Changeset 11544
- Timestamp:
- 2019-09-13T16:37:38+02:00 (5 years ago)
- Location:
- NEMO/trunk/doc/latex/NEMO/subfiles
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NEMO/trunk/doc/latex/NEMO/subfiles/apdx_algos.tex
r11543 r11544 18 18 % ------------------------------------------------------------------------------------------------------------- 19 19 \section{Upstream Biased Scheme (UBS) (\protect\np{ln\_traadv\_ubs}\forcode{ = .true.})} 20 \label{sec: TRA_adv_ubs}20 \label{sec:ALGOS_tra_adv_ubs} 21 21 22 22 The UBS advection scheme is an upstream biased third order scheme based on … … 25 25 For example, in the $i$-direction: 26 26 \begin{equation} 27 \label{eq: tra_adv_ubs2}27 \label{eq:ALGOS_tra_adv_ubs2} 28 28 \tau_u^{ubs} = \left\{ 29 29 \begin{aligned} … … 35 35 or equivalently, the advective flux is 36 36 \begin{equation} 37 \label{eq: tra_adv_ubs2}37 \label{eq:ALGOS_tra_adv_ubs2} 38 38 U_{i+1/2} \ \tau_u^{ubs} 39 39 =U_{i+1/2} \ \overline{ T_i - \frac{1}{6}\,\tau"_i }^{\,i+1/2} … … 85 85 NB 3: It is straight forward to rewrite \autoref{eq:TRA_adv_ubs} as follows: 86 86 \begin{equation} 87 \label{eq: tra_adv_ubs2}87 \label{eq:ALGOS_tra_adv_ubs2} 88 88 \tau_u^{ubs} = \left\{ 89 89 \begin{aligned} … … 95 95 or equivalently 96 96 \begin{equation} 97 \label{eq: tra_adv_ubs2}97 \label{eq:ALGOS_tra_adv_ubs2} 98 98 \begin{split} 99 99 e_{2u} e_{3u}\,u_{i+1/2} \ \tau_u^{ubs} … … 112 112 laplacian diffusion: 113 113 \begin{equation} 114 \label{eq: tra_ldf_lap}114 \label{eq:ALGOS_tra_ldf_lap} 115 115 \begin{split} 116 116 D_T^{lT} =\frac{1}{e_{1T} \; e_{2T}\; e_{3T} } &\left[ {\quad \delta_i … … 125 125 bilaplacian: 126 126 \begin{equation} 127 \label{eq: tra_ldf_lap}127 \label{eq:ALGOS_tra_ldf_lap} 128 128 \begin{split} 129 129 D_T^{lT} =&-\frac{1}{e_{1T} \; e_{2T}\; e_{3T}} \\ … … 138 138 it comes: 139 139 \begin{equation} 140 \label{eq: tra_ldf_lap}140 \label{eq:ALGOS_tra_ldf_lap} 141 141 \begin{split} 142 142 D_T^{lT} =&-\frac{1}{12}\,\frac{1}{e_{1T} \; e_{2T}\; e_{3T}} \\ … … 149 149 if the velocity is uniform (\ie\ $|u|=cst$) then the diffusive flux is 150 150 \begin{equation} 151 \label{eq: tra_ldf_lap}151 \label{eq:ALGOS_tra_ldf_lap} 152 152 \begin{split} 153 153 F_u^{lT} = - \frac{1}{12} … … 161 161 162 162 \begin{equation} 163 \label{eq: tra_adv_ubs2}163 \label{eq:ALGOS_tra_adv_ubs2} 164 164 \begin{split} 165 165 F_u^{lT} &= - \frac{1}{2} e_{2u} e_{3u}\,|u|_{i+1/2} \;\frac{1}{6} \;\delta_{i+1/2}[\tau"_i] … … 171 171 sol 1 coefficient at T-point ( add $e_{1u}$ and $e_{1T}$ on both side of first $\delta$): 172 172 \begin{equation} 173 \label{eq: tra_adv_ubs2}173 \label{eq:ALGOS_tra_adv_ubs2} 174 174 \begin{split} 175 175 F_u^{lT} &= - \frac{1}{12} \frac{e_{2u} e_{3u}}{e_{1u}}\;\delta_{i+1/2}\left[ \frac{e_{1T}^3\,|u|}{e_{1T}e_{2T}\,e_{3T}}\,\delta_i \left[ \frac{e_{2u} e_{3u} }{e_{1u} } \delta_{i+1/2}[\tau] \right] \right] … … 180 180 sol 2 coefficient at u-point: split $|u|$ into $\sqrt{|u|}$ and $e_{1T}$ into $\sqrt{e_{1u}}$ 181 181 \begin{equation} 182 \label{eq: tra_adv_ubs2}182 \label{eq:ALGOS_tra_adv_ubs2} 183 183 \begin{split} 184 184 F_u^{lT} &= - \frac{1}{12} {e_{1u}}^1 \sqrt{e_{1u}|u|} \frac{e_{2u} e_{3u}}{e_{1u}}\;\delta_{i+1/2}\left[ \frac{1}{e_{2T}\,e_{3T}}\,\delta_i \left[ \sqrt{e_{1u}|u|} \frac{e_{2u} e_{3u} }{e_{1u} } \delta_{i+1/2}[\tau] \right] \right] \\ … … 192 192 % ------------------------------------------------------------------------------------------------------------- 193 193 \section{Leapfrog energetic} 194 \label{sec: LF}194 \label{sec:ALGOS_LF} 195 195 196 196 We adopt the following semi-discrete notation for time derivative. … … 198 198 the time derivation and averaging operators at the mid time step are: 199 199 \[ 200 % \label{eq: dt_mt}200 % \label{eq:ALGOS_dt_mt} 201 201 \begin{split} 202 202 \delta_{t+\rdt/2} [q] &= \ \ \, q^{t+\rdt} - q^{t} \\ … … 210 210 The Leap-frog time stepping given by \autoref{eq:DOM_nxt} can be defined as: 211 211 \[ 212 % \label{eq: LF}212 % \label{eq:ALGOS_LF} 213 213 \frac{\partial q}{\partial t} 214 214 \equiv \frac{1}{\rdt} \overline{ \delta_{t+\rdt/2}[q]}^{\,t} … … 220 220 As such it respects the quadratic invariant in integral forms, \ie\ the following continuous property, 221 221 \[ 222 % \label{eq: Energy}222 % \label{eq:ALGOS_Energy} 223 223 \int_{t_0}^{t_1} {q\, \frac{\partial q}{\partial t} \;dt} 224 224 =\int_{t_0}^{t_1} {\frac{1}{2}\, \frac{\partial q^2}{\partial t} \;dt} … … 278 278 For example in the (\textbf{i},\textbf{k}) plane, the four triads are defined at the $(i,k)$ $T$-point as follows: 279 279 \begin{equation} 280 \label{eq: Gf_triads}280 \label{eq:ALGOS_Gf_triads} 281 281 _i^k \mathbb{T}_{i_p}^{k_p} (T) 282 282 = \frac{1}{4} \ {b_u}_{\,i+i_p}^{\,k} \ A_i^k \left( … … 291 291 and $_i^k \mathbb{R}_{i_p}^{k_p}$ is the slope associated with each triad: 292 292 \begin{equation} 293 \label{eq: Gf_slopes}293 \label{eq:ALGOS_Gf_slopes} 294 294 _i^k \mathbb{R}_{i_p}^{k_p} 295 295 =\frac{ {e_{3w}}_{\,i}^{\,k+k_p}} { {e_{1u}}_{\,i+i_p}^{\,k}} \ \frac … … 297 297 {\left(\alpha / \beta \right)_i^k \ \delta_{k+k_p}[T^i ] - \delta_{k+k_p}[S^i ] } 298 298 \end{equation} 299 Note that in \autoref{eq: Gf_slopes} we use the ratio $\alpha / \beta$ instead of299 Note that in \autoref{eq:ALGOS_Gf_slopes} we use the ratio $\alpha / \beta$ instead of 300 300 multiplying the temperature derivative by $\alpha$ and the salinity derivative by $\beta$. 