/[MITgcm]/manual/s_ecco/text/ecco_costfunction.tex
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revision 1.1 by heimbach, Tue May 11 21:55:14 2004 UTC revision 1.3 by heimbach, Thu Jul 8 23:18:08 2004 UTC
# Line 54  field & file name & deccription & unit \ Line 54  field & file name & deccription & unit \
54  \end{table}  \end{table}
55    
56    
57  \subsubsection{$nYears$ time mean SSH misfit}  \subsubsection{\textit{\textbf{nYears}} time mean SSH misfit}
58    
59  \begin{enumerate}  \begin{enumerate}
60  %  %
61  \item  \item
62  Compute 11yr model mean spatial distribution  Compute $nYears$ model mean spatial distribution
63  %  %
64  \begin{equation}  \begin{equation}
65  psmean(i,j)\, =\,  psmean(i,j)\, =\,
# Line 68  psbar(i,j) Line 68  psbar(i,j)
68  \end{equation}  \end{equation}
69  %  %
70  \item  \item
71  Compute global offset between 11-yr model and T/P mean:  Compute global offset between $nYears$ model and T/P mean:
72  %  %
73  \begin{equation}  \begin{equation}
74  \begin{split}  \begin{split}
# Line 161  cost_ssh Line 161  cost_ssh
161    
162  \end{verbatim}  \end{verbatim}
163    
164  \subsubsection{Weights}  \subsubsection{Weights and notes}
165    
166  \begin{itemize}  \begin{itemize}
167  %  %
# Line 227  sum over daily entries and plot daily av Line 227  sum over daily entries and plot daily av
227  \frac{1}{\text{daily entries}} \sum_{i,j} cost\_ssh\_anom(i,j,t)  \frac{1}{\text{daily entries}} \sum_{i,j} cost\_ssh\_anom(i,j,t)
228  \]  \]
229  \end{itemize}  \end{itemize}
230    
231    \subsection{Hydrographic constraints}
232    
233    Observation of temperature and salinity from various sources are
234    used to constrain the model. These are:
235    %
236    \begin{enumerate}
237    %
238    \item
239    CTD obs. for $T$, $S$ from various WOCE sections
240    %
241    \item
242    XBT obs. for $T$
243    %
244    \item
245    Sea surface temperature (SST) and salinity (SSS) from
246    Reynolds et al. (???)
247    %
248    \item
249    $T$, $S$ from ARGO floats
250    %
251    \item
252    $T$, $S$ from fields from Levitus (???)
253    %
254    \end{enumerate}
255    
256    \subsubsection{Input fields}
257    ~
258    
259    \begin{table}[h!]
260    \begin{center}
261    \begin{tabular}{lllc}
262    \hline \hline
263    ~&~&~&~\\
264    field & file name & deccription & unit \\
265    ~&~&~&~\\
266    \hline
267    ~&~&~&~\\
268    {\it tbar} & {\tt tbarfile} & monthly model mean pot. temperature &
269    [$^{\circ}$C] \\
270    {\it sbar} & {\tt sbarfile} & monthly model mean salinity &
271    [ppt] \\
272    {\it tdat} & {\tt tdatfile} & monthly mean Levitus pot. temperature &
273    [$^{\circ}$C] \\
274    {\it sdat} & {\tt sdatfile} & monthly mean Levitus salinity &
275    [ppt] \\
276    {\it ctdtobs}  & {\tt ctdtfile} & monthly WOCE CTD pot. temperature &
277    [$^{\circ}$C] \\
278    {\it ctdsobs}  & {\tt ctdsfile} & monthly WOCE CTD salinity &
279    [ppt] \\
280    {\it xbtobs} & {\tt xbtfile} & monthly XBT in-situ(!) temperature &
281    [$^{\circ}$C] \\
282    {\it sstdat}  & {\tt sstdatfile} & monthly Reynolds pot. SST &
283    [$^{\circ}$C] \\
284    {\it sssdat}  & {\tt sssdatfile} & monthly Reynolds SSS &
285    [ppt] \\
286    {\it argotobs}  & {\tt argotfile} & monthly ARGO in-situ(!) temperature &
287    [$^{\circ}$C] \\
288    {\it argosobs}  & {\tt argosfile} & monthly ARGO salinity &
289    [ppt] \\
290    {\it wti, wsi} & {\tt data\_errfile} & vert. stdev. profile for $T$, $S$ &
291    ~ \\
292    {\it wtvar} & {\tt temperrfile} & spatially varying stdev. & [$^{\circ}$C] \\
293    {\it wsvar} & {\tt salterrfile} & spatially varying stdev. & [ppt] \\
294    ~&~&~&~\\
295    \hline \hline
296    \end{tabular}
297    \end{center}
298    \end{table}
299    
300    \subsubsection{XBT data}
301    
302    \begin{equation}
303    \begin{split}
304    cost\_xbt\_t(i,j,k) & = \,
305    \left[ \, \frac{fac \cdot ratio}{wti^2 + wtvar^2} \sum_{\tau=1}^{nMonsRec}
306    \left\{ Tbar(\tau) \, - \, T2\theta[xbtobs(\tau)] \right\}^2 \, \right](i,j,k)
307     \\
308    \end{split}
309    \end{equation}
310    
311    \subsubsection{WOCE CTD data}
312    
313    \begin{equation}
314    \begin{split}
315    cost\_ctd\_t(i,j,k) & = \,
316    \left[ \, \frac{fac \cdot ratio}{wti^2 + wtvar^2} \sum_{\tau=1}^{nMonsRec}
317    \left\{ Tbar(\tau) \, - \, ctdTobs(\tau) \right\}^2 \, \right](i,j,k)
