
    823 The RGB attenuation coefficients (\ie the inverses of the extinction length scales) are tabulated over 
     833The RGB formulation is used when \np{ln\_qsr\_rgb}\forcode{=.true.}. 
     834The RGB attenuation coefficients (\ie\ the inverses of the extinction length scales) are tabulated over 
    82483561 nonuniform chlorophyll classes ranging from 0.01 to 10 g.Chl/L 
    825836(see the routine \rou{trc\_oce\_rgb} in \mdl{trc\_oce} module). 
     
    827838 
    828839\begin{description} 
    829 \item[\np{nn\_chdta}~\forcode{= 0}] 
    830   a constant 0.05 g.Chl/L value everywhere ;  
    831 \item[\np{nn\_chdta}~\forcode{= 1}] 
     840\item[\np{nn\_chldta}\forcode{=0}] 
     841  a constant 0.05 g.Chl/L value everywhere ; 
     842\item[\np{nn\_chldta}\forcode{=1}] 
    832843  an observed time varying chlorophyll deduced from satellite surface ocean color measurement spread uniformly in 
    833844  the vertical direction; 
    834 \item[\np{nn\_chdta}~\forcode{= 2}] 
     845\item[\np{nn\_chldta}\forcode{=2}] 
    835846  same as previous case except that a vertical profile of chlorophyl is used. 
    836   Following \cite{Morel_Berthon_LO89}, the profile is computed from the local surface chlorophyll value; 
    837 \item[\np{ln\_qsr\_bio}~\forcode{= .true.}] 
     847  Following \cite{morel.berthon_LO89}, the profile is computed from the local surface chlorophyll value; 
     848\item[\np{ln\_qsr\_bio}\forcode{=.true.}] 
    838849  simulated time varying chlorophyll by TOP biogeochemical model. 
    839850  In this case, the RGB formulation is used to calculate both the phytoplankton light limitation in 
    840   PISCES or LOBSTER and the oceanic heating rate. 
    841 \end{description}  
    842  
    843 The trend in \autoref{eq:tra_qsr} associated with the penetration of the solar radiation is added to 
     851  PISCES and the oceanic heating rate. 
     852\end{description} 
     853 
     854The trend in \autoref{eq:TRA_qsr} associated with the penetration of the solar radiation is added to 
    844855the temperature trend, and the surface heat flux is modified in routine \mdl{traqsr}. 
    845856 
     
    847858the depth of $w-$levels does not significantly vary with location. 
    848859The level at which the light has been totally absorbed 
    849 (\ie it is less than the computer precision) is computed once, 
     860(\ie\ it is less than the computer precision) is computed once, 
    850861and the trend associated with the penetration of the solar radiation is only added down to that level. 
    851862Finally, note that when the ocean is shallow ($<$ 200~m), part of the solar radiation can reach the ocean floor. 
    852863In this case, we have chosen that all remaining radiation is absorbed in the last ocean level 
    853 (\ie $I$ is masked). 
     864(\ie\ $I$ is masked). 
    854865 
    855866%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    856867\begin{figure}[!t] 
    857   \begin{center} 
    858     \includegraphics[]{Fig_TRA_Irradiance} 
    859     \caption{ 
    860       \protect\label{fig:traqsr_irradiance} 
    861       Penetration profile of the downward solar irradiance calculated by four models. 
    862       Two waveband chlorophyll-independent formulation (blue), 
    863       a chlorophyll-dependent monochromatic formulation (green), 
    864       4 waveband RGB formulation (red), 
    865       61 waveband Morel (1988) formulation (black) for a chlorophyll concentration of 
    866       (a) Chl=0.05 mg/m$^3$ and (b) Chl=0.5 mg/m$^3$. 
    867       From \citet{Lengaigne_al_CD07}. 
    868     } 
    869   \end{center} 
     868  \centering 
     869  \includegraphics[width=\textwidth]{Fig_TRA_Irradiance} 
     870  \caption[Penetration profile of the downward solar irradiance calculated by four models]{ 
     871    Penetration profile of the downward solar irradiance calculated by four models. 
     872    Two waveband chlorophyll-independent formulation (blue), 
     873    a chlorophyll-dependent monochromatic formulation (green), 
     874    4 waveband RGB formulation (red), 
     875    61 waveband Morel (1988) formulation (black) for a chlorophyll concentration of 
     876    (a) Chl=0.05 mg/m$^3$ and (b) Chl=0.5 mg/m$^3$. 
     877    From \citet{lengaigne.menkes.ea_CD07}.} 
     878  \label{fig:TRA_qsr_irradiance} 
    870879\end{figure} 
    871880%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
     