301 301 This is more efficient as the ratio $\alpha / \beta$ can to be evaluated directly. 302 302 303 Note that in \autoref{eq: Gf_triads}, we chose to use ${b_u}_{\,i+i_p}^{\,k}$ instead of ${b_{uw}}_{\,i+i_p}^{\,k+k_p}$.303 Note that in \autoref{eq:ALGOS_Gf_triads}, we chose to use ${b_u}_{\,i+i_p}^{\,k}$ instead of ${b_{uw}}_{\,i+i_p}^{\,k+k_p}$. 304 304 This choice has been motivated by the decrease of tracer variance and 305 the presence of partial cell at the ocean bottom (see \autoref{ apdx:Gf_operator}).305 the presence of partial cell at the ocean bottom (see \autoref{subsec:ALGOS_Gf_operator}). 306 306 307 307 %>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> … … 310 310 \includegraphics[width=\textwidth]{Fig_ISO_triad} 311 311 \caption{ 312 \protect\label{fig: ISO_triad}312 \protect\label{fig:ALGOS_ISO_triad} 313 313 Triads used in the Griffies's like iso-neutral diffision scheme for 314 314 $u$-component (upper panel) and $w$-component (lower panel). … … 321 321 They take the following expression: 322 322 \begin{flalign*} 323 % \label{eq: Gf_fluxes}323 % \label{eq:ALGOS_Gf_fluxes} 324 324 \begin{split} 325 325 {_i^k {\mathbb{F}_u}_{i_p}^{k_p} } (T) … … 334 334 the sum of the fluxes that cross the $u$- and $w$-face (\autoref{fig:TRIADS_ISO_triad}): 335 335 \begin{flalign} 336 \label{eq: iso_flux}336 \label{eq:ALGOS_iso_flux} 337 337 \textbf{F}_{iso}(T) 338 338 &\equiv \sum_{\substack{i_p,\,k_p}} … … 364 364 the divergence of the sum of all the four triad fluxes: 365 365 \begin{equation} 366 \label{eq: Gf_operator}366 \label{eq:ALGOS_Gf_operator} 367 367 D_l^T = \frac{1}{b_T} \sum_{\substack{i_p,\,k_p}} \left\{ 368 368 \delta_{i} \left[{_{i+1/2-i_p}^k {\mathbb{F}_u }_{i_p}^{k_p}} \right] … … 377 377 the limit of flat iso-neutral direction: 378 378 \[ 379 % \label{eq: Gf_property1a}379 % \label{eq:ALGOS_Gf_property1a} 380 380 D_l^T = \frac{1}{b_T} \ \delta_{i} 381 381 \left[ \frac{e_{2u}\,e_{3u}}{e_{1u}} \; \overline{A}^{\,i} \; \delta_{i+1/2}[T] \right] … … 401 401 The iso-neutral flux of locally referenced potential density is zero, \ie 402 402 \begin{align*} 403 % \label{eq: Gf_property2}403 % \label{eq:ALGOS_Gf_property2} 404 404 \begin{matrix} 405 405 &{_i^k {\mathbb{F}_u}_{i_p}^{k_p} (\rho)} … … 411 411 \end{matrix} 412 412 \end{align*} 413 This result is trivially obtained using the \autoref{eq: Gf_triads} applied to $T$ and $S$ and414 the definition of the triads' slopes \autoref{eq: Gf_slopes}.413 This result is trivially obtained using the \autoref{eq:ALGOS_Gf_triads} applied to $T$ and $S$ and 414 the definition of the triads' slopes \autoref{eq:ALGOS_Gf_slopes}. 415 415 416 416 \item[$\bullet$ conservation of tracer] 417 417 The iso-neutral diffusion term conserve the total tracer content, \ie 418 418 \[ 419 % \label{eq: Gf_property1}419 % \label{eq:ALGOS_Gf_property1} 420 420 \sum_{i,j,k} \left\{ D_l^T \ b_T \right\} = 0 421 421 \] … … 425 425 The iso-neutral diffusion term does not increase the total tracer variance, \ie 426 426 \[ 427 % \label{eq: Gf_property1}427 % \label{eq:ALGOS_Gf_property1} 428 428 \sum_{i,j,k} \left\{ T \ D_l^T \ b_T \right\} \leq 0 429 429 \] 430 The property is demonstrated in the \autoref{ apdx:Gf_operator}.430 The property is demonstrated in the \autoref{subsec:ALGOS_Gf_operator}. 431 431 It is a key property for a diffusion term. 432 432 It means that the operator is also a dissipation term, … … 438 438 The iso-neutral diffusion operator is self-adjoint, \ie 439 439 \[ 440 % \label{eq: Gf_property1}440 % \label{eq:ALGOS_Gf_property1} 441 441 \sum_{i,j,k} \left\{ S \ D_l^T \ b_T \right\} = \sum_{i,j,k} \left\{ D_l^S \ T \ b_T \right\} 442 442 \] … … 444 444 We just have to apply the same routine. 445 445 This properties can be demonstrated quite easily in a similar way the "non increase of tracer variance" property 446 has been proved (see \autoref{apdx: Gf_operator}).446 has been proved (see \autoref{apdx:ALGOS_Gf_operator}). 