============================================================================= Before proceeding, please read README.basics first to get some basic ideas on running WRFDA with conventional data. Then, if you are interested in radiance data assimilation, please read through this README.radiance to learn more on the settings and extra input files required for radiance data assimilation. Please see also Chapter 6 of WRF ARW User's Guide for more details. RTM (Radiative Transfer Model) that can be used in WRFDA: CRTM REL-2.0.2 RTTOV v10 DISCLAIMER: No support is to be expected on radiance data assimilation due to a lack of funding allocated to this task. ============================================================================= Setup and Run - with radiance data 1. Input files: In addition to the basic input files (LANDUSE.TBL, fg, ob.ascii, be.dat) mentioned in README.basics, the following extra files are required for radiance: radiance data in NCEP BUFR format, radiance_info files, VARBC.in, RTM (CRTM or RTTOV) coefficient files (see "Notes on coefficients" below). ln -sf ${DAT_DIR}/gdas1.t00z.1bamua.tm00.bufr_d ./amsua.bufr ln -sf ${DAT_DIR}/gdas1.t00z.1bamub.tm00.bufr_d ./amsub.bufr ln -sf WRFDA/var/run/radiance_info ./radiance_info # radiance_info is a directory ln -sf WRFDA/var/run/VARBC.in ./VARBC.in (CRTM only) ln -sf REL-2.0.2.JCSDA_CRTM/crtm_coeffs ./crtm_coeffs # crtm_coeffs is a directory (RTTOV only) ln -sf rttov10/rtcoef_rttov10/rttov7pred51L ./rttov_coeffs # rttov_coeffs is a directory 2. namelist.input Pay special attention to &wrfvar4, &wrfvar14, &wrfvar21, and &wrfvar22 See WRFDA/var/README.namelist for namelist descriptions. &wrfvar4 use_amsuaobs=true use_amsubobs=true / &wrfvar14 rtminit_nsensor=6, rtminit_platform=1,1,1,1,1,1, rtminit_satid=15,16,18,15,16,17, rtminit_sensor=3,3,3,4,4,4, thinning_mesh=120.0,120.0,120.0,120.0,120.0,120.0, thinning=true, qc_rad=true, write_iv_rad_ascii=false, write_oa_rad_ascii=true, rtm_option=2, only_sea_rad=false, use_varbc=true, use_crtm_kmatrix=true, use_rttov_kmatrix=true, rttov_emis_atlas_ir=0, rttov_emis_atlas_mw=0, / &wrfvar21 time_window_min="2008-02-05_10:30:00.0000", / &wrfvar22 time_window_max="2008-02-05_13:30:00.0000", / 3. Notes on coefficients (1) for CRTM Some CRTM coefficient files are included in the WRFDA tar file under WRFDA/var/run/crtm_coeffs directory (please see also WRFDA/var/run/README). The full set of CRTM coefficients can be downloaded from: ftp://ftp.emc.ncep.noaa.gov/jcsda/CRTM/REL-2.0.2/REL-2.0.2.Coeffs.JCSDA_CRTM.tar.gz After unzip/untar REL-2.0.2.Coeffs.JCSDA_CRTM.tar.gz, you will find all the coefficient files under the directory CRTM_Coefficients You will need to create another directory to copy or link the files that will be used in WRFDA. Please see also the CRTM user guide ftp://ftp.emc.ncep.noaa.gov/jcsda/CRTM/REL-2.0.2/REL-2.0.2.CRTM_User_Guide.pdf for the options of EmisCoeff and TauCoeff. mkdir crtm_coeffs cd crtm_coeffs ln -sf ../CRTM_Coefficients/AerosolCoeff/Big_Endian/AerosolCoeff.bin . ln -sf ../CRTM_Coefficients/CloudCoeff/Big_Endian/CloudCoeff.bin . ln -sf ../CRTM_Coefficients/EmisCoeff/Big_Endian/Wu-Smith.CM-PDF.HQS_HQS-RefInd.EmisCoeff.bin (or Nalli.EK-PDF.W_W-RefInd.EmisCoeff.bin) ./EmisCoeff.bin ln -sf ../CRTM_Coefficients/SpcCoeff/Big_Endian/*.bin . ln -sf ../CRTM_Coefficients/TauCoeff/ODAS(or ODPS)/Big_Endian/*.bin . (2) for RTTOV Please visit http://research.metoffice.gov.uk/research/interproj/nwpsaf/rtm for the RTTOV information. The RTTOV coefficient files that come with the RTTOV source code or that are downloaded separately are placed in different sub-directories. To run WRFDA, the coefficient files to be used should all be under the rttov_coeffs sub-directory in the WRFDA working directory. For most basic applications, the coefficient files available in the RTTOV source code rttov10/rtcoef_rttov10/rttov7pred51L would be sufficient.