WRF ARW User's Guide - MMM - UCAR

MODEL
if_zfac_ph (max_dom) 0 0= nudge ph in all layers, 1= limit nudging
to levels above k_zfac_ph (spectral
nudging only)
k_zfac_q 10 10=model level below which nudging is
switched off for water ph (spectral
nudging only)
guv (max_dom) 0.0003 nudging coefficient for u and v (sec-1)
gt (max_dom) 0.0003 nudging coefficient for temp (sec-1)
gq (max_dom) 0.0003 nudging coefficient for qvapor (sec-1)
gph (max_dom) 0.0003 nudging coefficient for ph (sec-1), spectral
nudging only
dk_zfac_uv (max_dom) 1 depth in k between k_zfac_X to
dk_zfac_X where nudging increases
linearly to full strength (spectral nudging
only)
dk_zfac_t (max_dom) 1
dk_zfac_ph (max_dom) 1
xwavenum 3 top wave number to nudge in x direction,
spectral nudging only
ywavenum 3 top wave number to nudge in y direction,
spectral nudging only
if_ramping 0 0= nudging ends as a step function, 1=
ramping nudging down at end of period
dtramp_min 60. time (min) for ramping function,
60.0=ramping starts at last analysis time,
-60.0=ramping ends at last analysis time
grid_sfdda (max_dom) 1 surface grid-nudging on (=0 off)
sgfdda_inname “wrfsfdda_d” defined name for surface nudging input
file (from program obsgrid)
sgfdda_interval
(max_dom)
360 time interval (min) between surface
analysis times
sgfdda_end_h (max_dom)6 time (in hours) to stop nudging after start
of forecast
io_form_sgfdda 2 surface analysis format (2 = netcdf)
guv_sfc (max_dom) 0.0003 nudging coefficient for u and v (sec-1)
gt_sfc (max_dom) 0.0003 nudging coefficient for temp (sec-1)
gq_sfc (max_dom) 0.0003 nudging coefficient for qvapor (sec-1)
rinblw 250. radius of influence used to determine the
confidence (or weights) for the analysis,
which is based on the distance between the
grid point to the nearest obs. The analysis
without nearby observation is used at a
WRF-ARW V3: User’s Guide 5-45