447 447 \end{description} 448 448 … … 462 462 The eddy induced velocity is given by: 463 463 \begin{equation} 464 \label{eq: eiv_v}464 \label{eq:ALGOS_eiv_v} 465 465 \begin{split} 466 466 u^* & = - \frac{1}{e_2\,e_{3}} \;\partial_k \left( e_2 \, A_e \; r_i \right) … … 487 487 % give here the expression using the triads. It is different from the one given in \autoref{eq:LDF_eiv} 488 488 % see just below a copy of this equation: 489 %\begin{equation} \label{eq: ldfeiv}489 %\begin{equation} \label{eq:ALGOS_ldfeiv} 490 490 %\begin{split} 491 491 % u^* & = \frac{1}{e_{2u}e_{3u}}\; \delta_k \left[e_{2u} \, A_{uw}^{eiv} \; \overline{r_{1w}}^{\,i+1/2} \right]\\ … … 495 495 %\end{equation} 496 496 \[ 497 % \label{eq: eiv_vd}497 % \label{eq:ALGOS_eiv_vd} 498 498 \textbf{F}_{eiv}^T \equiv \left( 499 499 \begin{aligned} … … 540 540 we end up with the skew form of the eddy induced advective fluxes: 541 541 \begin{equation} 542 \label{eq: eiv_skew_continuous}542 \label{eq:ALGOS_eiv_skew_continuous} 543 543 \textbf{F}_{eiv}^T = 544 544 \begin{pmatrix} … … 548 548 \end{equation} 549 549 The tendency associated with eddy induced velocity is then simply the divergence of 550 the \autoref{eq: eiv_skew_continuous} fluxes.550 the \autoref{eq:ALGOS_eiv_skew_continuous} fluxes. 551 551 It naturally conserves the tracer content, as it is expressed in flux form and, 552 552 as the advective form, it preserves the tracer variance. 553 Another interesting property of \autoref{eq: eiv_skew_continuous} form is that when $A=A_e$,553 Another interesting property of \autoref{eq:ALGOS_eiv_skew_continuous} form is that when $A=A_e$, 554 554 a simplification occurs in the sum of the iso-neutral diffusion and eddy induced velocity terms: 555 555 \begin{flalign*} 556 % \label{eq: eiv_skew+eiv_continuous}556 % \label{eq:ALGOS_eiv_skew+eiv_continuous} 557 557 \textbf{F}_{iso}^T + \textbf{F}_{eiv}^T &= 558 558 \begin{pmatrix} … … 576 576 This property has been used to reduce the computational time \citep{griffies_JPO98}, 577 577 but it is not of practical use as usually $A \neq A_e$. 578 Nevertheless this property can be used to choose a discret form of \autoref{eq: eiv_skew_continuous} which579 is consistent with the iso-neutral operator \autoref{eq: Gf_operator}.580 Using the slopes \autoref{eq: Gf_slopes} and defining $A_e$ at $T$-point(\ie\ as $A$,578 Nevertheless this property can be used to choose a discret form of \autoref{eq:ALGOS_eiv_skew_continuous} which 579 is consistent with the iso-neutral operator \autoref{eq:ALGOS_Gf_operator}. 580 Using the slopes \autoref{eq:ALGOS_Gf_slopes} and defining $A_e$ at $T$-point(\ie\ as $A$, 581 581 the eddy diffusivity coefficient), the resulting discret form is given by: 582 582 \begin{equation} 583 \label{eq: eiv_skew}583 \label{eq:ALGOS_eiv_skew} 584 584 \textbf{F}_{eiv}^T \equiv \frac{1}{4} \left( 585 585 \begin{aligned} … … 593 593 \right) 594 594 \end{equation} 595 Note that \autoref{eq: eiv_skew} is valid in $z$-coordinate with or without partial cells.595 Note that \autoref{eq:ALGOS_eiv_skew} is valid in $z$-coordinate with or without partial cells. 596 596 In $z^*$ or $s$-coordinate, the slope between the level and the geopotential surfaces must be added to 597 597 $\mathbb{R}$ for the discret form to be exact. … … 599 599 Such a choice of discretisation is consistent with the iso-neutral operator as 600 600 it uses the same definition for the slopes. 601 It also ensures the conservation of the tracer variance (see Appendix \autoref{apdx:eiv_skew}),601 It also ensures the conservation of the tracer variance (see \autoref{subsec:ALGOS_eiv_skew}), 602 602 \ie\ it does not include a diffusive component but is a "pure" advection term. 603 603 … … 607 607 % ================================================================ 608 608 \subsection{Discrete invariants of the iso-neutral diffrusion} 609 \label{subsec: Gf_operator}609 \label{subsec:ALGOS_Gf_operator} 610 610 611 611 Demonstration of the decrease of the tracer variance in the (\textbf{i},\textbf{j}) plane. … … 702 702 \intertext{ 703 703 Then outing in factor the triad in each of the four terms of the summation and 704 substituting the triads by their expression given in \autoref{eq: Gf_triads}.704 substituting the triads by their expression given in \autoref{eq:ALGOS_Gf_triads}. 705 705 It becomes: 706 706 } … … 774 774 % ================================================================ 775 775 \subsection{Discrete invariants of the skew flux formulation} 776 \label{subsec: eiv_skew}776 \label{subsec:ALGOS_eiv_skew} 777 777 778 778 Demonstration for the conservation of the tracer variance in the (\textbf{i},\textbf{j}) plane. … … 784 784 \int_D \nabla \cdot \textbf{F}_{eiv}(T) \; T \;dv \equiv 0 785 785 \end{align*} 786 The discrete form of its left hand side is obtained using \autoref{eq: eiv_skew}786 The discrete form of its left hand side is obtained using \autoref{eq:ALGOS_eiv_skew} 787 787 \begin{align*} 788 788 \sum\limits_{i,k} \sum_{\substack{i_p,\,k_p}} \Biggl\{ \;\; -
NEMO/trunk/doc/latex/NEMO/subfiles/chap_DIU.tex
