Changeset 3294 for trunk/DOC/TexFiles/Chapters/Annex_A.tex
- Timestamp:
- 2012-01-28T17:44:18+01:00 (12 years ago)
- File:
-
- 1 edited
Legend:
- Unmodified
- Added
- Removed
-
trunk/DOC/TexFiles/Chapters/Annex_A.tex
- Property svn:executable deleted
r2282 r3294 13 13 % Chain rule 14 14 % ================================================================ 15 \section{ Chain rule of $s-$coordinate}15 \section{The chain rule for $s-$coordinates} 16 16 \label{Apdx_A_continuity} 17 17 18 In order to establish the set of Primitive Equation in curvilinear $s -$coordinates18 In order to establish the set of Primitive Equation in curvilinear $s$-coordinates 19 19 ($i.e.$ an orthogonal curvilinear coordinate in the horizontal and an Arbitrary Lagrangian 20 20 Eulerian (ALE) coordinate in the vertical), we start from the set of equations established … … 62 62 % continuity equation 63 63 % ================================================================ 64 \section{Continuity Equation in $s-$coordinate }64 \section{Continuity Equation in $s-$coordinates} 65 65 \label{Apdx_A_continuity} 66 66 … … 128 128 Here, $w$ is the vertical velocity relative to the $z-$coordinate system. 129 129 Introducing the dia-surface velocity component, $\omega $, defined as 130 the v elocity relative to the moving $s-$surfaces and normal to them:130 the volume flux across the moving $s$-surfaces per unit horizontal area: 131 131 \begin{equation} \label{Apdx_A_w_s} 132 132 \omega = w - w_s - \sigma _1 \,u - \sigma _2 \,v \\ … … 429 429 This formulation of the pressure gradient is characterised by the appearance of a term depending on the 430 430 the sea surface height only (last term on the right hand side of expression \eqref{Apdx_A_grad_p}). 431 This term will be abusively named \textit{surface pressure gradient} whereas the first term will be named 431 This term will be loosely termed \textit{surface pressure gradient} 432 whereas the first term will be termed the 432 433 \textit{hydrostatic pressure gradient} by analogy to the $z$-coordinate formulation. 433 434 In fact, the the true surface pressure gradient is $1/\rho_o \nabla (\rho \eta)$, and … … 451 452 To sum up, in a curvilinear $s$-coordinate system, the vector invariant momentum equation 452 453 solved by the model has the same mathematical expression as the one in a curvilinear 453 $z-$coordinate, butthe pressure gradient term :454 $z-$coordinate, except for the pressure gradient term : 454 455 \begin{subequations} \label{Apdx_A_dyn_vect} 455 456 \begin{multline} \label{Apdx_A_PE_dyn_vect_u} … … 495 496 \end{subequations} 496 497 Both formulation share the same hydrostatic pressure balance expressed in terms of 497 hydrostatic pressure and density an malies, $p_h'$ and $d=( \frac{\rho}{\rho_o}-1 )$:498 hydrostatic pressure and density anomalies, $p_h'$ and $d=( \frac{\rho}{\rho_o}-1 )$: 498 499 \begin{equation} \label{Apdx_A_dyn_zph} 499 500 \frac{\partial p_h'}{\partial k} = - d \, g \, e_3 … … 502 503 It is important to realize that the change in coordinate system has only concerned 503 504 the position on the vertical. It has not affected (\textbf{i},\textbf{j},\textbf{k}), the 504 orthogonal curvilinear set of unit vector . ($u$,$v$) are always horizontal velocities505 orthogonal curvilinear set of unit vectors. ($u$,$v$) are always horizontal velocities 505 506 so that their evolution is driven by \emph{horizontal} forces, in particular 506 507 the pressure gradient. By contrast, $\omega$ is not $w$, the third component of the velocity, 507 but the dia-surface velocity component, $i.e.$ the v elocity relative tothe moving508 $s -$surfaces and normal to them.508 but the dia-surface velocity component, $i.e.$ the volume flux across the moving 509 $s$-surfaces per unit horizontal area. 509 510 510 511
Note: See TracChangeset
for help on using the changeset viewer.