    874883%        Bottom Boundary Condition 
    875884% ------------------------------------------------------------------------------------------------------------- 
    876 \subsection{Bottom boundary condition (\protect\mdl{trabbc})} 
     885\subsection[Bottom boundary condition (\textit{trabbc.F90}) - \forcode{ln_trabbc=.true.})] 
     886{Bottom boundary condition (\protect\mdl{trabbc})} 
    877887\label{subsec:TRA_bbc} 
    878888%--------------------------------------------nambbc-------------------------------------------------------- 
    879889 
    880 \nlst{nambbc} 
     890\begin{listing} 
     891  \nlst{nambbc} 
     892  \caption{\texttt{nambbc}} 
     893  \label{lst:nambbc} 
     894\end{listing} 
    881895%-------------------------------------------------------------------------------------------------------------- 
    882896%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    883897\begin{figure}[!t] 
    884   \begin{center} 
    885     \includegraphics[]{Fig_TRA_geoth} 
    886     \caption{ 
    887       \protect\label{fig:geothermal} 
    888       Geothermal Heat flux (in $mW.m^{-2}$) used by \cite{Emile-Geay_Madec_OS09}. 
    889       It is inferred from the age of the sea floor and the formulae of \citet{Stein_Stein_Nat92}. 
    890     } 
    891   \end{center} 
     898  \centering 
     899  \includegraphics[width=\textwidth]{Fig_TRA_geoth} 
     900  \caption[Geothermal heat flux]{ 
     901    Geothermal Heat flux (in $mW.m^{-2}$) used by \cite{emile-geay.madec_OS09}. 
     902    It is inferred from the age of the sea floor and the formulae of \citet{stein.stein_N92}.} 
     903  \label{fig:TRA_geothermal} 
    892904\end{figure} 
    893905%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    894906 
    895907Usually it is assumed that there is no exchange of heat or salt through the ocean bottom, 
    896 \ie a no flux boundary condition is applied on active tracers at the bottom. 
     908\ie\ a no flux boundary condition is applied on active tracers at the bottom. 
    897909This is the default option in \NEMO, and it is implemented using the masking technique. 
    898910However, there is a non-zero heat flux across the seafloor that is associated with solid earth cooling. 
    899 This flux is weak compared to surface fluxes (a mean global value of $\sim 0.1 \, W/m^2$ \citep{Stein_Stein_Nat92}), 
     911This flux is weak compared to surface fluxes (a mean global value of $\sim 0.1 \, W/m^2$ \citep{stein.stein_N92}), 
    900912but it warms systematically the ocean and acts on the densest water masses. 
    901913Taking this flux into account in a global ocean model increases the deepest overturning cell 
    902 (\ie the one associated with the Antarctic Bottom Water) by a few Sverdrups \citep{Emile-Geay_Madec_OS09}. 
    903  
    904 Options are defined through the  \ngn{namtra\_bbc} namelist variables. 
     914(\ie\ the one associated with the Antarctic Bottom Water) by a few Sverdrups \citep{emile-geay.madec_OS09}. 
     915 
     916Options are defined through the \nam{bbc} namelist variables. 
    905917The presence of geothermal heating is controlled by setting the namelist parameter \np{ln\_trabbc} to true. 
    906918Then, when \np{nn\_geoflx} is set to 1, a constant geothermal heating is introduced whose value is given by 
    907 the \np{nn\_geoflx\_cst}, which is also a namelist parameter. 
     919the \np{rn\_geoflx\_cst}, which is also a namelist parameter. 
    908920When \np{nn\_geoflx} is set to 2, a spatially varying geothermal heat flux is introduced which is provided in 
    909 the \ifile{geothermal\_heating} NetCDF file (\autoref{fig:geothermal}) \citep{Emile-Geay_Madec_OS09}. 
     921the \ifile{geothermal\_heating} NetCDF file (\autoref{fig:TRA_geothermal}) \citep{emile-geay.madec_OS09}. 
    910922 
    911923% ================================================================ 
    912924% Bottom Boundary Layer 
    913925% ================================================================ 
    914 \section{Bottom boundary layer (\protect\mdl{trabbl} - \protect\key{trabbl})} 
     926\section[Bottom boundary layer (\textit{trabbl.F90} - \forcode{ln_trabbl=.true.})] 
     927{Bottom boundary layer (\protect\mdl{trabbl} - \protect\np{ln\_trabbl}\forcode{=.true.})} 
    915928\label{sec:TRA_bbl} 
    916929%--------------------------------------------nambbl--------------------------------------------------------- 
    917930 
    918 \nlst{nambbl} 
     931\begin{listing} 
     932  \nlst{nambbl} 
     933  \caption{\texttt{nambbl}} 
     934  \label{lst:nambbl} 
     935\end{listing} 
    919936%-------------------------------------------------------------------------------------------------------------- 
    920937 
    921 Options are defined through the \ngn{nambbl} namelist variables. 
     938Options are defined through the \nam{bbl} namelist variables. 
    922939In a $z$-coordinate configuration, the bottom topography is represented by a series of discrete steps. 
    923940This is not adequate to represent gravity driven downslope flows. 
     
    931948sometimes over a thickness much larger than the thickness of the observed gravity plume. 
    932949A similar problem occurs in the $s$-coordinate when the thickness of the bottom level varies rapidly downstream of 
    933 a sill \citep{Willebrand_al_PO01}, and the thickness of the plume is not resolved. 
    934  
    935 The idea of the bottom boundary layer (BBL) parameterisation, first introduced by \citet{Beckmann_Doscher1997}, 
     950a sill \citep{willebrand.barnier.ea_PO01}, and the thickness of the plume is not resolved. 
     951 
     952The idea of the bottom boundary layer (BBL) parameterisation, first introduced by \citet{beckmann.doscher_JPO97}, 
    936953is to allow a direct communication between two adjacent bottom cells at different levels, 
    937954whenever the densest water is located above the less dense water. 
     
    939956In the current implementation of the BBL, only the tracers are modified, not the velocities. 
    940957Furthermore, it only connects ocean bottom cells, and therefore does not include all the improvements introduced by 
    941 \citet{Campin_Goosse_Tel99}. 
     958\citet{campin.goosse_T99}. 
    942959 
    943960% ------------------------------------------------------------------------------------------------------------- 
    944961%        Diffusive BBL 
    945962% ------------------------------------------------------------------------------------------------------------- 
    946 \subsection{Diffusive bottom boundary layer (\protect\np{nn\_bbl\_ldf}~\forcode{= 1})} 
     963\subsection[Diffusive bottom boundary layer (\forcode{nn_bbl_ldf=1})] 
     964{Diffusive bottom boundary layer (\protect\np{nn\_bbl\_ldf}\forcode{=1})} 
    947965\label{subsec:TRA_bbl_diff} 
    948966 
    949 When applying sigma-diffusion (\key{trabbl} defined and \np{nn\_bbl\_ldf} set to 1), 
    950 the diffusive flux between two adjacent cells at the ocean floor is given by  
     967When applying sigma-diffusion (\np{ln\_trabbl}\forcode{=.true.} and \np{nn\_bbl\_ldf} set to 1), 
     968the diffusive flux between two adjacent cells at the ocean floor is given by 
    951969\[ 
    952   % \label{eq:tra_bbl_diff} 
     970  % \label{eq:TRA_bbl_diff} 
    953971  \vect F_\sigma = A_l^\sigma \, \nabla_\sigma T 
    954972\] 
    955973with $\nabla_\sigma$ the lateral gradient operator taken between bottom cells, and 
    956974$A_l^\sigma$ the lateral diffusivity in the BBL. 
    957 Following \citet{Beckmann_Doscher1997}, the latter is prescribed with a spatial dependence, 
    958 \ie in the conditional form 
    959 \begin{equation} 
    960   \label{eq:tra_bbl_coef} 
     975Following \citet{beckmann.doscher_JPO97}, the latter is prescribed with a spatial dependence, 
     976\ie\ in the conditional form 
     977\begin{equation} 
     978  \label{eq:TRA_bbl_coef} 
    961979  A_l^\sigma (i,j,t) = 
    962980      \begin{cases} 
     
