Changeset 11296 for NEMO/branches/2019/dev_r11233_obsasm_docfixes/doc/latex/NEMO/subfiles/chap_ASM.tex

Timestamp:

2019-07-18T15:41:15+02:00 (5 years ago)

Author:

djlea

Message:

#2297 Updates to OBS and ASM documentation - first sweep.

File:

• NEMO/branches/2019/dev_r11233_obsasm_docfixes/doc/latex/NEMO/subfiles/chap_ASM.tex (modified) (8 diffs)

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

@@ -8 +8 @@
 \label{chap:ASM}
 
-Authors: D. Lea,  M. Martin, K. Mogensen, A. Weaver, ...   % do we keep
+Authors: D. Lea,  M. Martin, K. Mogensen, A. Weaver.
 
 \minitoc
@@ -15 +15 @@
 
 The ASM code adds the functionality to apply increments to the model variables: temperature, salinity,
-sea surface height, velocity and sea ice concentration. 
+sea surface height, velocity and sea ice concentration.
 These are read into the model from a NetCDF file which may be produced by separate data assimilation code.
 The code can also output model background fields which are used as an input to data assimilation code.
@@ -56 +56 @@
 Typically the increments are spread evenly over the full window.
 In addition, two different weighting functions have been implemented.
-The first function employs constant weights, 
+The first function (namelist option \np{niaufn} = 0) employs constant weights,
 \begin{align}
   \label{eq:F1_i}
@@ -66 +66 @@
     0     &    {\mathrm if} \; \; \; t_{i} > t_{n}
   \end{array}
-            \right. 
+            \right.
 \end{align}
 where $M = m-n$.
-The second function employs peaked hat-like weights in order to give maximum weight in the centre of the sub-window,
+The second function (namelist option \np{niaufn} = 1) employs peaked hat-like weights in order to give maximum weight in the centre of the sub-window,
 with the weighting reduced linearly to a small value at the window end-points:
 \begin{align}
@@ -83 +83 @@
                                    \right.
 \end{align}
-where $\alpha^{-1} = \sum_{i=1}^{M/2} 2i$ and $M$ is assumed to be even. 
+where $\alpha^{-1} = \sum_{i=1}^{M/2} 2i$ and $M$ is assumed to be even.
 The weights described by \autoref{eq:F2_i} provide a smoother transition of the analysis trajectory from
 one assimilation cycle to the next than that described by \autoref{eq:F1_i}.
@@ -105 +105 @@
   \right.,
 \end{equation}
-where
+where the divergence is defined as
 \[
   % \label{eq:asm_div}
@@ -122 +122 @@
 The divergence damping is activated by assigning to \np{nn\_divdmp} in the \textit{nam\_asminc} namelist
 a value greater than zero.
-By choosing this value to be of the order of 100 the increments in
-the vertical velocity will be significantly reduced.
+This specifies the number of iterations of the divergence damping. Setting a value of the order of 100 will result in a significant reduction in the vertical velocity induced by the increments.
 
 
@@ -131 +130 @@
 \label{sec:ASM_details}
 
-Here we show an example \ngn{namasm} namelist and the header of an example assimilation increments file on
+Here we show an example \ngn{nam\_asminc} namelist and the header of an example assimilation increments file on
 the ORCA2 grid.
 
-%------------------------------------------namasm-----------------------------------------------------
+%------------------------------------------nam_asminc-----------------------------------------------------
 %
 \nlst{nam_asminc}