r11435 r11544 57 57 %=============================================================== 58 58 \section{Warm layer model} 59 \label{sec: warm_layer_sec}59 \label{sec:DIU_warm_layer_sec} 60 60 %=============================================================== 61 61 … … 65 65 \frac{\partial{\Delta T_{\mathrm{wl}}}}{\partial{t}}&=&\frac{Q(\nu+1)}{D_T\rho_w c_p 66 66 \nu}-\frac{(\nu+1)ku^*_{w}f(L_a)\Delta T}{D_T\Phi\!\left(\frac{D_T}{L}\right)} \mbox{,} 67 \label{eq: ecmwf1} \\68 L&=&\frac{\rho_w c_p u^{*^3}_{w}}{\kappa g \alpha_w Q }\mbox{,}\label{eq: ecmwf2}67 \label{eq:DIU_ecmwf1} \\ 68 L&=&\frac{\rho_w c_p u^{*^3}_{w}}{\kappa g \alpha_w Q }\mbox{,}\label{eq:DIU_ecmwf2} 69 69 \end{align} 70 70 where $\Delta T_{\mathrm{wl}}$ is the temperature difference between the top of the warm layer and the depth $D_T=3$\,m at which there is assumed to be no diurnal signal. 71 In equation (\autoref{eq: ecmwf1}) $\alpha_w=2\times10^{-4}$ is the thermal expansion coefficient of water,71 In equation (\autoref{eq:DIU_ecmwf1}) $\alpha_w=2\times10^{-4}$ is the thermal expansion coefficient of water, 72 72 $\kappa=0.4$ is von K\'{a}rm\'{a}n's constant, $c_p$ is the heat capacity at constant pressure of sea water, 73 73 $\rho_w$ is the water density, and $L$ is the Monin-Obukhov length. … … 79 79 the relationship $u^*_{w} = u_{10}\sqrt{\frac{C_d\rho_a}{\rho_w}}$, where $C_d$ is the drag coefficient, 80 80 and $\rho_a$ is the density of air. 81 The symbol $Q$ in equation (\autoref{eq: ecmwf1}) is the instantaneous total thermal energy flux into81 The symbol $Q$ in equation (\autoref{eq:DIU_ecmwf1}) is the instantaneous total thermal energy flux into 82 82 the diurnal layer, \ie 83 83 \[ 84 84 Q = Q_{\mathrm{sol}} + Q_{\mathrm{lw}} + Q_{\mathrm{h}}\mbox{,} 85 % \label{eq: e_flux_eqn}85 % \label{eq:DIU_e_flux_eqn} 86 86 \] 87 87 where $Q_{\mathrm{h}}$ is the sensible and latent heat flux, $Q_{\mathrm{lw}}$ is the long wave flux, 88 88 and $Q_{\mathrm{sol}}$ is the solar flux absorbed within the diurnal warm layer. 89 89 For $Q_{\mathrm{sol}}$ the 9 term representation of \citet{gentemann.minnett.ea_JGR09} is used. 90 In equation \autoref{eq: ecmwf1} the function $f(L_a)=\max(1,L_a^{\frac{2}{3}})$,90 In equation \autoref{eq:DIU_ecmwf1} the function $f(L_a)=\max(1,L_a^{\frac{2}{3}})$, 91 91 where $L_a=0.3$\footnote{ 92 92 This is a global average value, more accurately $L_a$ could be computed as $L_a=(u^*_{w}/u_s)^{\frac{1}{2}}$, … … 99 99 4\zeta^2}{1+3\zeta+0.25\zeta^2} &(\zeta \ge 0) \\ 100 100 (1 - 16\zeta)^{-\frac{1}{2}} & (\zeta < 0) \mbox{,} 101 \end{array} \right. \label{eq: stab_func_eqn}101 \end{array} \right. \label{eq:DIU_stab_func_eqn} 102 102 \end{equation} 103 where $\zeta=\frac{D_T}{L}$. It is clear that the first derivative of (\autoref{eq: stab_func_eqn}),104 and thus of (\autoref{eq: ecmwf1}), is discontinuous at $\zeta=0$ (\ie\ $Q\rightarrow0$ in105 equation (\autoref{eq: ecmwf2})).103 where $\zeta=\frac{D_T}{L}$. It is clear that the first derivative of (\autoref{eq:DIU_stab_func_eqn}), 104 and thus of (\autoref{eq:DIU_ecmwf1}), is discontinuous at $\zeta=0$ (\ie\ $Q\rightarrow0$ in 105 equation (\autoref{eq:DIU_ecmwf2})). 106 106 107 The two terms on the right hand side of (\autoref{eq: ecmwf1}) represent different processes.107 The two terms on the right hand side of (\autoref{eq:DIU_ecmwf1}) represent different processes. 108 108 The first term is simply the diabatic heating or cooling of the diurnal warm layer due to 109 109 thermal energy fluxes into and out of the layer. … … 114 114 115 115 \section{Cool skin model} 116 \label{sec: cool_skin_sec}116 \label{sec:DIU_cool_skin_sec} 117 117 118 118 %=============================================================== … … 121 121 As the cool skin is so thin (~1\,mm) we ignore the solar flux component to the heat flux and the Saunders equation for the cool skin temperature difference $\Delta T_{\mathrm{cs}}$ becomes 122 122 \[ 123 % \label{eq: sunders_eqn}123 % \label{eq:DIU_sunders_eqn} 124 124 \Delta T_{\mathrm{cs}}=\frac{Q_{\mathrm{ns}}\delta}{k_t} \mbox{,} 125 125 \] … … 128 128 $\delta$ is the thickness of the skin layer and is given by 129 129 \begin{equation} 130 \label{eq: sunders_thick_eqn}130 \label{eq:DIU_sunders_thick_eqn} 131 131 \delta=\frac{\lambda \mu}{u^*_{w}} \mbox{,} 132 132 \end{equation} … … 134 134 \citet{saunders_JAS67} suggested varied between 5 and 10. 135 135 136 The value of $\lambda$ used in equation (\autoref{eq: sunders_thick_eqn}) is that of \citet{artale.iudicone.ea_JGR02},136 The value of $\lambda$ used in equation (\autoref{eq:DIU_sunders_thick_eqn}) is that of \citet{artale.iudicone.ea_JGR02}, 137 137 which is shown in \citet{tu.tsuang_GRL05} to outperform a number of other parametrisations at 138 138 both low and high wind speeds. 139 139 Specifically, 140 140 \[ 141 % \label{eq: artale_lambda_eqn}141 % \label{eq:DIU_artale_lambda_eqn} 142 142 \lambda = \frac{ 8.64\times10^4 u^*_{w} k_t }{ \rho c_p h \mu \gamma }\mbox{,} 143 143 \] … … 145 145 $\gamma$ is a dimensionless function of wind speed $u$: 146 146 \[ 147 % \label{eq: artale_gamma_eqn}147 % \label{eq:DIU_artale_gamma_eqn} 148 148 \gamma = 149 149 \begin{cases} -
