Meteorological data fields to run the model are usually already available or can be created from routine analysis archives or forecast model outputs. Archive meteorological data to run the model may be ordered from NOAA's National Climatic Data Center for the regional EDAS or global FNL archives. More recent data files can be copied from ARL's server ftp://gus.arlhq.noaa.gov. There are more complete descriptions of the different data sets available on-line. The meteorological data available through the menu system are summarized in the following three sections.
The meteorology menu is divided into four sections: forecast data, analysis data, data conversion, and data display. The forecast section provides access to various forecast data files that may be FTP'd from the ARL server compatible for immediate input for HYSPLIT. North America Mesoscale (NAM) or Global Forecast System (GFS) GRIB files can also be FTP'd from the NCEP server. These files must first be converted from GRIB, which is accomplished automatically through the GUI. In addition, the forecast menu tab also permits the processing of either NAM or GFS GRIB files that are local to the computer. The GRIB decoding of local files has more menu conversion options than the FTP menu tab.
The analysis menu tab is similarly divided between FTP of files and files local to the computer. The only FTP option for the analysis archives is from the ARL server for data files that are compatible with the ARL forecasts and the NCAR/NCEP reanalysis data, which have already been converted for HYSPLIT applications.
The convert menu gives GRIB data processing options for GDAS (the analysis equivalent of GFS), NDAS (the analysis equivalent of NAM), and ECMWF global data files. The local archive processing is fundamentally different that the forecast data, in that each file contains one time period, and the GUI script loops through all the time periods within a fixed number of days to generate one output file.
The display data menu tab provides some simple tools that can be used to examine the data already in ARL packed format. 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.
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.