OVERVIEW

The radiosonde data archive is composed of two distinct components: the CD-ROM Archive and the Real-Time Archive.

The CD-ROM Archive

The CD-ROM archive is produced jointly by the National Climatic Data Center (NCDC) and the Forecast Systems Laboratory (FSL).  NCDC provides data to us in a standard format (TD6201 series).  We take this data, combine it with all available North American Global Telecommunications Service (GTS) observations, collected at FSL.   These data undergo extensive gross error and hydrostatic consistancy checks before being incorporated into a randomly accessible compressed data archive developed at FSL.  Annual updates to the fifth CD-ROM (currently 1994-1997) are sent to NCDC for digital remastering.  The entire archive (1946-1997 on 5 CDs), individual CD's, or an update can be ordered by contacting NCDC customer service (828-271-4800) or be ordered through NCDC's online store.
 

The REAL-TIME ARCHIVE

The real-time archive is comprised of all GTS observations primarily from Northern and Central American civilian and some military radiosonde sites not yet available on CD-ROM (currently 1997 thru 1999).  Since late 1998, we have upgraded the archive to include all international observations transmitted via GTS.  All of this raw data goes through the same decoding and extensive QC analysis as the soundings in the CDROM archive.  Data is stored in the same randomly accessible compressed data format.  Users can access this data from FSL's web site.

 
 

The Tech Memo

Most questions regarding the processing of the data can be answered by reading the official NOAA Technical Memorandum: "A Hydrostatically Consistent North American Radiosonde Data Base At The Forecast Systems Laboratory, 1946-Present" . This PDF document is 67MB so it may take a few minutes to download.  Please refer to this document for answers to any technical questions that are not answered elsewhere in this site. 
 

STATION HISTORY

The station history is an integral part of the radiosonde archive.  Information contained in the station history are required for output of data.  As a result, a sounding will not be output unless a corresponding entry exists in the station history file.  We strive to maintain an updated station history tracking changes of location, station identifiers and dates station moves as they occur.  You are encouraged to update your copy of this station history frequently.  Additionally, we value your feedback on possible corrections to this file when a station moves or our information is incorrect.
 

Two versions of the international station history file are available:  a file sorted by WBAN (Weather Bureau Army Navy) identifier is required by the radiosonde database access routine, and a file sorted by WMO (World Meteorological Organization) identifier is provided for your convinience.  Since the WBAN identifer is only used for US controlled sites, missing values (99999) are used for international sites.  Note:  Station histories of the radiosonde sites are only available for North and Central American stations only.  Please refer to NCDC's CARDS data base for more station information.

Users of the CD-ROM archive should update their station history file with the latest version whenever a new CD update is obtained from NCDC. In order to update the software, remove the original file:  station.his and run "getraob" to get this program to rebuild the binary station history file.
 

CD-ROM ACCESS SOFTWARE

Since the CD-ROM data is stored in binary, a database access routine was been written to speed your access to the observations needed.  The user can select for output to the screen or file: a single station or multiple  stations for a defined time period, or all stations within a specified geographic region in either synoptic or station sort.  Data can be output in 4 currently supported data formats:   two ASCII FSL formats, a GTS format, and a NetCDF format.

Reports consist of data taken at mandatory, significant, and WMO regional and significant (PPBB) wind levels up to 100mb.    General information about radiosonde data is available from the Federal Meteorological Handbook.

Recently an effort has begun to include data above 100mb into the CD-ROM archive.  A gradual reprocessing of the data beginning with 1997 and working back to 1990 will eventually encompass all data on the fourth CD.  To incorporate these changes, modifications to the access software have been made and included into the latest software (version 2.0).  This software also includes modifications to support Y2K issues that will be required to access the next CD-ROM update (1997).  Users are encouraged to access the completely downward compatible software targetted for UNIX and DOS operating systems in the links below.


 


Access Software Version 2.5

 

SUN_Solaris              IBM_AIX               HP-UX

DEC_OSF1                 SGI_IRIX              LINUX              DOS
 


      DOS Access Software
             -  must be run in a DOS shell.
             -  was compressed using pkzip provided by  PKWARE