/[MITgcm]/manual/s_examples/rotating_tank/tank.tex
ViewVC logotype

Diff of /manual/s_examples/rotating_tank/tank.tex

Parent Directory Parent Directory | Revision Log Revision Log | View Revision Graph Revision Graph | View Patch Patch

revision 1.1 by afe, Tue Jun 22 15:07:37 2004 UTC revision 1.2 by afe, Tue Jun 22 16:56:31 2004 UTC
# Line 1  Line 1 
1  % $Header$  % $Header$
2  % $Name$  % $Name$
3    
4    \section{Simulating a Rotating Tank in Cylindrical Coordinates}
5    \label{www:tutorials}
6    \label{sect:eg-tank}
7    
8  \bodytext{bgcolor="#FFFFFFFF"}  \bodytext{bgcolor="#FFFFFFFF"}
9    
10  %\begin{center}  %\begin{center}
11  %{\Large \bf Using MITgcm to Simulate a Rotating Tank in Cylindrical  %{\Large \bf Simulating a Rotating Tank in Cylindrical Coordinates}
12  %Coordinates}  %
13  %  %
14  %\vspace*{4mm}  %\vspace*{4mm}
15  %  %
# Line 13  Line 17 
17  %{\large June 2004}  %{\large June 2004}
18  %\end{center}  %\end{center}
19    
20  This is the first in a series of tutorials describing  \subsection{Introduction}
 example MITgcm numerical experiments. The example experiments  
 include both straightforward examples of idealized geophysical  
 fluid simulations and more involved cases encompassing  
 large scale modeling and  
 automatic differentiation. Both hydrostatic and non-hydrostatic  
 experiments are presented, as well as experiments employing  
 Cartesian, spherical-polar and cube-sphere coordinate systems.  
 These ``case study'' documents include information describing  
 the experimental configuration and detailed information on how to  
 configure the MITgcm code and input files for each experiment.  
   
 \section{Barotropic Ocean Gyre In Cartesian Coordinates}  
 \label{sect:eg-baro}  
21  \label{www:tutorials}  \label{www:tutorials}
22    
23    This section illustrates an example of MITgcm simulating a laboratory
24    experiment on much smaller scales than those common to geophysical
25  \subsection{Equations Solved}  fluid dynamics.
26  \label{www:tutorials}  
27  The model is configured in hydrostatic form. The implicit free surface form of the  \subsection{Overview}
28    \label{www:tutorials}
29    
30    
31    This example experiment demonstrates using the MITgcm to simulate
32    a laboratory experiment with a rotating tank of water with an ice
33    bucket in the center. The simulation is configured for a laboratory
34    scale on a 3^{\circ} \times 20cm cyclindrical grid with twenty-nine vertical
35    levels.  
36    \\
37    
38    The model is forced with climatological wind stress data and surface
39    flux data from DaSilva \cite{DaSilva94}. Climatological data
40    from Levitus \cite{Levitus94} is used to initialize the model hydrography.
41    Levitus seasonal climatology data is also used throughout the calculation
42    to provide additional air-sea fluxes.
43    These fluxes are combined with the DaSilva climatological estimates of
44    surface heat flux and fresh water, resulting in a mixed boundary
45    condition of the style described in Haney \cite{Haney}.
46    Altogether, this yields the following forcing applied
47    in the model surface layer.
48    
49    
50    \noindent where ${\cal F}_{u}$, ${\cal F}_{v}$, ${\cal F}_{\theta}$,
51    ${\cal F}_{s}$ are the forcing terms in the zonal and meridional
52    momentum and in the potential temperature and salinity
53    equations respectively.
54    The term $\Delta z_{s}$ represents the top ocean layer thickness in
55    meters.
56    It is used in conjunction with a reference density, $\rho_{0}$
57    (here set to $999.8\,{\rm kg\,m^{-3}}$), a
58    reference salinity, $S_{0}$ (here set to 35~ppt),
59    and a specific heat capacity, $C_{p}$ (here set to
60    $4000~{\rm J}~^{\circ}{\rm C}^{-1}~{\rm kg}^{-1}$), to convert
61    input dataset values into time tendencies of
62    potential temperature (with units of $^{\circ}{\rm C}~{\rm s}^{-1}$),
63    salinity (with units ${\rm ppt}~s^{-1}$) and
64    velocity (with units ${\rm m}~{\rm s}^{-2}$).
