[Wrf-users] terrain-following geopotential height problem at t=0

[Case, Jonathan]

To wrf-users,
 
During the course of setting up a trial domain and examining the output,
our team has noticed a distinct terrain-following pattern in the
initialization geopotential height data.  We have eliminated
post-processing as a possible problem since the strange pattern
disappears shortly after the WRF initialization. The geopotential height
is the only variable we have noticed such a terrain-following pattern.  
 
I have attached images of the 0-hour and 3-hour 850-mb height fields at
5-m contour intervals from a 0000 UTC 31 July 2006 initialization off of
the 1-deg GFS model, as well as the wrfsi.nl file.  I ran this
particular simulation at 4-km horizontal grid spacing.  As you can see,
river valleys are showing up in the interpolated height field, even
where the terrain is only mildly sloping in AL and MS.  The height field
looks especially strange over Cuba and surrounding islands where there
is sharply sloping terrain.  The 3-hour forecast shows no such
terrain-following pattern.  The problem seems to be most severe when the
horizontal pressure (height) gradient is weak.  
 
Has anyone encountered this problem with WRFSI initialization height
fields?  If so, could someone provide us with some guidance or possibly
a code fix?
 
Thanks much,
Jonathan Case

*******************************************
Jonathan Case, ENSCO, Inc.
Aerospace Sciences & Engineering Division
Short-term Prediction Research and Transition Center
320 Sparkman Dr. NW, Room 3062
Huntsville, AL 35805-1912 
Voice: (256) 961-7504   Fax: (256) 961-7788
Emails: Jonathan.Case at nsstc.nasa.gov 
           case.jonathan at ensco.com
*******************************************


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&project_id
 SIMULATION_NAME = 'MAP06 Model Simulation v2.1.2'
 USER_DESC = 'MAP06 Modeling Group'
/
&filetimespec
 START_YEAR = 2006,
 START_MONTH = 07,
 START_DAY = 31,
 START_HOUR = 00,
 START_MINUTE = 00,
 START_SECOND = 00,
 END_YEAR = 2006,
 END_MONTH = 08,
 END_DAY = 01,
 END_HOUR = 00,
 END_MINUTE = 00,
 END_SECOND = 00,
 INTERVAL = 10800,
/
&hgridspec
 NUM_DOMAINS = 1
 XDIM = 500,
 YDIM = 500,
 PARENT_ID = 1,1,
 RATIO_TO_PARENT = 1,3,
 DOMAIN_ORIGIN_LLI = 1,56,
 DOMAIN_ORIGIN_LLJ = 1,30,
 DOMAIN_ORIGIN_URI = 500,80,
 DOMAIN_ORIGIN_URJ = 500,54,
 MAP_PROJ_NAME = 'lambert',
 MOAD_KNOWN_LAT = 28.5,
 MOAD_KNOWN_LON = -81.5,
 MOAD_STAND_LATS = 28.5, 28.5,
 MOAD_STAND_LONS = -81.5
 MOAD_DELTA_X = 4000.
 MOAD_DELTA_Y = 4000.
 SILAVWT_PARM_WRF = 0.
 TOPTWVL_PARM_WRF = 2.
/
&sfcfiles
 TOPO_30S = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/topo_30s',
 LANDUSE_30S = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/landuse_30s',
 SOILTYPE_TOP_30S = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/soiltype_top_30s',
 SOILTYPE_BOT_30S = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/soiltype_bot_30s',
 GREENFRAC = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/greenfrac',
 SOILTEMP_1DEG = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/soiltemp_1deg',
 ALBEDO_NCEP = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/albedo_ncep',
 MAXSNOWALB = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/maxsnowalb',
 ISLOPE = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/geog/islope',
/
&interp_control
 NUM_ACTIVE_SUBNESTS = 0,
 ACTIVE_SUBNESTS = 2,3,4,
 PTOP_PA = 10000,
 HINTERP_METHOD = 1,
 LSM_HINTERP_METHOD = 1,
 NUM_INIT_TIMES = 1, 
 INIT_ROOT = 'GFS',
 LBC_ROOT = 'GFS',
 LSM_ROOT = '',
 CONSTANTS_FULL_NAME = '',
 VERBOSE_LOG = .true.,
 OUTPUT_COORD = 'ETAP',
 LEVELS = 1.00,0.99,0.98,0.97,0.96,0.95,
                  0.94,0.93,0.92,0.91,0.90,0.89,
                  0.88,0.87,0.86,0.85,0.84,0.83,
                  0.82,0.81,0.80,0.78,0.76,0.74,
                  0.72,0.70,0.68,0.66,0.64,0.62,
                  0.60,0.57,0.54,0.51,0.48,0.45,
                  0.42,0.39,0.36,0.33,0.30,0.27,
                  0.24,0.21,0.18,0.15,0.12,0.09,
                  0.06,0.03,0.00,
/
&si_paths
 ANALPATH = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/extprd',
 LBCPATH = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/extprd',
 LSMPATH = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/extprd',
 CONSTANTS_PATH = '/nobackup/jonc/wrfdoms/wrfv2.1.2/global_data/extprd',
/