3. Inputs and Outputs

This section describes the input files used when running the UPP and the resulting output files

3.1. Input files

The UPP requires the following input files:
  • The itag namelist
  • The GRIB2 control file
  • Additional data files (e.g. lookup tables, coefficient files for satellite)

3.1.1. ITAG

The itag namelist that is read in by unipost.exe from stdin (unit 5) is generated automatically in the run_unipost script based on user-defined options. It should not be necessary to edit this. For description purposes, the namelist (itag) contains 7 lines for FV3:

  1. Name of the FV3 (pressure level) output file to be posted.
  2. Format of FV3 model output (netcdf, binarynemsio).
  3. Format of UPP output (GRIB2)
  4. Forecast valid time (not model start time) in FV3 format (the forecast time desired to be post-processed).
  5. Dynamic core used (GFS).
  6. Name of the FV3 (surface) output file to be post-processed.
  7. Name of configuration file (postxconfig-NT.txt)

3.1.2. Control File

The user interacts with unipost through the control file to define what fields and levels to output. It is composed of a header and a body. The header specifies the output file information. The body includes which fields and levels to process.

A default control file, postxconfig-NT.txt, is provided and read by unipost. For users wishing to customize the control file to add or remove fields and/or levels, they may do so by modyfying the postcntrl.xml and then remaking the text file required by unipost.

The GRIB2 Output Table lists basic and derived fields currently produced by unipost for grib2.

3.1.2.1. Controlling which variables unipost outputs

To output a field, the body of the control file needs to contain an entry for the appropriate variable. For variables found on isobaric or height levels, the desired levels to be output must be listed (see next section: Controlling which levels unipost outputs). If an entry for a particular field is not yet available in the control file, it may be added to the control file with the appropriate entries for that field.

3.1.2.2. Controlling which levels unipost outputs

The <level> tag in the postcntrl.xml is used to list the desired levels for output. The following levels are currently available for output:

  • For isobaric output, 46 levels are possible, from 2 to 1000 hPa (2, 5, 7, 10, 20, 30, 50, 70 mb and then every 25 mb from 75 to 1000 mb). The complete list of levels is specified in src/unipost/CTLBLK.f.

    • Modify specification of variable LSMDEF to change the number of pressure levels: LSMDEF=47
    • Modify specification of SPLDEF array to change the values of pressure levels: (/200.,500.,700.,1000.,2000.,3000. &,5000.,7000.,7500.,10000.,12500.,15000.,17500.,20000., …/)

  • For model-level output, all model levels are possible, from the highest to the lowest.

  • When using the Noah LSM, the soil layers are 0-10 cm, 10-40 cm, 40-100 cm, and 100-200 cm.

  • When using the RUC LSM, the soil levels are 0 cm, 1 cm, 4 cm, 10 cm, 30 cm, 60 cm, 100 cm, 160 cm, and 300 cm. (For the old RUC LSM, there are only 6 layers and if using this, you will need to change “RUC LSM” from 9 to 6 in the WRFPOST.f routine.)

  • When using Pliem-Xiu LSM, there are two layers: 0-1 cm, 1-100 cm

  • For low, mid, and high cloud layers, the layers are \(\geq\)642 hPa, \(\geq\)350 hPa, and <350 hPa, respectively.

  • For PBL layer averages, the levels correspond to 6 layers with a thickness of 30 hPa each.

  • For flight level, the levels are 30 m, 50 m, 80 m, 100 m, 305 m, 457 m, 610 m, 914 m, 1524 m, 1829 m, 2134 m, 2743 m, 3658 m, 4572 m, 6000 m, 7010 m.

  • For AGL radar reflectivity, the levels are 4000 and 1000 m (see Appendix A for details).

  • For surface or shelter-level output, the <level> is not necessary.

3.1.2.3. Creating the Flat Text File

For outputting GRIB2 format using version 4.0, a preprocessing step is required by the user to convert the xml file parm/postcntrl.xml to a flat text file parm/postxconfig-NT.txt. The flat file is quicker to process than the xml file. The user will first need to edit the postcntrl.xml file to declare which fields are to be output from UPP.

In order to ensure that the user-edited xml files are error free, XML stylesheets (parm/EMC_POST_CTRL_Schema.xsd and EMC_POST_Avblflds_Schema.xsd) are used to validate both the postcntrl.xml and post_avblflds.xml files, respectively. Confirmation of validation will be given (e.g. postcntrl.xml validates) or otherwise return errors if it does not match the schema. To run the validation:

xmllint –noout –schema EMC_POST_CTRL_Schema.xsd postcntrl.xml

xmllint –noout –schema EMC_POST_Avblflds_Schema.xsd post_avblflds.xml

Once the xmls are validated, the user will need to generate the flat file. Edit the parm/makefile if necessary to point to the desired flat file directory and xmls. The makefile will call the perl program parm/POSTXMLPreprocessor.pl to generate the post flat file postxconfig-NT.txt. Generate the flat file:

make

3.2. Output Files

Upon a successful run, unipost will generate GRIB2 output files GFSPRS.hh in the postprocessor working directory, where hh denotes the forecast hour. These files will include all fields that were requested in the control file.

If the run did not complete successfully, a log file in the post-processor working directory called unipost.hh.out, where hh is the forecast hour, may be consulted for further information.