65    The externally supplied forcing fields used in this
66    experiment are $\tau_{x}$, $\tau_{y}$, $\theta^{\ast}$, $S^{\ast}$,
67    $\cal{Q}$ and $\cal{E}-\cal{P}-\cal{R}$. The wind stress fields ($\tau_x$, $\tau_y$)
68    have units of ${\rm N}~{\rm m}^{-2}$. The temperature forcing fields
69    ($\theta^{\ast}$ and $Q$) have units of $^{\circ}{\rm C}$ and ${\rm W}~{\rm m}^{-2}$
70    respectively. The salinity forcing fields ($S^{\ast}$ and
71    $\cal{E}-\cal{P}-\cal{R}$) have units of ${\rm ppt}$ and ${\rm m}~{\rm s}^{-1}$
72    respectively.
73    \\
74    
75    
76    Figures (\ref{FIG:sim_config_tclim}-\ref{FIG:sim_config_empmr}) show the
77    relaxation temperature ($\theta^{\ast}$) and salinity ($S^{\ast}$) fields,
78    the wind stress components ($\tau_x$ and $\tau_y$), the heat flux ($Q$)
79    and the net fresh water flux (${\cal E} - {\cal P} - {\cal R}$) used
80    in equations \ref{EQ:eg-hs-global_forcing_fu}-\ref{EQ:eg-hs-global_forcing_fs}. The figures
81    also indicate the lateral extent and coastline used in the experiment.
82    Figure ({\ref{FIG:model_bathymetry}) shows the depth contours of the model
83    domain.
84    
85    
86  \subsection{Discrete Numerical Configuration}  \subsection{Discrete Numerical Configuration}
87  \label{www:tutorials}  \label{www:tutorials}
88    
89   The domain is discretised with  
90  a uniform grid spacing in the horizontal set to   The model is configured in hydrostatic form.  The domain is discretised with
91   $\Delta x=\Delta y=20$~km, so  a uniform grid spacing in latitude and longitude on the sphere
92  that there are sixty grid cells in the $x$ and $y$ directions. Vertically the   $\Delta \phi=\Delta \lambda=4^{\circ}$, so
93  model is configured with a single layer with depth, $\Delta z$, of $5000$~m.  that there are ninety grid cells in the zonal and forty in the
94    meridional direction. The internal model coordinate variables
95    $x$ and $y$ are initialized according to
96    \begin{eqnarray}
97    x=r\cos(\phi),~\Delta x & = &r\cos(\Delta \phi) \\
98    y=r\lambda,~\Delta x &= &r\Delta \lambda
99    \end{eqnarray}
100    
101    Arctic polar regions are not
102    included in this experiment. Meridionally the model extends from
103    $80^{\circ}{\rm S}$ to $80^{\circ}{\rm N}$.
104    Vertically the model is configured with twenty layers with the
105    following thicknesses
106    $\Delta z_{1} = 50\,{\rm m},\,
107     \Delta z_{2} = 50\,{\rm m},\,
108     \Delta z_{3} = 55\,{\rm m},\,
109     \Delta z_{4} = 60\,{\rm m},\,
110     \Delta z_{5} = 65\,{\rm m},\,
111    $
112    $
113     \Delta z_{6}~=~70\,{\rm m},\,
114     \Delta z_{7}~=~80\,{\rm m},\,
115     \Delta z_{8}~=95\,{\rm m},\,
116     \Delta z_{9}=120\,{\rm m},\,
117     \Delta z_{10}=155\,{\rm m},\,
118    $
119    $
120     \Delta z_{11}=200\,{\rm m},\,
121     \Delta z_{12}=260\,{\rm m},\,
122     \Delta z_{13}=320\,{\rm m},\,
123     \Delta z_{14}=400\,{\rm m},\,
124     \Delta z_{15}=480\,{\rm m},\,
125    $
126    $
127     \Delta z_{16}=570\,{\rm m},\,
128     \Delta z_{17}=655\,{\rm m},\,
129     \Delta z_{18}=725\,{\rm m},\,
130     \Delta z_{19}=775\,{\rm m},\,
131     \Delta z_{20}=815\,{\rm m}
132    $ (here the numeric subscript indicates the model level index number, ${\tt k}$).
133    The implicit free surface form of the pressure equation described in Marshall et. al
134    \cite{marshall:97a} is employed. A Laplacian operator, $\nabla^2$, provides viscous
135    dissipation. Thermal and haline diffusion is also represented by a Laplacian operator.
136    
137    Wind-stress forcing is added to the momentum equations for both
138    the zonal flow, $u$ and the meridional flow $v$, according to equations
139    (\ref{EQ:eg-hs-global_forcing_fu}) and (\ref{EQ:eg-hs-global_forcing_fv}).
140    Thermodynamic forcing inputs are added to the equations for
141    potential temperature, $\theta$, and salinity, $S$, according to equations
142    (\ref{EQ:eg-hs-global_forcing_ft}) and (\ref{EQ:eg-hs-global_forcing_fs}).
