background

Following previous work done by Bresch and Rizvi for KMA project and ASR project.

basic PREPBUFR features

status

mass and wind reports merged

fix the problems of double-counting of observation numbers and double-usage of pressure field.

thinning

Two new namelist variables for thinning are introduced in wrfvar4 record.
&wrfvar4
thin_conv = .true.
thin_mesh_conv = 20.0, 20.0, 20.0, ...

Thinning is mandatory as time-duplicate data are "thinned" within thinning routine,
however, thin_conv can be set to .false. in the namelist for debugging purpose.

Thinning mesh of each observation type is specified through a namelist variable
&wrfvar4 thin_mesh_conv. The unit is km and default values are 20km.
Each observation type can set its thinning mesh and the index/order follows the
definition in WRFDA/var/da/da_control/da_control.f90
integer, parameter :: sound = 1
integer, parameter :: synop = 2
integer, parameter :: pilot = 3
integer, parameter :: satem = 4
integer, parameter :: geoamv = 5
integer, parameter :: polaramv = 6
integer, parameter :: airep = 7
integer, parameter :: gpspw = 8
integer, parameter :: gpsref = 9
integer, parameter :: metar = 10
integer, parameter :: ships = 11
integer, parameter :: ssmi_rv = 12
integer, parameter :: ssmi_tb = 13
integer, parameter :: ssmt1 = 14
integer, parameter :: ssmt2 = 15
integer, parameter :: qscat = 16
integer, parameter :: profiler = 17
integer, parameter :: buoy = 18
integer, parameter :: bogus = 19
integer, parameter :: pseudo = 20
integer, parameter :: radar = 21
integer, parameter :: radiance = 22
integer, parameter :: airsr = 23
integer, parameter :: sonde_sfc = 24
integer, parameter :: mtgirs = 25

time window checking

only obs between time_window_min and time_window_max will be used.
&wrfvar21 time_window_min = '2007-08-15_10:00:00.0000
&wrfvar22 time_window_max = '2007-08-15_14:00:00.0000

assign u,v,t,q obs errors for synop and metar

u%err = 1.1 (m/s)
v%err = 1.1 (m/s)
t%err = 2.0 (degree)
q%err = 10%

assign pw obs errors for gpspw

pw%err = 0.2 (cm)

new feature as of Apr 4, 2009 - read in ob errors from an external ob error table (obs_errtable) if it exists.

The external ob error table follows the format of prepobs_errtable.nam from GSI.
If using external ob error table, ob errors for synop, metar, gpspw will be from the table as well. If the ob error of an ob type is missing (with a value of 0.1E10) in the ob error table, default large values of u%err=10(m/s), v%err=10(m/s), t%err=5(degree), p%err=200(Pa), q%err=10% will be used.

observation grouping

From http://www.emc.ncep.noaa.gov/mmb/data_processing/prepbufr.doc/table_6.htm

Report Type	Definition
         11	Fixed land RAOB and PIBAL by block and station number
         12	Fixed land RAOB and PIBAL by call letters
         13	Mobile land RAOB, including CLAS soundings
         22	Ship RAOB with name
         23	Ship RAOB without name (report id set to "SHIP")
         31	Reconnaissance aircraft or dropwinsonde
         41 	Aircraft flight-level (all types)
         61	Satellite soundings/retrievals/radiances
         63	Satellite-derived winds
         65	SSM/I total precipitable water (ocean) product
         66	SSM/I rain rate product
         68	SSM/I brightness temperatures
         69	SSM/I cloud water (ocean) product
         71	NOAA Profiler Network (NPN) Profiler winds
         72	NEXRAD Vertical Azimuth Display (VAD) winds
         73	Wind profiler originating in PIBAL bulletins (tropical and European)
         74	GPS-IPW (Integrated Precipitable Water)
         75	Multi-Agency  Profiler (MAP) Profiler winds
         76	Japanese Meteological Agency (JMA) profiler winds
         77	NOAA Profiler Network (NPN) or Multi-Agency Profiler (MAP) RASS temperatures
       511	Land surface by block and station number (synoptic, both unrestricted & restricted WMO Res. 40)
       512	Land surface by call letters (METAR)
       514	Mobile land surface (synoptic)
       522	Ship with name
       523	Ship without name (report id set to "SHIP")
       531	C-MAN platform
       532	Tide gauge report
       540	Mesonet surface
       551	Sea-level pressure bogus
       561	Fixed buoy
       562	Drifting buoy
       571	SSM/I wind speed (ocean) product
       573	SSM/I soil moisture product
       574	SSM/I snow depth product
       575	SSM/I additional products (surface tag, ice concentration, ice age, ice edge, calculated surface type)
       576	SSM/I surface (skin) temperature product
       577	SSM/I sea surface temperature product
       581	ERS scatterometer winds
       582	QuikSCAT scatterometer winds
       583	WindSAT scatterometer winds (Navy- or NESDIS- produced)
       584	ASCAT scatterometer winds

In WRF-Var:

 11,12,13,22,23,31 - sound and pilot
 41                - airep
 522,523           - ship
 531,532,561,562   - buoy
 511,514           - synop
 512               - metar
 63                - geoamv
 582,583           - qscat
 74                - gpspw
 71,73,75,76,77    - profiler
 571,65            - ssmi_rv
MPI-ready

Previous unstable problem is fixed in revision 3828 (April 24, 2009).

A patch tar file can be download from WRFDA users site (posted April 30, 2009) for the released V3.1 code (which is based on revision 3818).