Changeset 11314


Ignore:
Timestamp:
2019-07-19T19:04:20+02:00 (13 months ago)
Author:
djlea
Message:

#2297 Updates in response the P Mathiot's review

Location:
NEMO/branches/2019/dev_r11233_obsasm_docfixes/doc/latex/NEMO/subfiles
Files:
2 edited

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  • NEMO/branches/2019/dev_r11233_obsasm_docfixes/doc/latex/NEMO/subfiles/chap_ASM.tex

    r11311 r11314  
    100100\label{sec:ASM_div_dmp} 
    101101 
    102 The velocity increments may be initialized by the iterative application of a divergence damping operator. 
    103 In iteration step $n$ new estimates of velocity increments $u^{n}_I$ and $v^{n}_I$ are updated by: 
     102It is quite challenging for data assimilation systems to provide non-divergent velocity increments. 
     103Applying divergent velocity increments will likely cause spurious vertical velocities in the model. This section describes a method to take velocity increments provided to \NEMO ($u^0_I$ and $v^0_I$) and adjust them by the iterative application of a divergence damping operator. The method is also described in \citet{dobricic.pinardi.ea_OS07}. 
     104 
     105In iteration step $n$ (starting at $n=1$) new estimates of velocity increments $u^{n}_I$ and $v^{n}_I$ are updated by: 
     106 
    104107\begin{equation} 
    105108  \label{eq:asm_dmp} 
     
    113116  \right., 
    114117\end{equation} 
     118 
    115119where the divergence is defined as 
     120 
    116121\[ 
    117122  % \label{eq:asm_div} 
     
    120125      +\delta_j \left[ {e_{1v}\,e_{3v}\,v^{n-1}_I} \right]} \right). 
    121126\] 
     127 
    122128By the application of \autoref{eq:asm_dmp} the divergence is filtered in each iteration, 
    123129and the vorticity is left unchanged. 
  • NEMO/branches/2019/dev_r11233_obsasm_docfixes/doc/latex/NEMO/subfiles/chap_OBS.tex

    r11311 r11314  
    677677\item The standard grid-searching code is used to find the nearest model grid point to the observation location 
    678678  (see next subsection). 
    679 \item The maximum number of grid points is calculated in the local grid domain for which 
    680   the averaging is likely need to cover. 
     679\item The maximum number of grid points required for that observation in each local grid domain is calculated. Some of these points may later turn out to have zero weight depending on the shape of the footprint. 
    681680\item The longitudes and latitudes of the grid points surrounding the nearest model grid box are extracted using 
    682681  existing MPI routines. 
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