143    This produces a set of equations solved in this configuration as follows:
144    
145    \begin{eqnarray}
146    \label{EQ:eg-hs-model_equations}
147    \frac{Du}{Dt} - fv +
148      \frac{1}{\rho}\frac{\partial p^{'}}{\partial x} -
149      \nabla_{h}\cdot A_{h}\nabla_{h}u -
150      \frac{\partial}{\partial z}A_{z}\frac{\partial u}{\partial z}
151     & = &
152    \begin{cases}
153    {\cal F}_u & \text{(surface)} \\
154    0 & \text{(interior)}
155    \end{cases}
156    \\
157    \frac{Dv}{Dt} + fu +
158      \frac{1}{\rho}\frac{\partial p^{'}}{\partial y} -
159      \nabla_{h}\cdot A_{h}\nabla_{h}v -
160      \frac{\partial}{\partial z}A_{z}\frac{\partial v}{\partial z}
161    & = &
162    \begin{cases}
163    {\cal F}_v & \text{(surface)} \\
164    0 & \text{(interior)}
165    \end{cases}
166    \\
167    \frac{\partial \eta}{\partial t} + \nabla_{h}\cdot \vec{u}
168    &=&
169    0
170    \\
171    \frac{D\theta}{Dt} -
172     \nabla_{h}\cdot K_{h}\nabla_{h}\theta
173     - \frac{\partial}{\partial z}\Gamma(K_{z})\frac{\partial\theta}{\partial z}
174    & = &
175    \begin{cases}
176    {\cal F}_\theta & \text{(surface)} \\
177    0 & \text{(interior)}
178    \end{cases}
179    \\
180    \frac{D s}{Dt} -
181     \nabla_{h}\cdot K_{h}\nabla_{h}s
182     - \frac{\partial}{\partial z}\Gamma(K_{z})\frac{\partial s}{\partial z}
183    & = &
184    \begin{cases}
185    {\cal F}_s & \text{(surface)} \\
186    0 & \text{(interior)}
187    \end{cases}
188    \\
189    g\rho_{0} \eta + \int^{0}_{-z}\rho^{'} dz & = & p^{'}
190    \end{eqnarray}
191    
192    \noindent where $u=\frac{Dx}{Dt}=r \cos(\phi)\frac{D \lambda}{Dt}$ and
193    $v=\frac{Dy}{Dt}=r \frac{D \phi}{Dt}$
194    are the zonal and meridional components of the
195    flow vector, $\vec{u}$, on the sphere. As described in
196    MITgcm Numerical Solution Procedure \ref{chap:discretization}, the time
197    evolution of potential temperature, $\theta$, equation is solved prognostically.
198    The total pressure, $p$, is diagnosed by summing pressure due to surface
199    elevation $\eta$ and the hydrostatic pressure.
200    \\
201    
202  \subsubsection{Numerical Stability Criteria}  \subsubsection{Numerical Stability Criteria}
203  \label{www:tutorials}  \label{www:tutorials}
204    
205    The Laplacian dissipation coefficient, $A_{h}$, is set to $5 \times 10^5 m s^{-1}$.
206  \subsection{Code Configuration}  This value is chosen to yield a Munk layer width \cite{adcroft:95},
207    \begin{eqnarray}
208    \label{EQ:eg-hs-munk_layer}
209    M_{w} = \pi ( \frac { A_{h} }{ \beta } )^{\frac{1}{3}}
210    \end{eqnarray}
211    
212    \noindent  of $\approx 600$km. This is greater than the model
213    resolution in low-latitudes, $\Delta x \approx 400{\rm km}$, ensuring that the frictional
214    boundary layer is adequately resolved.
215    \\
216    
217    \noindent The model is stepped forward with a
218    time step $\delta t_{\theta}=30~{\rm hours}$ for thermodynamic variables and
219    $\delta t_{v}=40~{\rm minutes}$ for momentum terms. With this time step, the stability
220    parameter to the horizontal Laplacian friction \cite{adcroft:95}
221    \begin{eqnarray}
222    \label{EQ:eg-hs-laplacian_stability}
223    S_{l} = 4 \frac{A_{h} \delta t_{v}}{{\Delta x}^2}
224    \end{eqnarray}
225    
226    \noindent evaluates to 0.16 at a latitude of $\phi=80^{\circ}$, which is below the
227    0.3 upper limit for stability. The zonal grid spacing $\Delta x$ is smallest at
228    $\phi=80^{\circ}$ where $\Delta x=r\cos(\phi)\Delta \phi\approx 77{\rm km}$.
