The IPCC Data Distribution Centre

FM 92 GRIB is widely used to represent forecast and analysis products in binary. The GRIB specification is maintained and reviewed by the World Meteorological Organisation (WMO), through its Commission for Basic Systems (CBS) and Working Group on Data Management. The WMO make available the specifications of binary representation forms such as GRIB within the publication WMO - No. 306 Manual on Codes, Volume 1, International Codes, Part B - Binary Codes (find it here).

Deutsches Klimarechenzentrum (DKRZ) provides software to process GRIB data provided by the IPCC DDC as

• GRIB converter ( Readme )

Converts GRIB into ASCII or binary or just list the GRIB headers in short form. Available are the Source code in C and the executables for Solaris 2.5 as well as for DOS .

• GRIB -> GrADS mapper ( Readme )

Scans through the GRIB file and prepares index and control file. Available are the Source code in C and the executables for Solaris 2.5 as well as for DOS . The GRIB -> GrADS mapper uses a code table closely related to Code Table 2, Version 1 used for international exchange of binary data.

Gzip reduces the size of the named files using Lempel-Ziv coding (LZ77). The source code is available on most platforms. Beside UNIX-Systems a number of special targets like MSDOS, OS/2, VMS, Atari, Amiga, Primos are supported. The source code including installation hints is available for free from The GNU Project.

The data available at IPCC DDC DKRZ are zipped with GNU ZIP Version 1.2.4. In case of trouble on Windows, please try PKZIP.

Information on how to use unzipped ASCII data can be found in a README.

Missing data is indicated by the value -999. (floating point). No single data items are indicated as missing. Either a whole monthly dataset is missing or not.

Hans Luthardt, data(at)dkrz.de