WRF ARW User's Guide - MMM - UCAR

Observations
Background Error
Statistics
ASCII
(PREPBUFR also possible)
Binary
WRF-VAR
Observation Preprocessor
(OBSPROC)
WRF-Var gen_be utility
/Default CV3
In the test case, you will store data in a directory defined by the environment variable
$DAT_DIR. This directory can be at any location and it should have read access. Type
> setenv DAT_DIR your_choice_of_dat_dir
Here, "your_choice_of_dat_dir" is the directory where the WRF-Var input data is
stored. Create this directory if it does not exist, and type
> cd $DAT_DIR
Download the test data for a “Tutorial” case valid at 12 UTC 5 th February 2008 from
http://www.mmm.ucar.edu/wrf/users/wrfda/download/testdata.html
Once you have downloaded “WRFV3.1-Var-testdata.tar.gz” file to $DAT_DIR, extract
it by typing
> gunzip WRFV3.1-Var-testdata.tar.gz
> tar -xvf WRFV3.1-Var-testdata.tar
Now you should find the following three sub-directories/files under “$DAT_DIR”
ob/2008020512/ob.2008020512.gz # Observation data in “little_r” format
rc/2008020512/wrfinput_d01 # First guess file
rc/2008020512/wrfbdy_d01 # lateral boundary file
be/be.dat # Background error file
......
You should first go through the section “Running Observation Preprocessor (OB-
SPROC)” and have a WRF-3DVar-ready observation file (obs_gts_2008-02-
05_12:00:00.3DVAR) generated in your OBSPROC working directory. You could then
copy or move obs_gts_2008-02-05_12:00:00.3DVAR to be in
$DAT_DIR/ob/2008020512/ob.ascii.
If you want to try 4D-Var, please go through the section “Running Observation Preprocessor
(OBSPROC)” and have the WRF-4DVar-ready observation files (obs_gts_2008-
02-05_12:00:00.4DVAR,……). You could copy or move the observation files to
$DAT_DIR/ob using following commands:
> mv obs_gts_2008-02-05_12:00:00.4DVAR $DAT_DIR/ob/2008020512/ob.ascii+
> mv obs_gts_2008-02-05_13:00:00.4DVAR $DAT_DIR/ob/2008020513/ob.ascii
WRF-ARW V3: User’s Guide 6-13