Changeset 2242

Timestamp:

2010-10-13T11:13:58+02:00 (14 years ago)

Author:

gm

Message:

ticket:#658 update SBC with diurnal cycle

Location:

branches/DEV_r1826_DOC/DOC/TexFiles

Files:

• Chapters/Chap_SBC.tex (modified) (3 diffs)
• Figures/Fig_SBC_diurnal.pdf (modified) (previous)

branches/DEV_r1826_DOC/DOC/TexFiles/Chapters/Chap_SBC.tex

@@ -382 +382 @@
  the option for the user to increase vertical mixing in the vicinity of the rivermouth.
 
-However, this method is not very appropriate for coastal modelling.  As such its now possible
- to specify, in a netcdf input file, the temperature and salinity of the river, along with the 
+However, this method is not very appropriate for coastal modelling.  As such its now possible 
+to specify, in a NetCDF input file, the temperature and salinity of the river, along with the 
 depth (in metres) which the river should be added to.  This enables to river to be correctly 
 added through the water column, instead of as a surface flux, and also means the temperature 
@@ -433 +433 @@
 \includegraphics[width=0.8\textwidth]{./TexFiles/Figures/Fig_SBC_diurnal.pdf}
 \caption{Example of recontruction of the diurnal cycle variation of short wave flux  
-from daily mean values. The reconstructed diurnal cycle (red squares) is chosen 
-as the mid time step value of the analytically cycle (blue line), not as 
-the mean value of the analytical cycle over a time step (black line). 
-The misfit is however small and without systematic bias. From \citet{Bernie_al_CD07}.}
+from daily mean values. The reconstructed diurnal cycle (black line) is chosen 
+as the mean value of the analytical cycle (blue line) over a time step, not 
+as the mid time step value of the analytically cycle (red square). From \citet{Bernie_al_CD07}.}
 \end{center}   \end{figure}
 %>>>>>>>>>>>>>>>>>>>>>>>>>>>>
@@ -462 +461 @@
 CORE bulk formulea (\np{ln\_blk\_core}=true) or the flux formulation (\np{ln\_flx}=true). 
 The reconstruction is performed in the \mdl{sbcdcy} module. The detail of the algoritm used 
-can be found in the appendix~A of \cite{Bernie_al_CD07}. It is not a strictly conservative 
-algorithm as the mid time step analytical value is used instead of the mean value of 
-the analytical cycle over a time step (Fig.\ref{Fig_SBC_diurnal}). Nevertheless, the error is  
-quite small, reaching locally a maximum value of a few tenth of W/m$^2$ with a 2~h sampling, 
-the error decreasing with increasing the sampling. Moreover, the error is not a systematic, and 
-thus does not lead to seasonal bias. 
-           
-Fig.\ref{Fig_SBC_dcy} show an example of 12 reconstructed diurnal cycle, one every 2~hours 
-(from 1am to 11pm). The difference between the original daily mean and the daily mean 
-reconstructed diurnal cycle (not shown) is small (extrema of $\pm$0.4 W/m$^2$).
+can be found in the appendix~A of \cite{Bernie_al_CD07}. The algorithm preserve the daily 
+mean incomming SWF as the reconstructed SWF at a given time step is the mean value 
+of the analytical cycle over this time step (Fig.\ref{Fig_SBC_diurnal}). 
+The use of diurnal cycle reconstruction requires the input SWF to be daily 
+($i.e.$ a frequency of 24 and a time interpolation set to true in \np{sn\_qsr} namelist parameter).
+Furthermore, it is recommended to have a least 8 surface module time step per day,
+that is  $\rdt \ \np{nn\_fsbc} < 10,800~s = 3~h$. An example of recontructed SWF 
+is given in Fig.\ref{Fig_SBC_dcy} for a 12 reconstructed diurnal cycle, one every 2~hours 
+(from 1am to 11pm).
 
 %>>>>>>>>>>>>>>>>>>>>>>>>>>>>