Configure

Configure cindyhg Tue, 06/25/2019 - 09:26

PB2NC Tool: Configure

Start by making an output directory for PB2NC and changing directories:
mkdir -p ${METPLUS_TUTORIAL_DIR}/output/met_output/pb2nc
cd ${METPLUS_TUTORIAL_DIR}/output/met_output/pb2nc

The behavior of PB2NC is controlled by the contents of the configuration file passed to it on the command line. The default PB2NC configuration may be found in the data/config/PB2NCConfig_default file.

Prior to modifying the configuration file, users are advised to make a copy of the default:
cp ${MET_BUILD_BASE}/share/met/config/PB2NCConfig_default PB2NCConfig_tutorial_run1
Open up the PB2NCConfig_tutorial_run1 file for editing with your preferred text editor.
vi PB2NCConfig_tutorial_run1

The configurable items for PB2NC are used to filter out the PrepBufr observations that should be retained or derived. You may find a complete description of the configurable items in the pb2nc configuration file section of the MET User's Guide or in the Configuration File Overview.

For this tutorial, edit the PB2NCConfig_tutorial_run1 file as follows:

  • Set:
    message_type = [ "ADPUPA", "ADPSFC" ];

    to retain only those 2 message types. Message types are described in:
    http://www.emc.ncep.noaa.gov/mmb/data_processing/prepbufr.doc/table_1.htm

  • Set:
    obs_window = {
       beg = -1800;
       end =  1800;
    }

    so that only observations within 1800 second (30 minutes) of the file time will be retained.

  • Set:
    mask = {
       grid = "G212";
       poly = "";
    }

    to retain only those observations residing within NCEP Grid 212, on which the forecast data resides.

  • Set:
    obs_bufr_var = [ "QOB", "TOB", "UOB", "VOB", "D_WIND", "D_RH" ];

    to retain observations for specific humidity, temperature, the u-component of wind, and the v-component of wind and to derive observation values for wind speed and relative humidity.

    While we are request these observation variable names from the input file, the following corresponding strings will be written to the output file: SPFH, TMP, UGRD, VGRD, WIND, RH. This mapping of input PrepBufr variable names to output variable names is specified by the obs_prepbufr_map config file entry. This enables the new features in the current version of MET to be backward compatible with earlier versions.

Next, save the PB2NCConfig_tutorial_run1 file and exit the text editor.