Reference: Download the tutorial presentation
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.
Choice of your working directory
You should run each lesson in a separate directory, so that it will be easier to check for the necessary input files and look for what output files are created after a successful run.
We recommend you create /data1/${USER}/DA/radiance to be your working directory for this session.
mkdir /data1/${USER}/DA/radiance
cd /data1/${USER}/DA/radiance
Input files
The radiance case is the same CONUS60 case you have used in obsproc, running WRFDA-3DVAR and gen_be sessions. Keep in mind that when compiling WRFDA yourself, additional settings must be specified at compile time to utilize radiance data. This has been done for you in the pre-compiled code.
Radiance assimilation for 3DVAR is much the same procedure as Running WRFDA-3DVAR with conventional observations. To begin this exercise, link/copy the basic input files above that you should have been familiar with by now:
ln -sf /data1/${USER}/DA/WRFDA/run/LANDUSE.TBL ./LANDUSE.TBL
ln -sf /data1/${USER}/DA/obsproc/obs_gts_2008-02-05_12:00:00.3DVAR ./ob.ascii
ln -sf /data1/${USER}/DA/gen_be/be.dat ./be.dat
(use /wrfhelp/DATA/WRFDA/CONUS60/be/be.dat if you have not done the GEN_BE exercise)
cp -p /wrfhelp/DATA/WRFDA/CONUS60/rc/2008020512/wrfinput_d01 ./fg
In addition, the following extra files are required for radiance assimilation:
- Radiance data in NCEP BUFR format
ln -fs /wrfhelp/DATA/WRFDA/CONUS60/ob/2008020512/gdas1.t12z.1bamua.tm00.bufr_d.linux ./amsua.bufr
ln -fs /wrfhelp/DATA/WRFDA/CONUS60/ob/2008020512/gdas1.t12z.1bamub.tm00.bufr_d.linux ./amsub.bufr
- radiance_info files (you must link the whole directory)
ln -fs /data1/${USER}/DA/WRFDA/var/run/radiance_info ./radiance_info
- File for variational bias correction
ln -fs /data1/${USER}/DA/WRFDA/var/run/VARBC.in ./VARBC.in
- Radiative Transfer Model (CRTM or RTTOV) coefficient files (you must link the whole directory)
(CRTM only) ln -fs /data1/${USER}/DA/WRFDA/var/run/crtm_coeffs ./crtm_coeffs
(RTTOV only) ln -fs /wrfhelp/WRFDA/external/rttov10/rtcoef_rttov10/rttov7pred51L ./rttov_coeffs
Edit namelist.input
A sample namelist.input is provided in the WRFDA package as WRFDA/var/test/radiance/namelist.input
cp /data1/${USER}/DA/WRFDA/var/test/radiance/namelist.input ./namelist.input
vi namelist.input (pay special attention to the following radiance-related settings)
&wrfvar4
use_amsuaobs = .true.
use_amsubobs = .true.
/
&wrfvar14
rtminit_nsensor = 6,
rtminit_platform = 1,1,1,1,1,1
rtminit_satid = 15,16,18,15,16,17
rtminit_sensor = 3,3,3,4,4,4
thinning_mesh = 120.0,120.0,120.0,120.0,120.0,120.0,
thinning = .true.
qc_rad = .true.
write_iv_rad_ascii = .false.
write_oa_rad_ascii = .true.
rtm_option = 2
only_sea_rad = .false.
use_varbc = .true.
use_crtm_kmatrix = .true. (set "use_rttov_kmatrix" instead for RTTOV)
varbc_nbgerr = 5000
/
&wrfvar21
time_window_min = "2008-02-05_11:00:00"
/
&wrfvar22
time_window_max = "2008-02-05_13:00:00"
/
Run WRFDA
mpirun -np 4 /data1/${USER}/DA/WRFDA/var/build/da_wrfvar.exe_3dvar
Check output
Check analysis increments.
Check statistics.
There are extra diagnostic files when assimilating radiance data:
- 01_oma_*amsu*: Observation minus analysis statistics for each radiance instrument.
- 01_qcstat_*amsu*: Quality control statistics for each radiance instrument.
- VARBC.out: Output file for Variational Bias Correction. This process is described in further detail in the User's Guide
Graphics
/wrfhelp/SOURCE_CODE/WRFDA_SOURCE/TOOLS/scripts/da_rad_diags.ksh
Note: This version of da_rad_diag.ksh is customized to work for the directory structures for this tutorial. For your own applications, you should read through the default da_rad_diags.ksh and make proper changes.
The diagnostics netCDF files will be created in the /data1/$USER/DA/radiance/diags directory.
Other practice
- Try linking /wrfhelp/DATA/WRFDA/CONUS60/ob/2008020512/gdas1.t12z.1bamua.tm00.bufr_d as amsua.bufr in your working directory and run WRFDA to see what log messages you will get.
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