229    \\
230    
231    \noindent The vertical dissipation coefficient, $A_{z}$, is set to
232    $1\times10^{-3} {\rm m}^2{\rm s}^{-1}$. The associated stability limit
233    \begin{eqnarray}
234    \label{EQ:eg-hs-laplacian_stability_z}
235    S_{l} = 4 \frac{A_{z} \delta t_{v}}{{\Delta z}^2}
236    \end{eqnarray}
237    
238    \noindent evaluates to $0.015$ for the smallest model
239    level spacing ($\Delta z_{1}=50{\rm m}$) which is again well below
240    the upper stability limit.
241    \\
242    
243    The values of the horizontal ($K_{h}$) and vertical ($K_{z}$) diffusion coefficients
244    for both temperature and salinity are set to $1 \times 10^{3}~{\rm m}^{2}{\rm s}^{-1}$
245    and $3 \times 10^{-5}~{\rm m}^{2}{\rm s}^{-1}$ respectively. The stability limit
246    related to $K_{h}$ will be at $\phi=80^{\circ}$ where $\Delta x \approx 77 {\rm km}$.
247    Here the stability parameter
248    \begin{eqnarray}
249    \label{EQ:eg-hs-laplacian_stability_xtheta}
250    S_{l} = \frac{4 K_{h} \delta t_{\theta}}{{\Delta x}^2}
251    \end{eqnarray}
252    evaluates to $0.07$, well below the stability limit of $S_{l} \approx 0.5$. The
253    stability parameter related to $K_{z}$
254    \begin{eqnarray}
255    \label{EQ:eg-hs-laplacian_stability_ztheta}
256    S_{l} = \frac{4 K_{z} \delta t_{\theta}}{{\Delta z}^2}
257    \end{eqnarray}
258    evaluates to $0.005$ for $\min(\Delta z)=50{\rm m}$, well below the stability limit
259    of $S_{l} \approx 0.5$.
260    \\
261    
262    \noindent The numerical stability for inertial oscillations
263    \cite{adcroft:95}
264    
265    \begin{eqnarray}
266    \label{EQ:eg-hs-inertial_stability}
267    S_{i} = f^{2} {\delta t_v}^2
268    \end{eqnarray}
269    
270    \noindent evaluates to $0.24$ for $f=2\omega\sin(80^{\circ})=1.43\times10^{-4}~{\rm s}^{-1}$, which is close to
271    the $S_{i} < 1$ upper limit for stability.
272    \\
273    
274    \noindent The advective CFL \cite{adcroft:95} for a extreme maximum
275    horizontal flow
276    speed of $ | \vec{u} | = 2 ms^{-1}$
277    
278    \begin{eqnarray}
279    \label{EQ:eg-hs-cfl_stability}
280    S_{a} = \frac{| \vec{u} | \delta t_{v}}{ \Delta x}
281    \end{eqnarray}
282    
283    \noindent evaluates to $6 \times 10^{-2}$. This is well below the stability
284    limit of 0.5.
285    \\
286    
287    \noindent The stability parameter for internal gravity waves propagating
288    with a maximum speed of $c_{g}=10~{\rm ms}^{-1}$
289    \cite{adcroft:95}
290    
291    \begin{eqnarray}
292    \label{EQ:eg-hs-gfl_stability}
293    S_{c} = \frac{c_{g} \delta t_{v}}{ \Delta x}
294    \end{eqnarray}
295    
296    \noindent evaluates to $3 \times 10^{-1}$. This is close to the linear
297    stability limit of 0.5.
298      
299    \subsection{Experiment Configuration}
300  \label{www:tutorials}  \label{www:tutorials}
301  \label{SEC:eg-baro-code_config}  \label{SEC:eg-hs_examp_exp_config}
302    
303  The model configuration for this experiment resides under the  The model configuration for this experiment resides under the
304  directory {\it verification/exp0/}.  The experiment files  directory {\it verification/hs94.128x64x5}.  The experiment files
305  \begin{itemize}  \begin{itemize}
306  \item {\it input/data}  \item {\it input/data}
307  \item {\it input/data.pkg}  \item {\it input/data.pkg}
308  \item {\it input/eedata},  \item {\it input/eedata},
309  \item {\it input/windx.sin\_y},  \item {\it input/windx.bin},
310  \item {\it input/topog.box},  \item {\it input/windy.bin},
311    \item {\it input/salt.bin},
312    \item {\it input/theta.bin},
313    \item {\it input/SSS.bin},
314    \item {\it input/SST.bin},
315    \item {\it input/topog.bin},
316  \item {\it code/CPP\_EEOPTIONS.h}  \item {\it code/CPP\_EEOPTIONS.h}
317  \item {\it code/CPP\_OPTIONS.h},  \item {\it code/CPP\_OPTIONS.h},
318  \item {\it code/SIZE.h}.  \item {\it code/SIZE.h}.