    968986where $A_{bbl}$ is the BBL diffusivity coefficient, given by the namelist parameter \np{rn\_ahtbbl} and 
    969987usually set to a value much larger than the one used for lateral mixing in the open ocean. 
    970 The constraint in \autoref{eq:tra_bbl_coef} implies that sigma-like diffusion only occurs when 
     988The constraint in \autoref{eq:TRA_bbl_coef} implies that sigma-like diffusion only occurs when 
    971989the density above the sea floor, at the top of the slope, is larger than in the deeper ocean 
    972 (see green arrow in \autoref{fig:bbl}). 
     990(see green arrow in \autoref{fig:TRA_bbl}). 
    973991In practice, this constraint is applied separately in the two horizontal directions, 
    974 and the density gradient in \autoref{eq:tra_bbl_coef} is evaluated with the log gradient formulation:  
     992and the density gradient in \autoref{eq:TRA_bbl_coef} is evaluated with the log gradient formulation: 
    975993\[ 
    976   % \label{eq:tra_bbl_Drho} 
     994  % \label{eq:TRA_bbl_Drho} 
    977995  \nabla_\sigma \rho / \rho = \alpha \, \nabla_\sigma T + \beta \, \nabla_\sigma S 
    978996\] 
     
    9831001%        Advective BBL 
    9841002% ------------------------------------------------------------------------------------------------------------- 
    985 \subsection{Advective bottom boundary layer  (\protect\np{nn\_bbl\_adv}~\forcode{= 1..2})} 
     1003\subsection[Advective bottom boundary layer (\forcode{nn_bbl_adv=[12]})] 
     1004{Advective bottom boundary layer (\protect\np{nn\_bbl\_adv}\forcode{=[12]})} 
    9861005\label{subsec:TRA_bbl_adv} 
    9871006 
     
    9931012%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    9941013\begin{figure}[!t] 
    995   \begin{center} 
    996     \includegraphics[]{Fig_BBL_adv} 
    997     \caption{ 
    998       \protect\label{fig:bbl} 
    999       Advective/diffusive Bottom Boundary Layer. 
    1000       The BBL parameterisation is activated when $\rho^i_{kup}$ is larger than $\rho^{i + 1}_{kdnw}$. 
    1001       Red arrows indicate the additional overturning circulation due to the advective BBL. 
    1002       The transport of the downslope flow is defined either as the transport of the bottom ocean cell (black arrow), 
    1003       or as a function of the along slope density gradient. 
    1004       The green arrow indicates the diffusive BBL flux directly connecting $kup$ and $kdwn$ ocean bottom cells. 
    1005     } 
    1006   \end{center} 
     1014  \centering 
     1015  \includegraphics[width=\textwidth]{Fig_BBL_adv} 
     1016  \caption[Advective/diffusive bottom boundary layer]{ 
     1017    Advective/diffusive Bottom Boundary Layer. 
     1018    The BBL parameterisation is activated when $\rho^i_{kup}$ is larger than $\rho^{i + 1}_{kdnw}$. 
     1019    Red arrows indicate the additional overturning circulation due to the advective BBL. 
     1020    The transport of the downslope flow is defined either 
     1021    as the transport of the bottom ocean cell (black arrow), 
     1022    or as a function of the along slope density gradient. 
     1023    The green arrow indicates the diffusive BBL flux directly connecting 
     1024    $kup$ and $kdwn$ ocean bottom cells.} 
     1025  \label{fig:TRA_bbl} 
    10071026\end{figure} 
    10081027%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
     
    10141033%%%gmcomment   :  this section has to be really written 
    10151034 
    1016 When applying an advective BBL (\np{nn\_bbl\_adv}~\forcode{= 1..2}), an overturning circulation is added which 
     1035When applying an advective BBL (\np{nn\_bbl\_adv}\forcode{=1..2}), an overturning circulation is added which 
    10171036connects two adjacent bottom grid-points only if dense water overlies less dense water on the slope. 
    10181037The density difference causes dense water to move down the slope. 
    10191038 
    1020 \np{nn\_bbl\_adv}~\forcode{= 1}: 
     1039\np{nn\_bbl\_adv}\forcode{=1}: 
    10211040the downslope velocity is chosen to be the Eulerian ocean velocity just above the topographic step 
    1022 (see black arrow in \autoref{fig:bbl}) \citep{Beckmann_Doscher1997}. 
     1041(see black arrow in \autoref{fig:TRA_bbl}) \citep{beckmann.doscher_JPO97}. 
    10231042It is a \textit{conditional advection}, that is, advection is allowed only 
    1024 if dense water overlies less dense water on the slope (\ie $\nabla_\sigma \rho \cdot \nabla H < 0$) and 
    1025 if the velocity is directed towards greater depth (\ie $\vect U \cdot \nabla H > 0$). 
    1026  
    1027 \np{nn\_bbl\_adv}~\forcode{= 2}: 
     1043if dense water overlies less dense water on the slope (\ie\ $\nabla_\sigma \rho \cdot \nabla H < 0$) and 
     1044if the velocity is directed towards greater depth (\ie\ $\vect U \cdot \nabla H > 0$). 
     1045 
     1046\np{nn\_bbl\_adv}\forcode{=2}: 
    10281047the downslope velocity is chosen to be proportional to $\Delta \rho$, 
    1029 the density difference between the higher cell and lower cell densities \citep{Campin_Goosse_Tel99}. 
     1048the density difference between the higher cell and lower cell densities \citep{campin.goosse_T99}. 
    10301049The advection is allowed only  if dense water overlies less dense water on the slope 
    1031 (\ie $\nabla_\sigma \rho \cdot \nabla H < 0$). 
    1032 For example, the resulting transport of the downslope flow, here in the $i$-direction (\autoref{fig:bbl}), 
     1050(\ie\ $\nabla_\sigma \rho \cdot \nabla H < 0$). 
     1051For example, the resulting transport of the downslope flow, here in the $i$-direction (\autoref{fig:TRA_bbl}), 
    10331052is simply given by the following expression: 
    10341053\[ 
    1035   % \label{eq:bbl_Utr} 
     1054  % \label{eq:TRA_bbl_Utr} 
    10361055  u^{tr}_{bbl} = \gamma g \frac{\Delta \rho}{\rho_o} e_{1u} \, min ({e_{3u}}_{kup},{e_{3u}}_{kdwn}) 
    10371056\] 
     
    10411060The parameter $\gamma$ should take a different value for each bathymetric step, but for simplicity, 
    10421061and because no direct estimation of this parameter is available, a uniform value has been assumed. 
    1043 The possible values for $\gamma$ range between 1 and $10~s$ \citep{Campin_Goosse_Tel99}. 
     1062The possible values for $\gamma$ range between 1 and $10~s$ \citep{campin.goosse_T99}. 
    10441063 
    10451064Scalar properties are advected by this additional transport $(u^{tr}_{bbl},v^{tr}_{bbl})$ using the upwind scheme. 
     
