This Technical Note outlines the policy for the handling, sharing and distribution of the data that are submitted by the sites to the Lead Centre (LC).

A data-level and user classification scheme is defined, where access privileges to particular data levels are defined for various user categories. In this scheme data streams for which a certified GRUAN Data Product (GDP) exists, are provided to the global user-community with unrestricted access. Raw measurement data are only accessible to the Lead Centre, the site that provided the data, the processing centre, and the data product developers. Intermediate data, pre-release GDP versions, and data from accompanying instruments are restricted to GRUAN-internal and special users.

For measurement activities outside a site’s GRUAN commitment, e.g. campaign measurements, data retention for up to 12 months can be requested by site managers to ensure first-publication rights. This data distribution strategy is consistent with the WMO unified data policy (resolution 1 of Cg-Ex. 2021).

GRUAN-processing of data from non-GRUAN sites is available upon request as a service to the research community. However, these data shall be referred to as GRUAN-processed data to distinguish these from GDP data files, which are generated exclusively for measurements performed by GRUAN sites.

Finally, the GRUAN data policy for proper acknowledgement and referencing of GRUAN data usage and the guidelines for co-authorship are presented.

For completeness, a concise summary of the relevant aspects of the WMO unified data policy is included in the appendix.