319  \end{itemize}  \end{itemize}
320  contain the code customizations and parameter settings for this  contain the code customizations and parameter settings for these
321  experiments. Below we describe the customizations  experiments. Below we describe the customizations
322  to these files associated with this experiment.  to these files associated with this experiment.
323    
# Line 78  are Line 330  are
330    
331  \begin{itemize}  \begin{itemize}
332    
333  \item Line 7, \begin{verbatim} viscAh=4.E2, \end{verbatim} this line sets  \item Lines 7-10 and 11-14
334  the Laplacian friction coefficient to $400 m^2s^{-1}$  \begin{verbatim} tRef= 16.0 , 15.2 , 14.5 , 13.9 , 13.3 ,  \end{verbatim}
335  \item Line 10, \begin{verbatim} beta=1.E-11, \end{verbatim} this line sets  $\cdots$ \\
336  $\beta$ (the gradient of the coriolis parameter, $f$) to $10^{-11} s^{-1}m^{-1}$  set reference values for potential
337    temperature and salinity at each model level in units of $^{\circ}$C and
338  \item Lines 15 and 16  ${\rm ppt}$. The entries are ordered from surface to depth.
339  \begin{verbatim}  Density is calculated from anomalies at each level evaluated
340  rigidLid=.FALSE.,  with respect to the reference values set here.\\
341  implicitFreeSurface=.TRUE.,  \fbox{
342  \end{verbatim}  \begin{minipage}{5.0in}
343  these lines suppress the rigid lid formulation of the surface  {\it S/R INI\_THETA}({\it ini\_theta.F})
344  pressure inverter and activate the implicit free surface form  \end{minipage}
345  of the pressure inverter.  }
346    
347    
348    \item Line 15,
349    \begin{verbatim} viscAz=1.E-3, \end{verbatim}
350    this line sets the vertical Laplacian dissipation coefficient to
351    $1 \times 10^{-3} {\rm m^{2}s^{-1}}$. Boundary conditions
352    for this operator are specified later. This variable is copied into
353    model general vertical coordinate variable {\bf viscAr}.
354    
355    \fbox{
356    \begin{minipage}{5.0in}
357    {\it S/R CALC\_DIFFUSIVITY}({\it calc\_diffusivity.F})
358    \end{minipage}
359    }
360    
361    \item Line 16,
362    \begin{verbatim}
363    viscAh=5.E5,
364    \end{verbatim}
365    this line sets the horizontal Laplacian frictional dissipation coefficient to
366    $5 \times 10^{5} {\rm m^{2}s^{-1}}$. Boundary conditions
367    for this operator are specified later.
368    
369    \item Lines 17,
370    \begin{verbatim}
371    no_slip_sides=.FALSE.
372    \end{verbatim}
373    this line selects a free-slip lateral boundary condition for
374    the horizontal Laplacian friction operator
375    e.g. $\frac{\partial u}{\partial y}$=0 along boundaries in $y$ and
376    $\frac{\partial v}{\partial x}$=0 along boundaries in $x$.
377    
378    \item Lines 9,
379    \begin{verbatim}
380    no_slip_bottom=.TRUE.
381    \end{verbatim}
382    this line selects a no-slip boundary condition for bottom
383    boundary condition in the vertical Laplacian friction operator
384    e.g. $u=v=0$ at $z=-H$, where $H$ is the local depth of the domain.
385    
386    \item Line 19,
387    \begin{verbatim}
388    diffKhT=1.E3,
389    \end{verbatim}
390    this line sets the horizontal diffusion coefficient for temperature
391    to $1000\,{\rm m^{2}s^{-1}}$. The boundary condition on this
392    operator is $\frac{\partial}{\partial x}=\frac{\partial}{\partial y}=0$ on
393    all boundaries.
394    
395    \item Line 20,
396    \begin{verbatim}
397    diffKzT=3.E-5,
398    \end{verbatim}
399    this line sets the vertical diffusion coefficient for temperature
400    to $3 \times 10^{-5}\,{\rm m^{2}s^{-1}}$. The boundary
401    condition on this operator is $\frac{\partial}{\partial z}=0$ at both
402    the upper and lower boundaries.
403    
404    \item Line 21,
405    \begin{verbatim}
406    diffKhS=1.E3,
407    \end{verbatim}
408    this line sets the horizontal diffusion coefficient for salinity
409    to $1000\,{\rm m^{2}s^{-1}}$. The boundary condition on this
410    operator is $\frac{\partial}{\partial x}=\frac{\partial}{\partial y}=0$ on
411    all boundaries.