NEMO/trunk/doc/latex/NEMO/subfiles/chap_STO.tex
r11435 r11544 30 30 As detailed in \cite{brankart_OM13}, the stochastic formulation of the equation of state can be written as: 31 31 \begin{equation} 32 \label{eq: eos_sto}32 \label{eq:STO_eos_sto} 33 33 \rho = \frac{1}{2} \sum_{i=1}^m\{ \rho[T+\Delta T_i,S+\Delta S_i,p_o(z)] + \rho[T-\Delta T_i,S-\Delta S_i,p_o(z)] \} 34 34 \end{equation} … … 37 37 the scalar product of the respective local T/S gradients with random walks $\mathbf{\xi}$: 38 38 \begin{equation} 39 \label{eq: sto_pert}39 \label{eq:STO_sto_pert} 40 40 \Delta T_i = \mathbf{\xi}_i \cdot \nabla T \qquad \hbox{and} \qquad \Delta S_i = \mathbf{\xi}_i \cdot \nabla S 41 41 \end{equation} … … 59 59 60 60 \begin{equation} 61 \label{eq: autoreg}61 \label{eq:STO_autoreg} 62 62 \xi^{(i)}_{k+1} = a^{(i)} \xi^{(i)}_k + b^{(i)} w^{(i)} + c^{(i)} 63 63 \end{equation} … … 74 74 75 75 \[ 76 % \label{eq: ord1}76 % \label{eq:STO_ord1} 77 77 \left\{ 78 78 \begin{array}{l} … … 91 91 92 92 \begin{equation} 93 \label{eq: ord2}93 \label{eq:STO_ord2} 94 94 \left\{ 95 95 \begin{array}{l} … … 107 107 \noindent 108 108 In this way, higher order processes can be easily generated recursively using the same piece of code implementing 109 \autoref{eq: autoreg}, and using successive processes from order $0$ to~$n-1$ as~$w^{(i)}$.110 The parameters in \autoref{eq: ord2} are computed so that this recursive application of111 \autoref{eq: autoreg} leads to processes with the required standard deviation and correlation timescale,109 \autoref{eq:STO_autoreg}, and using successive processes from order $0$ to~$n-1$ as~$w^{(i)}$. 110 The parameters in \autoref{eq:STO_ord2} are computed so that this recursive application of 111 \autoref{eq:STO_autoreg} leads to processes with the required standard deviation and correlation timescale, 112 112 with the additional condition that the $n-1$ first derivatives of the autocorrelation function are equal to 113 113 zero at~$t=0$, so that the resulting processes become smoother and smoother as $n$ increases. … … 135 135 136 136 \mdl{stopts} : stochastic parametrisation associated with the non-linearity of the equation of 137 seawater, implementing \autoref{eq: sto_pert} so as specifics in the equation of state138 implementing \autoref{eq: eos_sto}.137 seawater, implementing \autoref{eq:STO_sto_pert} so as specifics in the equation of state 138 implementing \autoref{eq:STO_eos_sto}. 139 139 % \end{description} 140 140 141 141 The \mdl{stopar} module includes three public routines called in the model: 142 142 143 (\rou{sto\_par}) is a direct implementation of \autoref{eq: autoreg},143 (\rou{sto\_par}) is a direct implementation of \autoref{eq:STO_autoreg}, 144 144 applied at each model grid point (in 2D or 3D), and called at each model time step ($k$) to 145 145 update every autoregressive process ($i=1,\ldots,m$). -
NEMO/trunk/doc/latex/NEMO/subfiles/chap_conservation.tex
r11435 r11544 7 7 % ================================================================ 8 8 \chapter{Invariants of the Primitive Equations} 9 \label{chap:Invariant} 9 \label{chap:CONS} 10 10 11 \chaptertoc 11 12 … … 45 46 % ------------------------------------------------------------------------------------------------------------- 46 47 \section{Conservation properties on ocean dynamics} 47 \label{sec: Invariant_dyn}48 \label{sec:CONS_Invariant_dyn} 48 49 49 50 The non linear term of the momentum equations has been split into a vorticity term, … … 63 64 The continuous formulation of the vorticity term satisfies following integral constraints: 64 65 \[ 65 % \label{eq: vor_vorticity}66 % \label{eq:CONS_vor_vorticity} 66 67 \int_D {{\textbf {k}}\cdot \frac{1}{e_3 }\nabla \times \left( {\varsigma 67 68 \;{\mathrm {\mathbf k}}\times {\textbf {U}}_h } \right)\;dv} =0 … … 69 70 70 71 \[ 71 % \label{eq: vor_enstrophy}72 % \label{eq:CONS_vor_enstrophy} 72 73 if\quad \chi =0\quad \quad \int\limits_D {\varsigma \;{\textbf{k}}\cdot 73 74 \frac{1}{e_3 }\nabla \times \left( {\varsigma {\textbf{k}}\times {\textbf{U}}_h } \right)\;dv} =-\int\limits_D {\frac{1}{2}\varsigma ^2\,\chi \;dv} … … 76 77 77 78 \[ 78 % \label{eq: vor_energy}79 % \label{eq:CONS_vor_energy} 79 80 \int_D {{\textbf{U}}_h \times \left( {\varsigma \;{\textbf{k}}\times {\textbf{U}}_h } \right)\;dv} =0 80 81 \] … … 88 89 Using the symmetry or anti-symmetry properties of the operators (Eqs II.1.10 and 11), 89 90 it can be shown that the scheme (II.2.11) satisfies (II.4.1b) but not (II.4.1c), 90 while scheme (II.2.12) satisfies (II.4.1c) but not (II.4.1b) (see appendix C). 