The pseudo single ob test is usually the first step to try out WRFDA after you have generated your own be.dat.
Source code
Get the pre-compiled code, if you have not done so.
WRFDA/var/build/da_wrfvar.exe_3dvar is the executable that will be used in this session.
Choose your working directory
For this exercise you should create /data1/${USER}/DA/singleob and use this as your working directory for this session.
mkdir /data1/${USER}/DA/singleob
cd /data1/${USER}/DA/singleob
Input files
The procedure is the same as running WRFDA-3DVAR with real data (except that the observation file ob.ascii is not required):
ln -fs /data1/${USER}/DA/WRFDA/run/LANDUSE.TBL ./LANDUSE.TBL
ln -fs /wrfhelp/DATA/WRFDA/CONUS60/be/be.dat ./be.dat
ln -fs /wrfhelp/DATA/WRFDA/CONUS60/rc/2008020512/wrfinput_d01 ./fg
Edit namelist.input
Change and add the following namelist.input settings to activate the pseudo single ob test. You can do so by modifying the namelist.input used in the previous WRFDA-3DVAR tutorial case:
cp ../3dvar/namelist.input namelist.input
vi namelist.input
&wrfvar15
num_pseudo = 1,
pseudo_x = 23.0,
pseudo_y = 23.0,
pseudo_z = 14.0,
pseudo_err = 1.0,
pseudo_val = 1.0
/
&wrfvar19
pseudo_var = 'u'
/
Note: pseudo_var can be u, v, t, p, q. If pseudo_var is q, then the reasonable values of pseudo_err and pseudo_val are 0.001 in order to be able to view the analysis increments.
By setting num_pseudo = 1, WRFDA will ignore real data and simply assimilate the pseudo-observation
Run WRFDA (da_wrfvar.exe)
mpirun -np 4 /data1/${USER}/DA/WRFDA/var/build/da_wrfvar.exe_3dvar
Check output
Check the statistics file to view diagnostics related to your pseudo-obs run.
Use ncdiff and ncview to generate and view the analysis increment file.
ncdiff -v U,V,T,QVAPOR,MU,P,PSFC wrfvar_output fg increment.nc
ncview increment.nc
Graphics
Other useful NCL scripts for this exercise:
WRFDA/var/graphics/ncl/WRF-Var_plot.ncl
WRFDA/var/graphics/ncl/WRF_contributed.ncl.test
WRFDA/var/graphics/ncl/psot_xy_auto.ncl
WRFDA/var/graphics/ncl/psot_xz_auto.ncl
WRFDA/var/graphics/ncl/psot_yz_auto.ncl