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Glossary: fundamental WDCGG concepts and terms


A station is a platform from which observation is performed. It may be stationary with a tower or mobile (e.g., a ship or aircraft).


A contributor is an institute or organization designated to collect and submit certain types of observation data. Such parties include Collaborators, who technically or financially support observation.

 Observation data/metadata

Information collected from observation data and associated metadata

Observation data

Observation data relating to specific parameters consist of mole fractions or meteorological data and related information (e.g., data flags, standard deviations and numbers of data used for averaging). For mobile platforms, observation locations (e.g., latitude and longitude) are also included. Such data represent physical quantities rather than simply being raw data. This information for atmospheric constituents involves expression of units in mole fractions such as ppm(µmol/mol), ppb(nmol/mol), and ppt(pmol/mol), rather than in concentrations such as g/m3. Other gas species are reported in widely accepted units: ‰ for isotopic observations, Bq/m3 for 222Rn, 7Be and 85Kr, and mol/kg or mol/l for total inorganic carbon.


Metadata express basic observation parameters such as station locations, sampling conditions, observation methods, calibration details, traceability of scales employed and quality management information. Such information is essential in the utilization of observation data, and related scientific publications are useful for further reference. Against such a background, WDCGG encourages Contributors to keep their metadata up to date and clarify observation conditions for data users. When metadata are changed, the data version may also change. Data users should fully understand the nature of metadata to support appropriate usage.

 Archived data

Observation data and associated metadata are stored by WDCGG and provided to users as archived data.