Changeset 14644 for NEMO/branches/2020/dev_r14116_HPC-04_mcastril_Mixed_Precision_implementation_final/doc/latex/NEMO/subfiles/chap_time_domain.tex
- Timestamp:
- 2021-03-26T15:33:49+01:00 (3 years ago)
- Location:
- NEMO/branches/2020/dev_r14116_HPC-04_mcastril_Mixed_Precision_implementation_final
- Files:
-
- 3 edited
Legend:
- Unmodified
- Added
- Removed
-
NEMO/branches/2020/dev_r14116_HPC-04_mcastril_Mixed_Precision_implementation_final
- Property svn:externals
-
old new 9 9 10 10 # SETTE 11 ^/utils/CI/sette _wave@13990sette11 ^/utils/CI/sette@14244 sette
-
- Property svn:externals
-
NEMO/branches/2020/dev_r14116_HPC-04_mcastril_Mixed_Precision_implementation_final/doc/latex/NEMO/subfiles
- Property svn:ignore
-
old new 1 *.aux 2 *.bbl 3 *.blg 4 *.fdb* 5 *.fls 6 *.idx 7 *.ilg 1 8 *.ind 2 *.ilg 9 *.lo* 10 *.out 11 *.pdf 12 *.pyg 13 *.tdo 14 *.toc 15 *.xdv 16 cache*
-
- Property svn:ignore
-
NEMO/branches/2020/dev_r14116_HPC-04_mcastril_Mixed_Precision_implementation_final/doc/latex/NEMO/subfiles/chap_time_domain.tex
r11693 r14644 6 6 \label{chap:TD} 7 7 8 \thispagestyle{plain}9 10 8 \chaptertoc 11 9 … … 14 12 {\footnotesize 15 13 \begin{tabularx}{0.5\textwidth}{l||X|X} 16 Release & Author(s) & 14 Release & Author(s) & 17 15 Modifications \\ 18 16 \hline 19 {\em 4.0} & {\em J\'{e}r\^{o}me Chanut \newline Tim Graham} & 17 {\em 4.0} & {\em J\'{e}r\^{o}me Chanut \newline Tim Graham} & 20 18 {\em Review \newline Update } \\ 21 {\em 3.6} & {\em Christian \'{E}th\'{e} } & 19 {\em 3.6} & {\em Christian \'{E}th\'{e} } & 22 20 {\em Update } \\ 23 {\em $\leq$ 3.4} & {\em Gurvan Madec } & 21 {\em $\leq$ 3.4} & {\em Gurvan Madec } & 24 22 {\em First version } \\ 25 23 \end{tabularx} … … 46 44 47 45 The time stepping used in \NEMO\ is a three level scheme that can be represented as follows: 46 48 47 \begin{equation} 49 48 \label{eq:TD} 50 49 x^{t + \rdt} = x^{t - \rdt} + 2 \, \rdt \ \text{RHS}_x^{t - \rdt, \, t, \, t + \rdt} 51 50 \end{equation} 51 52 52 where $x$ stands for $u$, $v$, $T$ or $S$; 53 53 RHS is the \textbf{R}ight-\textbf{H}and-\textbf{S}ide of the corresponding time evolution equation; … … 99 99 first designed by \citet{robert_JMSJ66} and more comprehensively studied by \citet{asselin_MWR72}, 100 100 is a kind of laplacian diffusion in time that mixes odd and even time steps: 101 101 102 \begin{equation} 102 103 \label{eq:TD_asselin} 103 104 x_F^t = x^t + \gamma \, \lt[ x_F^{t - \rdt} - 2 x^t + x^{t + \rdt} \rt] 104 105 \end{equation} 106 105 107 where the subscript $F$ denotes filtered values and $\gamma$ is the Asselin coefficient. 106 108 $\gamma$ is initialized as \np{rn_atfp}{rn\_atfp} (namelist parameter). … … 134 136 The conditions for stability of second and fourth order horizontal diffusion schemes are 135 137 \citep{griffies_bk04}: 138 136 139 \begin{equation} 137 140 \label{eq:TD_euler_stability} … … 142 145 \end{cases} 143 146 \end{equation} 147 144 148 where $e$ is the smallest grid size in the two horizontal directions and 145 149 $A^h$ is the mixing coefficient. … … 153 157 To overcome the stability constraint, a backward (or implicit) time differencing scheme is used. 154 158 This scheme is unconditionally stable but diffusive and can be written as follows: 159 155 160 \begin{equation} 156 161 \label{eq:TD_imp} … … 170 175 where RHS is the right hand side of the equation except for the vertical diffusion term. 171 176 We rewrite \autoref{eq:TD_imp} as: 177 172 178 \begin{equation} 173 179 \label{eq:TD_imp_mat} 174 180 -c(k + 1) \; T^{t + 1}(k + 1) + d(k) \; T^{t + 1}(k) - \; c(k) \; T^{t + 1}(k - 1) \equiv b(k) 175 181 \end{equation} 182 176 183 where 184 177 185 \[ 178 186 c(k) = A_w^{vT} (k) \, / \, e_{3w} (k) \text{,} \quad … … 241 249 $Q$ is redistributed over several time step. 242 250 In the modified LF-RA environment, these two formulations have been replaced by: 251 243 252 \begin{gather} 244 253 \label{eq:TD_forcing} … … 248 257 - \gamma \, \rdt \, \lt( Q^{t + \rdt / 2} - Q^{t - \rdt / 2} \rt) 249 258 \end{gather} 259 250 260 The change in the forcing formulation given by \autoref{eq:TD_forcing} 251 261 (see \autoref{fig:TD_MLF_forcing}) has a significant effect: … … 377 387 % 378 388 \end{flalign*} 389 379 390 \begin{flalign*} 380 391 \allowdisplaybreaks … … 389 400 % 390 401 \end{flalign*} 402 391 403 \begin{flalign*} 392 404 \allowdisplaybreaks
Note: See TracChangeset
for help on using the changeset viewer.