WRF ARW User's Guide - MMM - UCAR

WRF-VAR
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)
/
Note: You may like to repeat this exercise for other observations like temperature (“t”),
pressure “p”, specific humidity “q” etc.
(b) Response of BE length scaling parameter:
Run single observation test with following additional parameters in record &wrfvar7 of
namelist.input
&wrfvar7
len_scaling1 = 0.5, # reduce psi length scale by 50%
len_scaling2 = 0.5, # reduce chi_u length scale by 50%
len_scaling3 = 0.5, # reduce T length scale by 50%
len_scaling4 = 0.5, # reduce q length scale by 50%
len_scaling5 = 0.5, # reduce Ps length scale by 50%
/
Note: You may like to try the response of individual variable by setting one parameter at
one time. See the spread of analysis increment.
(c) Response of changing BE variance:
Run single observation test with following additional parameters in record &wrfvar7 of
namelist.input
&wrfvar7
var_scaling1 = 0.25, # reduce psi variance by 75%
var_scaling2 = 0.25, # reduce chi_u variance by 75%
var_scaling3 = 0.25, # reduce T variance by 75%
var_scaling4 = 0.25, # reduce q variance by 75%
var_scaling5 = 0.25, # reduce Ps variance by 75%
/
Note: You may like to try the response of individual variable by setting one parameter at
one time. See the magnitude of analysis increments.
(d) Response of convergence criteria:
Run tutorial case with
&wrfvar6
eps = 0.0001,
/
WRF-ARW V3: User’s Guide 6-38