WRF ARW User's Guide - MMM - UCAR

You may like to compare various diagnostics with earlier run.
(e) Response of outer loop on minimization:
Run tutorial case with
&wrfvar6
max_ext_its = 2,
/
WRF-VAR
With this setting “outer loop” for the minimization procedure will get activated. You may
like to compare various diagnostics with earlier run.
Note: Maximum permissible value for “MAX_EXT_ITS” is 10
(f) Response of suppressing particular types of data in WRF-Var:
The types of observations that WRF-Var gets to use actually depend on what is included
in the observation file and the WRF-Var namelist settings. For example, if you have
SYNOP data in the observation file, you can suppress its usage in WRF-Var by setting
use_synopobs=false in record &wrfvar4 of namelist.input. It is OK if there is no
SYNOP data in the observation file and use_synopobs=true.
Turning on and off of certain types of observations are widely used for assessing impact
of observations on data assimilations.
Note: It is important to go through the default “use_*” settings in record &wrfvar4 in
WRFDA/Registry/Registry.wrfvar to know what observations are activated in default.
Description of Namelist Variables
WRF-Var namelist variables.
Variable Names
&wrfvar1
Default Value Description
write_increments false .true.: write out a binary analysis increment file.
var4d false .true.: 4D-Var mode
multi_inc 0 > 0: multi-incremental run
var4d_coupling 2 1: var4d_coupling_disk_linear, 2:
var4d_coupling_disk_simul
print_detail_radar false
print_detail_xa false
print_detail_xb false
print_detail_xxx: output extra (sometimes can be
too many) diagnostics for debugging; not recommended
to turn them on for production runs.
WRF-ARW V3: User’s Guide 6-39