Changeset 14018 for NEMO/branches/2020/dev_r13327_KERNEL-06_2_techene_e3/doc/latex/NEMO/subfiles/chap_SBC.tex

Timestamp:

2020-12-02T18:22:24+01:00 (3 years ago)

Author:

techene

Message:

#2385 branch updated with trunk 13970

Location:

NEMO/branches/2020/dev_r13327_KERNEL-06_2_techene_e3

Files:

• . (modified) (1 prop)
• doc/latex/NEMO/subfiles/chap_SBC.tex (modified) (4 diffs)

NEMO/branches/2020/dev_r13327_KERNEL-06_2_techene_e3

@@ -8 +8 @@
 
 # SETTE
-^/utils/CI/sette@13559        sette
+^/utils/CI/sette@13795        sette

@@ -8 +8 @@
 
 # SETTE
-^/utils/CI/sette@13559        sette
+^/utils/CI/sette@13795        sette

NEMO/branches/2020/dev_r13327_KERNEL-06_2_techene_e3/doc/latex/NEMO/subfiles/chap_SBC.tex

@@ -5 +5 @@
 \begin{document}
 
-\chapter{Surface Boundary Condition (SBC, SAS, ISF, ICB)}
+\chapter{Surface Boundary Condition (SBC, SAS, ISF, ICB, TDE)}
 \label{chap:SBC}
 
@@ -18 +18 @@
     Release & Author(s) & Modifications \\
     \hline
+    {\em  next} & {\em Simon M{\" u}ller} & {\em Update of \autoref{sec:SBC_TDE}}\\[2mm]
     {\em   4.0} & {\em ...} & {\em ...} \\
     {\em   3.6} & {\em ...} & {\em ...} \\
@@ -1013 +1014 @@
 
 %% =================================================================================================
-\section[Surface tides (\textit{sbctide.F90})]{Surface tides (\protect\mdl{sbctide})}
-\label{sec:SBC_tide}
+\section{Surface tides (TDE)}
+\label{sec:SBC_TDE}
 
 \begin{listing}
@@ -1022 +1023 @@
 \end{listing}
 
-The tidal forcing, generated by the gravity forces of the Earth-Moon and Earth-Sun sytems,
-is activated if \np{ln_tide}{ln\_tide} and \np{ln_tide_pot}{ln\_tide\_pot} are both set to \forcode{.true.} in \nam{_tide}{\_tide}.
-This translates as an additional barotropic force in the momentum \autoref{eq:MB_PE_dyn} such that:
+\subsection{Tidal constituents}
+Ocean model component TDE provides the common functionality for tidal forcing
+and tidal analysis in the model framework. This includes the computation of the gravitational
+surface forcing, as well as support for lateral forcing at open boundaries (see
+\autoref{subsec:LBC_bdy_tides}) and tidal harmonic analysis (see
+\autoref{subsec:DIA_diamlr} and \autoref{subsec:DIA_diadetide}). The module is
+activated with \np[=.true.]{ln_tide}{ln\_tide} in namelist
+\nam{_tide}{\_tide}. It provides the same 34 tidal constituents that are
+included in the
+\href{https://www.aviso.altimetry.fr/en/data/products/auxiliary-products/global-tide-fes.html}{FES2014
+  ocean tide model}: Mf, Mm, Ssa, Mtm, Msf, Msqm, Sa, K1, O1, P1, Q1, J1, S1,
+M2, S2, N2, K2, nu2, mu2, 2N2, L2, T2, eps2, lam2, R2, M3, MKS2, MN4, MS4, M4,
+N4, S4, M6, and M8; see file \hf{tide} and \mdl{tide\_mod} for further
+information and references\footnote{As a legacy option \np{ln_tide_var} can be
+  set to \forcode{0}, in which case the 19 tidal constituents (M2, N2, 2N2, S2,
+  K2, K1, O1, Q1, P1, M4, Mf, Mm, Msqm, Mtm, S1, MU2, NU2, L2, and T2; see file
+  \hf{tide}) and associated parameters that have been available in NEMO version
+  4.0 and earlier are available}. Constituents to be included in the tidal forcing
+(surface and lateral boundaries) are selected by enumerating their respective
+names in namelist array \np{sn_tide_cnames}{sn\_tide\_cnames}.\par
+
+\subsection{Surface tidal forcing}
+Surface tidal forcing can be represented in the model through an additional
+barotropic force in the momentum equation (\autoref{eq:MB_PE_dyn}) such that:
 \[
-  % \label{eq:SBC_PE_dyn_tides}
-  \frac{\partial {\mathrm {\mathbf U}}_h }{\partial t}= ...
-  +g\nabla (\Pi_{eq} + \Pi_{sal})
+  \frac{\partial {\mathrm {\mathbf U}}_h }{\partial t} = \ldots +g\nabla (\gamma
+  \Pi_{eq} + \Pi_{sal})
 \]
-where $\Pi_{eq}$ stands for the equilibrium tidal forcing and
-$\Pi_{sal}$ is a self-attraction and loading term (SAL).
-
-The equilibrium tidal forcing is expressed as a sum over a subset of
-constituents chosen from the set of available tidal constituents
-defined in file \hf{SBC/tide} (this comprises the tidal
-constituents \textit{M2, N2, 2N2, S2, K2, K1, O1, Q1, P1, M4, Mf, Mm,
-  Msqm, Mtm, S1, MU2, NU2, L2}, and \textit{T2}). Individual
-constituents are selected by including their names in the array
-\np{clname}{clname} in \nam{_tide}{\_tide} (e.g., \np{clname}{clname}\forcode{(1)='M2', }
-\np{clname}{clname}\forcode{(2)='S2'} to select solely the tidal consituents \textit{M2}
-and \textit{S2}). Optionally, when \np{ln_tide_ramp}{ln\_tide\_ramp} is set to
-\forcode{.true.}, the equilibrium tidal forcing can be ramped up
-linearly from zero during the initial \np{rdttideramp}{rdttideramp} days of the
-model run.
+where $\gamma \Pi_{eq}$ stands for the equilibrium tidal forcing scaled by a spatially
+uniform tilt factor $\gamma$, and $\Pi_{sal}$ is an optional
+self-attraction and loading term (SAL). These additional terms are enabled when,
+in addition to \np[=.true.]{ln_tide}{ln\_tide}),
+\np[=.true.]{ln_tide_pot}{ln\_tide\_pot}.\par
+
+The equilibrium tidal forcing is expressed as a sum over the subset of
+constituents listed in \np{sn_tide_cnames}{sn\_tide\_cnames} of
+\nam{_tide} (e.g.,
+\begin{forlines}
+      sn_tide_cnames(1) = 'M2'
+      sn_tide_cnames(2) = 'K1'
+      sn_tide_cnames(3) = 'S2'
+      sn_tide_cnames(4) = 'O1'
+\end{forlines}
+to select the four tidal constituents of strongest equilibrium tidal
+potential). The tidal tilt factor $\gamma = 1 + k - h$ includes the
+Love numbers $k$ and $h$ \citep{love_prsla1909}; this factor is
+configurable using \np{rn_tide_gamma} (default value 0.7). Optionally,
+when \np[=.true.]{ln_tide_ramp}{ln\_tide\_ramp}, the equilibrium tidal
+forcing can be ramped up linearly from zero during the initial
+\np{rn_tide_ramp_dt}{rn\_tide\_ramp\_dt} days of the model run.\par
 