318     \\
319    cost\_ctd\_s(i,j,k) & = \,
320    \left[ \, \frac{fac \cdot ratio}{wsi^2 + wsvar^2} \sum_{\tau=1}^{nMonsRec}
321    \left\{ Sbar(\tau) \, - \, ctdSobs(\tau) \right\}^2 \, \right](i,j,k)
322     \\
323    \end{split}
324    \end{equation}
325    
326    \subsubsection{ARGO float data}
327    
328    \begin{equation}
329    \begin{split}
330    cost\_argo\_t(i,j,k) & = \,
331    \left[ \, \frac{fac \cdot ratio}{wti^2 + wvar^2} \sum_{\tau=1}^{nMonsRec}
332    \left\{ Tbar(\tau) \, - \, T2\theta[argoTobs(\tau)] \right\}^2 \, \right](i,j,k)
333     \\
334    cost\_argo\_s(i,j,k) & = \,
335    \left[ \, \frac{fac \cdot ratio}{wsi^2 + wsvar^2} \sum_{\tau=1}^{nMonsRec}
336    \left\{ Sbar(\tau) \, - \, argoSobs(\tau) \right\}^2 \, \right](i,j,k)
337     \\
338    \end{split}
339    \end{equation}
340    
341    \subsubsection{Reynolds sea surface T, S data}
342    
343    \begin{equation}
344    \begin{split}
345    cost\_sst(i,j) & = \,
346    \left[ \, wsst \sum_{\tau=1}^{nMonsRec}
347    \left\{ Tbar(\tau) \, - \, sstDat(\tau) \right\}^2 \, \right](i,j)
348     \\
349    cost\_sss(i,j) & = \,
350    \left[ \, wsss \sum_{\tau=1}^{nMonsRec}
351    \left\{ Sbar(\tau) \, - \, sssDat(\tau) \right\}^2 \, \right](i,j)
352     \\
353    \end{split}
354    \end{equation}
355    
356    \subsubsection{Levitus montly T, S climatological data}
357    
358    Model vs. data misfits are taken from $nYears$ monthly model means
359    vs. Levitus monthly data.
360    The description below is for potential temperature.
361    Procedure for salinity is fully analogous.
362    Spatial indices $(i,j,k)$ are omitted throughout.
363    %
364    \begin{enumerate}
365    %
366    \item
367    Compute $nYears$ monthly model means for each month $imon$:
368    \[
369    \overline{Tbar}(imon) \, = \, \frac{1}{nYears}
370    \sum_{iyear=1}^{nYears} Tbar(iyear,imon)
371    \]
372    %
373    \item
374    Compute misfit:
375    \[
376    cost\_theta(i,j,k) \, = \, \left[
377    \frac{fac \cdot ratio}{wti^2} \sum_{imon=1}^{12}
378    \left\{ \overline{Tbar}(imon) \, - \, Tdat(imon) \right\}^2  \right] (i,j,k)
379    \]
380    
381    \end{enumerate}
382    
383    
384    \subsubsection{Weights and notes}
385    
386    \begin{itemize}
387    %
388    \item
389    $T2\theta$ is an operator mapping in-situ to potential temperatures
390    %
391    \item
392    Latitudinal weight not used:
393    \[
394    cosphi(i,j) \, = \, 1
395    \]
396    %
397    \item
398    $ fac \, = \, cosphi \cdot mask $
399    %
400    \item
401    Spatially {\it constant} weights:
402    %
403    \begin{enumerate}
404    %
405    \item
406    Read standard deviation vertical profiles for $T$, $S$ \\
407    $ {\tt data\_errfile} \, \longrightarrow \,
408    wti(k), \,\, wsi(k) $ \\
409    $ {\tt data\_errfile} \, \longrightarrow \,
410    ratio = 0.25 = \left( \frac{1}{2} \right)^2 $
411    %
412    \item
413    Take inverse squares:
414    \[
415    \begin{split}
416    wtheta(k) & = \, \frac{ratio}{wti(k)^2} \\
417    wsalt(k) & = \, \frac{ratio}{wsi(k)^2} \\
418    \end{split}
419    \]
420    %
421    \end{enumerate}
422    %
423    \item
424    Spatially {\it varying} weights:
425    %
426    \begin{enumerate}
427    %
428    \item
429    Read standard deviation fields \\
430    $ {\tt temperrfile} \, \longrightarrow \, wtvar(i,j,k) $ \\
431    $ {\tt salterrfile} \, \longrightarrow \, wsvar(i,j,k) $ \\
432    %
433    \item
434    Weights are combination of spatially constant and varying parts:
435    \[
436    \begin{split}
437    wtheta2(i,j,k) & = \, \frac{ratio}
438    {wti(k)^2 \, + \,wtvar(i,j,k)^2 } \\
439    wsalt2(i,j,k) & = \,
440    \frac{ratio}
441    {wsi(k)^2 \, + \,wsvar(i,j,k)^2 } \\
442    \end{split}
443    \]
444    %
445    \end{enumerate}
446    %
447    \item
448    Sea surface $T$, $S$ weights:
449    \begin{itemize}
450    \item
451    SST: $ wsst \, = \, fac \cdot wtheta(1)$: horizontally constant
452    \item
453    SSS: $ wsss \, = \, fac \cdot wsalt2(i,j,1)$: horizontally varying
454    \end{itemize}
455    (Why this difference? I don't know.)
456    %
457    \end{itemize}
458    
459    
460    \subsubsection{Diagnostics}
461    
462    \begin{itemize}
463    %
464    \item
465    Map out $wtheta2(i,j,k)$, $wsalt2(i,j,k)$.
466    
467    %
468    \end{itemize}
469    

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