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 994 for trunk/DOC/TexFiles/Chapters/Chap_DYN.tex – NEMO

Ignore:
Timestamp:
2008-05-28T11:01:09+02:00 (16 years ago)
Author:
gm
Message:

trunk - add steven correction + several other things + rename BETA into TexFiles?

Location:
trunk/DOC/TexFiles
Files:
1 copied
1 moved

Legend:

Unmodified
Added
Removed
  • trunk/DOC/TexFiles/Chapters/Chap_DYN.tex

    r817 r994  
    107107\left\{  
    108108\begin{aligned} 
    109 {-\frac{1}{e_{1u} } } & {\overline {\left( { \frac{\zeta +f}{e_{3f} }} \right)} }^{\,i} & {\overline{\overline {\left( {e_{1v} e_{3v} v} \right)}} }^{\,i, j+1/2}    \\ 
    110 {+\frac{1}{e_{2v} } } & {\overline {\left( {\frac{\zeta +f}{e_{3f} }} \right)} }^{\,j}  & {\overline{\overline {\left( {e_{2u} e_{3u} u} \right)}} }^{\,i+1/2, j}   
     109{+\frac{1}{e_{1u} } } & {\overline {\left( { \frac{\zeta +f}{e_{3f} }} \right)} }^{\,i} & {\overline{\overline {\left( {e_{1v} e_{3v} v} \right)}} }^{\,i, j+1/2}    \\ 
     110{-\frac{1}{e_{2v} } } & {\overline {\left( {\frac{\zeta +f}{e_{3f} }} \right)} }^{\,j}  & {\overline{\overline {\left( {e_{2u} e_{3u} u} \right)}} }^{\,i+1/2, j}   
    111111\end{aligned}  
    112112 \right. 
     
    124124\left\{ { 
    125125\begin{aligned} 
    126 {-\frac{1}{e_{1u} }\; {\overline {\left( {\frac{\zeta +f}{e_{3f} }} \right) 
     126{+\frac{1}{e_{1u} }\; {\overline {\left( {\frac{\zeta +f}{e_{3f} }} \right) 
    127127\;\overline {\left( {e_{1v} e_{3v} v} \right)} ^{\,i+1/2}} }^{\,j} }    \\ 
    128 {+\frac{1}{e_{2v} }\; {\overline {\left( {\frac{\zeta +f}{e_{3f} }} \right) 
     128{-\frac{1}{e_{2v} }\; {\overline {\left( {\frac{\zeta +f}{e_{3f} }} \right) 
    129129\;\overline {\left( {e_{2u} e_{3u} u} \right)} ^{\,j+1/2}} }^{\,i} } 
    130130\end{aligned}  
     
    145145\left\{ { 
    146146\begin{aligned} 
    147  {-\frac{1}{e_{1u} }\; {\overline {\left( {\frac{\zeta }{e_{3f} }} \right)} }^{\,i}  
     147 {+\frac{1}{e_{1u} }\; {\overline {\left( {\frac{\zeta }{e_{3f} }} \right)} }^{\,i}  
    148148 \; {\overline{\overline {\left( {e_{1v} \; e_{3v} \ v} \right)}} }^{\,i,j+1/2} -\frac{1}{e_{1u} } 
    149149 \; {\overline {\left( {\frac{f}{e_{3f} }} \right)  
    150150 \;\overline {\left( {e_{1v} \; e_{3v} \ v} \right)} ^{\,i+1/2}} }^{\,j} } \\ 
    151 {+\frac{1}{e_{2v} }\; {\overline {\left( {\frac{\zeta }{e_{3f} }} \right)} }^j 
     151{-\frac{1}{e_{2v} }\; {\overline {\left( {\frac{\zeta }{e_{3f} }} \right)} }^j 
    152152 \; {\overline{\overline {\left( {e_{2u} \; e_{3u} \ u} \right)}} }^{\,i+1/2,j} +\frac{1}{e_{2v} } 
    153153 \; {\overline {\left( {\frac{f}{e_{3f} }} \right) 
     
    220220-q\,e_3 \,u       &\equiv -\frac{1}{e_{2v} }  \left[  
    221221{{\begin{array}{*{20}c} 
    222    {\,\ \ a_{j-1/2}^{i   }  \left( {e_{2u} e_{3v} \ u} \right)_{j+1}^{i+1/2} }  
    223    {\,+\,b_{j-1/2}^{i+1}  \left( {e_{2u} e_{3v} \ u} \right)_{j+1/2}^{i+1} } \\ 
     222   {\,\ \ a_{j-1/2}^{i   }  \left( {e_{2u} e_{3u} \ u} \right)_{j+1}^{i+1/2} }  
     223   {\,+\,b_{j-1/2}^{i+1}  \left( {e_{2u} e_{3u} \ u} \right)_{j+1/2}^{i+1} } \\ 
    224224 \\ 
    225       {  +\,c_{j+1/2}^{i+1} \left( {e_{2u} e_{3v} \ u} \right)_{j+1/2}^{i+1} }  
    226    {\,+\,d_{j+1/2}^{i   }  \left( {e_{2u} e_{3v} \ u} \right)_{j+1/2}^{i   } } \\ 
     225      {  +\,c_{j+1/2}^{i+1} \left( {e_{2u} e_{3u} \ u} \right)_{j+1/2}^{i+1} }  
     226   {\,+\,d_{j+1/2}^{i   }  \left( {e_{2u} e_{3u} \ u} \right)_{j+1/2}^{i   } } \\ 
    227227\end{array} }} \right] 
    228228\end{aligned}  
     