 The SAL term should in principle be computed online as it depends on
 the model tidal prediction itself (see \citet{arbic.garner.ea_DSR04} for a
-discussion about the practical implementation of this term).
-Nevertheless, the complex calculations involved would make this
-computationally too expensive. Here, two options are available:
-$\Pi_{sal}$ generated by an external model can be read in
-(\np[=.true.]{ln_read_load}{ln\_read\_load}), or a ``scalar approximation'' can be
-used (\np[=.true.]{ln_scal_load}{ln\_scal\_load}). In the latter case
+discussion about the practical implementation of this term). The complex
+calculations involved in such computations, however, are computationally very
+expensive. Here, two mutually exclusive simpler variants are available:
+amplitudes generated by an external model for oscillatory $\Pi_{sal}$
+contributions from each of the selected tidal constituents can be read in
+(\np[=.true.]{ln_read_load}{ln\_read\_load}) from the file specified in
+\np{cn_tide_load}{cn\_tide\_load} (the variable names are comprised of the
+tidal-constituent name and suffixes \forcode{_z1} and \forcode{_z2} for the two
+orthogonal components, respectively); alternatively, a ``scalar approximation''
+can be used (\np[=.true.]{ln_scal_load}{ln\_scal\_load}), where
 \[
   \Pi_{sal} = \beta \eta,
 \]
-where $\beta$ (\np{rn_scal_load}{rn\_scal\_load} with a default value of 0.094) is a
-spatially constant scalar, often chosen to minimize tidal prediction
-errors. Setting both \np{ln_read_load}{ln\_read\_load} and \np{ln_scal_load}{ln\_scal\_load} to
-\forcode{.false.} removes the SAL contribution.
+with a spatially uniform coefficient $\beta$, which can be configured
+via \np{rn_scal_load}{rn\_scal\_load} (default value 0.094) and is
+often tuned to minimize tidal prediction errors.\par
+
+For diagnostic purposes, the forcing potential of the individual tidal
+constituents (incl. load ptential, if activated) and the total forcing
+potential (incl. load potential, if activated) can be made available
+as diagnostic output by setting
+\np[=.true.]{ln_tide_dia}{ln\_tide\_dia} (fields
+\forcode{tide_pot_<constituent>} and \forcode{tide_pot}).\par
 
 %% =================================================================================================

@@ -8 +8 @@
 
 # SETTE
-^/utils/CI/sette@13559        sette
+^/utils/CI/sette@13795        sette