412    
413    \item Line 22,
414    \begin{verbatim}
415    diffKzS=3.E-5,
416    \end{verbatim}
417    this line sets the vertical diffusion coefficient for salinity
418    to $3 \times 10^{-5}\,{\rm m^{2}s^{-1}}$. The boundary
419    condition on this operator is $\frac{\partial}{\partial z}=0$ at both
420    the upper and lower boundaries.
421    
422    \item Lines 23-26
423    \begin{verbatim}
424    beta=1.E-11,
425    \end{verbatim}
426    \vspace{-5mm}$\cdots$\\
427    These settings do not apply for this experiment.
428    
429  \item Line 27,  \item Line 27,
430  \begin{verbatim}  \begin{verbatim}
431  startTime=0,  gravity=9.81,
432  \end{verbatim}  \end{verbatim}
433  this line indicates that the experiment should start from $t=0$  Sets the gravitational acceleration coefficient to $9.81{\rm m}{\rm s}^{-1}$.\\
434  and implicitly suppresses searching for checkpoint files associated  \fbox{
435  with restarting an numerical integration from a previously saved state.  \begin{minipage}{5.0in}
436    {\it S/R CALC\_PHI\_HYD}~({\it calc\_phi\_hyd.F})\\
437    {\it S/R INI\_CG2D}~({\it ini\_cg2d.F})\\
438    {\it S/R INI\_CG3D}~({\it ini\_cg3d.F})\\
439    {\it S/R INI\_PARMS}~({\it ini\_parms.F})\\
440    {\it S/R SOLVE\_FOR\_PRESSURE}~({\it solve\_for\_pressure.F})
441    \end{minipage}
442    }
443    
444    
445  \item Line 29,  \item Line 28-29,
446  \begin{verbatim}  \begin{verbatim}
447  endTime=12000,  rigidLid=.FALSE.,
448    implicitFreeSurface=.TRUE.,
449  \end{verbatim}  \end{verbatim}
450  this line indicates that the experiment should start finish at $t=12000s$.  Selects the barotropic pressure equation to be the implicit free surface
451  A restart file will be written at this time that will enable the  formulation.
 simulation to be continued from this point.  
452    
453  \item Line 30,  \item Line 30,
454  \begin{verbatim}  \begin{verbatim}
455  deltaTmom=1200,  eosType='POLY3',
456  \end{verbatim}  \end{verbatim}
457  This line sets the momentum equation timestep to $1200s$.  Selects the third order polynomial form of the equation of state.\\
458    \fbox{
459    \begin{minipage}{5.0in}
460    {\it S/R FIND\_RHO}~({\it find\_rho.F})\\
461    {\it S/R FIND\_ALPHA}~({\it find\_alpha.F})
462    \end{minipage}
463    }
464    
465  \item Line 39,  \item Line 31,
466  \begin{verbatim}  \begin{verbatim}
467  usingCartesianGrid=.TRUE.,  readBinaryPrec=32,
468  \end{verbatim}  \end{verbatim}
469  This line requests that the simulation be performed in a  Sets format for reading binary input datasets holding model fields to
470  Cartesian coordinate system.  use 32-bit representation for floating-point numbers.\\
471    \fbox{
472    \begin{minipage}{5.0in}
473    {\it S/R READ\_WRITE\_FLD}~({\it read\_write\_fld.F})\\
474    {\it S/R READ\_WRITE\_REC}~({\it read\_write\_rec.F})
475    \end{minipage}
476    }
477    
478  \item Line 41,  \item Line 36,
479  \begin{verbatim}  \begin{verbatim}
480  delX=60*20E3,  cg2dMaxIters=1000,
481  \end{verbatim}  \end{verbatim}
482  This line sets the horizontal grid spacing between each x-coordinate line  Sets maximum number of iterations the two-dimensional, conjugate
483  in the discrete grid. The syntax indicates that the discrete grid  gradient solver will use, {\bf irrespective of convergence
484  should be comprise of $60$ grid lines each separated by $20 \times 10^{3}m$  criteria being met}.\\
485  ($20$~km).  \fbox{
486    \begin{minipage}{5.0in}
487    {\it S/R CG2D}~({\it cg2d.F})
488    \end{minipage}
489    }
490    
491    \item Line 37,
492    \begin{verbatim}
493    cg2dTargetResidual=1.E-13,
494    \end{verbatim}
495    Sets the tolerance which the two-dimensional, conjugate
496    gradient solver will use to test for convergence in equation
497    \ref{EQ:eg-hs-congrad_2d_resid} to $1 \times 10^{-13}$.
