Meteorology / Help

Meteorological data fields to run the model are usually already available or can be created from routine analysis archives or forecast model outputs. More complete descriptions of the different data sets are available on-line. The meteorological data available through the menu system are summarized in the following sections.

The meteorology menu is divided into four sections: data FTP, data conversion, data display, and utility programs.

• The FTP section provides access to various data files that may be FTP'd from the ARL server compatible for immediate input to HYSPLIT. These files include current and appended forecasts as well as various regional and global analysis archives. All data files have already been converted for HYSPLIT applications.
• The convert menu gives data processing options for files that are stored on the local computer. Processing of forecast or analysis files are available for archive, forecast, and regional or global data files in various formats. Processing for GRIB1 formatted input files is available for Global ECMWF/NOAA, and ERA-40. NetCDF is supported on UNIX systems permitting conversion of WRF-ARW data files. In addition, a simple interface has been created to permit the entry of user generated time-varying data at a single location.
• The display data menu tab provides some simple tools that can be used to examine the data already in ARL packed format. The most basic is the check file listing of the individual data records. The contour map program will display a contour plot of any variable at any one time in the file. Multiple time periods may be processed. The profile program returns a text file of the profile of meteorological parameters at a pre-selected point. The grid domain menu shows the extent of the meteorological grid with a mark at each point.
• The utility menu permits conversion of SVG files to any other graphical format and the creation of shapfiles.

More detailed information about the format of the ARL packed data is available. In addition, various library routines and utility programs are provided to manipulate both the GRIB and ARL packed data files.