91 while scheme (II.2.12) satisfies (II.4.1c) but not (II.4.1b) (see appendix C). 91 92 Note that the enstrophy conserving scheme on total vorticity has been chosen as the standard discrete form of 92 93 the vorticity term. … … 102 103 the horizontal gradient of horizontal kinetic energy: 103 104 104 \begin{equation} \label{eq: keg_zad}105 \int_D {{\textbf{U}}_h \cdot \nabla _h \left( {1/2\;{\textbf{U}}_h ^2} \right)\;dv} =-\int_D {{\textbf{U}}_h \cdot \frac{w}{e_3 }\;\frac{\partial 105 \begin{equation} \label{eq:CONS_keg_zad} 106 \int_D {{\textbf{U}}_h \cdot \nabla _h \left( {1/2\;{\textbf{U}}_h ^2} \right)\;dv} =-\int_D {{\textbf{U}}_h \cdot \frac{w}{e_3 }\;\frac{\partial 106 107 {\textbf{U}}_h }{\partial k}\;dv} 107 108 \end{equation} 108 109 109 110 Using the discrete form given in {\S}II.2-a and the symmetry or anti-symmetry properties of 110 the mean and difference operators, \autoref{eq: keg_zad} is demonstrated in the Appendix C.111 The main point here is that satisfying \autoref{eq: keg_zad} links the choice of the discrete forms of111 the mean and difference operators, \autoref{eq:CONS_keg_zad} is demonstrated in the Appendix C. 112 The main point here is that satisfying \autoref{eq:CONS_keg_zad} links the choice of the discrete forms of 112 113 the vertical advection and of the horizontal gradient of horizontal kinetic energy. 113 114 Choosing one imposes the other. … … 127 128 128 129 \[ 129 % \label{eq: hpg_pe}130 % \label{eq:CONS_hpg_pe} 130 131 \int_D {-\frac{1}{\rho_o }\left. {\nabla p^h} \right|_z \cdot {\textbf {U}}_h \;dv} \;=\;\int_D {\nabla .\left( {\rho \,{\textbf{U}}} \right)\;g\;z\;\;dv} 131 132 \] … … 133 134 Using the discrete form given in {\S}~II.2-a and the symmetry or anti-symmetry properties of 134 135 the mean and difference operators, (II.4.3) is demonstrated in the Appendix C. 135 The main point here is that satisfying (II.4.3) strongly constraints the discrete expression of the depth of 136 The main point here is that satisfying (II.4.3) strongly constraints the discrete expression of the depth of 136 137 $T$-points and of the term added to the pressure gradient in $s-$coordinates: the depth of a $T$-point, $z_T$, 137 138 is defined as the sum the vertical scale factors at $w$-points starting from the surface. … … 145 146 Nevertheless, the $\psi$-equation is solved numerically by an iterative solver (see {\S}~III.5), 146 147 thus the property is only satisfied with the accuracy required on the solver. 147 In addition, with the rigid-lid approximation, the change of horizontal kinetic energy due to the work of 148 In addition, with the rigid-lid approximation, the change of horizontal kinetic energy due to the work of 148 149 surface pressure forces is exactly zero: 149 150 \[ 150 % \label{eq: spg}151 % \label{eq:CONS_spg} 151 152 \int_D {-\frac{1}{\rho_o }\nabla _h } \left( {p_s } \right)\cdot {\textbf{U}}_h \;dv=0 152 153 \] … … 161 162 % ------------------------------------------------------------------------------------------------------------- 162 163 \section{Conservation properties on ocean thermodynamics} 163 \label{sec: Invariant_tra}164 \label{sec:CONS_Invariant_tra} 164 165 165 166 In continuous formulation, the advective terms of the tracer equations conserve the tracer content and 166 167 the quadratic form of the tracer, \ie 167 168 \[ 168 % \label{eq: tra_tra2}169 % \label{eq:CONS_tra_tra2} 169 170 \int_D {\nabla .\left( {T\;{\textbf{U}}} \right)\;dv} =0 170 171 \;\text{and} … … 176 177 Note that in both continuous and discrete formulations, there is generally no strict conservation of mass, 177 178 since the equation of state is non linear with respect to $T$ and $S$. 178 In practice, the mass is conserved with a very good accuracy. 179 In practice, the mass is conserved with a very good accuracy. 179 180 180 181 % ------------------------------------------------------------------------------------------------------------- … … 182 183 % ------------------------------------------------------------------------------------------------------------- 183 184 \subsection{Conservation properties on momentum physics} 184 \label{subsec: Invariant_dyn_physics}185 \label{subsec:CONS_Invariant_dyn_physics} 185 186 186 187 \textbf{* lateral momentum diffusion term} … … 188 189 The continuous formulation of the horizontal diffusion of momentum satisfies the following integral constraints~: 189 190 \[ 190 % \label{eq: dynldf_dyn}191 % \label{eq:CONS_dynldf_dyn} 191 192 \int\limits_D {\frac{1}{e_3 }{\mathrm {\mathbf k}}\cdot \nabla \times \left[ {\nabla 192 193 _h \left( {A^{lm}\;\chi } \right)-\nabla _h \times \left( {A^{lm}\;\zeta … … 195 196 196 197 \[ 197 % \label{eq: dynldf_div}198 % \label{eq:CONS_dynldf_div} 