    10471066the surrounding water at intermediate depths. 
    10481067The entrainment is replaced by the vertical mixing implicit in the advection scheme. 
    1049 Let us consider as an example the case displayed in \autoref{fig:bbl} where 
     1068Let us consider as an example the case displayed in \autoref{fig:TRA_bbl} where 
    10501069the density at level $(i,kup)$ is larger than the one at level $(i,kdwn)$. 
    10511070The advective BBL scheme modifies the tracer time tendency of the ocean cells near the topographic step by 
    1052 the downslope flow \autoref{eq:bbl_dw}, the horizontal \autoref{eq:bbl_hor} and 
    1053 the upward \autoref{eq:bbl_up} return flows as follows:  
     1071the downslope flow \autoref{eq:TRA_bbl_dw}, the horizontal \autoref{eq:TRA_bbl_hor} and 
     1072the upward \autoref{eq:TRA_bbl_up} return flows as follows: 
    10541073\begin{alignat}{3} 
    1055   \label{eq:bbl_dw} 
     1074  \label{eq:TRA_bbl_dw} 
    10561075  \partial_t T^{do}_{kdw} &\equiv \partial_t T^{do}_{kdw} 
    10571076                                &&+ \frac{u^{tr}_{bbl}}{{b_t}^{do}_{kdw}} &&\lt( T^{sh}_{kup} - T^{do}_{kdw} \rt) \\ 
    1058   \label{eq:bbl_hor} 
     1077  \label{eq:TRA_bbl_hor} 
    10591078  \partial_t T^{sh}_{kup} &\equiv \partial_t T^{sh}_{kup} 
    10601079                                &&+ \frac{u^{tr}_{bbl}}{{b_t}^{sh}_{kup}} &&\lt( T^{do}_{kup} - T^{sh}_{kup} \rt) \\ 
     
    10621081  \intertext{and for $k =kdw-1,\;..., \; kup$ :} 
    10631082  % 
    1064   \label{eq:bbl_up} 
     1083  \label{eq:TRA_bbl_up} 
    10651084  \partial_t T^{do}_{k} &\equiv \partial_t S^{do}_{k} 
    10661085                                &&+ \frac{u^{tr}_{bbl}}{{b_t}^{do}_{k}}   &&\lt( T^{do}_{k +1} - T^{sh}_{k}   \rt) 
     
    10741093% Tracer damping 
    10751094% ================================================================ 
    1076 \section{Tracer damping (\protect\mdl{tradmp})} 
     1095\section[Tracer damping (\textit{tradmp.F90})] 
     1096{Tracer damping (\protect\mdl{tradmp})} 
    10771097\label{sec:TRA_dmp} 
    10781098%--------------------------------------------namtra_dmp------------------------------------------------- 
    10791099 
    1080 \nlst{namtra_dmp} 
     1100\begin{listing} 
     1101  \nlst{namtra_dmp} 
     1102  \caption{\texttt{namtra\_dmp}} 
     1103  \label{lst:namtra_dmp} 
     1104\end{listing} 
    10811105%-------------------------------------------------------------------------------------------------------------- 
    10821106 
    10831107In some applications it can be useful to add a Newtonian damping term into the temperature and salinity equations: 
    10841108\begin{equation} 
    1085   \label{eq:tra_dmp} 
     1109  \label{eq:TRA_dmp} 
    10861110  \begin{gathered} 
    10871111    \pd[T]{t} = \cdots - \gamma (T - T_o) \\ 
    10881112    \pd[S]{t} = \cdots - \gamma (S - S_o) 
    10891113  \end{gathered} 
    1090 \end{equation}  
     1114\end{equation} 
    10911115where $\gamma$ is the inverse of a time scale, and $T_o$ and $S_o$ are given temperature and salinity fields 
    10921116(usually a climatology). 
    1093 Options are defined through the  \ngn{namtra\_dmp} namelist variables. 
     1117Options are defined through the  \nam{tra\_dmp} namelist variables. 
    10941118The restoring term is added when the namelist parameter \np{ln\_tradmp} is set to true. 
    1095 It also requires that both \np{ln\_tsd\_init} and \np{ln\_tsd\_tradmp} are set to true in 
    1096 \ngn{namtsd} namelist as well as \np{sn\_tem} and \np{sn\_sal} structures are correctly set 
    1097 (\ie that $T_o$ and $S_o$ are provided in input files and read using \mdl{fldread}, 
     1119It also requires that both \np{ln\_tsd\_init} and \np{ln\_tsd\_dmp} are set to true in 
     1120\nam{tsd} namelist as well as \np{sn\_tem} and \np{sn\_sal} structures are correctly set 
     1121(\ie\ that $T_o$ and $S_o$ are provided in input files and read using \mdl{fldread}, 
    10981122see \autoref{subsec:SBC_fldread}). 
    10991123The restoring coefficient $\gamma$ is a three-dimensional array read in during the \rou{tra\_dmp\_init} routine. 
     
    11011125The DMP\_TOOLS tool is provided to allow users to generate the netcdf file. 
    11021126 
    1103 The two main cases in which \autoref{eq:tra_dmp} is used are 
     1127The two main cases in which \autoref{eq:TRA_dmp} is used are 
    11041128\textit{(a)} the specification of the boundary conditions along artificial walls of a limited domain basin and 
    11051129\textit{(b)} the computation of the velocity field associated with a given $T$-$S$ field 
     
    11091133In the vicinity of these walls, $\gamma$ takes large values (equivalent to a time scale of a few days) whereas 
    11101134it is zero in the interior of the model domain. 
    1111 The second case corresponds to the use of the robust diagnostic method \citep{Sarmiento1982}. 
     1135The second case corresponds to the use of the robust diagnostic method \citep{sarmiento.bryan_JGR82}. 
    11121136It allows us to find the velocity field consistent with the model dynamics whilst 
    11131137having a $T$, $S$ field close to a given climatological field ($T_o$, $S_o$). 
     
