Changeset 10414 for NEMO/trunk/doc/latex/NEMO/subfiles/chap_ASM.tex
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NEMO/trunk/doc/latex/NEMO/subfiles/chap_ASM.tex
r10406 r10414 1 \documentclass[../tex_main/NEMO_manual]{subfiles} 1 \documentclass[../main/NEMO_manual]{subfiles} 2 2 3 \begin{document} 3 4 % ================================================================ … … 11 12 \minitoc 12 13 13 14 14 \newpage 15 $\ $\newline % force a new line16 15 17 16 The ASM code adds the functionality to apply increments to the model variables: temperature, salinity, … … 45 44 is corrected by adding the analysis increments for temperature, salinity, horizontal velocity and SSH as 46 45 additional tendency terms to the prognostic equations: 47 \begin{align } \label{eq:wa_traj_iau}48 {\bf x}^{a}(t_{i}) = M(t_{i}, t_{0})[{\bf x}^{b}(t_{0})] 49 \; + \; F_{i} \delta \tilde{\bf x}^{a} 50 \end{align }46 \begin{align*} 47 % \label{eq:wa_traj_iau} 48 {\bf x}^{a}(t_{i}) = M(t_{i}, t_{0})[{\bf x}^{b}(t_{0})] \; + \; F_{i} \delta \tilde{\bf x}^{a} 49 \end{align*} 51 50 where $F_{i}$ is a weighting function for applying the increments $\delta\tilde{\bf x}^{a}$ defined such that 52 51 $\sum_{i=1}^{N} F_{i}=1$. … … 58 57 In addition, two different weighting functions have been implemented. 59 58 The first function employs constant weights, 60 \begin{align} \label{eq:F1_i} 61 F^{(1)}_{i} 62 =\left\{ \begin{array}{ll} 63 0 & {\rm if} \; \; \; t_{i} < t_{m} \\ 64 1/M & {\rm if} \; \; \; t_{m} < t_{i} \leq t_{n} \\ 65 0 & {\rm if} \; \; \; t_{i} > t_{n} 66 \end{array} \right. 59 \begin{align} 60 \label{eq:F1_i} 61 F^{(1)}_{i} 62 =\left\{ 63 \begin{array}{ll} 64 0 & {\rm if} \; \; \; t_{i} < t_{m} \\ 65 1/M & {\rm if} \; \; \; t_{m} < t_{i} \leq t_{n} \\ 66 0 & {\rm if} \; \; \; t_{i} > t_{n} 67 \end{array} 68 \right. 67 69 \end{align} 68 70 where $M = m-n$. 69 71 The second function employs peaked hat-like weights in order to give maximum weight in the centre of the sub-window, 70 72 with the weighting reduced linearly to a small value at the window end-points: 71 \begin{align} \label{eq:F2_i} 72 F^{(2)}_{i} 73 =\left\{ \begin{array}{ll} 74 0 & {\rm if} \; \; \; t_{i} < t_{m} \\ 75 \alpha \, i & {\rm if} \; \; \; t_{m} \leq t_{i} \leq t_{M/2} \\ 76 \alpha \, (M - i +1) & {\rm if} \; \; \; t_{M/2} < t_{i} \leq t_{n} \\ 77 0 & {\rm if} \; \; \; t_{i} > t_{n} 78 \end{array} \right. 73 \begin{align} 74 \label{eq:F2_i} 75 F^{(2)}_{i} 76 =\left\{ 77 \begin{array}{ll} 78 0 & {\rm if} \; \; \; t_{i} < t_{m} \\ 79 \alpha \, i & {\rm if} \; \; \; t_{m} \leq t_{i} \leq t_{M/2} \\ 80 \alpha \, (M - i +1) & {\rm if} \; \; \; t_{M/2} < t_{i} \leq t_{n} \\ 81 0 & {\rm if} \; \; \; t_{i} > t_{n} 82 \end{array} 83 \right. 79 84 \end{align} 80 85 where $\alpha^{-1} = \sum_{i=1}^{M/2} 2i$ and $M$ is assumed to be even. … … 89 94 The velocity increments may be initialized by the iterative application of a divergence damping operator. 90 95 In iteration step $n$ new estimates of velocity increments $u^{n}_I$ and $v^{n}_I$ are updated by: 91 \begin{equation} \label{eq:asm_dmp} 92 \left\{ \begin{aligned} 93 u^{n}_I = u^{n-1}_I + \frac{1}{e_{1u} } \delta_{i+1/2} \left( {A_D 94 \;\chi^{n-1}_I } \right) \\ 95 \\ 96 v^{n}_I = v^{n-1}_I + \frac{1}{e_{2v} } \delta_{j+1/2} \left( {A_D 97 \;\chi^{n-1}_I } \right) \\ 98 \end{aligned} \right., 96 \begin{equation} 97 \label{eq:asm_dmp} 98 \left\{ 99 \begin{aligned} 100 u^{n}_I = u^{n-1}_I + \frac{1}{e_{1u} } \delta_{i+1/2} \left( {A_D 101 \;\chi^{n-1}_I } \right) \\ \\ 102 v^{n}_I = v^{n-1}_I + \frac{1}{e_{2v} } \delta_{j+1/2} \left( {A_D 103 \;\chi^{n-1}_I } \right) \\ 104 \end{aligned} 105 \right., 99 106 \end{equation} 100 107 where 101 \begin{equation} \label{eq:asm_div} 102 \chi^{n-1}_I = \frac{1}{e_{1t}\,e_{2t}\,e_{3t} } 103 \left( {\delta_i \left[ {e_{2u}\,e_{3u}\,u^{n-1}_I} \right] 104 +\delta_j \left[ {e_{1v}\,e_{3v}\,v^{n-1}_I} \right]} \right). 105 \end{equation} 108 \[ 109 % \label{eq:asm_div} 110 \chi^{n-1}_I = \frac{1}{e_{1t}\,e_{2t}\,e_{3t} } 111 \left( {\delta_i \left[ {e_{2u}\,e_{3u}\,u^{n-1}_I} \right] 112 +\delta_j \left[ {e_{1v}\,e_{3v}\,v^{n-1}_I} \right]} \right). 113 \] 106 114 By the application of \autoref{eq:asm_dmp} and \autoref{eq:asm_dmp} the divergence is filtered in each iteration, 107 115 and the vorticity is left unchanged. … … 169 177 \end{clines} 170 178 179 \biblio 180 171 181 \end{document}
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