498    Solver will iterate until
499    tolerance falls below this value or until the maximum number of
500    solver iterations is reached.\\
501    \fbox{
502    \begin{minipage}{5.0in}
503    {\it S/R CG2D}~({\it cg2d.F})
504    \end{minipage}
505    }
506    
507  \item Line 42,  \item Line 42,
508  \begin{verbatim}  \begin{verbatim}
509  delY=60*20E3,  startTime=0,
510  \end{verbatim}  \end{verbatim}
511  This line sets the horizontal grid spacing between each y-coordinate line  Sets the starting time for the model internal time counter.
512  in the discrete grid to $20 \times 10^{3}m$ ($20$~km).  When set to non-zero this option implicitly requests a
513    checkpoint file be read for initial state.
514    By default the checkpoint file is named according to
515    the integer number of time steps in the {\bf startTime} value.
516    The internal time counter works in seconds.
517    
518  \item Line 43,  \item Line 43,
519  \begin{verbatim}  \begin{verbatim}
520  delZ=5000,  endTime=2808000.,
521  \end{verbatim}  \end{verbatim}
522  This line sets the vertical grid spacing between each z-coordinate line  Sets the time (in seconds) at which this simulation will terminate.
523  in the discrete grid to $5000m$ ($5$~km).  At the end of a simulation a checkpoint file is automatically
524    written so that a numerical experiment can consist of multiple
525    stages.
526    
527    \item Line 44,
528    \begin{verbatim}
529    #endTime=62208000000,
530    \end{verbatim}
531    A commented out setting for endTime for a 2000 year simulation.
532    
533    \item Line 45,
534    \begin{verbatim}
535    deltaTmom=2400.0,
536    \end{verbatim}
537    Sets the timestep $\delta t_{v}$ used in the momentum equations to
538    $20~{\rm mins}$.
539    See section \ref{SEC:mom_time_stepping}.
540    
541    \fbox{
542    \begin{minipage}{5.0in}
543    {\it S/R TIMESTEP}({\it timestep.F})
544    \end{minipage}
545    }
546    
547  \item Line 46,  \item Line 46,
548  \begin{verbatim}  \begin{verbatim}
549    tauCD=321428.,
550    \end{verbatim}
551    Sets the D-grid to C-grid coupling time scale $\tau_{CD}$ used in the momentum equations.
552    See section \ref{SEC:cd_scheme}.
553    
554    \fbox{
555    \begin{minipage}{5.0in}
556    {\it S/R INI\_PARMS}({\it ini\_parms.F})\\
557    {\it S/R CALC\_MOM\_RHS}({\it calc\_mom\_rhs.F})
558    \end{minipage}
559    }
560    
561    \item Line 47,
562    \begin{verbatim}
563    deltaTtracer=108000.,
564    \end{verbatim}
565    Sets the default timestep, $\delta t_{\theta}$, for tracer equations to
566    $30~{\rm hours}$.
567    See section \ref{SEC:tracer_time_stepping}.
568    
569    \fbox{
570    \begin{minipage}{5.0in}
571    {\it S/R TIMESTEP\_TRACER}({\it timestep\_tracer.F})
572    \end{minipage}
573    }
574    
575    \item Line 47,
576    \begin{verbatim}
577  bathyFile='topog.box'  bathyFile='topog.box'
578  \end{verbatim}  \end{verbatim}
579  This line specifies the name of the file from which the domain  This line specifies the name of the file from which the domain
# Line 156  coordinate varying fastest. The points a Line 584  coordinate varying fastest. The points a
584  to high coordinate for both axes. The units and orientation of the  to high coordinate for both axes. The units and orientation of the
585  depths in this file are the same as used in the MITgcm code. In this  depths in this file are the same as used in the MITgcm code. In this
586  experiment, a depth of $0m$ indicates a solid wall and a depth  experiment, a depth of $0m$ indicates a solid wall and a depth
587  of $-5000m$ indicates open ocean. The matlab program  of $-2000m$ indicates open ocean. The matlab program
588  {\it input/gendata.m} shows an example of how to generate a  {\it input/gendata.m} shows an example of how to generate a
589  bathymetry file.  bathymetry file.
590    
591    
592  \item Line 49,  \item Line 50,
593  \begin{verbatim}  \begin{verbatim}
594  zonalWindFile='windx.sin_y'  zonalWindFile='windx.sin_y'
595  \end{verbatim}  \end{verbatim}
# Line 169  This line specifies the name of the file Line 597  This line specifies the name of the file
597  surface wind stress is read. This file is also a two-dimensional  surface wind stress is read. This file is also a two-dimensional
598  ($x,y$) map and is enumerated and formatted in the same manner as the  ($x,y$) map and is enumerated and formatted in the same manner as the
599  bathymetry file. The matlab program {\it input/gendata.m} includes example  bathymetry file. The matlab program {\it input/gendata.m} includes example
600  code to generate a valid {\bf zonalWindFile} file.    code to generate a valid
601    {\bf zonalWindFile}
602    file.  