    11211145only below the mixed layer (defined either on a density or $S_o$ criterion). 
    11221146It is common to set the damping to zero in the mixed layer as the adjustment time scale is short here 
    1123 \citep{Madec_al_JPO96}. 
     1147\citep{madec.delecluse.ea_JPO96}. 
    11241148 
    11251149For generating \ifile{resto}, see the documentation for the DMP tool provided with the source code under 
     
    11291153% Tracer time evolution 
    11301154% ================================================================ 
    1131 \section{Tracer time evolution (\protect\mdl{tranxt})} 
     1155\section[Tracer time evolution (\textit{tranxt.F90})] 
     1156{Tracer time evolution (\protect\mdl{tranxt})} 
    11321157\label{sec:TRA_nxt} 
    11331158%--------------------------------------------namdom----------------------------------------------------- 
    1134  
    1135 \nlst{namdom} 
    11361159%-------------------------------------------------------------------------------------------------------------- 
    11371160 
    1138 Options are defined through the \ngn{namdom} namelist variables. 
    1139 The general framework for tracer time stepping is a modified leap-frog scheme \citep{Leclair_Madec_OM09}, 
    1140 \ie a three level centred time scheme associated with a Asselin time filter (cf. \autoref{sec:STP_mLF}): 
    1141 \begin{equation} 
    1142   \label{eq:tra_nxt} 
     1161Options are defined through the \nam{dom} namelist variables. 
     1162The general framework for tracer time stepping is a modified leap-frog scheme \citep{leclair.madec_OM09}, 
     1163\ie\ a three level centred time scheme associated with a Asselin time filter (cf. \autoref{sec:TD_mLF}): 
     1164\begin{equation} 
     1165  \label{eq:TRA_nxt} 
    11431166  \begin{alignedat}{3} 
    11441167    &(e_{3t}T)^{t + \rdt} &&= (e_{3t}T)_f^{t - \rdt} &&+ 2 \, \rdt \,e_{3t}^t \ \text{RHS}^t \\ 
    11451168    &(e_{3t}T)_f^t        &&= (e_{3t}T)^t            &&+ \, \gamma \, \lt[ (e_{3t}T)_f^{t - \rdt} - 2(e_{3t}T)^t + (e_{3t}T)^{t + \rdt} \rt] \\ 
    1146     &                     &&                         &&- \, \gamma \, \rdt \, \lt[ Q^{t + \rdt/2} - Q^{t - \rdt/2} \rt]   
     1169    &                     &&                         &&- \, \gamma \, \rdt \, \lt[ Q^{t + \rdt/2} - Q^{t - \rdt/2} \rt] 
    11471170  \end{alignedat} 
    1148 \end{equation}  
     1171\end{equation} 
    11491172where RHS is the right hand side of the temperature equation, the subscript $f$ denotes filtered values, 
    11501173$\gamma$ is the Asselin coefficient, and $S$ is the total forcing applied on $T$ 
    1151 (\ie fluxes plus content in mass exchanges). 
     1174(\ie\ fluxes plus content in mass exchanges). 
    11521175$\gamma$ is initialized as \np{rn\_atfp} (\textbf{namelist} parameter). 
    1153 Its default value is \np{rn\_atfp}~\forcode{= 10.e-3}. 
     1176Its default value is \np{rn\_atfp}\forcode{=10.e-3}. 
    11541177Note that the forcing correction term in the filter is not applied in linear free surface 
    1155 (\jp{lk\_vvl}~\forcode{= .false.}) (see \autoref{subsec:TRA_sbc}). 
     1178(\jp{ln\_linssh}\forcode{=.true.}) (see \autoref{subsec:TRA_sbc}). 
    11561179Not also that in constant volume case, the time stepping is performed on $T$, not on its content, $e_{3t}T$. 
    11571180 
     
    11641187 
    11651188% ================================================================ 
    1166 % Equation of State (eosbn2)  
    1167 % ================================================================ 
    1168 \section{Equation of state (\protect\mdl{eosbn2}) } 
     1189% Equation of State (eosbn2) 
     1190% ================================================================ 
     1191\section[Equation of state (\textit{eosbn2.F90})] 
     1192{Equation of state (\protect\mdl{eosbn2})} 
    11691193\label{sec:TRA_eosbn2} 
    11701194%--------------------------------------------nameos----------------------------------------------------- 
    11711195 
    1172 \nlst{nameos} 
     1196\begin{listing} 
     1197  \nlst{nameos} 
     1198  \caption{\texttt{nameos}} 
     1199  \label{lst:nameos} 
     1200\end{listing} 
    11731201%-------------------------------------------------------------------------------------------------------------- 
    11741202 
     
    11761204%        Equation of State 
    11771205% ------------------------------------------------------------------------------------------------------------- 
    1178 \subsection{Equation of seawater (\protect\np{nn\_eos}~\forcode{= -1..1})} 
     1206\subsection[Equation of seawater (\texttt{ln}\{\texttt{\_teso10,\_eos80,\_seos}\})] 
     1207{Equation of seawater (\protect\np{ln\_teos10}, \protect\np{ln\_teos80}, or \protect\np{ln\_seos}) } 
    11791208\label{subsec:TRA_eos} 
     1209 
    11801210 
    11811211The Equation Of Seawater (EOS) is an empirical nonlinear thermodynamic relationship linking seawater density, 
     
    11861216Nonlinearities of the EOS are of major importance, in particular influencing the circulation through 
    11871217determination of the static stability below the mixed layer, 
    1188 thus controlling rates of exchange between the atmosphere and the ocean interior \citep{Roquet_JPO2015}. 
    1189 Therefore an accurate EOS based on either the 1980 equation of state (EOS-80, \cite{UNESCO1983}) or 
    1190 TEOS-10 \citep{TEOS10} standards should be used anytime a simulation of the real ocean circulation is attempted 
    1191 \citep{Roquet_JPO2015}. 
     1218thus controlling rates of exchange between the atmosphere and the ocean interior \citep{roquet.madec.ea_JPO15}. 
     1219Therefore an accurate EOS based on either the 1980 equation of state (EOS-80, \cite{fofonoff.millard_bk83}) or 
     1220TEOS-10 \citep{ioc.iapso_bk10} standards should be used anytime a simulation of the real ocean circulation is attempted 
     1221\citep{roquet.madec.ea_JPO15}. 
    11921222The use of TEOS-10 is highly recommended because 
    11931223\textit{(i)}   it is the new official EOS, 
    11941224\textit{(ii)}  it is more accurate, being based on an updated database of laboratory measurements, and 
    11951225\textit{(iii)} it uses Conservative Temperature and Absolute Salinity (instead of potential temperature and 
    1196 practical salinity for EOS-980, both variables being more suitable for use as model variables 
    1197 \citep{TEOS10, Graham_McDougall_JPO13}. 
    1198 EOS-80 is an obsolescent feature of the NEMO system, kept only for backward compatibility. 
     1226practical salinity for EOS-80, both variables being more suitable for use as model variables 
     1227\citep{ioc.iapso_bk10, graham.mcdougall_JPO13}. 
     1228EOS-80 is an obsolescent feature of the \NEMO\ system, kept only for backward compatibility. 
    11991229For process studies, it is often convenient to use an approximation of the EOS. 
    1200 To that purposed, a simplified EOS (S-EOS) inspired by \citet{Vallis06} is also available. 
     1230To that purposed, a simplified EOS (S-EOS) inspired by \citet{vallis_bk06} is also available. 
    12011231 
    12021232In the computer code, a density anomaly, $d_a = \rho / \rho_o - 1$, is computed, with $\rho_o$ a reference density. 
     