    670670\right]+\delta _j \left[ {e_{1v} e_{3v} v} \right]} \right)}  
    671671\end{equation} 
    672  
    673 where EMP is the surface freshwater budget, expressed in $Kg.m^{-2}.s^{-1}$,  
    674 and $\rho _w =1,000\,Kg.m^{-3}$ is the volumic mass of pure water. If river  
    675 runoff is expressed as a surface freshwater flux, see \S\ref{SBC}, then EMP  
    676 can be written as the evaporation minus precipitation, minus the river runoff.  
    677 The sea-surface height is evaluated using a leapfrog scheme in combination  
    678 with an Asselin time filter, $i.e.$ the velocity appearing in  
    679 \eqref{Eq_dynspg_ssh} is centred in time (\textit{now} velocity).  
     672where EMP is the surface freshwater budget, expressed in Kg/m$^2$/s  
     673(which is equal to mm/s), and $\rho _w$=1,000~Kg/m$^3$ is the volumic  
     674mass of pure water. If river runoff is expressed as a surface freshwater flux  
     675(see \S\ref{SBC}) then EMP can be written as the evaporation minus  
     676precipitation, minus the river runoff. The sea-surface height is evaluated  
     677using a leapfrog scheme in combination with an Asselin time filter, $i.e.$  
     678the velocity appearing in \eqref{Eq_dynspg_ssh} is centred in time  
     679(\textit{now} velocity).  
    680680 
    681681The surface pressure gradient, also evaluated using a leap-frog scheme, is  
     
    683683\begin{equation} \label{Eq_dynspg_exp} 
    684684\left\{ \begin{aligned} 
    685  - \frac{1}                      {e_{1u}} \; \delta _{i+1/2} \left[  \,\eta\,  \right]    \\ 
    686  \\ 
    687  - \frac{1}                      {e_{2v}} \; \delta _{j+1/2} \left[  \,\eta\,  \right]   
     685 - \frac{1}{e_{1u}} \;  \delta _{i+1/2} \left[  \,\eta\,  \right]    \\ 
     686 - \frac{1}{e_{2v}} \;  \delta _{j+1/2} \left[  \,\eta\,  \right]   
    688687\end{aligned} \right. 
    689688\end{equation}  
     
    704703proposed by \citet{Griffies2004}. The general idea is to solve the free surface  
    705704equation with a small time step \np{rdtbt}, while the three dimensional  
    706 prognostic variables are solved with a longer time step that is a multiple of \np{rdtbt}  
    707 (Fig.\ref {Fig_DYN_dynspg_ts}).  
     705prognostic variables are solved with a longer time step that is a multiple of  
     706\np{rdtbt} (Fig.\ref {Fig_DYN_dynspg_ts}).  
    708707 
    709708%>   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   >   > 
     
    711710\begin{center} 
    712711\includegraphics[width=0.90\textwidth]{./Figures/Fig_DYN_dynspg_ts.pdf} 
    713 \caption{Schematic of the split-explicit time stepping scheme for the barotropic  
    714 and baroclinic modes, after \citet{Griffies2004}. Time increases to the right.  
    715 Baroclinic time steps are denoted by $t-\Delta t$, $t, t+\Delta t$, and $t+2\Delta t$.  
    716 The curved line represents a leap-frog time step, and the smaller barotropic time  
    717 steps $N \Delta t=2\Delta t$ are denoted by the zig-zag line. The vertically  
    718 integrated forcing \textbf{M}(t) computed at the baroclinic time step $t$  
    719 represents the interaction between the barotropic and baroclinic motions.  
    720 While keeping the total depth, tracer, and freshwater forcing fields fixed, a  
    721 leap-frog integration carries the surface height and vertically integrated velocity  
    722 from $t$ to $t+2 \Delta t$ using N barotropic time steps of length $\Delta t$.  
    723 Time averaging the barotropic fields over the N+1 time steps (endpoints  
    724 included) centers the vertically integrated velocity at the baroclinic timestep  
    725 $t+\Delta t$. A baroclinic leap-frog time step carries the surface height to  
     712\caption{Schematic of the split-explicit time stepping scheme for the external  
     713and internal modes. Time increases to the right.  
     714Internal mode time steps (which are also the model time steps) are denoted  
     715by $t-\Delta t$, $t, t+\Delta t$, and $t+2\Delta t$.  
     716The curved line represents a leap-frog time step, and the smaller time  
     717steps $N \Delta t_e=\frac{3}{2}\Delta t$ are denoted by the zig-zag line. The vertically  
     718integrated forcing \textbf{M}(t) computed at the model time step $t$  
     719represents the interaction between the external and internal motions.  
     720While keeping \textbf{M} and freshwater forcing field fixed, a  
     721leap-frog integration carries the external mode variables (surface height and vertically integrated velocity) from $t$ to $t+\frac{3}{2} \Delta t$ using N external time steps of length $\Delta t_e$.  
     722Time averaging the external fields over the $\frac{2}{3}N+1$ time steps (endpoints  
     723included) centers the vertically integrated velocity and the sea surface height at the model timestep $t+\Delta t$. These averaged values are used to update \textbf{M}(t) with both the surface pressure gradient and the Coriolis force.  
     724A baroclinic leap-frog time step carries the surface height to The model time stepping scheme can then be achieved by  
    726725$t+\Delta t$ using the convergence of the time averaged vertically integrated  
    727726velocity taken from baroclinic time step t. } 
Note: See TracChangeset for help on using the changeset viewer.