198 199 \int\limits_D {\nabla _h \cdot \left[ {\nabla _h \left( {A^{lm}\;\chi } 199 200 \right)-\nabla _h \times \left( {A^{lm}\;\zeta \;{\mathrm {\mathbf k}}} \right)} … … 202 203 203 204 \[ 204 % \label{eq: dynldf_curl}205 % \label{eq:CONS_dynldf_curl} 205 206 \int_D {{\mathrm {\mathbf U}}_h \cdot \left[ {\nabla _h \left( {A^{lm}\;\chi } 206 207 \right)-\nabla _h \times \left( {A^{lm}\;\zeta \;{\mathrm {\mathbf k}}} \right)} … … 209 210 210 211 \[ 211 % \label{eq: dynldf_curl2}212 % \label{eq:CONS_dynldf_curl2} 212 213 \mbox{if}\quad A^{lm}=cste\quad \quad \int_D {\zeta \;{\mathrm {\mathbf k}}\cdot 213 214 \nabla \times \left[ {\nabla _h \left( {A^{lm}\;\chi } \right)-\nabla _h … … 217 218 218 219 \[ 219 % \label{eq: dynldf_div2}220 % \label{eq:CONS_dynldf_div2} 220 221 \mbox{if}\quad A^{lm}=cste\quad \quad \int_D {\chi \;\nabla _h \cdot \left[ 221 222 {\nabla _h \left( {A^{lm}\;\chi } \right)-\nabla _h \times \left( … … 250 251 251 252 \[ 252 % \label{eq: dynzdf_dyn}253 % \label{eq:CONS_dynzdf_dyn} 253 254 \begin{aligned} 254 255 & \int_D {\frac{1}{e_3 }} \frac{\partial }{\partial k}\left( \frac{A^{vm}}{e_3 }\frac{\partial {\textbf{U}}_h }{\partial k} \right) \;dv = \overrightarrow{\textbf{0}} \\ … … 258 259 conservation of vorticity, dissipation of enstrophy 259 260 \[ 260 % \label{eq: dynzdf_vor}261 % \label{eq:CONS_dynzdf_vor} 261 262 \begin{aligned} 262 263 & \int_D {\frac{1}{e_3 }{\mathrm {\mathbf k}}\cdot \nabla \times \left( {\frac{1}{e_3 … … 270 271 conservation of horizontal divergence, dissipation of square of the horizontal divergence 271 272 \[ 272 % \label{eq: dynzdf_div}273 % \label{eq:CONS_dynzdf_div} 273 274 \begin{aligned} 274 275 &\int_D {\nabla \cdot \left( {\frac{1}{e_3 }\frac{\partial }{\partial … … 289 290 % ------------------------------------------------------------------------------------------------------------- 290 291 \subsection{Conservation properties on tracer physics} 291 \label{subsec: Invariant_tra_physics}292 \label{subsec:CONS_Invariant_tra_physics} 292 293 293 294 The numerical schemes used for tracer subgridscale physics are written in such a way that … … 296 297 the quadratic form of these quantities (\ie\ their variance) globally tends to diminish. 297 298 As for the advective term, there is generally no strict conservation of mass even if, 298 in practice, the mass is conserved with a very good accuracy. 299 300 \textbf{* lateral physics: }conservation of tracer, dissipation of tracer 299 in practice, the mass is conserved with a very good accuracy. 300 301 \textbf{* lateral physics: }conservation of tracer, dissipation of tracer 301 302 variance, i.e. 302 303 303 304 \[ 304 % \label{eq: traldf_t_t2}305 % \label{eq:CONS_traldf_t_t2} 305 306 \begin{aligned} 306 307 &\int_D \nabla\, \cdot\, \left( A^{lT} \,\Re \,\nabla \,T \right)\;dv = 0 \\ … … 312 313 313 314 \[ 314 % \label{eq: trazdf_t_t2}315 % \label{eq:CONS_trazdf_t_t2} 315 316 \begin{aligned} 316 317 & \int_D \frac{1}{e_3 } \frac{\partial }{\partial k}\left( \frac{A^{vT}}{e_3 } \frac{\partial T}{\partial k} \right)\;dv = 0 \\ -
NEMO/trunk/doc/latex/NEMO/subfiles/chap_model_basics_zstar.tex
r11543 r11544 26 26 To overcome problems with vanishing surface and/or bottom cells, we consider the zstar coordinate 27 27 \[ 28 % \label{eq: PE_}28 % \label{eq:MBZ_PE_} 29 29 z^\star = H \left( \frac{z-\eta}{H+\eta} \right) 30 30 \] … … 75 75 \section[Surface pressure gradient and sea surface heigth (\textit{dynspg.F90})] 76 76 {Surface pressure gradient and sea surface heigth (\protect\mdl{dynspg})} 77 \label{sec: DYN_hpg_spg}77 \label{sec:MBZ_dyn_hpg_spg} 78 78 %-----------------------------------------nam_dynspg---------------------------------------------------- 79 79 … … 100 100 \subsubsection[Explicit (\texttt{\textbf{key\_dynspg\_exp}})] 101 101 {Explicit (\protect\key{dynspg\_exp})} 102 \label{subsec: DYN_spg_exp}102 \label{subsec:MBZ_dyn_spg_exp} 103 103 104 104 In the explicit free surface formulation, the model time step is chosen small enough to … … 106 106 The sea surface height is given by: 107 107 \begin{equation} 108 \label{eq: dynspg_ssh}108 \label{eq:MBZ_dynspg_ssh} 109 109 \frac{\partial \eta }{\partial t}\equiv \frac{\text{EMP}}{\rho_w }+\frac{1}{e_{1T} 110 110 e_{2T} }\sum\limits_k {\left( {\delta_i \left[ {e_{2u} e_{3u} u} … … 120 120 The surface pressure gradient, also evaluated using a leap-frog scheme, is then simply given by: 121 121 \begin{equation} 122 \label{eq: dynspg_exp}122 \label{eq:MBZ_dynspg_exp} 123 123 \left\{ 124 124 \begin{aligned} … … 137 137 \subsubsection[Split-explicit time-stepping (\texttt{\textbf{key\_dynspg\_ts}})] 138 138 {Split-explicit time-stepping (\protect\key{dynspg\_ts})} 139 \label{subsec: DYN_spg_ts}139 \label{subsec:MBZ_dyn_spg_ts} 140 140 %--------------------------------------------namdom---------------------------------------------------- 141 141 … … 152 152 \includegraphics[width=\textwidth]{Fig_DYN_dynspg_ts} 153 153 \caption{ 154 \protect\label{fig: DYN_dynspg_ts}154 \protect\label{fig:MBZ_dyn_dynspg_ts} 155 155 Schematic of the split-explicit time stepping scheme for the barotropic and baroclinic modes, 156 156 after \citet{Griffies2004?