    12041234This is a sensible choice for the reference density used in a Boussinesq ocean climate model, as, 
    12051235with the exception of only a small percentage of the ocean, 
    1206 density in the World Ocean varies by no more than 2$\%$ from that value \citep{Gill1982}. 
    1207  
    1208 Options are defined through the \ngn{nameos} namelist variables, and in particular \np{nn\_eos} which 
    1209 controls the EOS used (\forcode{= -1} for TEOS10 ; \forcode{= 0} for EOS-80 ; \forcode{= 1} for S-EOS). 
     1236density in the World Ocean varies by no more than 2$\%$ from that value \citep{gill_bk82}. 
     1237 
     1238Options which control the EOS used are defined through the \nam{eos} namelist variables. 
    12101239 
    12111240\begin{description} 
    1212 \item[\np{nn\_eos}~\forcode{= -1}] 
    1213   the polyTEOS10-bsq equation of seawater \citep{Roquet_OM2015} is used. 
     1241\item[\np{ln\_teos10}\forcode{=.true.}] 
     1242  the polyTEOS10-bsq equation of seawater \citep{roquet.madec.ea_OM15} is used. 
    12141243  The accuracy of this approximation is comparable to the TEOS-10 rational function approximation, 
    12151244  but it is optimized for a boussinesq fluid and the polynomial expressions have simpler and 
     
    12171246  use in ocean models. 
    12181247  Note that a slightly higher precision polynomial form is now used replacement of 
    1219   the TEOS-10 rational function approximation for hydrographic data analysis \citep{TEOS10}. 
     1248  the TEOS-10 rational function approximation for hydrographic data analysis \citep{ioc.iapso_bk10}. 
    12201249  A key point is that conservative state variables are used: 
    12211250  Absolute Salinity (unit: g/kg, notation: $S_A$) and Conservative Temperature (unit: \deg{C}, notation: $\Theta$). 
    12221251  The pressure in decibars is approximated by the depth in meters. 
    12231252  With TEOS10, the specific heat capacity of sea water, $C_p$, is a constant. 
    1224   It is set to $C_p = 3991.86795711963~J\,Kg^{-1}\,^{\circ}K^{-1}$, according to \citet{TEOS10}. 
     1253  It is set to $C_p = 3991.86795711963~J\,Kg^{-1}\,^{\circ}K^{-1}$, according to \citet{ioc.iapso_bk10}. 
    12251254  Choosing polyTEOS10-bsq implies that the state variables used by the model are $\Theta$ and $S_A$. 
    12261255  In particular, the initial state deined by the user have to be given as \textit{Conservative} Temperature and 
    12271256  \textit{Absolute} Salinity. 
    1228   In addition, setting \np{ln\_useCT} to \forcode{.true.} convert the Conservative SST to potential SST prior to 
     1257  In addition, when using TEOS10, the Conservative SST is converted to potential SST prior to 
    12291258  either computing the air-sea and ice-sea fluxes (forced mode) or 
    12301259  sending the SST field to the atmosphere (coupled mode). 
    1231 \item[\np{nn\_eos}~\forcode{= 0}] 
     1260\item[\np{ln\_eos80}\forcode{=.true.}] 
    12321261  the polyEOS80-bsq equation of seawater is used. 
    12331262  It takes the same polynomial form as the polyTEOS10, but the coefficients have been optimized to 
     
    12381267  The pressure in decibars is approximated by the depth in meters. 
    12391268  With thsi EOS, the specific heat capacity of sea water, $C_p$, is a function of temperature, salinity and 
    1240   pressure \citep{UNESCO1983}. 
     1269  pressure \citep{fofonoff.millard_bk83}. 
    12411270  Nevertheless, a severe assumption is made in order to have a heat content ($C_p T_p$) which 
    12421271  is conserved by the model: $C_p$ is set to a constant value, the TEOS10 value. 
    1243 \item[\np{nn\_eos}~\forcode{= 1}] 
    1244   a simplified EOS (S-EOS) inspired by \citet{Vallis06} is chosen, 
     1272\item[\np{ln\_seos}\forcode{=.true.}] 
     1273  a simplified EOS (S-EOS) inspired by \citet{vallis_bk06} is chosen, 
    12451274  the coefficients of which has been optimized to fit the behavior of TEOS10 
    1246   (Roquet, personal comm.) (see also \citet{Roquet_JPO2015}). 
     1275  (Roquet, personal comm.) (see also \citet{roquet.madec.ea_JPO15}). 
    12471276  It provides a simplistic linear representation of both cabbeling and thermobaricity effects which 
    1248   is enough for a proper treatment of the EOS in theoretical studies \citep{Roquet_JPO2015}. 
     1277  is enough for a proper treatment of the EOS in theoretical studies \citep{roquet.madec.ea_JPO15}. 
    12491278  With such an equation of state there is no longer a distinction between 
    12501279  \textit{conservative} and \textit{potential} temperature, 
    12511280  as well as between \textit{absolute} and \textit{practical} salinity. 
    12521281  S-EOS takes the following expression: 
     1282 
    12531283  \begin{gather*} 
    1254     % \label{eq:tra_S-EOS} 
     1284    % \label{eq:TRA_S-EOS} 
    12551285    \begin{alignedat}{2} 
    12561286    &d_a(T,S,z) = \frac{1}{\rho_o} \big[ &- a_0 \; ( 1 + 0.5 \; \lambda_1 \; T_a + \mu_1 \; z ) * &T_a \big. \\ 
    1257     &                                    &+ b_0 \; ( 1 - 0.5 \; \lambda_2 \; S_a - \mu_2 \; z ) * &S_a       \\   
     1287    &                                    &+ b_0 \; ( 1 - 0.5 \; \lambda_2 \; S_a - \mu_2 \; z ) * &S_a       \\ 
    12581288    &                              \big. &- \nu \;                           T_a                  &S_a \big] \\ 
    12591289    \end{alignedat} 
     
    12611291    \text{with~} T_a = T - 10 \, ; \, S_a = S - 35 \, ; \, \rho_o = 1026~Kg/m^3 
    12621292  \end{gather*} 
    1263   where the computer name of the coefficients as well as their standard value are given in \autoref{tab:SEOS}. 
     1293  where the computer name of the coefficients as well as their standard value are given in \autoref{tab:TRA_SEOS}. 
    12641294  In fact, when choosing S-EOS, various approximation of EOS can be specified simply by 
    12651295  changing the associated coefficients. 
     
