WRF - Developmental Testbed Center

that lists the variables and attributes in a NetCDF file. This can be useful, in particular,for checking the domain parameters (e.g., west-east dimension, south-north dimension, ordomain center point) in geogrid domain files, or for listing the fields in a file. The ncviewprogram provides an interactive way to view fields in NetCDF files. Also, for userswishing to produce plots of fields suitable for use in publications, the new release of theRIP4 program may be of interest. The new RIP4 is capable of plotting horizontalcontours, map backgrounds, and overlaying multiple fields within the same plot.Output from the ungrib program is always written in a simple binary format (either‘WPS’, ‘SI’, or ‘MM5’), so software for viewing NetCDF files will almost certainly be ofno use. However, an NCAR Graphics-based utility, plotfmt, is supplied with the WPSsource code. This utility produces contour plots of the fields found in an intermediateformatfile. If the NCAR Graphics libraries are properly installed, the plotfmt program isautomatically compiled, along with other utility programs, when WPS is built.WPS Utility ProgramsBesides the three main WPS programs – geogrid, ungrib, and metgrid – there are anumber of utility programs that come with the WPS, and which are compiled in the utildirectory. These utilities may be used to examine data files, visualize the location ofnested domains, compute pressure fields, and compute average surface temperaturefields.A. avg_tsfc.exeThe avg_tsfc.exe program computes a daily mean surface temperature given input files inthe intermediate format. Based on the range of dates specified in the "share" namelistsection of the namelist.wps file, and also considering the interval between intermediatefiles, avg_tsfc.exe will use as many complete days' worth of data as possible incomputing the average, beginning at the starting date specified in the namelist. If acomplete day's worth of data is not available, no output file will be written, and theprogram will halt as soon as this can be determined. Similarly, any intermediate files fordates that cannot be used as part of a complete 24-hour period are ignored; for example,if there are five intermediate files available at a six-hour interval, the last file would beignored. The computed average field is written to a new file named TAVGSFC using thesame intermediate format version as the input files. This daily mean surface temperaturefield can then be ingested by metgrid by specifying 'TAVGSFC' for the constants_namevariable in the "metgrid" namelist section.B. mod_levs.exeThe mod_levs.exe program is used to remove levels of data from intermediate formatfiles. The levels which are to be kept are specified in new namelist record in thenamelist.wps file:WRF-NMM V3: User’s Guide 3-21