FSL/NCDC Radiosonde Data
Archive
(updated for Y2K)
General Overview
Station
History Files
Download
Access Software
Data
Restrictions / Disclaimer
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 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
DOS Access Software
- must be run in a DOS
shell.
- was compressed using
pkzip provided by PKWARE
Access Software
Version 2.6
LINUX
MAC-OSX
Data Disclaimer / Restrictions
Please note: This is recent, research-quality
data that has not been subjected to production quality control procedures.
Nor has the data acquisition system been designed to be continuously-available
for operational use.
We are making this available for research use, but
be warned that the Forecast Systems Laboratory makes no guarantees as
the the accuracy, timeliness or availability of this service or data provided
by it. We cannot be held responsible for any circumstances resulting
from its use, unavailability, or possible inaccuracy. We reserve the right
to suspend or discontinue this service or portions thereof at any time.
We also reserve the right to deny access to any
individual or organization that we determine is abusing this service.
Examples of abuse include automated transfers resulting in excessive data
requests (because it hinders others from accessing the service) and attempting
to gain access to documents and host machines not intended for public use.
Prepared by:
Mark Govett, mark.w.govett@noaa.gov
Date of last update: 3-Apr-2001