    12721302%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    12731303\begin{table}[!tb] 
    1274   \begin{center} 
    1275     \begin{tabular}{|l|l|l|l|} 
    1276       \hline 
    1277       coeff.      & computer name   & S-EOS           & description                      \\ 
    1278       \hline 
    1279       $a_0$       & \np{rn\_a0}     & $1.6550~10^{-1}$ & linear thermal expansion coeff. \\ 
    1280       \hline 
    1281       $b_0$       & \np{rn\_b0}     & $7.6554~10^{-1}$ & linear haline  expansion coeff. \\ 
    1282       \hline 
    1283       $\lambda_1$ & \np{rn\_lambda1}& $5.9520~10^{-2}$ & cabbeling coeff. in $T^2$       \\ 
    1284       \hline 
    1285       $\lambda_2$ & \np{rn\_lambda2}& $5.4914~10^{-4}$ & cabbeling coeff. in $S^2$       \\ 
    1286       \hline 
    1287       $\nu$       & \np{rn\_nu}     & $2.4341~10^{-3}$ & cabbeling coeff. in $T \, S$    \\ 
    1288       \hline 
    1289       $\mu_1$     & \np{rn\_mu1}    & $1.4970~10^{-4}$ & thermobaric coeff. in T         \\ 
    1290       \hline 
    1291       $\mu_2$     & \np{rn\_mu2}    & $1.1090~10^{-5}$ & thermobaric coeff. in S         \\ 
    1292       \hline 
    1293     \end{tabular} 
    1294     \caption{ 
    1295       \protect\label{tab:SEOS} 
    1296       Standard value of S-EOS coefficients. 
    1297     } 
    1298 \end{center} 
     1304  \centering 
     1305  \begin{tabular}{|l|l|l|l|} 
     1306    \hline 
     1307    coeff.     & computer name   & S-EOS           & description                      \\ 
     1308    \hline 
     1309    $a_0$       & \np{rn\_a0}     & $1.6550~10^{-1}$ & linear thermal expansion coeff. \\ 
     1310    \hline 
     1311    $b_0$         & \np{rn\_b0}     & $7.6554~10^{-1}$ & linear haline  expansion coeff. \\ 
     1312    \hline 
     1313    $\lambda_1$   & \np{rn\_lambda1}& $5.9520~10^{-2}$ & cabbeling coeff. in $T^2$       \\ 
     1314    \hline 
     1315    $\lambda_2$   & \np{rn\_lambda2}& $5.4914~10^{-4}$ & cabbeling coeff. in $S^2$       \\ 
     1316    \hline 
     1317    $\nu$       & \np{rn\_nu}     & $2.4341~10^{-3}$ & cabbeling coeff. in $T \, S$      \\ 
     1318    \hline 
     1319    $\mu_1$     & \np{rn\_mu1}   & $1.4970~10^{-4}$ & thermobaric coeff. in T         \\ 
     1320    \hline 
     1321    $\mu_2$     & \np{rn\_mu2}   & $1.1090~10^{-5}$ & thermobaric coeff. in S         \\ 
     1322    \hline 
     1323  \end{tabular} 
     1324  \caption{Standard value of S-EOS coefficients} 
     1325  \label{tab:TRA_SEOS} 
    12991326\end{table} 
    13001327%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
     
    13031330%        Brunt-V\"{a}is\"{a}l\"{a} Frequency 
    13041331% ------------------------------------------------------------------------------------------------------------- 
    1305 \subsection{Brunt-V\"{a}is\"{a}l\"{a} frequency (\protect\np{nn\_eos}~\forcode{= 0..2})} 
     1332\subsection[Brunt-V\"{a}is\"{a}l\"{a} frequency] 
     1333{Brunt-V\"{a}is\"{a}l\"{a} frequency} 
    13061334\label{subsec:TRA_bn2} 
    13071335 
     
    13121340In particular, $N^2$ has to be computed at the local pressure 
    13131341(pressure in decibar being approximated by the depth in meters). 
    1314 The expression for $N^2$  is given by:  
     1342The expression for $N^2$  is given by: 
    13151343\[ 
    1316   % \label{eq:tra_bn2} 
     1344  % \label{eq:TRA_bn2} 
    13171345  N^2 = \frac{g}{e_{3w}} \lt( \beta \; \delta_{k + 1/2}[S] - \alpha \; \delta_{k + 1/2}[T] \rt) 
    13181346\] 
     
    13211349The coefficients are a polynomial function of temperature, salinity and depth which expression depends on 
    13221350the chosen EOS. 
    1323 They are computed through \textit{eos\_rab}, a \fortran function that can be found in \mdl{eosbn2}. 
     1351They are computed through \textit{eos\_rab}, a \fortran\ function that can be found in \mdl{eosbn2}. 
    13241352 
    13251353% ------------------------------------------------------------------------------------------------------------- 
     
    13291357\label{subsec:TRA_fzp} 
    13301358 
    1331 The freezing point of seawater is a function of salinity and pressure \citep{UNESCO1983}: 
    1332 \begin{equation} 
    1333   \label{eq:tra_eos_fzp} 
     1359The freezing point of seawater is a function of salinity and pressure \citep{fofonoff.millard_bk83}: 
     1360\begin{equation} 
     1361  \label{eq:TRA_eos_fzp} 
    13341362  \begin{split} 
    13351363    &T_f (S,p) = \lt( a + b \, \sqrt{S} + c \, S \rt) \, S + d \, p \\ 
    1336     &\text{where~} a = -0.0575, \, b = 1.710523~10^{-3}, \, c = -2.154996~10^{-4} \\  
     1364    &\text{where~} a = -0.0575, \, b = 1.710523~10^{-3}, \, c = -2.154996~10^{-4} \\ 
    13371365    &\text{and~} d = -7.53~10^{-3} 
    13381366    \end{split} 
    13391367\end{equation} 
    13401368 
    1341 \autoref{eq:tra_eos_fzp} is only used to compute the potential freezing point of sea water 
    1342 (\ie referenced to the surface $p = 0$), 
    1343 thus the pressure dependent terms in \autoref{eq:tra_eos_fzp} (last term) have been dropped. 
     1369\autoref{eq:TRA_eos_fzp} is only used to compute the potential freezing point of sea water 
     1370(\ie\ referenced to the surface $p = 0$), 
     1371thus the pressure dependent terms in \autoref{eq:TRA_eos_fzp} (last term) have been dropped. 
    13441372The freezing point is computed through \textit{eos\_fzp}, 
    1345 a \fortran function that can be found in \mdl{eosbn2}. 
    1346  
    1347 % ------------------------------------------------------------------------------------------------------------- 
    1348 %        Potential Energy      
     1373a \fortran\ function that can be found in \mdl{eosbn2}. 
     1374 
     1375% ------------------------------------------------------------------------------------------------------------- 
     1376%        Potential Energy 
    13491377% ------------------------------------------------------------------------------------------------------------- 
    13501378%\subsection{Potential Energy anomalies} 
     