603    
604  \end{itemize}  \end{itemize}
605    
# Line 177  code to generate a valid {\bf zonalWindF Line 607  code to generate a valid {\bf zonalWindF
607  that are described in the MITgcm Getting Started and MITgcm Parameters  that are described in the MITgcm Getting Started and MITgcm Parameters
608  notes.  notes.
609    
610  %%\begin{small}  \begin{small}
611  %%\input{part3/case_studies/barotropic_gyre/input/data}  \input{part3/case_studies/climatalogical_ogcm/input/data}
612  %%\end{small}  \end{small}
613    
614  \subsubsection{File {\it input/data.pkg}}  \subsubsection{File {\it input/data.pkg}}
615  \label{www:tutorials}  \label{www:tutorials}
616    
617  This file uses standard default values and does not contain  This file uses standard default values and does not contain
618  customizations for this experiment.  customisations for this experiment.
619    
620  \subsubsection{File {\it input/eedata}}  \subsubsection{File {\it input/eedata}}
621  \label{www:tutorials}  \label{www:tutorials}
622    
623  This file uses standard default values and does not contain  This file uses standard default values and does not contain
624  customizations for this experiment.  customisations for this experiment.
625    
626  \subsubsection{File {\it input/windx.sin\_y}}  \subsubsection{File {\it input/windx.sin\_y}}
627  \label{www:tutorials}  \label{www:tutorials}
# Line 210  code for creating the {\it input/windx.s Line 640  code for creating the {\it input/windx.s
640    
641  The {\it input/topog.box} file specifies a two-dimensional ($x,y$)  The {\it input/topog.box} file specifies a two-dimensional ($x,y$)
642  map of depth values. For this experiment values are either  map of depth values. For this experiment values are either
643  $0m$ or {\bf -delZ}m, corresponding respectively to a wall or to deep  $0m$ or $-2000\,{\rm m}$, corresponding respectively to a wall or to deep
644  ocean. The file contains a raw binary stream of data that is enumerated  ocean. The file contains a raw binary stream of data that is enumerated
645  in the same way as standard MITgcm two-dimensional, horizontal arrays.  in the same way as standard MITgcm two-dimensional, horizontal arrays.
646  The included matlab program {\it input/gendata.m} gives a complete  The included matlab program {\it input/gendata.m} gives a complete
# Line 233  axis aligned with the x-coordinate. Line 663  axis aligned with the x-coordinate.
663  the lateral domain extent in grid points for the  the lateral domain extent in grid points for the
664  axis aligned with the y-coordinate.  axis aligned with the y-coordinate.
665    
666    \item Line 49,
667    \begin{verbatim} Nr=4,   \end{verbatim} this line sets
668    the vertical domain extent in grid points.
669    
670  \end{itemize}  \end{itemize}
671    
672  \begin{small}  \begin{small}
673  \input{part3/case_studies/barotropic_gyre/code/SIZE.h}  \input{part3/case_studies/climatalogical_ogcm/code/SIZE.h}
674  \end{small}  \end{small}
675    
676  \subsubsection{File {\it code/CPP\_OPTIONS.h}}  \subsubsection{File {\it code/CPP\_OPTIONS.h}}
677  \label{www:tutorials}  \label{www:tutorials}
678    
679  This file uses standard default values and does not contain  This file uses standard default values and does not contain
680  customizations for this experiment.  customisations for this experiment.
681    
682    
683  \subsubsection{File {\it code/CPP\_EEOPTIONS.h}}  \subsubsection{File {\it code/CPP\_EEOPTIONS.h}}
684  \label{www:tutorials}  \label{www:tutorials}
685    
686  This file uses standard default values and does not contain  This file uses standard default values and does not contain
687  customizations for this experiment.  customisations for this experiment.
688    
689    \subsubsection{Other Files }
690    \label{www:tutorials}
691    
692    Other files relevant to this experiment are
693    \begin{itemize}
694    \item {\it model/src/ini\_cori.F}. This file initializes the model
695    coriolis variables {\bf fCorU}.
696    \item {\it model/src/ini\_spherical\_polar\_grid.F}
697    \item {\it model/src/ini\_parms.F},
698    \item {\it input/windx.sin\_y},
699    \end{itemize}
700    contain the code customisations and parameter settings for this
701    experiments. Below we describe the customisations
702    to these files associated with this experiment.
Legend:
Removed from v.1.1  
changed lines
  Added in v.1.2
  ViewVC Help
Powered by ViewVC 1.1.22