GRIB2 Meta Data and grib_api Keys for Section 4: Product Definition Section

Last updated: January 2013

The Product Definition Section characterizes the special variable (or product) under consideration. While in GRIB1, a product was determined by the Parameter Number, the Table Number and the Level Type, more meta data are necessary to determine a special product in GRIB2. The main classification is done by the Discipline, the Parameter Category and the Parameter Number. Depending on the product, the Product Definition Section can have different entries. Therefore, products with the same shape of the Product Definition Section are grouped together and have a special template, how meta data in this section looks like. For the products (variables) in the COSMO-Model, only few different templates are necessary.

The following table lists the GRIB2 meta data and associated grib_api keys for the main part of the Product Definition Section of GRIB2 messages, which is common to all products. The sub pages, which can be accessed with the links below, list the full Product Definition Section for the different templates used.


Octets Key Name Comments
1-4 section4Length Length of section in octets (nn)
5 numberOfSection Number of section (4)
6-7 NV Number of coordinate values after Template. Coordinates values are intended to document the vertical discretisation associated with model data on hybrid coordinate vertical levels. A number of zero in octets 6-7 indicates that no such values are present. Otherwise the number corresponds to the whole set of values.
8-9 productDefinitionTemplateNumber Product definition template number according to Code Table 4.0
0Analysis or forecast at a horizontal level or in a horizontal layer at a point in time
1Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time (the same as 0, but for ensemble members)
8Average, accumulation, extreme values or other statistically processed values at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval
11Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer, in a continuous or non-continuous interval (the same as 8, but for ensemble members)
32Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for simulated (synthetic) satellite data
40Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for atmospheric chemical constituents
41Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for atmospheric chemical constituents
42Average, accumulation, and/or extreme values or other statistically processed values at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval for atmospheric chemical constituents
43Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval for atmospheric chemical constituents
10-xx Product Definition Template Nr. X to be included here, where X is the Product Definition Template Number given in octets 8-9.
4.0Standard products: Analysis or forecast at a horizontal level or in a horizontal layer at a point in time
4.1Standard products for Ensemble forecasts Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time (the same as 0, but for ensemble members)
4.8Statistically processed products: Average, accumulation, extreme values or other statistically processed values at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval
4.11Statistically processed products for Ensemble forecasts: Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer, in a continuous or non-continuous interval
4.32Synthetic satellite images: Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for simulated (synthetic) satellite data
4.40Atmospheric chemical constituents: Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for atmospheric chemical constituents
4.41Atmospheric chemical constituents for Ensemble forecasts: ndividual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for atmospheric chemical constituents
[xx+1]-nn pv Optional list of coordinate values. These are encoded in IEEE 32-bit floating point format


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