    13551383 
    13561384% ================================================================ 
    1357 % Horizontal Derivative in zps-coordinate  
    1358 % ================================================================ 
    1359 \section{Horizontal derivative in \textit{zps}-coordinate (\protect\mdl{zpshde})} 
     1385% Horizontal Derivative in zps-coordinate 
     1386% ================================================================ 
     1387\section[Horizontal derivative in \textit{zps}-coordinate (\textit{zpshde.F90})] 
     1388{Horizontal derivative in \textit{zps}-coordinate (\protect\mdl{zpshde})} 
    13601389\label{sec:TRA_zpshde} 
    13611390 
    1362 \gmcomment{STEVEN: to be consistent with earlier discussion of differencing and averaging operators,  
     1391\gmcomment{STEVEN: to be consistent with earlier discussion of differencing and averaging operators, 
    13631392I've changed "derivative" to "difference" and "mean" to "average"} 
    13641393 
    1365 With partial cells (\np{ln\_zps}~\forcode{= .true.}) at bottom and top (\np{ln\_isfcav}~\forcode{= .true.}), 
     1394With partial cells (\np{ln\_zps}\forcode{=.true.}) at bottom and top (\np{ln\_isfcav}\forcode{=.true.}), 
    13661395in general, tracers in horizontally adjacent cells live at different depths. 
    13671396Horizontal gradients of tracers are needed for horizontal diffusion (\mdl{traldf} module) and 
    13681397the hydrostatic pressure gradient calculations (\mdl{dynhpg} module). 
    1369 The partial cell properties at the top (\np{ln\_isfcav}~\forcode{= .true.}) are computed in the same way as 
     1398The partial cell properties at the top (\np{ln\_isfcav}\forcode{=.true.}) are computed in the same way as 
    13701399for the bottom. 
    13711400So, only the bottom interpolation is explained below. 
     
    13731402Before taking horizontal gradients between the tracers next to the bottom, 
    13741403a linear interpolation in the vertical is used to approximate the deeper tracer as if 
    1375 it actually lived at the depth of the shallower tracer point (\autoref{fig:Partial_step_scheme}). 
     1404it actually lived at the depth of the shallower tracer point (\autoref{fig:TRA_Partial_step_scheme}). 
    13761405For example, for temperature in the $i$-direction the needed interpolated temperature, $\widetilde T$, is: 
    13771406 
    13781407%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
    13791408\begin{figure}[!p] 
    1380   \begin{center} 
    1381     \includegraphics[]{Fig_partial_step_scheme} 
    1382     \caption{ 
    1383       \protect\label{fig:Partial_step_scheme} 
    1384       Discretisation of the horizontal difference and average of tracers in the $z$-partial step coordinate 
    1385       (\protect\np{ln\_zps}~\forcode{= .true.}) in the case $(e3w_k^{i + 1} - e3w_k^i) > 0$. 
    1386       A linear interpolation is used to estimate $\widetilde T_k^{i + 1}$, 
    1387       the tracer value at the depth of the shallower tracer point of the two adjacent bottom $T$-points. 
    1388       The horizontal difference is then given by: $\delta_{i + 1/2} T_k = \widetilde T_k^{\, i + 1} -T_k^{\, i}$ and 
    1389       the average by: $\overline T_k^{\, i + 1/2} = (\widetilde T_k^{\, i + 1/2} - T_k^{\, i}) / 2$. 
    1390     } 
    1391   \end{center} 
     1409  \centering 
     1410  \includegraphics[width=\textwidth]{Fig_partial_step_scheme} 
     1411  \caption[Discretisation of the horizontal difference and average of tracers in 
     1412  the $z$-partial step coordinate]{ 
     1413    Discretisation of the horizontal difference and average of tracers in 
     1414    the $z$-partial step coordinate (\protect\np{ln\_zps}\forcode{=.true.}) in 
     1415    the case $(e3w_k^{i + 1} - e3w_k^i) > 0$. 
     1416    A linear interpolation is used to estimate $\widetilde T_k^{i + 1}$, 
     1417    the tracer value at the depth of the shallower tracer point of 
     1418    the two adjacent bottom $T$-points. 
     1419    The horizontal difference is then given by: 
     1420    $\delta_{i + 1/2} T_k = \widetilde T_k^{\, i + 1} -T_k^{\, i}$ and 
     1421    the average by: 
     1422    $\overline T_k^{\, i + 1/2} = (\widetilde T_k^{\, i + 1/2} - T_k^{\, i}) / 2$.} 
     1423  \label{fig:TRA_Partial_step_scheme} 
    13921424\end{figure} 
    13931425%>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
     
    14021434  \rt. 
    14031435\] 
    1404 and the resulting forms for the horizontal difference and the horizontal average value of $T$ at a $U$-point are:  
    1405 \begin{equation} 
    1406   \label{eq:zps_hde} 
     1436and the resulting forms for the horizontal difference and the horizontal average value of $T$ at a $U$-point are: 
     1437\begin{equation} 
     1438  \label{eq:TRA_zps_hde} 
    14071439  \begin{split} 
    14081440    \delta_{i + 1/2} T       &= 
     
    14281460Instead of forming a linear approximation of density, we compute $\widetilde \rho$ from the interpolated values of 
    14291461$T$ and $S$, and the pressure at a $u$-point 
    1430 (in the equation of state pressure is approximated by depth, see \autoref{subsec:TRA_eos}):  
     1462(in the equation of state pressure is approximated by depth, see \autoref{subsec:TRA_eos}): 
    14311463\[ 
    1432   % \label{eq:zps_hde_rho} 
     1464  % \label{eq:TRA_zps_hde_rho} 
    14331465  \widetilde \rho = \rho (\widetilde T,\widetilde S,z_u) \quad \text{where~} z_u = \min \lt( z_T^{i + 1},z_T^i \rt) 
    14341466\] 
     
    14411473Note that in almost all the advection schemes presented in this Chapter, 
    14421474both averaging and differencing operators appear. 
    1443 Yet \autoref{eq:zps_hde} has not been used in these schemes: 
     1475Yet \autoref{eq:TRA_zps_hde} has not been used in these schemes: 
    14441476in contrast to diffusion and pressure gradient computations, 
    14451477no correction for partial steps is applied for advection. 
Note: See TracChangeset for help on using the changeset viewer.