}. … … 186 186 We have 187 187 \[ 188 % \label{eq: DYN_spg_ts_eta}188 % \label{eq:MBZ_dyn_spg_ts_eta} 189 189 \eta^{(b)}(\tau,t_{n+1}) - \eta^{(b)}(\tau,t_{n+1}) (\tau,t_{n-1}) 190 190 = 2 \Delta t \left[-\nabla \cdot \textbf{U}^{(b)}(\tau,t_n) + \text{EMP}_w(\tau) \right] 191 191 \] 192 192 \begin{multline*} 193 % \label{eq: DYN_spg_ts_u}193 % \label{eq:MBZ_dyn_spg_ts_u} 194 194 \textbf{U}^{(b)}(\tau,t_{n+1}) - \textbf{U}^{(b)}(\tau,t_{n-1}) \\ 195 195 = 2\Delta t \left[ - f \textbf{k} \times \textbf{U}^{(b)}(\tau,t_{n}) … … 207 207 This is also the time that sets the barotropic time steps via 208 208 \[ 209 % \label{eq: DYN_spg_ts_t}209 % \label{eq:MBZ_dyn_spg_ts_t} 210 210 t_n=\tau+n\Delta t 211 211 \] … … 213 213 The density scaled surface pressure is evaluated via 214 214 \[ 215 % \label{eq: DYN_spg_ts_ps}215 % \label{eq:MBZ_dyn_spg_ts_ps} 216 216 p_s^{(b)}(\tau,t_{n}) = 217 217 \begin{cases} … … 222 222 To get started, we assume the following initial conditions 223 223 \[ 224 % \label{eq: DYN_spg_ts_eta}224 % \label{eq:MBZ_dyn_spg_ts_eta} 225 225 \begin{split} 226 226 \eta^{(b)}(\tau,t_{n=0}) &= \overline{\eta^{(b)}(\tau)} \\ … … 230 230 with 231 231 \[ 232 % \label{eq: DYN_spg_ts_etaF}232 % \label{eq:MBZ_dyn_spg_ts_etaF} 233 233 \overline{\eta^{(b)}(\tau)} = \frac{1}{N+1} \sum\limits_{n=0}^N \eta^{(b)}(\tau-\Delta t,t_{n}) 234 234 \] … … 236 236 Likewise, 237 237 \[ 238 % \label{eq: DYN_spg_ts_u}238 % \label{eq:MBZ_dyn_spg_ts_u} 239 239 \textbf{U}^{(b)}(\tau,t_{n=0}) = \overline{\textbf{U}^{(b)}(\tau)} \\ \\ 240 240 \textbf{U}(\tau,t_{n=1}) = \textbf{U}^{(b)}(\tau,t_{n=0}) + \Delta t \ \text{RHS}_{n=0} … … 242 242 with 243 243 \[ 244 % \label{eq: DYN_spg_ts_u}244 % \label{eq:MBZ_dyn_spg_ts_u} 245 245 \overline{\textbf{U}^{(b)}(\tau)} = \frac{1}{N+1} \sum\limits_{n=0}^N\textbf{U}^{(b)}(\tau-\Delta t,t_{n}) 246 246 \] … … 251 251 produce the updated vertically integrated velocity at baroclinic time $\tau + \Delta \tau$ 252 252 \[ 253 % \label{eq: DYN_spg_ts_u}253 % \label{eq:MBZ_dyn_spg_ts_u} 254 254 \textbf{U}(\tau+\Delta t) = \overline{\textbf{U}^{(b)}(\tau+\Delta t)} 255 255 = \frac{1}{N+1} \sum\limits_{n=0}^N\textbf{U}^{(b)}(\tau,t_{n}) … … 258 258 a baroclinic leap-frog using the following form 259 259 \begin{equation} 260 \label{eq: DYN_spg_ts_ssh}260 \label{eq:MBZ_dyn_spg_ts_ssh} 261 261 \eta(\tau+\Delta) - \eta^{F}(\tau-\Delta) = 2\Delta t \ \left[ - \nabla \cdot \textbf{U}(\tau) + \text{EMP}_w \right] 262 262 \end{equation} … … 267 267 268 268 In general, some form of time filter is needed to maintain integrity of the surface height field due to 269 the leap-frog splitting mode in equation \autoref{eq: DYN_spg_ts_ssh}.269 the leap-frog splitting mode in equation \autoref{eq:MBZ_dyn_spg_ts_ssh}. 270 270 We have tried various forms of such filtering, 271 271 with the following method discussed in Griffies et al. (2001) chosen due to its stability and … … 273 273 274 274 \begin{equation} 275 \label{eq: DYN_spg_ts_sshf}275 \label{eq:MBZ_dyn_spg_ts_sshf} 276 276 \eta^{F}(\tau-\Delta) = \overline{\eta^{(b)}(\tau)} 277 277 \end{equation} … … 279 279 280 280 \[ 281 % \label{eq: DYN_spg_ts_sshf2}281 % \label{eq:MBZ_dyn_spg_ts_sshf2} 282 282 \eta^{F}(\tau-\Delta) = \eta(\tau) 283 283 + (\alpha/2) \left[\overline{\eta^{(b)}}(\tau+\Delta t) … … 288 288 This isolation allows for an easy check that tracer conservation is exact when eliminating tracer and 289 289 surface height time filtering (see ?? for more complete discussion). 290 However, in the general case with a non-zero $\alpha$, the filter \autoref{eq: DYN_spg_ts_sshf} was found to290 However, in the general case with a non-zero $\alpha$, the filter \autoref{eq:MBZ_dyn_spg_ts_sshf} was found to 291 291 be more conservative, and so is recommended. 292 292 … … 296 296 \subsubsection[Filtered formulation (\texttt{\textbf{key\_dynspg\_flt}})] 297 297 {Filtered formulation (\protect\key{dynspg\_flt})} 298 \label{subsec: DYN_spg_flt}298 \label{subsec:MBZ_dyn_spg_flt} 299 299 300 300 The filtered formulation follows the \citet{Roullet2000?} implementation. … … 311 311 \subsection[Non-linear free surface formulation (\texttt{\textbf{key\_vvl}})] 312 312 {Non-linear free surface formulation (\protect\key{vvl})} 313 \label{subsec: DYN_spg_vvl}313 \label{subsec:MBZ_dyn_spg_vvl} 314 314 315 315 In the non-linear free surface formulation, the variations of volume are fully taken into account.
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